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February 2026
January 2026 December 2025 November 2025 October 2025 September 2025 August2025 July 2025 June2025 June2025 May 2025 April 2025 March 2025 February 2025 January 2025 December 2024 November 2024 October 2024 September 2024 August 2024 July 2024 June 2024 May 2024 April 2024 March 2024 February 2024 January 2024 December 2022 December 2021 December 2020 December 2019 | Leca, N., Barbosa, F., Rodriguez-Calado, S., Esposito Verza, A., Moura, M., Pedroso, P. D., Pinto, I., Artes, E., Bange, T., Sunkel, C. E., Barisic, M., Maresca, T. J., Conde, C. (2025). Proximity-based activation of AURORA A by MPS1 potentiates error correction Curr Biol, 35(8):1935-1947.e1938 PubMed ID: 40203828
Summary: Faithful cell division relies on mitotic chromosomes becoming bioriented with each pair of sister kinetochores bound to microtubules oriented toward opposing spindle poles. Erroneous kinetochore-microtubule attachments often form during early mitosis but are destabilized through the phosphorylation of outer kinetochore proteins by centromeric AURORA B kinase (ABK) and centrosomal AURORA A kinase (AAK), thus allowing for re-establishment of attachments until biorientation is achieved. MPS1-mediated phosphorylation of NDC80 has also been shown to directly weaken the kinetochore-microtubule interface in yeast. In human cells, MPS1 has been proposed to transiently accumulate at end-on attached kinetochores and phosphorylate SKA3 to promote microtubule release. Whether MPS1 directly targets NDC80 and/or promotes the activity of AURORA kinases in metazoans remains unclear. This study reports a novel mechanism involving communication between kinetochores and centrosomes, wherein MPS1 acts upstream of AAK to promote error correction. MPS1 on pole-proximal kinetochores phosphorylates the C-lobe of AAK, thereby increasing its activation at centrosomes. This proximity-based activation ensures the establishment of a robust AAK activity gradient that locally destabilizes mal-oriented kinetochores near spindle poles. Accordingly, MPS1 depletion from Drosophila cells causes severe chromosome misalignment and erroneous kinetochore-microtubule attachments, which can be rescued by tethering either MPS1 or constitutively active AAK mutants to centrosomes. Proximity-based activation of AAK by MPS1 also occurs in human cells to promote AAK-mediated phosphorylation of the NDC80 N-terminal tail. These findings uncover an MPS1-AAK crosstalk that is required for efficient error correction, showcasing the ability of kinetochores to modulate centrosome outputs to ensure proper chromosome segregation. | Goldstein, B., Sheikh-Suliman, S., Bakhrat, A., Abdu, U. (2025). The differential roles of rad9 alternatively spliced forms in double- strand DNA break repair during Drosophila meiosis DNA Repair (Amst), 149:103833 PubMed ID: 40250145
Summary: The 9-1-1 complex, comprising the Rad9, Hus1 and Rad1 proteins, is believed to operate as a component of a DNA damage checkpoint pathway. An initial analysis of the Drosophila hus1 gene showed that Hus1 plays a dual role in meiosis, regulating both meiotic DNA damage checkpoint and homologous recombination repair. This study further analyzed the meiotic roles of another protein in the complex, Rad9, which has two alternatively spliced forms, Rad9A and Rad9B. Using CRISPR/Cas9, this study generated flies mutant for both rad9 isoforms. Similarly to hus1, mutations in rad9 lead to female sterility. Also, double-strand DNA breaks (DSBs) that form during meiosis are not processed efficiently, and the DNA within the oocyte nucleus fails to form its characteristic shape in rad9 mutants. On the other hand, the hus1 mutation completely disrupts checkpoint activation in DSB repair enzyme mutants, whereas the rad9 mutation only partially impairs checkpoint activation in this context. Moreover, spatial rescue experiments revealed that Rad9B is efficient in repairing meiotic DSBs, while Rad9A is not. Furthermore, female fertility in rad9 mutants depends on early efficient meiotic DSB repair but not on karyosome formation. In summary, these results demonstrate a differential role of Rad9 alternatively spliced forms during Drosophila meiosis in oogenesis, and while former studies showed that Hus1 is sufficient for the effective activation of the meiotic recombination checkpoint, these results revealed that this is not true for Rad9. |
| Hylton, C. A., Hansen, K., Tomkiel Dean, J. E. (2025). Pairing between homologous sequences on the X and chromosome 3 in Drosophila male meiosis Genetics, 230(2) PubMed ID: 40147874
Summary: Pairing between sex chromosomes in male Drosophila normally occurs at intergenic spacer (IGS) sequences within the tandemly repeated rDNA genes that are located proximally in the heterochromatin on both the X and Y. Pairing is not limited to these sequences, however, and can also occur with high fidelity between the X and segments of X euchromatin that have been translocated to the Y. Such euchromatic pairings can lead to segregation of the X and Y, even when the X is rDNA-deficient, suggesting X-Y conjunction remains at these euchromatic sequences until anaphase I. From these previous observations, however, it was unclear if conjunction occurred directly at euchromatic sequences. To ask if pairing and conjunction of X euchromatin could occur completely independent of the rDNA, this study used fluorescent in situ hybridization to examine pairing between the X chromosome and Dp(1;3) chromosomes that contain a transposed segment of the X. As little as 120 kb of euchromatic homology was sufficient to ensure nearly complete pairing and could contribute to directing segregation. The ability to direct segregation was independent of the conjunction complex proteins Mod(mdg4)-in-meiosis and Teflon. It is concluded that pairing can occur at X euchromatin homologies, and these interactions may persist even in the absence of the conjunction complex and contribute to segregation of the paired elements to opposite spindle poles at meiosis I. | Meng, Z., Norwitz, N. G., Bickel, S. E. (2025). Meiotic cohesion requires Sirt1 and preserving its activity in aging oocytes reduces missegregation bioRxiv, PubMed ID: 40161738
Summary: Chromosome segregation errors in human oocytes increase dramatically as women age and premature loss of meiotic cohesion is one factor that contributes to a higher incidence of segregation errors in older oocytes. This study showed that cohesion maintenance during meiotic prophase in Drosophila oocytes requires the NAD(+)-dependent deacetylase, Sirt1. Knockdown of Sirt1 during meiotic prophase causes premature loss of arm cohesion and chromosome segregation errors. Previously work has demonstrated that when Drosophila oocytes arrest and age in diplotene, segregation errors increase significantly. By quantifying acetylation of the Sirt1 substrate H4K16 on oocytes chromosomes,this study found that Sirt1 deacetylase activity declines markedly during aging. However, if females are fed the Sirt1 activator SRT1720 as their oocytes age, the H4K16ac signal on oocyte DNA remains low in aged oocytes, consistent with preservation of Sirt1 activity during aging. Strikingly, age-dependent segregation errors are significantly reduced if mothers are fed SRT1720 while their oocytes age. These data suggest that maintaining Sirt1 activity in aging oocytes may provide a viable therapeutic strategy to decrease age-dependent segregation errors. |
| Hirai, K., Sakamoto, H., Keira, Y., Ozaki, M., Yamazoe, K., Ishikawa, H. O., Inoue, Y. H., Sawamura, K. (2025). The Drosophila nucleoporin ELYS is required for parental chromosome arrangement at fertilization G3 (Bethesda), 15(7) PubMed ID: 40359232
Summary: One key aspect of fertilization is the unification of the maternal and paternal genomes driven by the first mitotic spindle. However, little is known about the mechanisms that underlie the formation of a bipolar spindle that interacts with the two discrete chromosome sets in juxtaposition. This study showed that, in Drosophila, the maternally provided ELYS-an evolutionarily conserved subunit of the nuclear pore complex-localizes to female and male pronuclei and then redistributes to the interior of the spindle and the resulting zygotic nuclei. Both Elys loss-of-function mutations and ELYS overexpression in the female germline were associated with maternal-effect lethality. Cytological studies of fertilized eggs revealed that ELYS is primarily involved in the apposition of female and male pronuclei, potentially impacting the parental genome configuration of the first mitotic spindle. It is proposed that pronuclear apposition is essential for centrosome localization at the emergent pronuclear junction to promote bipolar spindle formation for the first mitosis. In addition,the possible involvement of ELYS in interspecific hybrid incompatibility is discussed. | Meng, X., Yamashita, Y. M. (2025). Intrinsically weak sex chromosome drive through sequential asymmetric meiosisSci Adv, 11(19):eadv7089 PubMed ID: 40333966
Summary: Meiotic drivers are selfish genetic elements that bias their own transmission, violating Mendel's Law of Equal Segregation. It has long been recognized that sex chromosome-linked drivers present a paradox: Their success in transmission can severely distort populations' sex ratio and lead to extinction. This paradox is typically solved by the presence of suppressors or fitness costs associated with the driver, limiting the propagation of the driver. This study shows that Stellate (Ste) in Drosophila melanogaster represents a novel class of X chromosome-linked driver that operates with an inherent mechanism that weakens its drive strength. Ste protein asymmetrically segregates into Y-bearing cells during meiosis I, subsequently causing their death. Unexpectedly, Ste segregates asymmetrically again during meiosis II, sparing half of the Y-bearing spermatids from Ste-induced defects, thereby weakening the drive strength. These findings reveal a mechanism by which sex chromosome drivers avoid suicidal success. |
Thursday April 2nd - Larval and adult neural development, structure and function |
| Jones, J. D., Holder, B. L., Montgomery, A. C., McAdams, C. V., He, E., Burns, A. E., Eiken, K. R., Vogt, A., Velarde, A. I., Elder, A. J., McEllin, J. A., Dissel, S. (2025). The dorsal fan-shaped body is a neurochemically heterogeneous sleep-regulating center in Drosophila PLoS Biol, 23(3):e3003014 PubMed ID: 40138668
Summary: Sleep is a behavior that is conserved throughout the animal kingdom. Yet, despite extensive studies in humans and animal models, the exact function or functions of sleep remain(s) unknown. In Drosophila, neurons projecting to the dorsal fan-shaped body (dFB) have been proposed to be key regulators of sleep, particularly sleep homeostasis. It was recently demonstrated that the most widely used genetic tool to manipulate dFB neurons, the 23E10-GAL4 driver, expresses in 2 sleep-regulating neurons (VNC-SP neurons) located in the ventral nerve cord (VNC), the fly analog of the vertebrate spinal cord. Since most data supporting a role for the dFB in sleep regulation have been obtained using 23E10-GAL4, it is unclear whether the sleep phenotypes reported in these studies are caused by dFB neurons or VNC-SP cells. A recent publication replicated the finding that 23E10-GAL4 contains sleep-promoting neurons in the VNC. However, it also proposed that the dFB is not involved in sleep regulation at all, but this suggestion was made using genetic tools that are not dFB-specific and a very mild sleep deprivation protocol. This study, using a newly created dFB-specific genetic driver line, demonstrated that optogenetic activation of the majority of 23E10-GAL4 dFB neurons promotes sleep and that these neurons are involved in sleep homeostasis. dFB neurons require stronger stimulation than VNC-SP cells to promote sleep. In addition, this study demonstrated that dFB-induced sleep can consolidate short-term memory (STM) into long-term memory (LTM), suggesting that the benefit of sleep on memory is not circuit-specific. Finally, this study showed that dFB neurons are neurochemically heterogeneous and can be divided in 3 populations. Most dFB neurons express both glutamate and acetylcholine, while a minority of cells expresses only one of these 2 neurotransmitters. Importantly, dFB neurons do not express GABA, as previously suggested. Using neurotransmitter-specific dFB tools, these data also points at cholinergic dFB neurons as particularly potent at regulating sleep and sleep homeostasis. | Ludke, A., Kumaraswamy, A., Galizia, C. G. (2025). Olfactory Receptor Responses to Pure Odorants in Drosophila melanogaster Eur J Neurosci, 61(5):e70036 PubMed ID: 40062376
Summary: Olfactory coding relies on primary information from olfactory receptor cells that respond to volatile airborne substances. Despite extensive efforts, understanding of odor-response profiles across receptors is still poor, because of the vast number of possible ligands (odorants), the high sensitivity even to trace compounds (creating false positive responses), and the diversity of olfactory receptors. This study linked chemical purification with a gas chromatograph to single-receptor type recording with transgenic flies using calcium imaging to record olfactory responses to a large panel of chemicals in seven Drosophila ORs: Or10a, Or13a, Or22a, Or42b, Or47a, Or56a, and Or92a. The data was analyzed using linear-nonlinear modeling and reveal that most receptors have "simple" response types (mostly positive: Or10a, Or13a, Or22a, Or47a, and Or56a). However, two receptors (Or42b and Or92a) have, in addition to "simple" responses, "complex" response types to some ligands, either positive with a negative second phase or negative with a positive second phase, suggesting the presence of multiple binding sites and/or transduction cascades. Some ligands reported in the literature are false positives, because of contaminations in the stimulus. All stimuli were recorded across concentrations, showing that at different concentrations, different substances appear as best ligands. The data show that studying combinatorial olfactory coding must consider temporal response properties and odorant concentration and, in addition, is strongly influenced by the presence of trace amounts of ligands (contaminations) in the samples. These observations have important repercussions for thinking about how animals navigate their olfactory environment. |
| Jiang, R., Tian, Y., Yuan, X., Guo, F. (2025). Regulation of pre-dawn arousal in Drosophila by a pair of trissinergic descending neurons of the visual and circadian networks Curr Biol, 35(8):1750-1764.e1753 PubMed ID: 40107265
Summary: Circadian neurons form a complex neural network that generates circadian oscillations. How the circadian neural network transmits circadian signals to other brain regions, thereby regulating the activity patterns in fruit flies, is not well known. Using the FlyWire database, this study identified a cluster of descending neurons, DNp27, which is densely connected with key circadian neurons and the visual circuit, projecting extensively across the brain. DNp27 receives excitatory inputs from the circadian neurons DN3s at night and photo-inhibitory signals predominantly during the day, resulting in calcium oscillations that peak in the early morning and dip at dusk. Experimental manipulation of DNp27 revealed its role in activity regulation: artificial activation of DNp27 decreased flies' activity, while ablation or silencing led to an advance in the morning anticipatory peak. Similar alterations in the morning peak were observed following pan-neuronal knockdown of either Trissin or TrissinR, suggesting the involvement of this neuropeptide signaling pathway in DNp27 function. Moreover, neural circuitry and connectivity analyses indicate that DNp27 may regulate circadian neurons via extra-clock electrical oscillators (xCEOs). Lastly, this study found that DNp27 modulates arousal thresholds by inhibiting light-responsive activity in the central brain, thereby promoting sleep stability, particularly in the pre-dawn period. Together, these findings suggest that DNp27 plays a crucial role in maintaining stable sleep patterns. | Lyu, C., Li, Z., Xu, C., Kalai, J., Luo, L. (2025). Rewiring an olfactory circuit by altering the combinatorial code of cell-surface proteins Res Sq, PubMed ID: 40162206
Summary: Proper brain function requires the precise assembly of neural circuits during development. Despite the identification of many cell-surface proteins (CSPs) that help guide axons to their targets, it remains largely unknown how multiple CSPs work together to assemble a functional circuit. This study used synaptic partner matching in the Drosophila circuitsolfactory receptor neuron (ORN) type, which senses a male pheromone that inhibits male-male courtship, its connection was switched from its endogenous postsynaptic projection neuron (PN) type nearly completely to a new PN type that promotes courtship. To achieve this switch, a combinatorial code including CSPs was deduced that mediate both attractive and repulsive interactions between synaptic partners. The deduced anatomical switch changed the odor response of the new PN partner and markedly increased male-male courtship. Three manipulation strategies were generalized from this rewiring to successfully rewire a second ORN type to multiple distinct PN types. This work demonstrates that manipulating a small set of CSPs is sufficient to respecify synaptic connections, paving ways to explore how neural systems evolve through changes of circuit connectivity. |
| Li, Z., Lyu, C., Xu, C., Hu, Y., Luginbuhl, D. J., Lehovic, A. B., Priest, J. M., Ozkan, E., Luo, L. (2025). Repulsive interactions instruct synaptic partner matching in an olfactory circuit Res Sq, PubMed ID: 40162214
Summary: Neurons exhibit extraordinary precision in selecting synaptic partners. Whereas cell-surface proteins (CSPs) mediating attractive interactions between developing axons and dendrites have been shown to instruct synaptic partner matching, it is less clear the degree to which repulsive interactions play a role. Using a genetic screen guided by single cell transcriptomes, this study identified three CSP pairs-Toll2-Ptp10D, Fili-Kek1, and Hbs/Sns-Kirre-in mediating repulsive interactions between non-partner olfactory receptor neuron (ORN) axons and projection neuron (PN) dendrites in the developing Drosophila olfactory circuit. Each CSP pair exhibits inverse expression patterns in the select PN-ORN partners. Loss of each CSP in ORNs led to similar synaptic partner matching deficits as the loss of its partner CSP in PNs, and mistargeting phenotypes caused by overexpressing one CSP could be suppressed by loss of its partner CSP. Each CSP pair is also differentially expressed in other brain regions. Together, these data reveal that multiple repulsive CSP pairs work together to ensure precise synaptic partner matching during development by preventing neurons from forming connections with non-cognate partners. | Kautzmann, S., Rey, S., Krebs, A., Klambt, C. (2025). Cholinergic and Glutamatergic Axons Differentially Require Glial Support in the Drosophila PNS Glia, 73(7):1365-1382 PubMed ID: 40097245
Summary: In vertebrates, there is a differential interaction between peripheral axons and their associated glial cells. While large-caliber axons are covered by a myelin sheath, small-diameter axons are simply wrapped in Remak fibers. In peripheral nerves of Drosophila larvae, axons are covered by wrapping glial cell processes similar to vertebrate Remak fibers. Whether differences in axonal diameter influence the interaction with glial processes in Drosophila has not yet been analyzed. Likewise, it is not understood whether the modality of the neuron affects the interaction with the wrapping glia. To start to decipher the mechanisms underlying glial wrapping, this study employed APEX2 labeling in larval filet preparations. This allowed following of individual axons of defined segmental nerves at ultrastructural resolution in the presence or absence of wrapping glia. Using these tools, it was first demonstrated that motor axons are larger compared to sensory axons. Sensory axons fasciculate in larger groups than motor axons, suggesting that they do not require direct contact with wrapping glia. However, unlike motor axons, sensory axons show length-dependent degeneration upon ablation of wrapping glia. These data suggest that Drosophila may help to understand peripheral neuropathies caused by defects in Schwann cell function, in which a similar degeneration of sensory axons is observed. |
Wednesday April 1st - Larval and adult development |
| Carrillo, J. A., Murakawa, H., Sato, M., Wang, M. (2025). A new paradigm considering multicellular adhesion, repulsion and attraction represent diverse cellular tile patterns PLoS Comput Biol, 21(4):e1011909 PubMed ID: 40258228
Summary: Cell sorting by differential adhesion is one of the basic mechanisms explaining spatial organization of neurons in early stage brain development of fruit flies. The columnar arrangements of neurons determine the large-scale patterns in the fly visual center. Experimental studies indicate that hexagonal configurations regularly appear in the fly compound eye, which is connected to the visual center by photoreceptor axons, while tetragonal configurations can be induced in mutants. A mathematical framework is needed to study the mechanisms of such a transition between hexagonal and tetragonal arrangements. This study proposes a new mathematical model based on macroscopic approximations of agent-based models that produces a similar behavior changing from hexagonal to tetragonal steady configurations when medium-range repulsion and longer-range attraction between individuals are incorporated in previous successful models for cell sorting based on adhesion and volume constraints. The angular configurations of these patterns was analyzed based on angle summary statistics and experimental data and parameter fitted ARA (Adhesion-Repulsion-Attraction) models showing that intermediate patterns between hexagonal and tetragonal configuration are common in experimental data as well as in the ARA mathematical model. These studies indicate an overall qualitative agreement of ARA models in tile patterning and pave the way for their quantitative studies. This study opens up a new avenue to explore tile pattern transitions, found not only in the column arrangement in the brain, but also in the other related biological processes. | Alber, D. S., Zhao, S., Jacinto, A. O., Wieschaus, E. F., Shvartsman, S. Y., Haas, P. A. (2025). A model for boundary-driven tissue morphogenesis ArXiv, PubMed ID: 40093362
