Surviving Drosophila eye development: integrating cell death with differentiation during formation of a neural structure.

Normal differentiation requires an appropriately orchestrated sequence of developmental events. Regulation of cell survival and cell death is integrated with these events to achieve proper cell number, cell type, and tissue structure. Here we review regulation of cell survival in the context of a precisely patterned neural structure: the Drosophila compound eye. Numerous mutations lead to altered differentiation and are frequently accompanied by altered patterns of cell death. We discuss various critical times of normal eye development, highlighting how inappropriate regulation of cell death contributes to different mutant phenotypes associated with genes that specify the entire eye primordia, others that pattern the retina, and those that eliminate extraneous cells to refine the precise pigment cell lattice. Finally, we address how the Drosophila eye may allow identification of additional mechanisms that contribute to the normal integration of cell survival with appropriate events of cellular differentiation.