|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:
Morphogenetic events are described in more detail in the stages section.
Direct links to Drosophila images:
1)adult heads - normal and mutant
Antenna are transformed into metathoracic (second second thoracic segment) legs.
Labial palps are transformed into prothoracic (first thoracic segment) legs and antenna are transformed into metathoracic (second) legs.
Syncytial blastoderm prior to cellularization
Cellularization of the blastoderm
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.
Rapid germ band elongation. There is no sign of segmentation. Showing procephalon and amnioserosa.
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.
Germ band retraction. Posterior spiracles present. Dorsal ridge and hypopharyngeal lobe evident. Head, thorax and abdominal segments are identified.
Cellularization of blastoderm. Showing pole cells.
Pole cells in the process of being included in the posterior midgut primordium (amnioproctodeal invagination forming the proctodeum). Cephalic furrow forming.
Slow germ band elongation. Shows procephalon, cephalic furrow and amnioserosa.
Parasegmental furrows evident. Maximum germ band extention
Germ band retraction. Parasegmental furrows.
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.
End of germ band retraction.
Dorsal closure and head involution. Dorsal fold evident.
End of dorsal closure. Head involution. Antennomaxillary complex and posterior spiracles evident.
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.
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.
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.
The hypopharyngeal lobes have invaginated through the stomodeum. Surrounding the stomodeum are anteriorly, the clypelabium, laterally, the mandibular appendages, and posteriorly, the labial appendages.
Stage 15 at the completion of dorsal closure and near the completion of head involution.
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.
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
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