Summary: Tissue deformations during morphogenesis can be active, driven by internal processes, or passive, resulting from stresses applied at their boundaries. This study introduces the Drosophila hindgut primordium as a model for studying boundary-driven tissue morphogenesis. Its deformations were characterized and its complex shape changes can be a passive consequence of the deformations of the active regions of the embryo that surround it. First, an intermediate characteristic triangular shape was found in the 3D deformations of the hindgut. A minimal model of the hindgut primordium was constructed as an elastic ring deformed by active midgut invagination and germ band extension on an ellipsoidal surface, which robustly captures the symmetry-breaking into this triangular shape. The 3D kinematics of the tissue were quantified by a set of contours, and dthe hindgut was found to deform in two stages: an initial translation on the curved embryo surface followed by a rapid breaking of shape symmetry. This model was extended to show that the contour kinematics in both stages are consistent with the passive picture. These results suggest that the role of in-plane deformations during hindgut morphogenesis is to translate the tissue to a region with anisotropic embryonic curvature and show that uniform boundary conditions are sufficient to generate the observed nonuniform shape change. This work thus provides a possible explanation for the various characteristic shapes of blastopore-equivalents in different organisms and a framework for the mechanical emergence of global morphologies in complex developmental systems. |
| Lee, J. I., Park, S., Park, H., Lee, Y., Park, J., Lee, D., Kim, M. J., Choe, K. M. (2025). The matrix glycoprotein Papilin maintains the haematopoietic progenitor pool in Drosophila lymph glands Development, 152(7) PubMed ID: 40094323
Summary: Differentiation of prohaemocytes, the precursors of Drosophila blood cells (haemocytes), and the release of haemocytes from the lymph gland, a major larval haematopoietic organ, are vital responses to wasp infestation or tissue degeneration. Although cells and extracellular matrix (ECM) in the lymph gland are known to play a crucial role in haemocyte differentiation, the underlying mechanisms remain unclear. This study shows that the matrix glycoprotein Papilin (Ppn) is essential for maintaining the prohaemocyte population in lymph glands. In Ppn-depleted larvae, haemocyte differentiation increased with a reduction in the prohaemocyte-containing medullary zone, and lymph gland lobes dispersed prematurely. Ppn was synthesised by plasmatocytes, forming lamellae mainly in the medullary zone. Microbial infection or wasp infestation disrupted the Ppn meshwork within lymph glands. Ppn colocalised with collagen, laminin, nidogen and perlecan. Ppn depletion disrupted the ECM structure, including perlecan organisation. Phenotypes caused by Ppn depletion were partially rescued by perlecan overexpression or inactivation of the epidermal growth factor receptor pathway. Thus, Ppn is crucial for maintaining lymph gland architecture and regulating haemocyte differentiation, highlighting an intricate interaction between the ECM and signalling pathways in haematopoiesis. | Marcetteau, J., Duarte, P., Leitao, A. B., Sucena, E. (2025). Transdifferentiation of plasmatocytes to crystal cells in the lymph gland of Drosophila melanogaster EMBO Rep, 26(8):2077-2097 PubMed ID: 40075235
Summary: Under homeostatic conditions, haematopoiesis in Drosophila larvae occurs in the lymph gland and sessile haemocyte clusters to produce two functionally and morphologically different cells: plasmatocytes and crystal cells. It is well-established that in the lymph gland both cell types stem from a binary decision of the medullary prohaemocyte precursors. However, in sessile clusters and dorsal vessel, crystal cells have been shown to originate from the transdifferentiation of plasmatocytes in a Notch/Serrate-dependent manner. This study show shows that transdifferentiation occurs also in the lymph gland. In vivo phagocytosis assays confirm that cortical plasmatocytes are functionally differentiated phagocytic cells. A double-positive population in the cortical zone was uncovered that lineage-tracing and long-term live imaging experiments show will differentiate into crystal cells. The reduction of Notch levels within the lymph gland plasmatocyte population reduces crystal cell number. This extension of a transdifferentiation mechanism reinforces the growing role of haematopoietic plasticity in maintaining homeostasis in Drosophila and vertebrate systems. Future work should test the regulation and relative contribution of these two processes under different immunological and/or metabolic conditions. |
| Lee, T., Kim, C. J., Lim, D. H., Lee, Y. S. (2025). microRNA miR-315-5p regulates developmental growth in Drosophila wings by targeting S6k Insect Sci, PubMed ID: 40166978
Summary: Tissue growth in Drosophila is regulated by various factors, with microRNAs (miRNAs) emerging as key players over the past decade. However, the precise roles of miRNAs in growth regulation remain incompletely understood. This study explored the biological role of miR-315 in wing growth regulation. Inhibition of miR-315-5p activity using a miR-315 sponge led to an increase in wing size, whereas its overexpression resulted in reduced wing size, primarily through a decrease in wing cell size. Ribosomal protein kinase p-70-S6k (S6k) was identified as a target of miR-315-5p in relation to wing growth control. Overexpression of miR-315 reduced both total S6k and phosphorylated S6k protein levels in Drosophila S2 cells and wing discs. Additionally, a luciferase reporter assay confirmed that miR-315-5p directly binds to the 3'-untranslated region of S6k. Consistently, RNAi-mediated depletion of S6k led to smaller wings, primarily due to a reduction in cell size. Notably, co-overexpression of active S6k rescued the wing defects caused by miR-315 overexpression. Overall, these findings demonstrate that miR-315 regulates wing growth by suppressing S6k expression. | Delage, S., Zadhoosh, A., You, W., Brown, T. J., Ringuette, M. J. (2025). Drosophila SPARC collagen IV chaperone-like activity essential for development is unique to the fat body iScience, 28(4):112111 PubMed ID: 40241767
Summary: Drosophila fat body-derived SPAR acts as a chaperone for collagen IV (Col(IV)), enabling their diffusion and incorporation into distal tissue basement membranes (BMs). Disruption of SPARC or Col(IV) production by the fat body is lethal, despite expression by other tissues such as imaginal discs. Wing disc-derived SPARC does not associate with Col(IV) in BMs and is not essential for survival. Differential association of fat body- and wing disc-derived SPARC with Col(IV) is not due to differences in SPARC glycosylation nor to the absence of SPARC and Col(IV) co-expression. Further, SPARC domain II/III produced by the fat body is sufficient for Col(IV) diffusion to both proximal and distal BMs, and rescues lethality associated with loss of SPARC. However, SPARC domain II/III does not diffuse beyond the hemolymph. Thus, the essential Col(IV) chaperone-like activity specific to fat body-derived SPARC is not required beyond the hemolymph. |
Monday March 31st - Disease Models |
| Farmer, S. M., Solbach, A., Xu, S., Rios, B., Ye, X., Gao, A., Covarrubias, D., Yu, Y., Ye, L., Chuong, V., Furr Stimming, E., Zhao, H., Zhang, S. (2025). Structural-functional analyses of the huntingtin/HAP40 complex in Drosophila and humans J Biomol Struct Dyn:1-16 PubMed ID: 40091796
Summary: Huntington's disease (HD) is a neurodegenerative disorder caused by an abnormal CAG expansion in the Huntingtin (HTT) gene. Given its simple genetic cause but complex pathogenic mechanisms, interest in targeting HTT for HD treatment is growing, necessitating a clear understanding of HTT regulation. HTT protein primarily exists in a core complex with HAP40, forming a highly ordered structure with two large globular domains connected by a bridge. Previous work demonstrated that HAP40 is conserved in Drosophila, controls HTT's function, protein stability, and levels, and is a potential modifier of HD pathogenesis, supporting its central role in HTT regulation. This study showed that HTT synergizes with HAP40 to induce novel gain-of-function effects in Drosophila when overexpressed. Protein modeling revealed that despite their prominent evolutionary and sequence divergence, the fly and human HTT-HAP40 complexes share a high degree of structural similarity. Protein-contact maps and molecular simulations showed that HAP40 preferentially binds to HTT's C-terminal domain in both complexes. By examining the interfacial contacts between HTT and HAP40 in fly and human complexes, this study identified ten conserved bonds that are important for HAP40's affinity for HTT. Finally, this study showed that the conserved N-terminal BΦ motif in HAP40 is not essential for HTT binding but important for HAP40's functions. Through the structural-functional analyses of the fly and human HTT-HAP40 complexes, these results support that the structural similarity underlies the functional conservation of the two complexes from these evolutionarily distant species and further uncover novel insight into HAP40 regulation and its interaction with HTT. | Geier, B., Roy, B., Reiter, L. T. (2025). Small molecule ion channel agonist/antagonist screen reveals seizure suppression via glial Irk2 activation in a Drosophila model of Dup15q syndrome Neurobiol Dis, 208:106882 PubMed ID: 40122181
Summary: The neurogenetic disorder duplication 15q syndrome (Dup15q) is characterized by a high incidence of autism spectrum disorder (ASD) and pharmacoresistant epilepsy. Standard-of-care broad-spectrum anti-seizure medications (ASM) often fail to control seizures in Dup15q, emphasizing the need for the identification of new therapeutic compounds. Previously, a model of Dup15q in Drosophila melanogaster was generated by overexpressing Dube3a in glial cells, instead of neurons. This model recapitulates the spontaneous seizures present in Dup15q patients. This study screened a set of FDA-approved compounds for their ability to suppress seizures in repo > Dube3a flies. 72 compounds were used from the Enzo SCREEN-WELL Ion Channel Library for primary screening of seizure suppression. Six compounds were identified that significantly reduced seizure duration. Furthermore, the compounds that passed the primary and secondary screenings were associated with K(+) channels. Glial-specific knockdown of the inward rectifying potassium (Irk) 2 channel exacerbated the seizure phenotype in these animals indicating a mechanism of action for drugs that bind irk2, like minoxidil, and can suppress seizures through the rebalancing of K(+) extracellularly. This pharmacological and molecular investigation further supports the role of extracellular K(+) content in Dup15q seizure activation and provides a putative target for therapeutic intervention. |
| Huang, J. C., Pan, X. K., Li, S. C., Zeng, W. H., Zhong, Y. J., Pan, H. Y., Zhuang, Y. L. (2025). Polyphenol extracts from rambutan peel promote longevity via the attenuation of the Toll/Imd pathway Food Funct, 16(7):2793-2807 PubMed ID: 40094275
Summary: Peel from Rambutan fruit is rich in polyphenols such as ellagic acid, corilagin, geraniin, quercetin, and rutin, which contribute to its diverse health benefits, including antioxidant, antimicrobial, antiviral, anti-inflammatory, hypoglycemic, and potential anticancer properties. The polyphenols present in the rambutan peel demonstrate potential for delaying cellular aging by mitigating oxidative stress within cells. Moreover, no study has systematically explored the anti-aging effects and the underlying mechanisms of polyphenols derived from rambutan peel. Drosophila melanogaster has often been used in aging studies to reveal the mechanisms of aging onset and development. Using Drosophila melanogaster as an in vivo aging model, the aim of the present study was to probe whether rambutan peel polyphenol extracts (RPPEs) exert a lifespan extending effect in vivo and to gain insights into the mechanism of action. Results highlighted that the optimized concentration of RPPEs for the anti-aging treatment in Drosophila melanogaster was 5 mg mL(-1). In addition, RPPEs extended the lifespan of Drosophila melanogaster in a manner that was related to the dose and gender. Meanwhile, RPPEs improved the climbing ability and sleep and maintained the antioxidant capacity of aged Drosophila. RPPEs also ameliorated intestinal barrier damage in aging Drosophila. Transcriptome sequencing analysis showed that RPPEs extended the lifespan of Drosophila by down-regulating the Toll/IMD signaling pathway. | Ma, X., Li, H., Li, Y., Xie, X., Wang, Y., Wang, M., Peng, X. (2025). Potential Antidiabetic Activity of Nordihydroguaiaretic Acid: An Insight into Its Inhibitory Mechanisms on Carbohydrate-Hydrolyzing Enzymes, the Binding Behaviors with Enzymes, and In Vivo Antihyperglycemic Effect J Agric Food Chem, 73(14):8290-8304 PubMed ID: 40152424
Summary: The inhibitory mechanisms and binding behaviors of nordihydroguaiaretic acid (NDGA) to α-glucosidase/α-amylase were investigated by in vitro multispectroscopic methods and in silico modeling technique. The results demonstrated that NDGA reversibly and uncompetitively inhibited α-glucosidase, exhibiting stronger inhibition than acarbose, while it displayed noncompetitive inhibition against α-amylase. Additionally, NDGA could spontaneously bind to α-glucosidase/α-amylase mainly through hydrogen bonds and hydrophobic forces, thus altering the spatial structure of enzymes and reducing their catalytic activity. The presence of crowding reagents/polysaccharides/undigested milk proteins would decrease the inhibitory ability of NDGA, whereas fatty acids exhibited the opposite phenomenon on α-glucosidase. Furthermore, the antidiabetic activity of NDGA in vivo was evaluated using the diabetic Drosophila model induced by a high-sugar diet. It was found that NDGA significantly reduced the glucose levels of diabetic Drosophila. These findings suggested that NDGA was a potential inhibitor of α-glucosidase/αamylase and could be used as a nutritional adjuvant to prevent diabetes. |
| Ismael, S., Baitamouni, S., Lee, D. (2025). Neuroprotective Role of Cyclic AMP Signaling in Dopaminergic Degeneration Induced by a Parkinson's Disease Toxin, Rotenone NeuroSci, 6(1) PubMed ID: 40137868
Summary: Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the selective loss of dopaminergic (DA) neurons in the midbrain. While dopamine precursor levodopa and D2 receptor agonists are commonly used to alleviate PD symptoms, these treatments do not halt or reverse disease progression. Thus, developing effective neuroprotective strategies remains a critical goal. This study explored neuroprotective mechanisms in a Drosophila primary neuronal culture model of PD, created by administering the environmental toxin rotenone. Using the chemogenetic DREADD (designer receptors exclusively activated by designer drugs) system, cAMP signaling was selectively activated in DA neurons within the rotenone-induced model. The results demonstrate that increasing cAMP signaling via Gs-coupled DREADD (rM3Ds) is protective against DA neurodegeneration. Furthermore, overexpression of the catalytic PKA-C1 subunit fully rescued DA neurons from rotenone-induced degeneration, with this effect restricted to DA neurons where PKA-C1 was specifically overexpressed. These findings reveal that cAMP-PKA signaling activation is neuroprotective in DA neurons against rotenone-induced degeneration, offering promising insights for developing targeted therapeutic strategies to slow or prevent PD pathology progression. | Jia, K., Wu, L., Li, Z., Wei, T., Fan, T., Xiao, G. (2025). Thymoquinone Ameliorates Gut Epithelial Injury by Suppressing the JNK Signaling Pathway Based on Its Anti-Oxidant Property Food Sci Nutr, 13(4):e70113 PubMed ID: 40129997
Summary: Ulcerative colitis is one of the most common sorts of inflammatory bowel disease. This study investigates the protective effects of thymoquinone against sodium dodecyl sulfate (SDS)-induced intestinal damage and elucidates the underlying mechanisms using the Drosophila melanogaster model of ulcerative colitis. Drosophila fed thymoquinone from larval to adult stages were resistant to SDS injury in adulthood. Thymoquinone pretreatment significantly restored the abnormal behaviors and intestinal morphological defects in Drosophila exposed to SDS. Moreover, thymoquinone protected the intestinal barrier function by inhibiting the overactivated c-Jun N-terminal kinase (JNK) pathway in the intestine induced by SDS. Further studies indicated that thymoquinone inhibits the JNK pathway by reducing intestinal reactive oxygen species (ROS) levels. This research provides novel pathological and mechanistic insights into the potential application of thymoquinone in developing functional foods or natural medicines, highlighting its significance in treating ulcerative colitis. |
Monday March 30th - Adult Neural Development, Structure and Function |
| Epiney, D., Morales Chaya, G. N., Dillon, N. R., Lai, S. L., Doe, C. Q. (2025). Transcriptional complexity in the insect central complex: single nuclei RNA-sequencing of adult brain neurons derived from type 2 neuroblasts bioRxiv, PubMed ID: 40093129
Summary: In both invertebrates such as Drosophila and vertebrates such as mouse or human, the brain contains the most diverse population of cell types of any tissue. It is generally accepted that transcriptional diversity is an early step in generating neuronal and glial diversity, followed by the establishment of a unique gene expression profile that determines morphology, connectivity, and function. In Drosophila, there are two types of neural stem cells, called Type 1 (T1) and Type 2 (T2) neuroblasts. In contrast to T1 neuroblasts, T2 neuroblasts generate intermediate neural progenitors (INPs) that expand the number and diversity of cell types. The diversity of T2-derived neurons contributes a large portion of the central complex (CX), a conserved brain region that plays a role in sensorimotor integration. Recent work has revealed much of the connectome of the CX, but how this connectome is assembled remains unclear. Mapping the transcriptional diversity of neurons derived from T2 neuroblasts is a necessary step in linking transcriptional profile to the assembly of the adult brain. This study performed single nuclei RNA sequencing of T2 neuroblast-derived adult neurons and glia. Clusters containing all known classes of glia, clusters that are male/female enriched, and 161 neuron-specific clusters were identified. Neurotransmitter and neuropeptide expression were mapped and unique transcription factor combinatorial codes were identified for each cluster (presumptive neuron subtype). This is a necessary step that directs functional studies to determine whether each transcription factor combinatorial code specifies a distinct neuron type within the CX. Several columnar neuron subtypes were mapped to distinct clusters, and two neuronal classes (NPF+ and AstA+) were identified that both map to two closely related clusters. These data support the hypothesis that each transcriptional cluster represents one or a few closely related neuron subtypes. | Doran, S., Bradlaugh, A. A., Corke, J., Baines, R. A. (2025). Circadian control in the timing of critical periods during Drosophila larval neuronal development Curr Biol. 65-1671. PubMed ID: 40132587
Summary: Developing neural circuits are maximally open to modification during defined critical periods (CPs). Previous work identified a CP in the Drosophila embryo, from 17 to 19 h after egg laying (AEL), during which activity manipulation (optogenetic and/or pharmacological) permanently alters locomotor network stability. Analysis of excitatory and inhibitory inputs to an identified motoneuron shows that CP activity manipulation preferentially enhances excitation. This effect is permanent, persisting through to third instars (5 days post manipulation). A manifestation of this effect is a marked increase in seizure recovery time (RT) in response to an electric shock. The induced seizure results in immediate paralysis, followed by uncoordinated peristalsis until the larva recovers sufficiently to move away from its original position (i.e., the seizure endpoint). Significantly, exposure to blue light (BL) during this same embryonic temporal window is similarly able to lead to an increased seizure RT, an effect that requires the presence of CRYPTOCHROME (CRY). This study identified a series of BL-sensitive CPs, occurring at ∼24-h intervals, from embryogenesis through larval development. Exposure to BL during these CPs increases the time taken for wandering larvae to recover from electroshock-induced seizure activity. This effect is absent when CRY or the principal clock-signaling neuropeptide-pigment-dispersing factor (PDF)-is absent. Thus, this study uncover a novel role for the circadian clock during the embryonic and larval stages of Drosophila neural development. |
| Held, M., Bisen, R. S., Zandawala, M., Chockley, A. S., Balles, I. S., Hilpert, S., Liessem, S., Cascino-Milani, F., Ache, J. M. (2025). Aminergic and peptidergic modulation of insulin-producing cells in Drosophila Elife, 13 PubMed ID: 40063677
Summary: Insulin plays a critical role in maintaining metabolic homeostasis. Since metabolic demands are highly dynamic, insulin release needs to be constantly adjusted. These adjustments are mediated by different pathways, most prominently the blood glucose level, but also by feedforward signals from motor circuits and different neuromodulatory systems. This study analyzed how neuromodulatory inputs control the activity of the main source of insulin in Drosophila - a population of insulin-producing cells (IPCs) located in the brain. IPCs are functionally analogous to mammalian pancreatic beta cells, but their location makes them accessible for in vivo recordings in intact animals. Functional inputs to IPCs were characterized using single-nucleus RNA sequencing analysis, anatomical receptor expression mapping, connectomics, and an optogenetics-based 'intrinsic pharmacology' approach. The results show that the IPC population expresses a variety of receptors for neuromodulators and classical neurotransmitters. Interestingly, IPCs exhibit heterogeneous receptor profiles, suggesting that the IPC population can be modulated differentially. This is supported by electrophysiological recordings from IPCs, which was performed while activating different populations of modulatory neurons. This analysis revealed that some modulatory inputs have heterogeneous effects on the IPC activity, such that they inhibit one subset of IPCs, while exciting another. Monitoring calcium activity across the IPC population uncovered that these heterogeneous responses occur simultaneously. Certain neuromodulatory populations shifted the IPC population activity towards an excited state, while others shifted it towards inhibition. Taken together, this study provides a comprehensive, multi-level analysis of neuromodulation in the insulinergic system of Drosophila. | Fernandez-Acosta, M., Zanini, R., Heredia, F., Y, A. V., Menezes, J., Pruger, K., Ibarra, J., Arana, M., Perez, M. S., Veenstra, J. A., Wegener, C., Gontijo, A. M., Garelli, A. (2025). Triggering and modulation of a complex behavior by a single peptidergic command neuron in Drosophila Proc Natl Acad Sci U S A, 122(11):e2420452122 PubMed ID: 40085652
