logo Images of Drosophila Embryonic Development

FlyBase, created and maintained by a consortium of Drosophila researchers and computer scientists at Harvard University, University of Cambridge (UK), and Indiana University has assembled a collection of images illustrating Drosophila development. Dr. Rudi Turner provided the scanning electron microscope photographs. 5 folders contain the following:

    1) adult heads - normal and homeotically transformed (3 images)
    2) gastrulating embryos viewed laterally (12 images)
    3) gastrulating embryos viewed dorsally (18 images)
    4) ventral views of embryos showing mesoderm invagination (6 images)
    5) ventral anterior views of head involution (19 images).

Morphogenetic events are described in more detail in the stages section.

Direct links to Drosophila images:

1)adult heads - normal and mutant


frontal view of mutant antennapedia head [ 32kb]

Antenna are transformed into metathoracic (second second thoracic segment) legs.

frontal view of mutant antennapedia/proboscipedia head [46kb]

Labial palps are transformed into prothoracic (first thoracic segment) legs and antenna are transformed into metathoracic (second) legs.

frontal view of wild-type head [ 35kb]

2) gastrulating embryos viewed laterally (12 images)

Gastrulating embryo - lateral view - stage 4 [30kb]

Syncytial blastoderm prior to cellularization

Gastrulating embryo - lateral view - stage 5 [28kb]

Cellularization of the blastoderm

Gastrulating embryo - lateral view - stage 6 [31kb]
Gastrulating embryo - lateral view - stage 6 [26kb]

Pole cells have been included in the posterior midgut primordium. Beginning of germ band elongation. Showing amnioproctodeal invagination (the formation of the proctodeum), procephalon and cephalic furrow.

Gastrulating embryo - lateral view - stage 8 [28kb]

Rapid germ band elongation. There is no sign of segmentation. Showing procephalon and amnioserosa.

Gastrulating embryo - lateral view - stage 11 [31kb]

Head features including clypeolabrum, procephalon, and gnathal lobes, i.e. mandibular, maxillary and labial lobes. Maximum germ band extention. Shows parasegmental furrows posterior spiracle and amnioserosa.

Gastrulating embryo - lateral view - stage 11 [29kb]
Gastrulating embryo - lateral view - stage 11 [34kb]
Gastrulating embryo - lateral view - stage 12 [30kb]

Germ band retraction. Posterior spiracles present. Dorsal ridge and hypopharyngeal lobe evident. Head, thorax and abdominal segments are identified.

Gastrulating embryo - lateral view - stage 13 [29kb]
Gastrulating embryo - lateral view - stage 13 [29kb]

Nearing the end of germ band retraction.


3) gastrulating embryos viewed dorsally (18 images)

Gastrulating embryo - dorsal view - stage 5 [23kb]
Gastrulating embryo - dorsal view - stage 5 [26kb]

Cellularization of blastoderm. Showing pole cells.

Gastrulating embryo - dorsal view - stage 6 [28kb]

Pole cells in the process of being included in the posterior midgut primordium (amnioproctodeal invagination forming the proctodeum). Cephalic furrow forming.

Gastrulating embryo - dorsal view - stage 7 [28kb]
Gastrulating embryo - dorsal view - stage 8 [28kb]
Gastrulating embryo - dorsal view - stage 9 [26kb]

Slow germ band elongation. Shows procephalon, cephalic furrow and amnioserosa.

Gastrulating embryo - dorsal view - stage 10 [26kb]
Gastrulating embryo - dorsal view - stage 11 [30kb]

Parasegmental furrows evident. Maximum germ band extention

Gastrulating embryo - dorsal view - stage 12 [30kb]

Germ band retraction. Parasegmental furrows.

Gastrulating embryo - dorsal view - stage 12 [31kb]
Gastrulating embryo - dorsal view - stage 12 [30kb]

Half way point in germband retraction. Parasegmental furrows and posterior spiracles. Amnioserosa is stretching out to cover the yolk sac, exposed during germband shortening. Optic lobe and dorsal ridge and thoracic segments evident.

Gastrulating embryo - dorsal view - stage 13 [30kb]
Gastrulating embryo - dorsal view - stage 13 [32kb]

End of germ band retraction.

Gastrulating embryo - dorsal view - stage 14 [28kb]
Gastrulating embryo - dorsal view - stage 15 [28kb]

Dorsal closure and head involution. Dorsal fold evident.

End of dorsal closure. Head involution. Antennomaxillary complex and posterior spiracles evident.


4) ventral views of embryos showing mesoderm invagination (6 images)

Mesodermal invagination - stage 6 [82kb]
Mesodermal invagination - stage 6 [96kb]
Mesodermal invagination - stage 7 [80kb]
Mesodermal invagination - stage 7 [80kb]
Mesodermal invagination - stage 8 [76kb]

5) ventral anterior views of head involution (19 images)

Head involution 1 [100kb]
Head involution 2 [100kb]
Head involution 3 [96kb]

A nine hour embryo (stage 12) near the half way point of germ band shortening. Shown from anterior to posterior are the clypeolabrum, stomodeum, flanked laterally and posteriorly by developing hypopharyngeal lobes. Posterior and more laterally are the mandibular lobes and more posteriorly the maxillary lobes. Behind and medial to the maxillary lobes are salivary gland invaginations. Posterior to the maxillary lobes are labial lobes, and even more posterior are the first thoracic segments.

Head involution 4 [99kb]
Head involution 5 [95kb]
Head involution 6 [96kb]
Head involution 7 [102kb]
Head involution 8 [102kb]
Head involution 9 [95kb]

A ten hour embryo (stage 13) at the end of germ band shortening. Shown from anterior to posterior are the clypeolabrum, stomodeum, flanked laterally and posteriorly by prominent hypopharyngeal lobes. More posteriorly and laterally are the mandibular lobes. The labial lobes, flanking the salivary gland invaginations which have fused to form a common duct, have moved toward the midline. Maxillary lobes are posterior to and lateral of the mandibular lobes.

Head involution 10 [103kb]

Head involution 11 [101kb]

A stage 14 embryo at the beginning of hypopharyngeal lobe invagination through the stomodeum. The labial appendages have moved closer to the midline. The anlagen of the mandibular sense organs show as depressions in the middle of the mandibular appendages.

Head involution 12 [94kb]
Head involution 14 [115kb]
Head involution 15 [114kb]

The hypopharyngeal lobes have invaginated through the stomodeum. Surrounding the stomodeum are anteriorly, the clypelabium, laterally, the mandibular appendages, and posteriorly, the labial appendages.

Head involution 16 [120kb]
Head involution 17 [122kb]

Stage 15 at the completion of dorsal closure and near the completion of head involution.

Head involution 18 [110kb]
Head involution 19 [111kb]

The clypeolabrum has invaginated and the maxillary-mandibular segment complexes have become the dominant head features. Mouth hooks are prominent as are the maxillary sense organs (looking like eyes). Dorsal and medial of the maxillary sense organs are antennal sense organs. The first thoracic segment is just posterior to the mouth hooks.


Reference

Turner, F.R. and Mahowald, A.P. (1979). Scanning electron microscopy of Drosophila melanogaster embryogenesis. III. Formation of the head and caudal segments. Dev. Biol. 68: 96-109


date revised: 10 June 2007

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