Chapter 258 - Reiterative and Concurrent Use of EGFR and Notch Signaling during Drosophila Eye Developmement

Notch and epidermal growth factor receptor (EGFR) pathways are conserved throughout evolution and function together in many different developmental contexts. During the specification of the Drosophila eye, these two pathways either function in synergy or in opposition to achieve different outcomes. Similarly, in some instances, EGFR activation causes a serial activation of the Notch pathway through the control of the Notch ligand Delta, while in others, the two pathways act together on the same enhancer element in parallel to control target gene expression. This chapter proposes that the combinatorial effects of these two pathways have evolved as a network that generates a significant diversity in output with a small number of components used in a reiterative fashion.