Summary: At the end of their growth phase, Drosophila larvae remodel their bodies, glue themselves to a substrate, and harden their cuticle in preparation for metamorphosis. This process-termed pupariation-is triggered by a surge in the hormone ecdysone. Substrate attachment is achieved by a pupariation subprogram called glue expulsion and spreading behavior (GSB). An epidermis-to-CNS Dilp8-Lgr3 relaxin signaling event that occurs downstream of ecdysone is critical for unlocking progression of the pupariation motor program toward GSB, but the factors and circuits acting downstream of Lgr3 signaling remain unknown. Using cell-type-specific RNA interference and behavioral monitoring, this study identified Myoinhibiting peptide (Mip) as a neuromodulator of multiple GSB action components, such as tetanic contraction, peristaltic contraction alternation, and head-waving. Mip is required in a pair of brain descending neurons, which act temporally downstream of Dilp8-Lgr3 signaling. Mip modulates GSB via ventral nerve cord neurons expressing its conserved receptor, sex peptide receptor (SPR). Silencing of Mip descending neurons by hyperpolarization completely abrogates GSB, while their optogenetic activation at a restricted competence time window triggers GSB-like behavior. Hence, Mip descending neurons have at least two functions: to act as GSB command neurons and to secrete Mip to modulate GSB action components. The results provide insight into conserved aspects of Mip-SPR signaling in animals, reveal the complexity of GSB control, and contribute to the understanding of how multistep innate behaviors are coordinated in time and with other developmental processes through command neurons and neuropeptidergic signaling. |
| Deluca, A., Bascom, B., Key Planas, D. A., Kocher, M. A., Torres, M., Arbeitman, M. N. (2025). Contribution of neurons that express fruitless and Clock transcription factors to behavioral rhythms and courtship iScience, 28(3):112037 PubMed ID: 40104074
Summary: Animals need to integrate information across neuronal networks that direct reproductive behaviors and circadian rhythms. The Drosophila master regulatory transcription factors that direct courtship and circadian rhythms are co-expressed. Sex differences were found in the number of these fruitless (fru) and Clock (Clk)-expressing neurons (fru ∩ Clk neurons) regulated by male-specific Fru. The fru ∩ Clk neurons were mapped to the electron microscopy connectome and to subtypes of clock neurons. Sex differences were found in fru-expressing neurons that are post-synaptic targets of Clk-expressing neurons. When fru ∩ Clk neurons are activated or silenced, we observe a male-specific shortening of period length. Activation of fru ∩ Clk neurons also changes the rate a courtship behavior is performed. We examine male courtship behavior over 24 h and courtship activities were found to peak at lights-on. These results reveal how neurons that subserve the two processes can impact behavioral outcomes in a sex-specific manner. | Gupta, H. P., Azevedo, A. W., Chen, Y. D., Xing, K., Sims, P. A., Varol, E., Mann, R. S. (2025). Decoding neuronal wiring by joint inference of cell identity and synaptic connectivity bioRxiv, PubMed ID: 40093165
Summary: Animal behaviors are executed by motor neurons (MNs), which receive information from complex pre-motor neuron (preMN) circuits and output commands to muscles. How motor circuits are established during development remains an important unsolved problem in neuroscience. Here we focus on the development of the motor circuits that control the movements of the adult legs in Drosophila melanogaster. After generating single-cell RNA sequencing (scRNAseq) datasets for leg MNs at multiple time points, the time course of gene expression for multiple gene families is described. This analysis reveals that transcription factors (TFs) and cell adhesion molecules (CAMs) appear to drive the molecular diversity between individual MNs. In parallel, ConnectionMiner, a novel computational tool that integrates scRNAseq data with electron microscopy-derived connectomes, is introduced. ConnectionMiner probabilistically refines ambiguous cell type annotations by leveraging neural wiring patterns, and, in turn, it identifies combinatorial gene expression signatures that correlate with synaptic connectivity strength. Applied to the Drosophila leg motor system, ConnectionMiner yields a comprehensive transcriptional annotation of both MNs and preMNs and uncovers candidate effector gene combinations that likely orchestrate the assembly of neural circuits from preMNs to MNs and ultimately to muscles. |
Friday March 27th - Evolution |
| Cridland, J. M., Polston, E. S., Begun, D. J. (2025). New perspectives on Drosophila melanogaster de novo gene origination revealed by investigation of ancient African genetic variation Genetics, 230(1) PubMed ID: 40106667
Summary: De novo genes can be defined as sequences producing evolutionarily derived transcripts that are not homologous to transcripts produced in an ancestor. While they appear to be taxonomically widespread, there is little agreement regarding their abundance, their persistence times in genomes, the population genetic processes responsible for their spread or loss, or their possible functions. In Drosophila melanogaster, 2 approaches have been used to discover these genes and investigate their properties. One uses traditional comparative approaches and existing genomic resources and annotations. A second approach uses raw transcriptome data to discover unannotated genes for which there is no evidence of presence in related species. Investigations using the second approach have focused on D. melanogaster genotypes from recently established cosmopolitan populations. However, most of the genetic variation in the species is found in African populations. This study investigated de novo gene candidates expressed in testis and accessory glands in a sample of flies from Zambia and compared them with candidate de novo genes expressed in North American populations. A large number of previously undiscovered de novo gene candidates is reported, most of which are expressed polymorphically. Many are predicted to code for secreted proteins. In spite of much different levels of genomic variation in Zambian and North American populations, they express similar numbers of candidate de novo genes. Evidence from genetic analysis of Raleigh inbred lines was found that a fraction of rarely expressed gene candidates in this population represent deleterious transcription promoted by inbreeding depression. Many de novo gene candidates are expressed in multiple tissues and both sexes, raising questions about how they may interact with natural selection. The relative importance of positive and negative selection, however, remains unclear. | McAllester, C. S., Pool, J. E. (2025. The potential of inversions to accumulate balanced sexual antagonism is supported by simulations and Drosophila experiments Elife, 12 PubMed ID: 40237307
Summary: Chromosomal inversion polymorphisms can be common, but the causes of their persistence are often unclear. A model is proposed for the maintenance of inversion polymorphism, which requires that some variants contribute antagonistically to two phenotypes, one of which has negative frequency-dependent fitness. These conditions yield a form of frequency-dependent disruptive selection, favoring two predominant haplotypes segregating alleles that favor opposing antagonistic phenotypes. An inversion associated with one haplotype can reduce the fitness load incurred by generating recombinant offspring, reinforcing its linkage to the haplotype and enabling both haplotypes to accumulate more antagonistic variants than expected otherwise. A forward simulator was developed and applied to examine these dynamics under a tradeoff between survival and male display. These simulations indeed generate inversion-associated haplotypes with opposing sex-specific fitness effects. Antagonism strengthens with time, and can ultimately yield karyotypes at surprisingly predictable frequencies, with striking genotype frequency differences between sexes and between developmental stages. To test whether this model may contribute to well-studied yet enigmatic inversion polymorphisms in Drosophila melanogaster, inversion frequencies were tracked in laboratory crosses to test whether they influence male reproductive success or survival. Two of the four tested inversions showed significant evidence for the tradeoff examined, with In(3 R)K favoring survival and In(3 L)Ok favoring male reproduction. In line with the apparent sex-specific fitness effects implied for both of those inversions, In(3 L)Ok was also found to be less costly to the viability and/or longevity of males than females, whereas In(3 R)K was more beneficial to female survival. Based on this work, it is expected that balancing selection on antagonistically pleiotropic traits may provide a significant and underappreciated contribution to the maintenance of natural inversion polymorphism. |
| Sarkar, S., Shit, B., Bose, J., De, S., Kawecki, T. J., Khan, I. (2025. Evolutionary History With Chronic Malnutrition Enhances Pathogen Susceptibility at Older Ages Ecol Evol, 15(4):e71070 PubMed ID: 40190800
Summary: Juvenile malnutrition is a global public health concern that negatively impacts the development and maturation of the immune system, leading to increased susceptibility to infectious diseases. Such adverse effects on immunity might increase with ageing, worsening disease conditions later in life. Furthermore, malnutrition may persist across generations, imposing strong natural selection to survive the nutrient shortage. However, it is unclear how the evolutionary history of ancestral generations with chronic malnutrition could influence pathogen resistance and infection susceptibility, as well as their age-specific changes in extant generations. To address this, this study used Drosophila melanogaster populations adapted to chronic juvenile malnutrition and exposed them to a bacterial pathogen, Providencia rettgeri, during their early and late adulthood. Surprisingly, it was observed that in populations adapted to chronic malnutrition, young flies survived infection better by tolerating the infection, while control flies displayed higher infection susceptibility despite carrying a similar pathogen load. However, this pattern in post-infection survival is reversed with ageing. There was no change in pathogen resistance, but evolved flies succumbed more to infection than control flies regardless of the input infection doses. This study thus revealed new evolutionary insights into the development of contrasting early-late-life immune strategies and age-specific vulnerabilities to infection as a function of early-life malnutrition. | Detcharoen, M., Pramual, P., Nilsai, A. (2025). Phylogenomic Analysis Reveals Evolutionary Relationships of Tropical Drosophilidae: From Drosophila to Scaptodrosophila Ecol Evol, 15(3):e71100 PubMed ID: 40065921
Summary: Species radiation in the family Drosophilidae has led to a diversity of species occupying a wide range of ecological niches. Despite the high diversity within this family, with over thousands of species and more than a hundred species recorded in Thailand and the Malay Peninsula, taxonomic classifications remain complicated due to morphological plasticity and inconsistent phylogenetic reconstructions based on limited genetic data. In this study, new mitochondrial genomes were assembled from Drosophila and Scaptodrosophila species collected in Thailand, expanding the genomic resources for these underexplored tropical regions. Phylogenetic analyses of 13 mitochondrial protein-coding genes revealed well-supported evolutionary relationships, with Scaptodrosophila forming a distinct lineage and several Drosophila subgroups, such as ananassae, montium, and melanogaster, exhibiting monophyly. Notable discrepancies were observed in the placement of the suzukii subgroup, which was not recovered as monophyletic, and the position of the punjabiensis subgroup, reflecting the complexities of lineage sorting and hybridization events. This comprehensive genomic analysis provides a more accurate understanding of evolutionary relationships within the family Drosophilidae's diversification in the tropics. |
| Lev, A., Gutierrez, A. I., Srinivasan, A. S., Herrick, C. M., Stewart, A. D., Pischedda, A. (2025). Indirect fitness benefits can reinforce the direct fitness benefits of male mate choice. Evolution. PubMed ID: 40202795
Summary: Mating preferences frequently evolve because they confer fitness benefits to the chooser. While there is strong evidence for both direct and indirect fitness benefits in the context of female mate choice, the potential for males to receive indirect benefits from mate choice remains understudied. Male mate choice for larger female body size is widespread among ectotherms and is generally attributed to the direct fitness benefits larger females provide due to their higher fecundity. However, when female size is heritable or condition-dependent, males could also receive indirect benefits from mating with larger females in the form of increased offspring fitness. This possibility was tested in Drosophila melanogaster by first confirming the direct fitness benefits associated with large females and then comparing the fitness of offspring produced by large versus small females. Although female body size did not influence offspring juvenile viability, large females produced daughters with higher reproductive success than the daughters of small females. Males only received these indirect benefits through their daughters, however, as reproductive success did not differ significantly between the sons of large and small females. These findings demonstrate that indirect fitness benefits can serve to reinforce the direct benefits of male mate choice, suggesting that indirect effects may play an underappreciated role in the evolution of male preferences. | Leigh, S., Thorpe, P., Snook, R. R., Ritchie, M. G. (2025). Sexual selection, genomic evolution and population fitness in Drosophila pseudoobscura Proc Biol Sci, 292(2044):20242744 PubMed ID: 40169023
Summary: Sexual selection shapes the genome in unique ways. It is also likely to have significant fitness consequences, such as purging deleterious mutations from the genome or conversely maintaining genetic load in a population via sexual conflict. This study examined what the influence of sexual selection has on genomic variation potentially underlying population fitness using experimentally evolved Drosophila pseudoobscura populations. Sexual selection was manipulated by keeping replicate lines in elevated polyandry or strict monogamy for approximately 200 generations followed by individual-based sequencing. Using pi (π), fixation index (F(st)) and recombination rate measures, signatures of selection were confirmed to not bevdispersed but mainly localized to the third and X chromosome. Overall mutational load was similar between lines but analysis of the distribution of fitness effects revealed considerable variation between lines and chromosomes. Furthermore, the distribution of transposable elements was found to differ between the lines, with a higher load in monogamous lines. These results suggest that complex interactions between purifying selection and sexual conflict are shaping the genome, particularly on chromosome 3 and the sex chromosome; sexual selection influences divergence across chromosomes but in a more complex way than proposed by simple 'purging' of deleterious loci. |
Thursday March 26th - Adult neural structure, development and function |
| Zhang, J., Brown, E. B., Lloyd, E., Farhy-Tselnicker, I., Keene, A. C. (2025). Sleep rescues age-associated loss of glial engulfment. bioRxiv, PubMed ID: 40236052
Summary: Neuronal injury due to trauma or neurodegeneration is a common feature of aging. The clearance of damaged neurons by glia is thought to be critical for maintenance of proper brain function. Sleep loss has been shown to inhibit the motility and function of glia that clear damaged axons while enhancement of sleep promotes clearance of damaged axons. Despite the potential role of glia in maintenance of brain function and protection against neurodegenerative disease, surprisingly little is known about how sleep loss impacts glial function in aged animals. Axotomy of the Drosophila antennae triggers Wallerian degeneration, where specialized olfactory ensheathing glia engulf damaged neurites. This glial response provides a robust model system to investigate the molecular basis for glial engulfment and neuron-glia communication. Glial engulfment is impaired in aged and sleep-deprived animals, raising the possibility that age-related sleep loss underlies deficits in glial function. To define the relationship between sleep- and age-dependent reductions in glial function, sleep was restored to aged animals, and the effects were examined on glial clearance of damaged axons. Both pharmacological and genetic induction of sleep restores clearance of damaged neurons in aged flies. Further analysis revealed that sleep restored post-injury induction of the engulfment protein Draper to aged flies, fortifying the notion that loss of sleep contributes to reduced glial-mediated debris clearance in aged animals. To identify age-related changes in the transcriptional response to neuronal injury, single-nucleus RNA-seq of the central brains from axotomized young and old flies were used. Broad transcriptional changes were seen within the ensheathing glia of young flies, and the loss of transcriptional induction of autophagy-associated genes. Age-dependent loss was identified of transcriptional induction of 18 transcripts encoding for small and large ribosomal protein subunits following injury in old flies, suggesting dysregulation of ribosomal biogenesis contributes to loss of glial function. Together, these findings demonstrate a functional link between sleep loss, aging and Wallerian degeneration. | Chong, B., Kumar, V., Nguyen, D. L., Hopkins, M. A., Ferry, F. S., Spera, L. K., Paul, E. M., Hutson, A. N., Tabuchi, M. (2025). Neuropeptide-Dependent Spike Time Precision and Plasticity in Circadian Output Neurons. Eur J Neurosci, 61(5):e70037 PubMed ID: 40080910
Summary: Circadian rhythms influence various physiological and behavioral processes such as sleep-wake cycles, hormone secretion, and metabolism. In Drosophila, an important set of circadian output neurons is called pars intercerebralis (PI) neurons, which receive input from specific clock neurons called DN1. These DN1 neurons can further be subdivided into functionally and anatomically distinctive anterior (DN1a) and posterior (DN1p) clusters. The neuropeptide diuretic hormones 31 (Dh31) and 44 (Dh44) are the insect neuropeptides known to activate PI neurons to control activity rhythms. However, the neurophysiological basis of how Dh31 and Dh44 affect circadian clock neural coding mechanisms underlying sleep in Drosophila is not well understood. This study identified Dh31/Dh44-dependent spike time precision and plasticity in PI neurons. A mixture of Dh31 and Dh44 was found to enhance the firing of PI neurons, compared to the application of Dh31 alone and Dh44 alone. Next, the application of synthesized Dh31 and Dh44 was found to affect membrane potential dynamics of PI neurons in the precise timing of the neuronal firing through their synergistic interaction, possibly mediated by calcium-activated potassium channel conductance. Further, Dh31/Dh44 enhances postsynaptic potentials in PI neurons. Together, these results suggest multiplexed neuropeptide-dependent spike time precision and plasticity as circadian clock neural coding mechanisms underlying sleep in Drosophila. |
| Wolff, T., Eddison, M., Chen, N., Nern, A., Sundaramurthi, P., Sitaraman, D., Rubin, G. M. (2025). Cell type-specific driver lines targeting the Drosophila central complex and their use to investigate neuropeptide expression and sleep regulation. Elife, 14 PubMed ID: 40244684
Summary: The central complex (CX) plays a key role in many higher-order functions of the insect brain including navigation and activity regulation. Genetic tools for manipulating individual cell types, and knowledge of what neurotransmitters and neuromodulators they express, will be required to gain mechanistic understanding of how these functions are implemented. This study generated and characterized split-GAL4 driver lines that express in individual or small subsets of about half of CX cell types. Neuropeptide and neuropeptide receptor expression was serveyed in the central brain using fluorescent in situ hybridization. About half of the neuropeptides examined were expressed in only a few cells, while the rest were expressed in dozens to hundreds of cells. Neuropeptide receptors were expressed more broadly and at lower levels. Using GAL4 drivers to mark individual cell types, 51 of the 85 CX cell types examined expressed at least one neuropeptide and 21 expressed multiple neuropeptides. Surprisingly, all co-expressed a small molecule neurotransmitter. Finally, the driver lines were used to identify CX cell types whose activation affects sleep, and other central brain cell types were identified that link the circadian clock to the CX. The well-characterized genetic tools and information on neuropeptide and neurotransmitter expression this study provided should enhance studies of the CX. | de Queiroz, B. R., Laghrissi, H., Rajeev, S., Blot, L., De Graeve, F., Dehecq, M., Hallegger, M., Dag, U., Dunoyer de Segonzac, M., Ramialison, M., Cazevieille, C., Keleman, K., Ule, J., Hubstenberger, A., Besse, F. (2025). Axonal RNA localization is essential for long-term memory. Nat Commun, 16(1):2560 PubMed ID: 40089499
Summary: Localization of mRNAs to neuronal terminals, coupled to local translation, has emerged as a prevalent mechanism controlling the synaptic proteome. However, the physiological regulation and function of this process in the context of mature in vivo memory circuits has remained unclear. This study combined synaptosome RNA profiling with whole brain high-resolution imaging to uncover mRNAs with different localization patterns in the axons of Drosophila Mushroom Body memory neurons, some exhibiting regionalized, input-dependent, recruitment along axons. By integrating transcriptome-wide binding approaches and functional assays, this study showed that the conserved Imp RNA binding protein controls the transport of mRNAs to Mushroom Body axons, and a mutant was characterize in which this transport is selectively impaired. Using this unique mutant, we demonstrate that axonal mRNA localization is required for long-term, but not short-term, behavioral memory. This work uncovers circuit-dependent mRNA targeting in vivo and demonstrates the importance of local RNA regulation in memory consolidation. |
