How a fully formed organism develops from a single fertilized egg cell is a complex process. That process is no less complex in inverterbrates than in verterbrates, and much is known about just how development occurs in Drosophila. In the following series of posts, I'll detail the just how you can get a complete fly from a simple cell.
(Links will be available as I write and post each individual part)
Part II: Setting up the Anterior - Posterior Axis: Hunchback, Nanos & Caudal
Part III: The Terminators
Part IV: Setting up the Dorsal-Ventral Axis: Spätzle, Toll and Dorsal
Part V: Zygotic Gene Expression along the D-V Axis
Part VI: Gap-gene Expression
Part VII: TBD