Signals specifying polarity, adhesion, developmental timing, and cell identity are important for border cell migration in Drosophila

Abstract

Cell migration is important in many developmental processes, including neural crest cell migration, gastrulation, and organogenesis. Proper regulation of cell migration is also necessary in adult organisms for immune responses including wound healing. Here, I use the established system of Drosophila border cell migration during oogenesis to provide valuable insight into understanding how collective cell migration is regulated. I have taken a genetic approach to studying cell migration by identifying mutants affecting genes that are important for border cell migration to occur, and a cell biological approach to characterizing the affected cellular behaviors and phenotypes. Through this work, I have mapped novel mutations to genes with previously uncharacterized roles in border cell migration. This analysis has enabled me to describe how Rickets, a G-protein-coupled receptor with a previously unknown role in border cell migration, can coordinate polarity, adhesion, and intercellular communication in the outer border cells. My work has contributed to our understanding of how the ecdysone biosynthesis pathway contributes to producing a threshold level of ecdysone activity that is required in the follicle cells for border cell migration to initiate. Furthermore, my approach has identified a role for a previously uncharacterized gene, CG14535, in specification of the migratory border cells. These findings represent valuable contributions to the field concerning the coordination and regulation of cell migration in developmental systems.