| Churgin, M. A., Lavrentovich, D. O., Smith, M. A., Gao, R., Boyden, E. S., de Bivort, B. L. (2025). A neural correlate of individual odor preference in Drosophila. Elife, 12 PubMed ID: 40067954
Summary: Behavior varies even among genetically identical animals raised in the same environment. However, little is known about the circuit or anatomical origins of this individuality. This study demonstrates a neural correlate of Drosophila odor preference behavior in the olfactory sensory periphery. Namely, idiosyncratic calcium responses in projection neuron (PN) dendrites and densities of the presynaptic protein Bruchpilot in olfactory receptor neuron (ORN) axon terminals correlate with individual preferences in a choice between two aversive odorants. The ORN-PN synapse appears to be a locus of individuality where microscale variation gives rise to idiosyncratic behavior. Simulating microscale stochasticity in ORN-PN synapses of a 3062 neuron model of the antennal lobe recapitulates patterns of variation in PN calcium responses matching experiments. Conversely, stochasticity in other compartments of this circuit does not recapitulate those patterns. These results demonstrate how physiological and microscale structural circuit variations can give rise to individual behavior, even when genetics and environment are held constant. | Atif, M., Lee, Y. (2025). Taste detection of flonicamid in Drosophila melanogaster. Insect Biochem Mol Biol, 180:104302 PubMed ID: 40112957
Summary: Flonicamid, a widely used insecticide, presents an intriguing question: does it function as an antifeedant by directly activating bitter-sensing gustatory receptor neurons (GRNs) in Drosophila melanogaster. This study found that electrophysiological recordings revealed that S-type labellar sensilla exhibited strong neuronal responses to flonicamid, while inhibition of bitter-sensing GRNs nullified this response. Genetic screening identified Gr28b, Gr93a, and Gr98b as essential gustatory receptors for flonicamid detection. Isoform-specific rescue experiments confirmed that Gr28b.a is responsible for restoring sensory responses in Gr28b mutants. Proboscis extension response assays demonstrated that wild-type flies avoided flonicamid, whereas Gr28b, Gr93a, and Gr98b mutants failed to. Functional rescue of these mutants restored the behavioral response, confirming the involvement of these receptors in mediating gustatory aversion. These findings uncover a novel sensory mechanism for detecting flonicamid through specific gustatory receptors and highlight their potential as molecular targets for insect control strategies. |
Wednesday March 25th - Disease Models |
| Cheng, G., Chang, J., Ke, S., Dai, Z., Gong, D., Gong, H., Zhou, W. (2025). The inter-organelle cross-talk finely orchestrated in the amyloidogenic processing of amyloid precursor protein in dendritic arborization neurons of Drosophila. Theranostics, 15(7):2951-2966 PubMed ID: 40083942
Summary Organelles in neuronal dendrites facilitate local metabolic processes and energy supply, crucial for dendrite development and neurodegenerative diseases. The distinct functions of dendritic organelles have been well studied, however, their crosstalk under physiological and pathological contexts remains elusive. This study aimed to establish an in vivo model system of contacts between multi-organelles for investigating the modulation of inter-organelle crosstalk in Alzheimer's disease (AD). A dendrite model of organelle contacts was developed in Drosophila neurons using a set of proximity-driven probes and four-color Airyscan super-resolution imaging. The systematic modulations among multiple contact sites (CSs) between organelles were examined by manipulating CS tethers and vesicular transporters. Finally, perturbations of these CSs and the dendrite structure in the amyloidogenic processing of amyloid precursor protein (APP) were evaluated by introducing three stages of the processing in this model system. A dynamic network, interconnected via CSs and organized with multi-organelle contacts, was presented among Golgi outposts, the endoplasmic reticulum, lysosomes, and mitochondria (GELM). The CS modulations were found to encompass both their density and motility. Notably, multi-CSs participated in complementary modulations spanning across different cellular pathways. Furthermore, the CS network was revealed to be progressively disturbed in APP amyloidogenic processing, with upregulations in density and motility extending from single- to multi-CSs. These CS perturbations, along with defects in dendrite structural plasticity, could be partially rescued by knocking down Miro. It is concluded that the elucidation of CS modulation modes in the GELM network model reveals a cascaded dysregulation of organelle crosstalk during APP amyloidogenic processing. It expands the mechanisms of inter-organelle communication and provides novel insights into neurodegeneration in AD pathology. | Bereshneh, A. H., Andrews, J. C., Eberl, D. F., Bademci, G., Borja, N. A., Bivona, S., Chung, W. K., Yamamoto, S., Wangler, M. F., McKee, S., Tekin, M., Bellen, H. J., Kanca, O. (2025). De novo variants in CDKL1 and CDKL2 are associated with neurodevelopmental symptoms. Am J Hum Genet, 112(4):846-862 PubMed ID: 40088891
Summary: The CDKL (cyclin-dependent kinase-like) family consists of five members in humans, CDKL1-5, that encode serine-threonine kinases. The only member that has been associated with a Mendelian disorder is CDKL5, and variants in CDKL5 cause developmental and epileptic encephalopathy type 2 (DEE2). Four de novo variants were studied in CDKL2 identified in five individuals, including three unrelated probands and monozygotic twins. These individuals present with overlapping symptoms, including global developmental delay, intellectual disability, childhood-onset epilepsy, dyspraxia, and speech deficits. Two individuals were identified with de novo missense variants in CDKL1 in the published Deciphering Developmental Disorders (DDD) and GeneDx cohorts with developmental disorders. Drosophila has a single ortholog of CDKL1-5, CG7236 (Cdkl). Cdkl is expressed in sensory neurons that project to specific regions of the brain that control sensory inputs. Cdkl loss causes semi-lethality, climbing defects, heat-induced seizures, hearing loss, and reduced lifespan. These phenotypes can be rescued by expression of the human reference CDKL1, CDKL2, or CDKL5, showing that the functions of these genes are conserved. In contrast, the CDKL1 and CDKL2 variants do not fully rescue the observed phenotypes, and overexpression of the variant proteins leads to phenotypes that are similar to Cdkl loss. Co-expression of CDKL1 or CDKL2 variants with CDKL1, CDKL2, or CDKL5 references in the mutant background suppresses the rescue ability of the reference genes. These results suggest that the variants act as dominant negative alleles and are causative of neurological symptoms in these individuals. |
| Bar, S., Hilsabeck, T. A. U., Pattavina, B., Lopez-Dominguez, J. A., Basisty, N., Bons, J., Watson, M., Schilling, B., Campisi, J., Kapahi, P., Sharma, A. (2025). Inhibition of the metalloprotease ADAM19 as a novel senomorphic strategy to ameliorate gut permeability and senescence markers by modulating senescence-associated secretory phenotype (SASP). Aging (Albany NY), 17(3):757-777 PubMed ID: 40117561
Summary: Accumulation of DNA damage can accelerate aging through cellular senescence. Previousl work established a Drosophila model to investigate the effects of radiation-induced DNA damage on the intestine. In this model, irradiation-responsive senescence was examined in the fly intestine. Through an unbiased genome-wide association study (GWAS) utilizing 156 strains from the Drosophila Genetic Reference Panel (DGRP), meltrin (the drosophila orthologue of mammalian ADAM19) was identified as a potential modulator of the senescence-associated secretory phenotype (SASP). Knockdown of meltrin resulted in reduced gut permeability, DNA damage, and expression of the senescence marker β-galactosidase (SA-β-gal) in the fly gut following irradiation. Additionally, inhibition of ADAM19 in mice using batimastat-94 reduced gut permeability and inflammation in the gut. These findings extend to human primary fibroblasts, where ADAM19 knockdown or pharmacological inhibition decreased expression of specific SASP factors and SA-β-gal. Furthermore, proteomics analysis of the secretory factor of senescent cells revealed a significant decrease in SASP factors associated with the ADAM19 cleavage site. These data suggest that ADAM19 inhibition could represent a novel senomorphic strategy. | Yasuda, R., Hashimoto, H., Oka, M., Mok, J. W., Waqar, M., Dauwalder, B., Kanca, O., Mizuno, T., Yamamoto, S. (2025). Functional analysis of pathogenic variants in LAMB1-related leukoencephalopathy reveals genotype-phenotype correlations and suggests its role in glial cells. Hum Mol Genet, 34(11):990-999 PubMed ID: 40237576
Summary: Laminin B1 (LAMB1) is one of the extracellular matrix (ECM) proteins that make up the basement membrane. Early frameshift, late frameshift, and missense variants in LAMB1 have been reported to cause rare monogenic neurological disorders that are collectively known as LAMB1-related leukoencephalopathy. Although there is some genotype-phenotype correlation, functional consequences of pathogenic LAMB1 variants are largely unknown. This study aimed to elucidate function of the fly ortholog of this gene (LanB1) in the nervous system and to further study the functional consequences of the LAMB1 variants using Drosophila melanogaster. LanB1 gene is expressed on the surface of adult fly brains in a subset of glia cells. LanB1 protein localizes to the blood-brain barrier (BBB) in adult fly brains and knockdown of LanB1 in the BBB resulted in short life span and locomotor defects. Although human LAMB1 was not able to function in flies, in vivo overexpression and rescue experiments using analogous variants in fly LanB1 suggested that the frameshift variants behave as strong loss-of-function (LoF) alleles whereas a missense variant functions as a milder LoF allele. In vitro assay in HEK293T cells revealed that late-truncated LAMB1 is uniquely detected as a monomer in the culture medium, which might be the basis of dominant inheritance of these variants through a gain-of-function mechanism. These data contributes to the understanding of the ECM component of the fly BBB and lays the foundation to unravel the molecular consequences of different pathogenic variants in LAMB1. |
| Aparicio, R., Salazar, A. M., Schmid, E. T., Khanbabaei, A., Rajgopal, A., Randolph, R. K., Walker, D. W. (2025). The Impact of Rosemary and Ginger Extracts on Aging and Healthspan in Drosophila. Aging Dis, PubMed ID: 40072366
Summary: Aging leads to a decline in physiological functions and increased risk of mortality, yet therapeutic avenues are limited. Dietary phytochemicals provide an attractive approach to counteract age-related health decline.This study examined the impact of feeding extracts of rosemary and ginger, prepared via three different extraction methods, on markers of aging and healthspan in the fruit fly Drosophila. Certain, but not all, extracts of ginger produce modest prolongevity effects. Feeding extracts of rosemary, produced via the three different methods, each produced prolongevity effects. Feeding combinations of both rosemary and ginger extracts leads to robust lifespan extension. Prolongevity effects of rosemary and ginger extracts are linked to improved intestinal barrier function in aged flies. Importantly, this study showed that the anti-aging effects observed are not linked to reduced food intake. Interestingly, several instances were observe where the combination of rosemary plus ginger produces effects which are more pronounced or not seen for either extract alone. In terms of cellular hallmarks of aging, rosemary plus ginger feeding leads to AMPK activation and improved markers of autophagy and proteostasis in aged flies. Furthermore, feeding the combination of rosemary plus ginger feeding improves cognitive function in aged flies. These results demonstrate that rosemary and ginger extracts can counteract aging and prolong healthspan in flies. | Zhu, K., Du, D., Shi, Y., Hu, F., Zhang, W., Ni, H., Hafeez, E., Chen, D. (2025). Poria cocos Polysaccharide Delays Aging by Enhancing the Antioxidant Ability and Suppressing the Expression of the Branched-Chain Amino Acid Transferase-Encoding Gene in Drosophila melanogaster. J Agric Food Chem, 73(15):9033-9046 PubMed ID: 40178444
Summary: Poria cocos polysaccharides (PCP), the main component of Poria cocos, possess a variety of biological activities, including antitumor, immunomodulatory, and antioxidant effects. However, whether PCP has an antiaging effect remains unclear. The beneficial effects and the mechanism of PCP were studied on delaying aging using the Drosophila model. The results showed that the dietary supplementation of PCP significantly extended the lifespan, improved the climbing ability, attenuated intestinal barrier dysfunction, alleviated gastrointestinal acid-base imbalance, and prevented intestinal stem cells (ISCs) hyperproliferation. In addition, PCP notably increased the activities of SOD and CAT and reduced the content of MDA. Furthermore, RNA-Seq showed that PCP supplementation led to the differential expression of 638 genes. KEGG analysis revealed that these differentially expressed genes were strongly enriched in the signaling pathway of cofactor biosynthesis. Among these genes, the expression of the branched-chain amino acid transferase-encoding gene (bcat) was significantly downregulated. The bcat-knockdown prolonged the flies' lifespan, while bcat-overexpression reduced the lifespan. Interestingly, PCP addition can rescue the flies' lifespan in the background of bcat-overexpression. Taken together, these data indicate that PCP delays aging by enhancing the antioxidant ability and suppressing the expression of the bcat gene in Drosophila. |
Monday March 23rd - Adult Physiology and Metabolism |
| Waller, T. J., Collins, C. A., Dus, M. (2025). Pyruvate kinase deficiency links metabolic perturbations to neurodegeneration and axonal protection. bioRxiv, PubMed ID: 40235982
Summary: Neurons rely on tightly regulated metabolic networks to sustain their high-energy demands, particularly through the coupling of glycolysis and oxidative phosphorylation. This study investigated the role of pyruvate kinase (PyK), a key glycolytic enzyme, in maintaining axonal and synaptic integrity in the Drosophila melanogaster neuromuscular system. Using genetic deficiencies in PyK, disrupting glycolysis was shown to induce progressive synaptic and axonal degeneration and severe locomotor deficits. These effects require the conserved dual leucine zipper kinase (DLK), Jun N-terminal kinase (JNK), and activator protein 1 (AP-1) Fos transcription factor axonal damage signaling pathway and the SARM1 NADase enzyme, a key driver of axonal degeneration. As both DLK and SARM1 regulate degeneration of injured axons (Wallerian degeneration), the effect of PyK loss on this process was probed. Consistent with the idea that metabolic shifts may was found to influence neuronal resilience in context-dependent ways, pyk knockdown delays Wallerian degeneration following nerve injury, suggesting that reducing glycolytic flux can promote axon survival under stress conditions. This protective effect is partially blocked by DLK knockdown and fully abolished by SARM1 overexpression. Together, these findings help bridge metabolism and neurodegenerative signaling by demonstrating that glycolytic perturbations causally activate stress response pathways that dictate the balance between protection and degeneration depending on the system's state. These results provide a mechanistic framework for understanding metabolic contributions to neurodegeneration and highlight the potential of metabolism as a target for therapeutic strategies. | Baeza Icaza, A., Poblete Ahumada, G., Rezende, E. L., Peralta-Maraver, I. (2025). Warm acclimation reduces the sensitivity of Drosophila species to heat stress at ecologically relevant scales. J Anim Ecol, 94(5):896-907 PubMed ID: 40143530
Summary: Thermal acclimation is presumed to affect heat tolerance, though it is unclear how this should impact populations under realistic natural conditions. This study quantified how thermal acclimation affects heat tolerance landscapes in Drosophila and, as a consequence, their predicted mortality in the field based on modelling with a dynamic thermal tolerance algorithm. The thermal tolerance was measured of four Drosophila species (D. repleta, D. hydei, D. simulans and D. virilis) acclimated to five constant temperatures covering a range from 18 to 30^deg;C. This information was combined with field temperatures to construct dynamic tolerance landscapes for these species and examine how survival varies over the course of a year. This analyses reveal the effect of acclimation on an ecologically relevant scale, specifically through the study of cumulative mortality under natural thermal regimes. How different species respond to thermal challenges during acclimation, generally showing an increase in critical temperature (CT(max)) was explored while either reducing or maintaining constant thermal sensitivity (z). Furthermore, it was shown that while acclimation presents a relatively modest improvement in thermal tolerance during short ramping laboratory trials, this response becomes stronger when tolerance estimates are translated into ecologically relevant timescales, such as annual survival. The results indicate that acclimation to warm conditions can substantially increase Drosophila thermal tolerance, contradicting the idea that thermal acclimation in ectotherms has only a minor effect. This work applies novel approaches to studying thermal tolerance and aims to highlight the role of acclimation in ameliorating the impact of global warming. |
| Biswal, A., Purohit, S. S., Mishra, L., Mishra, M., Routray, B. R., Biswal, S. B., Nayak, S., Behera, B. C., Swain, S. K. (2025). Nano CaCO(3) mediated in vitro and in vivo wound healing characteristics of chitosan films without added drugs. Int J Biol Macromol, 307(Pt 3):142057 PubMed ID: 40090639
Summary: The proposed investigation aims towards introducing a facile and cost-effective chitosan-based material for healing of full thickness wounds via stimulation of keratinocyte at wound junction to yield faster closure. Chitosan (CS) crosslinked polyacrylic acid (PAA) polymeric networks are chosen as the matrix element to incorporate gold nanoparticles (Au Nps) and nano calcium carbonate (CaCO(3) Nps) via covalent and electrostatic interactions. The as-synthesized CS/PAA@Au/CaCO(3) nanocomposite hydrogels reveal high in vitro and in vivo biocompatibility against human kidney epithelial (HKE) cells and drosophila larvae, with minimum cell viability of 88.45 % at high doses of 87.5 μg/μL. The innate pH responsive swelling behaviour (1450 %) and WVTR (8.451 mg·cm-2h·h-1), hemocompatibility, bioadhesivity along with antibacterial and anti-biofilm activity of the nanocomposite hydrogels against S. aureus and E. coli provide prior motivation to escalate the study towards in vivo wound healing in invertebrates (D.melanogaster) and vertebrates (Sprague-Dawley rats). The proposed hydrogels show accelerated healing in invertebrates and vertebrates, i.e., complete recovery in 3 h and 11 days, respectively. The histopathology analysis establishes the deposition of highly aligned collagen fibers on the wound surface supported by the tight keratinocyte junction at wound surface by the action of calcium ions for which the material becomes promising for wound healing applications. | Cadena Del Castillo, C. E., Deniz, O., van Geest, F., Rosseels, L., Stockmans, I., Robciuc, M., Carpentier, S., Wolnerhanssen, B. K., Meyer-Gerspach, A. C., Peterli, R., Hietakangas, V., Shimobayashi, M. (2025). MLX phosphorylation stabilizes the ChREBP-MLX heterotetramer on tandem E-boxes to control carbohydrate and lipid metabolism. Sci Adv, 11(11):eadt4548 PubMed ID: 40073115
Summary: Carbohydrate-responsive element binding protein (ChREBP) and Max-like protein X (MLX) form a heterodimeric transcription factor complex that couples intracellular sugar levels to carbohydrate and lipid metabolism. To promote the expression of target genes, two ChREBP-MLX heterodimers form a heterotetramer to bind a tandem element with two adjacent E-boxes, called carbohydrate-responsive element (ChoRE). How the ChREBP-MLX hetero-tetramerization is achieved and regulated remains poorly understood. This study shows that MLX phosphorylation on an evolutionarily conserved motif is necessary for the heterotetramer formation on the ChoRE and the transcriptional activity of the ChREBP-MLX complex. Casein kinase 2 (CK2) and glycogen synthase kinase 3 (GSK3) were identified as MLX kinases. High intracellular glucose-6-phosphate accumulation inhibits MLX phosphorylation and heterotetramer formation on the ChoRE, impairing ChREBP-MLX activity. Physiologically, MLX phosphorylation is necessary in Drosophila to maintain sugar tolerance and lipid homeostasis. Our findings suggest that MLX phosphorylation is a key mechanism for the ChREBP-MLX heterotetramer formation to regulate carbohydrate and lipid metabolism. |
| Akagi, K., Jin, Y. J., Koizumi, K., Oku, M., Ito, K., Shen, X., Imura, J. I., Aihara, K., Saito, S. (2025). Integration of Dynamical Network Biomarkers, Control Theory and Drosophila Model Identifies Vasa/DDX4 as the Potential Therapeutic Targets for Metabolic Syndrome. Cells, 14(6) PubMed ID: 40136664
Summary: Metabolic syndrome (MetS) is a subclinical disease, resulting in increased risk of type 2 diabetes (T2D), cardiovascular diseases, cancer, and mortality. Dynamical network biomarkers (DNB) theory has been developed to provide early-warning signals of the disease state during a preclinical stage. To improve the efficiency of DNB analysis for the target genes discovery, the DNB intervention analysis based on the control theory has been proposed. However, its biological validation in a specific disease such as MetS remains unexplored. This study identified eight candidate genes from adipose tissue of MetS model mice at the preclinical stage by the DNB intervention analysis. Using Drosophila, RNAi-mediated knockdown screening was conducted of these candidate genes, and vasa (also known as DDX4), encoding a DEAD-box RNA helicase, was identified as a fat metabolism-associated gene. Fat body-specific knockdown of vasa abrogated high-fat diet (HFD)-induced enhancement of starvation resistance through up-regulation of triglyceride lipase. This study also confirmed that DDX4 expressing adipocytes are increased in HFD-fed mice and high BMI patients using the public datasets. These results prove the potential of the DNB intervention analysis to search the therapeutic targets for diseases at the preclinical stage. | Chen, X., Wang, B., Sarkar, A., Huang, Z., Ruiz, N. V., Yeung, A. T., Chen, R., Han, C. (2025). Phagocytosis-driven neurodegeneration through opposing roles of an ABC transporter in neurons and phagocytes. Sci Adv, 11(11):eadr5448 PubMed ID: 40073145
