Stage 17
Key events: completion of organogenesis,
movements of the embryo within the vitelline envelope
Stage
17 lasts until hatching of the embryo. The tracheal tree fills with air,
thus becoming clearly visible in the living embryo. Retraction of the
ventral cord continues.
Except
for the involuted head, the shortened ventral cord, whose tip reaches
60% egg length (0% egg length = posterior pole) during this stage, and
further elaboration of cuticle specializations, e.g. sensilla, no conspicuous
differences can be discerned in the morphology of the embryo relative
to that in stage
16.
Media list
Stage 17, in vivo (1.2 MB)
Stage 17, sagittal sections (0.5 MB)..........additional
information
Stage 17, horizontal sections (0.7 MB)..........additional
information
Stage
17, virtual microscope, sagittal sections..........additional
informationStage
17, virtual microscope, horizontal sections..........additional
information
Stage
17, anti-Crumbs staining..........additional
informationGenes discussed
|
Gene
|
Gene product - Domains
|
Function
|
Links
|
|
crumbs (crb)
|
transmembrane -EGF repeats - laminin A homolog
|
involved in epithelial polarity, expressed in the apical
membrane of ectodermal cells
|