A Summary of Drosophila Embryogenesis
During embryonic development profound modifications of an original form, the fertilized egg, take place. Although embryonic development is continuous, embryologists have frequently emphasized definite events which permitted subdivision of the embryogenetic process into a series of different stages. All subdivisions of embryogenesis in stages are necessarily artificial, in the sense that they seem to imply the interruption of the embryogenetic process at each stage; yet staging is very useful while describing embryonic development, because it provides a temporal reference framework for embryogenetic events. In embryology several stages have been distinguished which apply to most animals, e.g. formation of the blastula and gastrula. In this chapter we present a summary of Drosophila embryogenesis referring to this more general, widely used classification of stages; in the next chapter we shall present another, more detailed staging system supported by the characteristics of the embryogenetic process in Drosophila melanogaster. The main purpose of this chapter consists in introducing the reader to both the main embryogenetic events and the embryologic terminology.
KeywordsMalpighian Tubule Germ Band Posterior Midgut Dorsal Closure Anterior Midgut
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