Summary: Lipid homeostasis is critical to neuronal survival. ATP-binding cassette A (ABCA) proteins are lipid transporters associated with neurodegenerative diseases. How ABCA transporters regulate lipid homeostasis in neurodegeneration is an outstanding question. This study reports that the Drosophila ABCA protein engulfment ABC transporter in the ovary (Eato) regulates phagocytosis-dependent neurodegeneration by playing opposing roles in neurons and phagocytes: In neurons, Eato prevents dendrites and axons from being attacked by neighboring phagocytes; in phagocytes, Eato sensitizes the cell for detecting neurons as engulfment targets. Thus, Eato deficiency in neurons alone causes phagocytosis-dependent neurite degeneration, but additional Eato loss from phagocytes suppresses the neurite degeneration. Mechanistically, Eato functions by removing the eat-me signal phosphatidylserine from the cell surface in both neurons and phagocytes. Multiple human and worm ABCA homologs can rescue Eato loss in phagocytes but not in neurons, suggesting both conserved and cell type-specific activities of ABCA proteins. These results imply possible mechanisms of neuron-phagocyte interactions in neurodegenerative diseases. |
Friday March 20th - Synapse and Vesicles |
| Yasunaga, R., Nakano, M., Kyuma, T., Fujii, K., Inui, H., Akutsu, J., Yonemura, I., Inoue, T., Suwa, A., Yoshizane, T., Nakao, A., Mori, Y. (2025). A novel insecticide cybenzoxasulfyl potently binds to vesicular acetylcholine transporter and disrupts the storage and release of acetylcholine in insects. Biochem Biophys Res Commun, 763:151792 PubMed ID: 40233436
Summary: Agrochemicals play an important role in solving global food problems and achieving a safe and sustainable society by protecting crops from pests and diseases, controlling weeds, and protecting human and animal health. The evolution of insecticide-resistant pests is a serious problem worldwide, and repeated use of insecticides with the same mode of action (MoA) promotes the evolution of resistance. Therefore, the development of insecticides with novel MoAs is important for controlling pests that are resistant to existing insecticides, thereby preventing the depletion of effective insecticides. Based on genetic studies in Caenorhabditis elegans and biochemical studies in Drosophila melanogaster, this study found that a new insecticide under development, cybenzoxasulfyl, binds directly to the vesicular acetylcholine transporter (VAChT) with low nanomolar K(d) values and inhibits acetylcholine (ACh) storage in synaptic vesicles and cholinergic signaling, thereby exerting insecticidal effects. Competitive binding assays against [(3)H]-vesamicol suggested that cybenzoxasulfyl occupies the same binding site on VAChT in a different way than vesamicol, which has long been studied as a VAChT inhibitor. This study has also revealed the metabolic pathway of cybenzoxasulfyl in Spodoptera litura, an agriculturally important lepidopteran pest, and the inhibitory effects retained by its immediately downstream metabolites using pharmacokinetic analysis and binding assay. Hence, cybenzoxasulfyl represents a promising new insecticide that acts on the VAChT and is expected to provide long-lasting activity against a variety of invertebrate pests that have evolved resistance. | Richens, J. H., Dmitrieva, M., Zenner, H. L., Muschalik, N., Butler, R., Glashauser, J., Camelo, C., Luschnig, S., Munro, S., Rittscher, J., St Johnston, D. (2025). MSP-tracker: A versatile vesicle tracking software tool used to reveal the spatial control of polarized secretion in Drosophila epithelial cells. PLoS Biol, 23(4):e3003099 PubMed ID: 40208901
Summary: Understanding how specific secretory cargoes are targeted to distinct domains of the plasma membrane in epithelial cells requires analyzing the trafficking of post-Golgi vesicles to their sites of secretion. We used the RUSH (retention using selective hooks) system to synchronously release an apical cargo, Cadherin 99C (Cad99C), and a basolateral cargo, the ECM protein Nidogen, from the endoplasmic reticulum and followed their movements to the plasma membrane. An interactive vesicle tracking framework, MSP-tracker and viewer, was developed that exploits developments in computer vision and deep learning to determine vesicle trajectories in a noisy environment without the need for extensive training data. MSP-tracker outperformed other tracking software in detecting and tracking post-Golgi vesicles, revealing that Cad99c vesicles predominantly move apically with a mean speed of 1.1μm/sec. This is reduced to 0.85 μm/sec by a dominant slow dynein mutant, demonstrating that dynein transports Cad99C vesicles to the apical cortex. Furthermore, both the dynein mutant and microtubule depolymerization cause lateral Cad99C secretion. Thus, microtubule organization plays a central role in targeting apical secretion, suggesting that Drosophila does not have distinct apical versus basolateral vesicle fusion machinery. Nidogen vesicles undergo planar-polarized transport to the leading edge of follicle cells as they migrate over the ECM, whereas most Collagen is secreted at trailing edges. The follicle cells therefore bias secretion of different ECM components to opposite sides of the cell, revealing that the secretory pathway is more spatially organized than previously thought. |
| Bhupana, J. N., Pabon, A., Leung, H. H., Rajmohamed, M. A., Kim, S. H., Tong, Y., Jang, M. H., Wong, C. O. (2025). Endolysosomal processing of neuron-derived signaling lipids regulates autophagy and lipid droplet degradation in astrocytes. Nat Commun, 16(1):5073 PubMed ID: 40450042
Summary: Dynamic regulation of metabolic activities in astrocytes is critical to meeting the demands of other brain cells. During neuronal stress, lipids are transferred from neurons to astrocytes, where they are stored in lipid droplets (LDs). However, it is not clear whether and how neuron-derived lipids trigger metabolic adaptation in astrocytes. This study uncovered an endolysosomal function that mediates neuron-astrocyte transcellular lipid signaling. Tweety homolog 1 (TTYH1) was identified as an astrocyte-enriched endolysosomal protein that facilitates autophagic flux and LD degradation. Astrocyte-specific deletion of mouse Ttyh1 and loss of its Drosophila ortholog tweety) lead to brain accumulation of neutral lipids. Computational and experimental evidence suggests that a TTYH1 mediates endolysosomal clearance of ceramide 1-phosphate (C1P), a sphingolipid that dampens autophagic flux and LD breakdown in mouse and human astrocytes. Furthermore, neuronal C1P secretion induced by inflammatory cytokine interleukin-1β causes TTYH1-dependent autophagic flux and LD adaptations in astrocytes. These findings reveal a neuron-initiated signaling paradigm that culminates in the regulation of catabolic activities in astrocytes. | Rosenthal, J. S., Zhang, D., Yin, J., Long, C., Yang, G., Li, Y., Lu, Z., Li, W. P., Yu, Z., Li, J., Yuan, Q. (2025). Molecular organization of central cholinergic synapses. Proc Natl Acad Sci U S A, 122(17):e2422173122 PubMed ID: 40273107
Summary: Synapses have undergone significant diversification and adaptation, contributing to the complexity of the central nervous system. Understanding their molecular architecture is essential for deciphering the brain's functional evolution. While nicotinic acetylcholine receptors (nAchRs) are widely distributed across metazoan brains, their associated protein networks remain poorly characterized. Using in vivo proximity labeling, this study generated proteomic maps of subunit-specific nAchR interactomes in developing and mature Drosophila brains. The findings reveal a developmental expansion and reconfiguration of the nAchR interactome. Proteome profiling with genetic perturbations showed that removing individual nAchR subunits consistently triggers compensatory shifts in receptor subtypes, highlighting mechanisms of synaptic plasticity. The Rho-GTPase regulator Still life (Sif) was identified as a key organizer of cholinergic synapses, with loss of Sif disrupting their molecular composition and structural integrity. These results provide molecular insights into the development and plasticity of central cholinergic synapses, advancing understanding of synaptic identity conservation and divergence. |
| Hoagland, A., Schultz, R., Cai, Z., Newman, Z. L., Isacoff, E. Y. (2025). Behavioral resilience via dynamic circuit firing homeostasis.Proc Natl Acad Sci U S A, 122(18):e2421386122 PubMed ID: 40299703
Summary: Homeostatic regulation ensures stable neural circuit output under changing conditions. This study found that in Drosophila larval neuromuscular junction, either presynaptic weakening due to perturbation of transmitter release or postsynaptic weakening due to perturbation of glutamate receptors at synapses between motor neuron (MN) and muscle has little impact on locomotion, suggesting a nonsynaptic compensatory mechanism. In vivo imaging shows that five different forms of synaptic weakening increase the duration of activity bouts in type I MNs. Strikingly, this compensation is input selective: occurring only in the tonic type Ib MN, not the phasic type Is MN that innervates the same muscle. Moreover, an inhibitory class of central pre-MNs that innervates the tonic-but not phasic-input decreases in activity. The adjustment in activity occurs remarkably quickly: within minutes of synapse perturbation. It is proposed that MN firing is dynamically regulated by two coordinated mechanisms: a cell-autonomous adjustment of MN excitability and a circuit adjustment of inhibitory central drive. The input selectivity of this process suggests homeostatic adjustment to maintain tonic drive but hold constant the phasic drive that organizes locomotory wave patterns. | Kakanj, P., Bonse, M., Kshirsagar, A., Gokmen, A., Gaedke, F., Sen, A., Molla, B., Vogelsang, E., Schauss, A., Wodarz, A., Pla-Martin, D. (2025). Retromer promotes the lysosomal turnover of mtDNA. Sci Adv, 11(14):eadr6415 PubMed ID: 40184468
Summary: Mitochondrial DNA (mtDNA) is exposed to multiple insults produced by normal cellular function. Upon mtDNA replication stress, the mitochondrial genome transfers to endosomes for degradation. Using proximity biotinylation, this study found that mtDNA stress leads to the rewiring of the mitochondrial proximity proteome, increasing mitochondria's association with lysosomal and vesicle-related proteins. Among these, the retromer complex, particularly VPS35, plays a pivotal role by extracting mitochondrial components. The retromer promotes the formation of mitochondrial-derived vesicles shuttled to lysosomes. The mtDNA, however, directly shuttles to a recycling organelle in a BAX-dependent manner. Moreover, using a Drosophila model carrying a long deletion on the mtDNA (ΔmtDNA), this study found that ΔmtDNA activates a specific transcriptome profile to counteract mitochondrial damage. Here, Vps35 expression restores mtDNA homoplasmy and alleviates associated defects. Hence, this study has demonstrated the existence of a previously unknown quality control mechanism for the mitochondrial matrix and the essential role of lysosomes in mtDNA turnover to relieve mtDNA damage. |
Thursday March 19th - Disease Models |
| Strachan, E. L., Dillon, E. T., Sullivan, M., Glennon, J. C., Peyrel, A., Sarniguet, J., Dubois, K., Delprat, B., Kennedy, B. N., O'Sullivan, N. C. (2025). Novel in vivo models of autosomal optic atrophy reveal conserved pathological changes in neuronal mitochondrial structure and function. Faseb j, 39(7):e70497 PubMed ID: 40202868
Summary: Autosomal optic atrophy (AOA) is a form of hereditary optic neuropathy characterized by the irreversible and progressive degermation of the retinal ganglion cells. Most cases of AOA are associated with a single dominant mutation in OPA1, which encodes a protein required for fusion of the inner mitochondrial membrane. It is unclear how loss of OPA1 leads to neuronal death, and despite ubiquitous expression appears to disproportionately affect the RGCs. This study introduces two novel in vivo models of OPA1-mediated AOA, including the first developmentally viable vertebrate Opa1 knockout (KO). These models allow for the study of Opa1 loss in neurons, specifically RGCs. Though survival is significantly reduced in Opa1 deficient zebrafish and Drosophila, both models permit the study of viable larvae. Moreover, zebrafish Opa1 KO larvae show impaired visual function but unchanged locomotor function, indicating that retinal neurons are particularly sensitive to Opa1 loss. Proteomic profiling of both models reveals marked disruption in protein expression associated with mitochondrial function, consistent with an observed decrease in mitochondrial respiratory function. Similarly, mitochondrial fragmentation and disordered cristae organization were observed in neuronal axons in both models highlighting Opa1's highly conserved role in regulating mitochondrial morphology and function in neuronal axons. Importantly, in Opa1 deficient zebrafish, mitochondrial disruption and visual impairment precede degeneration of RGCs. These novel models mimic key features of AOA and provide valuable tools for therapeutic screening. These findings suggest that therapies enhancing mitochondrial function may offer a potential treatment strategy for AOA. | Stephens, M. C., Li, J., Mair, M., Moore, J., Zhu, K., Tarkunde, A., Amoh, B., Perez, A. M., Bhakare, A., Guo, F., Shulman, J. M., Al-Ramahi, I., Botas, J. (2025). Computational and functional prioritization identifies genes that rescue behavior and reduce tau protein in fly and human cell models of Alzheimer disease. Am J Hum Genet, 112(5):1081-1096 PubMed ID: 40215969
Summary: Genome-wide association studies (GWASs) in Alzheimer disease (AD) have uncovered over 70 loci significantly associated with AD risk, but identifying the true causal gene(s) at these loci requires systematic functional validation that is rarely performed due to limitations of time and cost. This study disintegrated transcriptome-wide association study (TWAS) with colocalization analysis, fine-mapping, and additional annotation of AD GWAS variants to identify 123 genes at known and suggestive AD risk loci. A comparison with human AD brain transcriptome data confirmed that many of these candidate genes are dysregulated in human AD and correlate with neuropathology. All available orthologs were studied in two well-established Drosophila AD models that express either wild-type tau or secreted β-amyloid (β42). Experimental perturbation of the 60 available candidates pinpointed 46 that modulated neuronal dysfunction in one or both fly models. The effects of 18 of these genes were concordant with the TWAS prediction, such that the direction of misexpression predicted to increase AD risk in humans exacerbated behavioral impairments in the AD fly models. Reversing the aberrant down- or upregulation of 11 of these genes (MTCH2, ELL, TAP2, HDC, DMWD, MYCL, SLC4A9, ABCA7, CSTF1, PTK2B, and CD2AP) proved neuroprotective in vivo. MTCH2 was further studied, and it was found to regulate steady-state Tau protein levels in the Drosophila brain and reduces Tau accumulation in human neural progenitor cells. This systematic, integrative approach effectively prioritizes genes at GWAS loci and reveals promising AD-relevant candidates for further investigation as risk factors or targets for therapeutic intervention. |
| Sivanantharajah, L., Mudher, A., Shepherd, D. (2025). Examining the vulnerability of adult neuron subtypes to tau-mediated toxicity in Drosophila. Transl Psychiatry, 15(1):127 PubMed ID: 40188067
Summary: Selective vulnerability of nerve cells is a feature of neurodegenerative disease. To date, animal models have been limited to examining pathogenic protein expression in broad or heterogeneous neuronal populations. Consequently, noted pathological hallmarks represent an average of disease phenotypes over multiple neuron types, rather than exact measures of individual responses. This study targeted gene expression to small, precisely defined and homogenous neuronal populations in the Drosophila melanogaster central nervous system (CNS), allowing dissection of selective vulnerability of single types of neurons with single-neuron resolution. Using cellular degeneration as a readout for vulnerability, this study found while all neurons were affected by tau some neuron types were more affected (vulnerable) than others (resilient). The Tau-mediated pathogenic effects fell on a spectrum, demonstrating that neurons in the fly CNS are differentially vulnerable to Tau pathology. Mechanistically, total Tau levels did not correlate with vulnerability; rather, the best correlatives of degeneration were significant age-dependent increases in phospho-Tau levels in the same neuron type, and Tau mislocalisation into dendrites. Lastly, this study found that Tau phosphorylation in vulnerable neuron types correlated with downstream vesicular and mitochondrial trafficking defects. However, all vulnerable neuron types did not show the same pattern, suggesting multiple paths to degeneration. Beyond highlighting the heterogeneity of neuronal responses to Tau in determining vulnerability, this work provides a new, high-resolution, tractable model for studying the age-dependent effects of Tau, or any pathogenic protein, on postmitotic neurons with sub-cellular resolution. | Wu, K., Zhou, J., Tang, Y., Zhang, Q., Xiong, L., Li, X., Zhuo, Z., Luo, M., Yuan, Y., Liu, X., Zhong, Z., Guo, X., Yu, Z., Sheng, X., Luo, G., Chen, H. (2025). Werner syndrome exonuclease promotes gut regeneration and causes age-associated gut hyperplasia in Drosophila. PLoS Biol, 23(4):e3003121 PubMed ID: 40261911
Summary: Human Werner syndrome (adult progeria, a well-established model of human aging) is caused by mutations in the Werner syndrome (WRN) gene. However, the expression patterns and functions of WRN in natural aging remain poorly understood. Despite the link between WRN deficiencies and progeria, analyses of human colon tissues, mouse crypts, and Drosophila midguts revealed that WRN expression does not decrease but rather increases in intestinal stem cells (ISCs) with aging. Mechanistically, this study found that the Drosophila WRN homologue (WRNexo) binds to Heat shock 70-kDa protein cognate 3 (Hsc70-3/Bip) to regulate the unfolded protein response of the endoplasmic reticulum (UPRER). Activation of the WRNexo-mediated UPRER in ISCs is required for ISC proliferation during injury repair. However, persistent DNA damage during aging leads to chronic upregulation of WRNexo in ISCs, where excessive WRNexo-induced ER stress drives age-associated gut hyperplasia in Drosophila. This study reveals how elevated WRNexo contributes to stem cell aging, providing new insights into organ aging and the pathogenesis of age-related diseases, such as colon cancer. |
| Shen, Y., Maxson, R., McKenney, R. J., Ori-McKenney, K. M. (2025). Microtubule acetylation is a biomarker of cytoplasmic health during cellular senescence. bioRxiv, PubMed ID: 40236247
Summary: Cellular senescence is marked by cytoskeletal dysfunction, yet the role of microtubule post-translational modifications (PTMs) remains unclear. This study demonstrates that microtubule acetylation increases during drug-induced senescence in human cells and during natural aging in Drosophila. Elevating acetylation via HDAC6 inhibition or α TAT1 overexpression in BEAS-2B cells disrupts anterograde Rab6A vesicle transport, but spares retrograde transport of Rab5 endosomes. Hyperacetylation results in slowed microtubule polymerization and decreased cytoplasmic fluidity, impeding diffusion of micron-sized condensates. These effects are distinct from enhanced detyrosination, and correlate with altered viscoelasticity and resistance to osmotic stress. Modulating cytoplasmic viscosity reciprocally perturbs microtubule dynamics, revealing bidirectional mechanical regulation. Senescent cells phenocopy hyperacetylated cells, exhibiting analogous effects on transport and microtubule polymerization. These findings establish acetylation as a biomarker for cytoplasmic health and a potential driver of age-related cytoplasmic densification and organelle transport decline, linking microtubule PTMs to biomechanical feedback loops that exacerbate senescence. This work highlights the role of acetylation in bridging cytoskeletal changes to broader aging hallmarks. | Yang, Y., Mayo, A., Levy, T., Raz, N., Shenhar, B., Jarosz, D. F., Alon, U. (2025). Compression of morbidity by interventions that steepen the survival curve. Nat Commun, 16(1):3340 PubMed ID: 40199852
Summary: Longevity research aims to extend the healthspan while minimizing the duration of disability and morbidity, known as the sickspan. Most longevity interventions in model organisms extend healthspan, but it is not known whether they compress sickspan relative to the lifespan. This study presents a theory that predicts which interventions compress relative sickspan, based on the shape of the survival curve. Interventions such as caloric restriction that extend mean lifespan while preserving the shape of the survival curve, are predicted to extend the sickspan proportionally, without compressing it. Conversely, a subset of interventions that extend lifespan and steepen the shape of the survival curve are predicted to compress the relative sickspan. This is explained to be based on the saturating-removal mathematical model of aging, and present evidence from longitudinal health data in mice, Caenorhabditis elegans and Drosophila melanogaster. This theory was applied to identify potential interventions for compressing the sickspan in mice, and to combinations of longevity interventions. This approach offers potential strategies for compressing morbidity and extending healthspan. |
Monday March 16th - Gonads |
| Yu, J., Huang, Q., Fu, Y., He, L., Shen, C., Chen, X., Li, Z., Li, J., Wang, C., Wang, X., Yang, B., Lin, Z., Qiao, C., Tan, X., Yang, X., Chen, H., Zheng, Y., Zheng, B., Sun, F. (2025). Multi-omics integration reveals Vha68-3 as a testicular aging-specific factor that coordinates spermatid elongation through mitochondrial metabolic homeostasis. Cell Mol Biol Lett, 30(1):58 PubMed ID: 40346547
Summary: Testicular aging has profound effects on spermatogenesis, sperm function, and the spermatogenic microenvironment, contributing to reduced male fertility. However, the precise molecular mechanisms by which mitochondria influence spermiogenesis during aging still remain largely unclear. Vha68-3 KO flies were generated using the CRISPR/Cas9 technique. Testicular phenotypes and functions were mainly observed through immunofluorescence staining and transmission electron microscopy. Multi-omics study was mainly conducted through single-cell RNA sequencing and transcriptome-metabolomics association analysis. Vha68-3 binding proteins were identified via liquid chromatography-tandem mass spectrometry. The therapeutic potential of modulating mitochondrial metabolism for testicular aging mainly relied on the dietary intake of related compounds in fruit flies. This study identified Vha68-3, a testis-specific subunit of the V-type adenosine triphosphate (ATP) synthase, predominantly localized in the tails of elongated spermatids, as a key age-related regulator of male fertility and spermatid elongation in Drosophila testes. Crucially, Vha68-3 deficiency impaired mitochondrial homeostasis in elongated spermatids during testicular aging. Through a multi-omics approach, including single-cell transcriptomics, protein interaction mapping of Vha68-3, and transcriptome-metabolome integration, pyruvate metabolism was identified as a critical pathway disrupted by Vha68-3 deficienc. Moreover, dietary supplementation with pyruvate (PA), S-lactoylglutathione (SLG), and phosphoenolpyruvate (PEP) effectively alleviated mitochondrial dysfunction and testicular aging linked to Vha68-3 deficiency. These findings uncover novel mechanisms by which mitochondrial metabolism regulates spermatid elongation, and potential therapeutic strategies were identified to combat mitochondrial metabolic disorders in aging testes. | Zike, A. B., Abel, M. G., Fleck, S. A., DeWitt, E. D., Weaver, L. N. (2025). Estrogen-related receptor is required in adult Drosophila females for germline stem cell maintenance.. Dev Biol, 524:132-143 PubMed ID: 40348318
Summary: Adult tissue function is dependent on intrinsic factors that mediate stem cell self-renewal and proliferation in response to changes in physiology and the environment. The estrogen-related receptor (ERR) subfamily of orphan nuclear receptors are major transcriptional regulators of metabolism and animal physiology. In mammals, ERRs (NR3B1, NR3B2, NR3B3) have roles in regulating mitochondrial biosynthesis, lipid metabolism, as well as stem cell maintenance. The sole Drosophila ERR ortholog promotes larval growth by establishing a metabolic state during the latter half of embryogenesis. In addition, ERR is required in adult Drosophila males to coordinate glycolytic metabolism with lipid synthesis and within the testis to regulate spermatogenesis gene expression and fertility. Despite extensive work characterizing the role of ERR in Drosophila metabolism, whether ERR has a conserved requirement in regulating stem cell behavior has been understudied. To determine whether ERR regulates stem cell activity in Drosophila, the established adult female germline stem cell (GSC) lineage was used as a model. Whole-body ERR knockout in adult females using conditional heat shock-driven FLP-FRT recombination was found to significantly decreases GSC number and glycolytic enzyme expression in GSCs. In addition, ERR activity was found to be required cell-autonomously in the adult female germline for maintenance of GSCs; whereas ERR regulation of GSCs is independent of its activity in adult female adipocytes. These results highlight an ancient and conserved role for ERRs in the regulation of stem cell self-renewal. |
| Mercer, M., Dasgupta, A., Pawlowski, K., Buszczak, M. (2025). Bourbon and Mycbp function with Otu to promote Sxl protein expression in the Drosophila female germline. Proc Natl Acad Sci U S A, 122(15):e2426524122 PubMed ID: 40215271
Summary: In Drosophila ovaries, germ cells differentiate through several stages of cyst development before entering meiosis. This early differentiation program depends on both the stepwise deployment of specific regulatory mechanisms and on maintenance of germline sexual identity. The study of female sterile mutations that result in formation of germ cell tumors has been invaluable in identifying the mechanisms that control these developmental events. This study characterized the germ cell-enriched gene bourbon (bbn), null mutants of which cause the formation of a mixture of agametic ovarioles and cystic germ cell tumors. Proteomic analysis found Bbn forms a complex with Ovarian tumor (Otu), a protein previously linked with regulation of the sex determination factor Sex lethal (Sxl), and the Drosophila ortholog of c-Myc binding protein (Mycbp). Loss of Mycbp also results in the formation of cystic germ cell tumors. Bbn promotes the stability of Otu and fosters interactions between Otu and Mycbp. Germ cells from bbn and Mycbp mutants display a loss of Sxl expression specifically in the germline. Transgenic rescue experiments show the bbn sterile phenotype is independent from Sxl splicing defects. Further evidence suggests Otu physically interacts with and promotes Sxl protein stability. This function does not depend on Otu's deubiquitinase activity. Last, this study found the human orthologs of Otu and Mycbp, OTUD4, and MYCBP, also physically interact, suggesting conservation of function. Together these data provide insights into how a conserved complex promotes the germline expression of Sxl protein and the differentiation of Drosophila germ cells. | Tindell, S. J., Boeving, A. G., Aebersold, J., Arkov, A. L. (2025). Multiple domains of scaffold Tudor protein play non-redundant roles in Drosophila germline. bioRxiv, PubMed ID: 40166263
Summary: Scaffold proteins play crucial roles in subcellular organization and function. In many organisms, proteins with multiple Tudor domains are required for the assembly of membraneless RNA-protein organelles (germ granules) in germ cells. Tudor domains are protein-protein interaction modules which bind to methylated polypeptides. Drosophila Tudor protein contains eleven Tudor domains, which is the highest number known in a single protein. The role of each of these domains in germ cell formation has not been systematically tested and it is not clear if some domains are functionally redundant. Using CRISPR methodology, this study generated mutations in several uncharacterized Tudor domains and showed that they all caused defects in germ cell formation. Mutations in individual domains affected Tudor protein differently causing reduction in protein levels, defects in subcellular localization and in the assembly of germ granules. These data suggest that multiple domains of Tudor protein are all needed for efficient germ cell formation highlighting the rational for keeping many Tudor domains in protein scaffolds of biomolecular condensates in Drosophila and other organisms. |
| Sanghvi, K., Shandilya, S., Brown, A., Todorova, B., Jahn, M., Gascoigne, S. J. L., Camilleri, T. L., Pizzari, T., Sepil, I. (2025). Reproductive output of old males is limited by seminal fluid, not sperm number. Evol Lett, 9(2):282-291 PubMed ID: 40191416
Summary: Male reproductive senescence is typically characterized by a decline in the number of sperm produced and transferred by old males, a phenomenon that may be exacerbated in polygynous species where males mate multiply. However, males also transfer seminal fluid to females, and little is known about its role in modulating male reproductive senescence. Here, we explore the contributions of sperm and seminal fluid towards male reproductive senescence in a series of sequential matings, using Drosophila melanogaster. As expected, old males produce fewer offspring than young males. However, this pattern is not driven by sperm limitation: old males have more sperm and transfer similar numbers to females, compared to young males. Instead, females storing fewer sperm of old males compared to that of young males, over a long term, drives male reproductive senescence. It was shown that it is possible to mitigate the age-related decline in male reproductive output by supplementing females with the seminal fluid of a young male, before she mates with an old male. Similarly, the reduction in reproductive output across sequential matings is alleviate by supplementing females with seminal fluid. These findings highlight that seminal fluid, rather than sperm number, limits reproductive success in old or multiply mating males, highlighting its underappreciated role in reproductive aging. | Harsh, S., Liu, H. Y., Bhaskar, P. K., Rushlow, C., Bach, E. A. (2025). The pioneer factor Zelda induces male-to-female somatic sex reversal in adult tissues. bioRxiv, PubMed ID: 40236223
Summary: Somatic sex identity must be maintained throughout adulthood for tissue function. Adult somatic stem cells in the Drosophila testis (i.e., CySCs) lacking the transcription factor Chinmo are reprogrammed to their ovarian counterparts by induction of female-specific Tra (F), but this is not mechanistically understood. Pioneer factors play central roles in direct reprogramming, and many upregulated genes in chinmo-/- CySCs contain binding sites for the pioneer factor Zelda (Zld). microRNAs repress zld mRNA in wild type CySCs, but they are downregulated after Chinmo loss, allowing for zld mRNA translation. Zld depletion from chinmo-/- CySCs suppresses feminization, and ectopic Zld induces Tra (F) and feminizes wild-type CySCs. qkr58E-2 and ecdysone receptor ( EcR ), direct Zld targets in the embryo, are female-biased in adult gonads and upregulated in chinmo-/- CySCs. The RNA-binding protein Qkr58E-2 produces Tra (F), while EcR promotes female-biased gene expression. Ectopic Zld feminizes adult male adipose tissue, demonstrating that Zld can instruct female and override male identity in adult XY tissues. |
Thursday March 12th - Larval and adult neural development, structure, and function |
| Sears, J. C., Broadie, K. (2025). PKA restricts ERK signaling in learning and memory Kenyon cell neurons. Cell Signal, 132:111818 PubMed ID: 40250698
Summary: Protein Kinase A (PKA) and Extracellular Signal-Regulated Kinase (ERK) have core roles in learning and memory. This study investigated kinase-kinase signaling interactions in the Drosophila brain Kenyon cell learning/memory circuit using separation of phases-based activity reporter of kinase (SPARK) biosensors to image circuit-localized functions in vivo. We find that constitutively active Rapidly Accelerated Fibrosarcoma (RAF(gof)) enhances ERK signaling only in Kenyon cell domains with low baseline PKA signaling, and that transgenic inhibition of PKA function elevates ERK signaling. Conversely, loss of ERK has no impact on PKA signaling, whereas RAF(gof) expands PKA signaling. Importantly, transgenic PKA inhibition together with RAF(gof) synergistically elevates ERK signaling. These findings indicate a negative PKA-ERK pathway interaction within learning/memory Kenyon cells. Potentiating circuit activity using an exogenous NaChBac ion channel elevates PKA signaling in circuit domains with low baseline PKA function, and uniformly strongly increases ERK signaling. Similarly, thermogenetic stimulation of circuit activity with a temperature-sensitive TRPA1 channel increases PKA signaling in circuit domains of low baseline PKA, and elevates ERK signaling. Importantly, potentiating circuit activity (NaChBac) while also inhibiting PKA function synergistically elevates ERK signaling. Likewise, conditional induction of circuit activity (TRPA1) together with PKA inhibition increases activity-dependent ERK signaling. Finally, a mechanically-induced seizure model (bang-sensitive sesB mutant) elevates PKA signaling, while simultaneous transgenic PKA inhibition in this model acts to synergistically increase ERK signaling. Taken together, it is concluded that PKA limits ERK signaling in Kenyon cells within the learning and memory circuit, with PKA function acting to restrict activity-dependent ERK signaling. | Matos, Y. B., Velichkova, N., Kirchknopf Riera, M., da Luz, M. G. E., Berni, J. (2025).. Characterizing stage-dependent neuromotor patterns in Drosophila melanogaster larvae through a graph construction approach. Front Neurosci, 19:1557624 PubMed ID: 40182146
Summary: This study investigated developmental changes in neuromotor activity patterns in Drosophila melanogaster larvae by combining calcium imaging with a novel graph-based mathematical framework. This allows to perform relevant quantitative comparisons between first (L1) and early third (L3) instar larvae. L1 larvae were found to exhibit higher frequencies of spontaneous neural activity that fail to propagate, indicating a less mature neuromotor system. In contrast, L3 larvae show efficient initiation and propagation of neural activity along the entire ventral nerve cord (VNC), resulting in longer activity chains. The time of chain propagation along the entire VNC is shorter in L1 than in L3, probably reflecting the increased length of the VNC. On the other hand, the time of peristaltic waves through the whole body during locomotion is much faster in L3 than in L1, so correlating with higher velocities and greater dispersal rates. Hence, the VNC-body interaction determines the characteristics of peristaltic waves propagation in crawling larvae. Further, asymmetrical neuronal activity, predominantly in anterior segments of L3 larvae, was associated with turning behaviors and enhanced navigation. These findings illustrate that the proposed quantitative model provides a systematic method to analyze neuromotor patterns across developmental stages, for instance, helping to uncover the maturation stages of neural circuits and their role in locomotion. |
| Rachad, E. Y., Deimel, S. H., Epple, L., Gadgil, Y. V., Jurgensen, A. M., Springer, M., Lin, C. H., Nawrot, M. P., Lin, S., Fiala, A. (2025). Functional dissection of a neuronal brain circuit mediating higher-order associative learning. Cell Rep, 44(5):115593 PubMed ID: 40249705
Summary: A central feature characterizing the neural architecture of many species' brains is their capacity to form associative chains through learning. In elementary forms of associative learning, stimuli coinciding with reward or punishment become attractive or repulsive. Notably, stimuli previously learned as attractive or repulsive can themselves serve as reinforcers, establishing a cascading effect whereby they become associated with additional stimuli. When this iterative process is perpetuated, it results in higher-order associations. This study used odor conditioning in Drosophila and computational modeling to dissect the architecture of neuronal networks underlying higher-order associative learning. The responsible circuit, situated in the mushroom bodies of the brain, is characterized by parallel processing of odor information and by recurrent excitatory and inhibitory feedback loops that empower odors to gain control over the dopaminergic valence-signaling system. These findings establish a paradigmatic framework of a neuronal circuit diagram enabling the acquisition of associative chains. | Tadres, D., Riedl, J., Eden, A., Bontempo, A. E., Lin, J., Reid, S. F., Roehrich, B., Williams, K., Sepunaru, L., Louis, M. (2025). Sensation of electric fields in the Drosophila melanogaster larva. Curr Biol, 35(8):1848-1860.e1844 PubMed ID: 40174584
Summary: Electrosensation has emerged as a crucial sensory modality for social communication, foraging, and predation across the animal kingdom. However, its presence and functional role as well as the neural basis of electric field perception in Drosophila and other invertebrates remain unclear. In environments with controlled electric fields, this study identified electrosensation as a new sense in the Drosophila melanogaster larva. The Drosophila larva performs robust electrotaxis: when exposed to a uniform electric field, larvae migrate toward the cathode (negatively charged elecrode) and quickly respond to changes in the orientation of the field to maintain cathodal movement. Through a behavioral screen, a subset of sensory neurons located at the tip of the larval head was identified that are necessary for electrotaxis. Calcium imaging revealed that a pair of Gr66a-positive sensory neurons (one on each side of the head) encodes the strength and orientation of the electric field. These results indicate that electric fields elicit robust behavioral and neural responses in the Drosophila larva, providing new evidence for the significance of electrosensation in invertebrates. |
| Nhuchhen Pradhan, R., Montell, C., Lee, Y. (2025). Cholesterol taste avoidance in Drosophila melanogaster. Elife, 14 PubMed ID: 40244888
Summary: The question as to whether animals taste cholesterol taste is not resolved. This study investigates whether the fruit fly, Drosophila melanogaster, is capable of detecting cholesterol through their gustatory system. Flies were found to be indifferent to low levels of cholesterol and avoid higher levels. The avoidance is mediated by gustatory receptor neurons (GRNs), demonstrating that flies can taste cholesterol. The cholesterol-responsive GRNs comprise a subset that also responds to bitter substances. Cholesterol detection depends on five ionotropic receptor (IR) family members, and disrupting any of these genes impairs the flies' ability to avoid cholesterol. Ectopic expressions of these IRs in GRNs reveals two classes of cholesterol receptors, each with three shared IRs and one unique subunit. Additionally, expressing cholesterol receptors in sugar-responsive GRNs confers attraction to cholesterol. This study reveals that flies can taste cholesterol, and that the detection depends on IRs in GRNs. | Mathada, J. H., Romrig, L., Poissonnier, L. A. (2025). Single-trial learning leads to mid-term memory formation in ants during an appetitive, but not an aversive, task. Proc Biol Sci, 292(2045):20243054 PubMed ID: 40262645
Summary: Insects have been models of associative learning and its underlying memory mechanisms. Research on the fruit fly Drosophila melanogaster and the honeybee Apis mellifera yielded deep insights into the different memory types and their formation dynamics following repeated stimulus exposure. However, less is understood about the ability of insects to learn from a single exposure. Accumulating evidence reveals that several insect species are able to learn from a single trial. Studies have largely focused on odour appetitive learning. In this study, we investigated the ability of the ant Lasius niger to learn from a single trial to associate a reward or a punishment with one side of a Y-maze. The ants successfully demonstrated appetitive learning but no aversive learning. This appetitive learning led to the rapid formation of mid-term memory, remaining sensitive to anaesthesia for at least 15 min post-training. Contrary to single-trial appetitive odour learning described in other species, this learning did not induce the formation of long-term memory, calling for further comparison between learning types. |
Monday March 9th - Physiology and Metabolism |
| Novikov, B., Boland, D. J., Mertsalov, I., Scott, H., Dauletbayeva, S., Monagas-Valentin, P., Panin, V. (2025). CMP-sialic acid synthetase in Drosophila requires N-glycosylation of a noncanonical site. J Biol Chem, 301(6):108483 PubMed ID: 40204091
Summary: Sialylation plays important roles in animals, affecting numerous molecular and cell interactions. In Drosophila, sialylation regulates neural transmission and mediates communication between neurons and glia. Drosophila CMP-sialic acid synthetase (CSAS), a key enzyme of the sialylation pathway, is localized to the Golgi and modified by N-glycosylation, suggesting that this modification can affect CSAS function. This hypothesis was tested using in vitro and in vivo approaches. CSAS proteins from divergent Drosophila species were found to have two conserved N-glycosylation sites, including the rarely glycosylated noncanonical N-X-C sequon. CSAS glycosylation was investigated by generating CSAS "glycomutants" lacking glycosylation sites and these were analyzed in vivo in transgenic rescue assays. The removal of noncanonical glycosylation significantly decreased CSAS activity, while the canonical site mutation did not affect CSAS function. Although all glycomutants were similarly localized to the Golgi, the non-canonical glycosylation, unlike the canonical one, affected CSAS stability in vivo and in vitro. These results suggested that CSAS functions as a dimer, which was also supported by protein structure predictions that produced a dimer recapitulating the crystal structures of mammalian and bacterial counterparts, highlighting the evolutionary conservation of the CSAS structure-function relationship. This conclusion was supported by the rescue of CSAS mutants using the human ortholog. The noncanonical CSAS glycosylation was discussed in terms of a potential mechanism of temperature-dependent regulation of sialylation in poikilotherms that modulates neural activity in heat shock conditions. Taken together, this study uncovered an important regulation of sialylation in Drosophila, highlighting a novel interplay between glycosylation pathways in neural regulation. | Singh, A. S., Pathak, D., Jain, S., Devi, M. S., Nongthomba, U. (2025). Evaluating the potential toxicity of ampicillin using Drosophila melanogaster as a model organism. Toxicol Rep, 14:101992 PubMed ID: 40206788
Summary: Antibiotic resistance is an indispensable threat facing in the present era. However, the studies on long term and trans-generational effects of using drugs or antibiotics on living organisms are scarce. Emphasizing the necessity to address such problems, this study investigated the potential effects of antibiotic, ampicillin (AMP) stress on the physiology of Drosophila melanogaster across multiple generations with mechanistic details. The larval feeding behavior, fertility, cell viability in ovary and testis, longevity, expression of methylation-related genes (dDnmt2 and dMBD2/3), and antimicrobial peptide production were evaluated. Larvae exposed to AMP exhibited increased mouth hook movement, indicating altered behaviour. AMP stress significantly reduced fertility across generations, with eclosion counts decreasing notably in F(3) and F(4) generations compared to controls. Moreover, AMP-treated flies showed decreased cell viability in ovary and testis, leading to impaired reproductive function. AMP exposure shortened the mean lifespan of flies and upregulated the expression of apoptosis-related gene p53 in females. However, there was no significant difference in p53 expression in males. Additionally, AMP stress caused a significant decrease in Drosomycin expression in treated males, while no significant changes were observed in Drosocin and Metchnikowin. In treated females, Drosocin and Drosomycin expression increased significantly, whereas the increase in Metchnikowin was not significant. The study also revealed downregulation of methylation-related genes (dDnmt2 and dMBD2/3) in AMP-treated female flies which was normalised in the rescue flies suggesting disrupted epigenetic mechanisms. Overall, the findings highlighted the importance of evaluating the trans-generational impacts of AMP stress on Drosophila physiology and gene expression, particularly in reproductive function and epigenetic regulation. The study of the impact of widely used antibiotic, AMP on model organism, Drosophila (model organism known for its genetic similarity to human), will help in predicting potential impacts on higher organisms and human. The finding would ultimately promote proper use of antibiotics and use of alternative medicine. |
| Nedbalova, P., Kaislerova, N., Chodakova, L., Moos, M., Doleaal, T. (2025). SAM transmethylation pathway and adenosine recycling to ATP are essential for systemic regulation and immune response. Elife, 13 PubMed ID: 40193491
Summary: During parasitoid wasp infection, activated immune cells of Drosophila melanogaster larvae release adenosine to conserve nutrients for immune response. S-adenosylmethionine (SAM) is a methyl group donor for most methylations in the cell and is synthesized from methionine and ATP. After methylation, SAM is converted to S-adenosylhomocysteine, which is further metabolized to adenosine and homocysteine. This study shows that the SAM transmethylation pathway is up-regulated during immune cell activation and that the adenosine produced by this pathway in immune cells acts as a systemic signal to delay Drosophila larval development and ensure sufficient nutrient supply to the immune system. This study further showed that the up-regulation of the SAM transmethylation pathway and the efficiency of the immune response also depend on the recycling of adenosine back to ATP by adenosine kinase and adenylate kinase. We therefore hypothesize that adenosine may act as a sensitive sensor of the balance between cell activity, represented by the sum of methylation events in the cell, and nutrient supply. If the supply of nutrients is insufficient for a given activity, adenosine may not be effectively recycled back into ATP and may be pushed out of the cell to serve as a signal to demand more nutrients. | Nath, D. K., Dhakal, S. and Lee, Y. (2025). TRPγ regulates lipid metabolism through Dh44 neuroendocrine cells. Elife, 13 PubMed ID: 40243537
Summary: Understanding how the brain controls nutrient storage is pivotal. Transient receptor potential (TRP) channels are conserved from insects to humans. They serve in detecting environmental shifts and in acting as internal sensors. Previous work demonstrated the role of TRPγ in nutrient-sensing behavior. This study found that a TRPγ mutant exhibited in Drosophila melanogaster is required for maintaining normal lipid and protein levels. In animals, lipogenesis and lipolysis control lipid levels in response to food availability. Lipids are mostly stored as triacylglycerol in the fat bodies (FBs) of D. melanogaster. Interestingly, trpγ deficient mutants exhibited elevated TAG levels and genetic data indicated that Dh44 neurons (for information on Dh44 neurons, go to Google and enter Dh44 neurons Drosophila) are indispensable for normal lipid storage but not protein storage. The trpγ mutants also exhibited reduced starvation resistance, which was attributed to insufficient lipolysis in the FBs. This could be mitigated by administering lipase or metformin orally, indicating a potential treatment pathway. Gene expression analysis indicated that trpγ knockout downregulated brummer, a key lipolytic gene, resulting in chronic lipolytic deficits in the gut and other fat tissues. The study also highlighted the role of specific proteins, including neuropeptide DH44 and its receptor DH44R2 in lipid regulation. These findings provide insight into the broader question of how the brain and gut regulate nutrient storage. |
| Ratnawati, R., Aswad, M., Jumriani, J., Nurhidayah, A., Azmin, M. R., Filmaharani, F., Roosevelt, A., Hardiyanti, W., Latada, N. P., Mudjahid, M., Nainu, F. (2025). In Silico and In Vivo Investigation of the Anti-Hyperglycemic Effects of Caffeic Acid. ACS Omega, 10(14):14052-14062 PubMed ID: 40256540
Summary: Hyperglycemia, characterized by elevated blood glucose levels, is a major risk factor for diabetes mellitus and its complications. While conventional therapies are effective, they are often associated with side effects and high costs, necessitating alternative strategies. This study evaluates the potential of caffeic acid (CA), a phenolic compound with reported antihyperglycemic properties, using both in silico and in vivo approaches. Molecular docking simulations revealed that CA demonstrates a strong binding affinity to protein tyrosine phosphatase 1B (PTP1B), a critical enzyme in glucose metabolism, with superior interaction profiles compared to the reference drug, ertiprotafib. In the in vivo studies, a Drosophila melanogaster model was used to investigate the effects of CA under hyperglycemic conditions induced by a high-sugar diet. Treatment with CA, particularly at a concentration of 500 μM, significantly reduced hemolymph glucose levels and improved several physiological and behavioral parameters, including survival rates, body size, body weight, and larval movement. Furthermore, gene expression analysis demonstrated that CA modulates key metabolic and stress-related pathways, enhancing glucose homeostasis and reducing metabolic stress. These findings highlight the dual utility of in silico and in vivo methodologies in elucidating the antihyperglycemic potential of CA. The results support the development of CA as a cost-effective and ethically viable therapeutic candidate with implications for diabetes management in resource-limited settings. | Pimentel, A. C., Cesar, C. S., Martins, A. H. B., Martins, M., Cogni, R. (2025). Wolbachia Offers Protection Against Two Common Natural Viruses of Drosophila. Microb Ecol. 88(1):24
88(1):24. PubMed ID: 40202691
Summary: Wolbachia pipientis is a maternally transmitted endosymbiont infecting more than half of terrestrial arthropod species. Wolbachia can express parasitic phenotypes such as manipulation of host reproduction and mutualist phenotypes such as protection against RNA virus infections. Because Wolbachia can invade populations by reproductive manipulation and block virus infection, it is used to modify natural insect populations. However, the ecological importance of virus protection is not yet clear, especially due to scarce information on Wolbachia protection against viruses that are common in nature. This study used systemic infection to investigate whether Wolbachia protects its host by suppressing the titer of DMELDAV and DMelNora virus, two viruses that commonly infect Drosophila melanogaster flies in natural populations. Antiviral protection was tested in three systems to assess the impact of Wolbachia strains across species: (1) a panel of Wolbachia strains transfected into Drosophila simulans, (2) two Wolbachia strains introgressed into the natural host D. melanogaster, and (3) two native Wolbachia strains in their natural hosts Drosophila baimaii and Drosophila tropicalis. Certain Wolbachia strains were shown to provide protection against DMelNora virus and DMELDAV, and this protection is correlated with Wolbachia density, which is consistent with what has been observed in protection against other RNA viruses. Additionally, Wolbachia does not protect its original host, D. melanogaster, from DMELDAV infection. While native Wolbachia can reduce DMELDAV titers in D. baimaii, this effect was not detected in D. tropicalis. Although the Wolbachia protection-induced phenotype seems to depend on the virus, the specific Wolbachia strain, and the host species, these findings suggest that antiviral protection may be one of the mutualistic effects that helps explain why Wolbachia is so widespread in arthropod populations. |
Friday March 7th - Disease Models |
| Roy, P. R., Link, N. (2025). Loss of Neuronal Imp Contributes to Seizure Behavior through Syndecan Function. eNeuro, 12(5) PubMed ID: 40258646
Summary: Seizures affect a large proportion of the global population and occur due to abnormal neuronal activity in the brain. Unfortunately, widespread genetic and phenotypic heterogeneity contributes to insufficient treatment options. It is critical to identify the genetic underpinnings of how seizures occur to better understand seizure disorders and improve therapeutic development. The Drosophila melanogaster model was used to identify that IGF-II mRNA-binding protein (Imp) is linked to the onset of this phenotype. Specific reduction of Imp in neurons causes seizures after mechanical stimulation. Importantly, gross motor behavior is unaffected, showing Imp loss does not affect general neuronal activity. Developmental loss of Imp is sufficient to cause seizures in adults; thus, Imp-modulated neuron development affects mature neuronal function. Since Imp is an RNA-binding protein, this study sought to identify the mRNA target that Imp regulates in neurons to ensure proper neuronal activity after mechanical stress. Imp protein was found to bind Syndecan (Sdc) mRNA, and the reduction of Sdc also causes mechanically induced seizures. Expression of Sdc in Imp-deficient neurons rescues seizure defects, showing that Sdc is sufficient to restore normal behavior after mechanical stress. It is suggested that the Imp protein binds Sdc mRNA in neurons, and this functional interaction is important for normal neuronal biology and animal behavior in a mechanically induced seizure model. Since Imp and Sdc are conserved, this work highlights a neuronal-specific pathway that might contribute to seizure disorder when mutated in humans. | Pech, U., Janssens, J., Schoovaerts, N., Kuenen, S., Calatayud Aristoy, C., Gallego, S. F., Makhzami, S., Hulselmans, G. J., Poovathingal, S., Davie, K., Bademosi, A. T., Swerts, J., Vilain, S., Aerts, S., Verstreken, P. (2025). Synaptic deregulation of cholinergic projection neurons causes olfactory dysfunction across five fly Parkinsonism models. Elife, 13 PubMed ID: 40178224
Summary: The classical diagnosis of Parkinsonism is based on motor symptoms that are the consequence of nigrostriatal pathway dysfunction and reduced dopaminergic output. However, a decade prior to the emergence of motor issues, patients frequently experience non-motor symptoms, such as a reduced sense of smell (hyposmia). The cellular and molecular bases for these early defects remain enigmatic. To explore this, a new collection of five fruit fly models of familial Parkinsonism was developed, and single-cell RNA sequencing was conducted on young brains of these models. Interestingly, cholinergic projection neurons are the most vulnerable cells, and genes associated with presynaptic function are the most deregulated. Additional single nucleus sequencing of three specific brain regions of Parkinson's disease patients confirms these findings. Indeed, the disturbances lead to early synaptic dysfunction, notably affecting cholinergic olfactory projection neurons crucial for olfactory function in flies. Correcting these defects specifically in olfactory cholinergic interneurons in flies or inducing cholinergic signaling in Parkinson mutant human induced dopaminergic neurons in vitro using nicotine, both rescue age-dependent dopaminergic neuron decline. Hence, this research uncovers that one of the earliest indicators of disease in five different models of familial Parkinsonism is synaptic dysfunction in higher-order cholinergic projection neurons and this contributes to the development of hyposmia. Furthermore, the shared pathways of synaptic failure in these cholinergic neurons ultimately contribute to dopaminergic dysfunction later in life. |
| Okonta, C., Ogunyemi, O. M., Olabuntu, B., Abolaji, A. O. (2025). Ameliorative role of naringenin in MPTP- induced Parkinsonism: Insights from Drosophila melanogaster experimental model combined with computational biology. Toxicol Rep, 14:102004 PubMed ID: 40213420
Summary: This study probed the ameliorative effects of naringenin in a D. melanogaster model of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism, incorporating computational analysis. Initially, flies were treated with naringenin (100-500 μM) and MPTP (250-750 μM) for 14 days in two separate studies to determine the optimum concentrations for the treatments. Following this, optimum naringenin concentrations (100 and 300 μM) were administered to MPTP (500 μM)-exposed flies in a 4-day study. Motor function, survival rate, and neurotoxicity biomarkers were assessed alongside biological network analysis and molecular docking simulation. Results indicate that naringenin exhibits hormetic behavior, with 100-300 μM providing optimal neuroprotection. The treatments significantly improved negative geotaxis and acetylcholinesterase activity, and reduced MPTP-induced oxidative stress as indicated by reduced nitric oxide, hydrogen peroxide, and protein carbonyl levels. Furthermore, naringenin restored thiol contents, and enhanced catalase and glutathione-S-transferase activities. Network analysis helped to identify key targets, including DRD4, DRD2, NFKB1, MAOB, MAPK14, and CYP2A6, which function in dopaminergic signaling and oxido-inflammatory pathways. Molecular docking analysis revealed strong binding interactions of naringenin with DRD2, MAO, MAPK, and NF-kappaB protein targets, primarily through hydrogen bonding and hydrophobic interactions. Overall, these findings suggest that naringenin mitigates MPTP-induced neurotoxicity by enhancing dopaminergic neurotransmission and suppressing oxidative stress and inflammation. This study further supports the neuroprotective potential of naringenin and could be suggested as a promising nutraceutical/drug candidate for Parkinson's disease. | Mok, J. W., Mackay, L., Blazo, M., Mizerik, E., Gecz, J., Carroll, R., Nizon, M., Rondeau, S., Joubert, M., Cuinat, S., Deb, W., Valle Sirias, F., Weisz-Hubshman, M., Ketkar, S., Polak, U., Tran, A. A., Kearney, D., Hanchard, N. A., Kanca, O., Wangler, M. F., Bellen, H. J., Lee, B. H., Yamamoto, S., Machol, K. (2025). C-terminal frameshift variants in GPKOW are associated with a multisystemic X-linked disorder. Genet Med, 27(7):101429 PubMed ID: 40221893
Summary: GPKOW, a gene on the X-chromosome, encodes a nuclear RNA-binding protein important in messenger RNA (mRNA) processing as a spliceosome subunit. This work aims to establish GPKOW as a disease-associated gene. 3 males from 2 unrelated families are described with hemizygous frameshift variants affecting the last exon of GPKOW p.(Arg441SerfsTer30) and p.(Ser444GlufsTer28). The effect of p.(Ser444GlufsTer28) on gene expression was evaluated in patient's fibroblasts. In vivo studies in Drosophila melanogaster targeting the sole GPKOW fly ortholog, CG10324 (Gpkow) were performed. Clinical presentations included intrauterine growth restriction, microcephaly/microencephaly, and eye, brain, skin, and skeletal abnormalities. Heterozygote females presented with short stature, microcephaly, and vision problems. Sequencing of fibroblasts' mRNA confirmed that GPKOW mRNA escapes nonsense-mediated decay. Yet, reduced protein levels suggested protein instability. Studies in Drosophila showed that Gpkow is essential and broadly expressed. It is enriched in neurons and glia in eyes and head of developing and adult flies. Knockdown and overexpression of Gpkow in the fly eye cause eyeless/headless phenotype, suggesting that the gene is dosage sensitive. Importantly, overexpression of the p.(Ser444GlufsTer28) variant caused milder defects than the reference allele, indicating that the truncated protein behaves as a partial loss-of-function allele. It is concluded that variants in GPKOW cause a multisystemic X-linked syndrome. |
| Shen, D., Vincent, A., Udine, E., Buhidma, Y., Anoar, S., Tsintzas, E., Maeland, M., Xu, D., Carcole, M., Osumi-Sutherland, D., Aleyakpo, B., Hull, A., Martinez Corrales, G., Woodling, N., Rademakers, R., Isaacs, A. M., Frigerio, C., van Blitterswijk, M., Lashley, T., Niccoli, T. (2025). Differential neuronal vulnerability to C9orf72 repeat expansion driven by Xbp1-induced endoplasmic reticulum-associated degradation. Cell Rep, 44(4):115459 PubMed ID: 40203833
Summary: Neurodegenerative diseases are characterized by the localized loss of neurons. Why cell death is triggered only in specific neuronal populations and whether it is the response to toxic insults or the initial cellular state that determines their vulnerability is unknown. To understand individual cell responses to disease, their transcriptional signatures were profiled throughout disease development in a Drosophila model of C9orf72 (G4C2) repeat expansion (C9), the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis. Neuronal populations were identified specifically vulnerable or resistant to C9 expression; and an upregulation of protein homeostasis pathways was found in resistant neurons at baseline. Overexpression of Xbp1s, a key regulator of the unfolded protein response and a central node in the resistance network, rescues C9 toxicity. This study shows that neuronal vulnerability depends on the intrinsic transcriptional state of neurons and that leveraging resistant neurons' properties can boost resistance in vulnerable neurons. | Mohar, N. P., Langland, C. J., Darr, Z., Viles, J., Moore, S. A., Darbro, B. W., Wallrath, L. L. (2025). A genetic variant in SMAD7 acts as a modifier of LMNA-associated muscular dystrophy, implicating SMAD signaling as a therapeutic target. Sci Adv, 11(16):eads7903 PubMed ID: 40249815
Summary: Mutations in LMNA cause multiple types of muscular dystrophy (LMNA-MD). The symptoms of LMNA-MD are highly variable and sensitive to genetic background. To identify genetic contributions to this phenotypic variability, whole-genome sequencing was performed on four siblings possessing the same LMNA mutation with differing degrees of skeletal muscle disease severity. A variant in SMAD7 was identified that segregated with severe muscle disease. To functionally test the SMAD7 variant, a Drosophila model was generated possessing the LMNA mutation and the SMAD7 variant in the orthologous fly genes. The SMAD7 variant increased SMAD signaling and enhanced muscle defects caused by the mutant lamin. Conversely, overexpression of wild-type SMAD7 rescued muscle function. These findings were extended to humans by showing that SMAD signaling is increased in muscle biopsy tissue from individuals with LMNA-MD compared to age-matched controls. Collectively, these findings support SMAD7 as the first functionally tested genetic modifier for LMNA-MD and suggest components of the SMAD pathway as therapeutic targets. |
Thursday March 5th - RNAs, RNA interference, Splicing |
| Kawaguchi, S., Xu, X., Soga, T., Yamaguchi, K., Kawasaki, R., Shimouchi, R., Date, S., Kai, T. (2025). In silico screening by AlphaFold2 program revealed the potential binding partners of nuage-localizing proteins and piRNA-related proteins. Elife, 13 PubMed ID: 40259744
Summary: Protein-protein interactions are fundamental to understanding the molecular functions and regulation of proteins. Despite the availability of extensive databases, many interactions remain uncharacterized due to the labor-intensive nature of experimental validation. This study, utilized the AlphaFold2 program to predict interactions among proteins localized in the nuage, a germline-specific non-membrane organelle essential for piRNA biogenesis in Drosophila. 20 nuage proteins were screened for 1:1 interactions and predicted dimer structures. Among these, five represented novel interaction candidates. Three pairs, including Spn-E_Squ, were verified by co-immunoprecipitation. Disruption of the salt bridges at the Spn-E_Squ interface confirmed their functional importance, underscoring the predictive model's accuracy. This analysis was extended to include interactions between three representative nuage components-Vas, Squ, and Tej-and approximately 430 oogenesis-related proteins. Co-immunoprecipitation verified interactions for three pairs: Mei-W68_Squ, CSN3_Squ, and Pka-C1_Tej. Furthermore, the majority of Drosophila proteins (~12,000) was screened for potential interaction with the Piwi protein, a central player in the piRNA pathway, identifying 164 pairs as potential binding partners. This in silico approach not only efficiently identifies potential interaction partners but also significantly bridges the gap by facilitating the integration of bioinformatics and experimental biology. | Gao, S. Y., Lu, H. G., Wang, Y. H., Yan, D. (2025). Screening of Drosophila melanogaster RNA m(6)A modification pathway factors. Journal and Yi Chuan, 47(4):476-488 PubMed ID: 40204521
Summary: N(6)-methyladenosine (m(6)A), one of the most prevalent mRNA modifications, plays crucial roles during animal and plant development and in various physiological and pathological processes. Previous studies have characterized m(6)A methyltransferase complexes, demethylases, and m(6)A-binding proteins, but as a relatively new epitranscriptomic pathway, it is likely that new m(6)A components remain to be discovered. To explore the effects of m(6)A modification on tissues and organs, the m(6)A reader Ythdc1 was overexpressed in Drosophila melanogaster eye imaginal discs. The results showed that overexpression of Ythdc1 leads to ectopic expression of Sxl in males, the rough eye in both males and females, and the activation of JNK signaling and apoptotic pathway. In order to screen m(6)A modifiers using the rough eye phenotype, a stable Drosophila strain overexpressing Ythdc1 was further constructed. By screening of more than 1,500 RNAi lines, several repressors and enhancers that may be involved in m(6)A modification were successfully identified. These genes are less studied in m(6)A pathway, and therefore they were further verified and preliminary mechanistic analyses on them was conducted. In summary, this study identified multiple potential factors of the m(6)A modification pathway, expanded understanding of the m(6)A modification network, and provided ideas and directions for exploring new regulatory mechanisms of this important pathway. |
| Rivera, A. J., Lee, J. R., Gupta, S., Yang, L., Goel, R. K., Zaia, J., Lau, N. C. (2025). Traffic Jam activates the Flamenco piRNA cluster locus and the Piwi pathway to ensure transposon silencing and Drosophila fertility. Cell Rep, 44(4):115354 PubMed ID: 40209716
Summary: Flamenco (Flam) is a prominent Piwi-interacting RNA (piRNA) locus expressed in Drosophila ovarian follicle cells that silences gypsy/mdg4 transposons to ensure female fertility. Promoter-bashing reporter assays in ovarian somatic sheet (OSS) cells uncover compact enhancer sequences within Flam. The enhancer sequence relevance was confirmed in vivo with Drosophila Flam deletion mutants that compromise Flam piRNA levels and female fertility. Proteomic analysis of proteins associated with Flam enhancer sequences discover the transcription factor Traffic Jam (TJ). Tj knockdown in OSS cells causes a decrease in Flam transcripts, Flam piRNAs, and multiple Piwi pathway genes. TJ chromatin immunoprecipitation sequencing (ChIP-seq) analysis confirms TJ binding at enhancer sequences deleted in the distinct Flam mutants. TJ also binds multiple Piwi pathway gene enhancers and long terminal repeats of transposons that decrease in expression after Tj knockdown. TJ plays an integral role in the ongoing arms race between selfish transposons and their suppression by the host Piwi pathway and Flam piRNA locus. | Lee, S. K., Shen, W., Wen, W., Joo, Y., Xue, Y., Park, A., Qiang, A., Su, S., Zhang, T., Zhang, M., Fan, J., Zhang, Y., De, S., Gainetdinov, I., Sharov, A., Maragkakis, M., Wang, W. (2025). Topoisomerase 3b facilitates piRNA biogenesis to promote transposon silencing and germ cell development. Cell Rep, 44(4):115495 PubMed ID: 40184251
Summary: Topoisomerases typically function in the nucleus to relieve topological stress in DNA. This study shows that a dual-activity topoisomerase, Top3b, and its partner, TDRD3, largely localize in the cytoplasm and interact biochemically and genetically with PIWI-interacting RNA (piRNA) processing enzymes to promote piRNA biogenesis, post-transcriptional gene silencing (PTGS) of transposons, and Drosophila germ cell development. Top3b requires its topoisomerase activity to promote PTGS of a transposon reporter and preferentially silences long and highly expressed transposons, suggesting that RNAs with these features may produce more topological stress for topoisomerases to solve. The double mutants between Top3b and piRNA processing enzymes exhibit stronger disruption of the signatures and levels of germline piRNAs, more de-silenced transposons, and larger defects in germ cells than either single mutant. These data suggest that Top3b can act in an RNA-based process-piRNA biogenesis and PTGS of transposons-and this function is required for Top3b to promote normal germ cell function. |
| Alizada, A., Martins, A., Mouniee, N., Rodriguez Suarez, J. V., Bertin, B., Gueguen, N., Mirouse, V., Papameletiou, A. M., Rivera, A. J., Lau, N. C., Akkouche, A., Maupetit-Méhouas, S., Hannon, G. J., Czech Nicholson, B., Brasset, E. (2025). The transcription factor Traffic jam orchestrates the somatic piRNA pathway in Drosophila ovaries. Cell Rep, 44(4):115453 PubMed ID: 40209715
Summary: The PIWI-interacting RNA (piRNA) pathway is essential for transposable element (TE) silencing in animal gonads. While the transcriptional regulation of piRNA pathway components in germ cells has been documented in mice and flies, their control in somatic cells of Drosophila ovaries remains unresolved. This study demonstrates that Traffic jam (Tj), the Drosophila ortholog of large Maf transcription factors in mammals, is a master regulator of the somatic piRNA pathway. Tj binds to regulatory regions of somatic piRNA factors and the major piRNA cluster flamenco, which carries a Tj-bound enhancer downstream of its promoter. Depletion of Tj in somatic follicle cells causes downregulation of piRNA factors, loss of flamenco expression, and derepression of gypsy-family TEs. It is proposed that the arms race between the host and TEs led to the co-evolution of promoters in piRNA pathway genes as well as TE regulatory regions, which both rely on a shared transcription factor. | Soldatova, I. V., Beginyazova, O., Georgiev, P. G., Tikhonov, M. V. (2025). Investigation of the Functional Role of the Conserved Sequence at the 5'-End of the Fourth Intron of the mod(mdg4) Gene in Trans-Splicing in Drosophila melanogaster. Dokl Biochem Biophys, 521(1):169-173 PubMed ID: 40216715
Summary: Alternative splicing is an important mechanism that provides genetic diversity of proteins. Unique loci have been identified in Drosophila melanogaster, where mRNA diversity arises as a result of trans-splicing-a process in which exons from different pre-mRNAs are joined together. The trans-splicing in the mod(mdg4) locus, which encodes more than 31 isoforms, has been studied in detail. Important elements for this process include previously described conserved sequences in the fourth intron. The aim of this study is to further characterize the conserved motifs of the fourth intron, specifically the element at the 5'-end of the intron. Using model transgenic lines, it has been shown that introduced changes in the sequence of the studied element lead to a disruption of trans-splicing. In contrast, similar changes in the endogenous locus did not result in a disruption of trans-splicing. Thus, the conserved element plays a role in trans-splicing but is not critical. |
Wednesday March 4th - Tumors and Growth |
| Rai, M., Okah, P., Shefali, S. A., Fitt, A. J., Shen, M. Z., Molomjamts, M., Pepin, R., Nemkov, T., D'Alessandro, A., Tennessen, J. M. (2025). New alleles of D-2-hydroxyglutarate dehydrogenase enable studies of oncometabolite function in Drosophila melanogaster. bioRxiv, PubMed ID: 40236175
Summary: D-2-hydroxyglutarate (D-2HG) is a potent oncometabolite capable of disrupting chromatin architecture, altering metabolism, and promoting cellular dedifferentiation. As a result, ectopic D-2HG accumulation induces neurometabolic disorders and promotes progression of multiple cancers. However, the disease-associated effects of ectopic D-2HG accumulation are dependent on genetic context. Specifically, neomorphic mutations in the mammalian genes Isocitrate dehydrogenase 1 (IDH1) and IDH2 result in the production of enzymes that inappropriately generate D-2HG from α-ketoglutarate (αKG). Within this genetic background, D-2HG acts as an oncometabolite and is associated with multiple cancers, including several diffuse gliomas. In contrast, loss-of-function mutations in the gene D-2-hydroxyglutarate dehydrogenase (D2hgdh) render cells unable to degrade D-2HG, resulting in excessive buildup of this molecule. D2hgdh mutations, however, are not generally associated with elevated cancer risk. This discrepancy raises the question as to why ectopic D-2HG accumulation in humans induces context-dependent disease outcomes. To enable such genetic studies in vivo, two novel loss-of-function mutations were generated in the Drosophila melanogaster gene "http://flybase.org/reports/FBgn0023507">D2hgdh, and these alleles result in ectopic D-2HG. Moreover, it was observed that D2hgdh mutations induce developmental and metabolomic phenotypes indicative of elevated D-2HG accumulation. Overall, these efforts provide the Drosophila community with new mutant strains that can be used to study D-2HG function in human disease models as well as in the context of normal growth, metabolism, and physiology. | Dillard, C., Teles-Reis, J., Jain, A., Antunes, M. G., Ruiz-Duran, P., Qi, Y., Le Borgne, R., Jasper, H., Rusten, T. E. (2025). NF-kappaB signaling driven by oncogenic Ras contributes to tumorigenesis in a Drosophila carcinoma model.. PLoS Biol, 23(4):e3002663 PubMed ID: 40294135
Summary: Cancer-driving mutations synergize with inflammatory stress signaling pathways during carcinogenesis. Drosophila melanogaster tumor models are increasingly recognized as models to inform conserved molecular mechanisms of tumorigenesis with both local and systemic effects of cancer. Although initial discoveries of the Toll-NFkappaB signaling pathway in development and immunity were pioneered in Drosophila, limited information is available for its role in cancer progression. Using a well-studied cooperative RasV12-driven epithelial-derived tumor model, this study describes functions of Toll-NF-kappaB signaling in malignant RasV12, scrib- tumors. The extracellular Toll pathway components ModSP and PGRP-SA and intracellular signaling Kinase, Pelle/IRAK, are rate-limiting for tumor growth. The Toll pathway NFkappaB protein Dorsal as well as /IkappaΒ show elevated expression in tumors with highest expression in invasive cell populations. Oncogenic RasV12, and not loss of scribble, confers increased expression and heterogenous distribution of two Dorsal isoforms, DorsalA and DorsalB, in different tumor cell populations. Mechanistic analyses demonstrates that Dorsal, in concert with the BTB-transcription factor Chinmo, drives growth and malignancy by suppressing differentiation, counteracting apoptosis, and promoting invasion of RasV12, scrib- tumors. |
| Li, M., Tian, A., Jiang, J. (2025). Numb provides a fail-safe mechanism for intestinal stem cell self-renewal in adult Drosophila midgut. Journal and Elife, 14 PubMed ID: 40202131
Summary: Stem cell self-renewal often relies on asymmetric fate determination governed by niche signals and/or cell-intrinsic factors but how these regulatory mechanisms cooperate to promote asymmetric fate decision remains poorly understood. In adult Drosophila midgut, asymmetric Notch (N) signaling inhibits intestinal stem cell (ISC) self-renewal by promoting ISC differentiation into enteroblast (EB). Previous work has shown that epithelium-derived Bone Morphogenetic Protein (BMP) promotes ISC self-renewal by antagonizing N pathway activity. This study showed that loss of BMP signaling (Decapentaplegic (Dpp) and Glass bottom boat (Gbb) heterodimers) results in ectopic N pathway activity even when the N ligand Delta (Dl) is depleted, and that the N inhibitor Numb acts in parallel with BMP signaling to ensure a robust ISC self-renewal program. Although Numb is asymmetrically segregated in about 80% of dividing ISCs, its activity is largely dispensable for ISC fate determination under normal homeostasis. However, Numb becomes crucial for ISC self-renewal when BMP signaling is compromised. Whereas neither Mad RNA interference nor its hypomorphic mutation led to ISC loss, inactivation of Numb in these backgrounds resulted in stem cell loss due to precocious ISC-to-EB differentiation. Furthermore, numb mutations resulted in stem cell loss during midgut regeneration in response to epithelial damage that causes fluctuation in BMP pathway activity, suggesting that the asymmetrical segregation of Numb into the future ISC may provide a fail-save mechanism for ISC self-renewal by offsetting BMP pathway fluctuation, which is important for ISC maintenance in regenerative guts. | Church, S. J., Pulianmackal, A. J., Dixon, J. A., Loftus, L. V., Amend, S. R., Pienta, K., Cackowski, F. C., Buttitta, L. A. (2025). Oncogenic signaling in the Drosophila prostate-like accessory gland activates a pro-tumorigenic program in the absence of proliferation. Dis Model Mech, 18(4) PubMed ID: 40304035
Summary: Drosophila models for tumorigenesis have revealed conserved mechanisms of signaling involved in mammalian cancer. Many of these models use highly mitotically active Drosophila tissues. Few Drosophila tumorigenesis models use adult tissues, when most cells are terminally differentiated and postmitotic. The Drosophila accessory glands are prostate-like tissues, and a model for prostate tumorigenesis using this tissue has been explored. In this prior model, oncogenic signaling was induced during the proliferative stages of accessory gland development, raising the question of how oncogenic activity impacts the terminally differentiated, postmitotic adult tissue. This study showed that oncogenic signaling in the adult Drosophila accessory gland leads to activation of a conserved pro-tumorigenic program, similar to that of mitotic tissues, but in the absence of proliferation. In these experiments, oncogenic signaling in the adult gland led to tissue hypertrophy with nuclear anaplasia, in part through endoreduplication. Oncogene-induced gene expression changes in the adult Drosophila prostate-like model overlapped with those in polyploid prostate cancer cells after chemotherapy, which potentially mediate tumor recurrence. Thus, the adult accessory glands provide a useful model for aspects of prostate cancer progression that lack cellular proliferation. |
| Li, J., Taniguchi, K., Ye, W., Kondo, S., Kobayashi, T., Matsuyama, M., Saito, K., Ohsawa, S., Igaki, T. (2025). Epithelial cell-fate switch triggering ectopic ligand-receptor-mediated JAK-STAT signaling promotes tumorigenesis in Drosophila. iScience, 28(4):112191 PubMed ID: 40230533
Summary: Disruption of epithelial architecture is a hallmark of human malignant cancers, yet whether and how epithelial deformation influences tumor progression has been elusive. Through a genetic screen in Drosophila eye disc, this study explored mutations that potently promoted Ras-activated (Ras(V12)) tumor growth and identified eyes absent (eya), an eye determination gene, whose mutation compromised tissue growth but synergized with Ras(V12) to cause massive overgrowth. Furthermore, induction of cell-fate switch by mis-expression of Abd-B in the eye disc also induced massive Ras(V12) overgrowth. Mechanistically, cell-fate switch caused epithelial invagination accompanied by partial mislocalization of the transmembrane receptor Domeless (Dome) from the apical to the basal membrane of the eye epithelium, where its ligand Unpaired3 (Upd3) is present. This led to JAK-STAT activation that cooperates with Ras(V12) to drive tumor progression. These data provide a mechanistic explanation for how cell-fate switch and subsequent epithelial deformation creates a cancer-prone environment in the epithelium. | Wang, Y., Huang, R., Deng, M., He, J., Deng, M., Ishibashi, T., Yu, C., Zhai, Z., Yan, Y. (2025). Oncogenic Ras, Yki and Notch signals converge to confer clone competitiveness through Upd2. J Genet Genomics, PubMed ID: 40320143
Summary: Cell competition is an evolutionarily ancient mechanism that functions to remove unfit or dangerous clonal cells in a multicellular community. A classical model is the removal of polarity-deficient clones, such as the precancerous scribble (scrib) mutant clones, in Drosophila imaginal discs. The activation of Ras, Yki, or Notch signaling robustly reverses the scrib mutant clonal fate from elimination to tumorous growth. Whether these signals converge to adopt a common mechanism to overcome the elimination pressure posed by cell competition remains unclear. Using single-cell transcriptomics, this study found that a critical converging point downstream of Ras, Yki, and Notch signals is the upregulation of Upd2, an IL-6 family cytokine. Overexpression of Upd2 is sufficient to rescue the scrib mutant clones from elimination. Depletion of Upd2 blocks the growth of the scrib mutant clones with active Ras, Yki, and Notch signals. Moreover, Upd2 overexpression promotes robust intestinal stem cell (ISC) proliferation, while Upd2 is intrinsically required in ISCs for the growth of the adult intestine. Together, these results identify Upd2 as a crucial cell fitness factor that sustains tissue growth but can potentiate tumorigenesis when deregulated. |
Tuesday March 3rd - Genes, Enzymes RNA and Protein Expression Evolution Structure and Function |
| Perez-Roldan, J., Henn, L., Bernues, J., Torras, L. M., Tamirisa, S., Belloc, E., Rodriguez-Munoz, L., Timinszky, G., Jimenez, G., Mendez, R., Carbonell, A., Azoran, F. (2025). Maternal histone mRNAs are uniquely processed through polyadenylation in a Stem-Loop Binding Protein (SLBP) dependent manner. Nucleic Acids Res, 53(7) PubMed ID: 40239992
Summary: >During early embryogenesis the zygotic genome remains transcriptionally silent and expression relies on maternally deposited products. Maternal deposition of histones is crucial to preserve chromatin integrity during early embryo development, when the number of nuclei exponentially increases in the absence of zygotic expression. In the Drosophila embryo, histones are maternally deposited as both proteins and mRNAs. Histone transcripts are the only nonpolyadenylated cellular mRNAs. They contain a highly conserved 3'UTR stem-loop structure, which is recognized by the Stem-Loop Binding Protein (SLBP) that, in conjunction small nuclear RNA U7, regulates their unique 3'-end processing. This study reports that, unexpectedly, maternal histone mRNAs are polyadenylated and have a truncated 3' stem-loop. This noncanonical 3'-end processing of maternal histone mRNAs occurs at their synthesis during oogenesis and requires SLBP, but not U7 snRNP. Maternal histone transcripts are subjected to cytoplasmic poly(A) tail elongation by Wisp, which results in their stabilization and is a requisite for translation. Maternal histone transcripts remain largely quiescent, their translation is activated upon loss of the embryonic linker histone dBigH1, which impairs chromatin assembly and induces DNA damage. Possible models to integrate these observations are discussed. | Zukowska, J., Gregory, K. S., Robinson, A., Isaac, R. E., Acharya, K. R. (2025). Molecular Basis of Dipeptide Recognition in Drosophila melanogaster Angiotensin I-Converting Enzyme Homologue, AnCE. Biomolecules, 15(4) PubMed ID: 40305366
Summary: Human angiotensin-I-converting enzyme (ACE) is involved in vasoregulation, inflammation, and neurodegenerative disorders. The enzyme is formed of two domains; the C-domain (cACE) is primarily involved in blood pressure regulation, whereas the N-domain (nACE) is strongly linked to fibrosis; hence, designing domain-specific inhibitors could make a difference between treating one condition without having a negative effect on another. AnCE (a close homologue of ACE) is derived from Drosophila melanogaster and has a high similarity specifically to cACE. Due to high similarity and ease of crystallisation, AnCE has been chosen as a model protein for ACE studies and for the design of ACE inhibitors. In this study, enzyme kinetic assays and X-ray crystallography techniques revealed the significance of using dipeptides as selective inhibitors for AnCE and how this knowledge could be applied to cACE and nACE. All the dipeptides tested in this study were shown to bind AnCE in two distinct locations, i.e., the non-prime and prime subsites. It was found that a hydrophobic residue at the S1 and S1' subsites, with a tryptophan at the S2 and S2' subsites, showed highest affinity towards AnCE. It was also observed that a key pocket within the S2' subsite had a major influence on the binding orientation within the prime subsites and could potentially explain ACE's dipeptidyl carboxypeptidase activity. Importantly these dipeptides are found in functional foods, making them potentially available from diets. Knowledge of the dipeptide binding presented in this study could aid in the development of ACE domain-specific inhibitors. |
| Cheng, Y., Chen, Y. X., Gao, J. N., Chen, J., Huang, J., Qiao, X. (2025). Multiple Mutations in the beta1 Subunit of the Nicotinic Acetylcholine Receptor Confer Resistance to Neonicotinoids. J Agric Food Chem, 73(20):12176-12183 PubMed ID: 40353574
Summary: The evolution of resistance to neonicotinoid insecticides threatens global agriculture. To elucidate its molecular basis, this study employed Drosophila melanogaster as a model system to investigate resistance-associated mutations in the β1 subunit of nicotinic acetylcholine receptors (nAChRs). Using a CRISPR/Cas9-mediated allele replacement, homozygous knock-in mutants (V62I, V101I, R81E, and A60T,R81E) were generated without apparent fitness costs. Toxicity bioassays revealed that these mutations confer varying resistance levels, with the R81E mutation exhibiting over 225-fold resistance to thiamethoxam, clothianidin, and dinotefuran. A heteropentameric α1β1 nAChR model, generated using an AI-based protein-ligand prediction (Chai-1), showed that imidacloprid binds at the orthosteric site, where R81 forms a critical electrostatic interaction. Residues A60, V62, and V101, positioned further from the binding site, showed spatial distances correlated with their resistance ratios. These findings provide genetic and structural insights into neonicotinoid resistance mechanisms, offering a foundation for the design of next-generation insecticides and resistance management strategies. | Kasuya, J., Kruth, K., Lee, D., Kim, J. S., Williams, A., Kitamoto, T. (2025). Effects of lithium on mortality and metabolite profiles in Drosophila lithium-inducible SLC6 transporter mutants. Environ Toxicol Pharmacol, 116:104684 PubMed ID: 40194719
Summary: Lithium has long been the primary treatment for bipolar disorder and shows promise for managing other neurological and psychiatric conditions. The has been identified in Drosophila melanogaster as a gene significantly upregulated in response to lithium chloride supplementation. List encodes a putative amino acid transporter belonging to the Na+-dependent solute carrier family 6. List is expressed in the Malpighian tubules, glia, and hindgut. RNA interference-mediated List knockdown in the Malpighian tubules drastically increases lithium-induced mortality. Additionally, List loss-of-function mutants (ListTG4.2) accumulate six times more internal lithium than controls after lithium exposure. Metabolomic analysis revealed disrupted amino acid metabolism and a shift toward a more oxidized cellular redox state in lithium-treated List(TG4.2) mutants. Overall, these findings suggest that List protects flies from lithium toxicity by regulating internal lithium levels and maintaining metabolic and redox balance. |
| Dean, D. M., Codd, L. E., Constanza, R., Segel, X. M. (2025). purpleoid (1), a classic Drosophila eye color mutation, is an allele of the t-SNARE-encoding gene SNAP29. MicroPubl Biol, 2025 PubMed ID: 40270683
Summary: The Drosophila mutant eye color trait purpleoid (pd) was first observed by Calvin Bridges over a century ago. Although pd mutant strains have been maintained ever since, the pd locus has not been identified. Using complementation tests, genetic rescue, and DNA sequencing, this study showed that pd1 is a missense mutation in SNAP29; this gene encodes a key component of the SNARE complex, which facilitates vesicle docking and fusion at cellular membranes. After describing how pd1 was mapped, ways that the mutation could be used in future studies of eye pigmentation, SNARE complex assembly, and vesicle trafficking, are discussed. | Komp, E., Phillips, C., Lee, L. M., Fallin, S. M., Alanzi, H. N., Zorman, M., McCully, M. E., Beck, D. A. C. (2025). Neural network conditioned to produce thermophilic protein sequences can increase thermal stability. Sci Rep, 15(1):14124 PubMed ID: 40268970
Summary: This work presents Neural Optimization for Melting-temperature Enabled by Leveraging Translation (NOMELT), a novel approach for designing and ranking high-temperature stable proteins using neural machine translation. The model, trained on over 4 million protein homologous pairs from organisms adapted to different temperatures, demonstrates promising capability in targeting thermal stability. A designed variant of the Drosophila melanogaster Engrailed Homeodomain shows a melting temperature increase of 15.5 K. Furthermore, NOMELT achieves zero-shot predictive capabilities in ranking experimental melting and half-activation temperatures across a number of protein families. It achieves this without requiring extensive homology data or massive training datasets as do existing zero-shot predictors by specifically learning thermophilicity, as opposed to all natural variation. These findings underscore the potential of leveraging organismal growth temperatures in context-dependent design of proteins for enhanced thermal stability. |
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