Culturing Drosophila egg chambers and imaging border cell migration

Abstract

Border cell migration in the Drosophila egg chamber is a powerful, genetically tractable model to study cell invasion1. Studying border cell migration in Drosophila has allowed identification and characterization of several genes needed for cell migration and their guidance. The big drawback in studying border cell migration has been lack of success culturing stage 9 egg chambers and so border cell migration has been studied only in fixed ovaries. We have established conditions for culturing stage 9 and 10 egg chambers for 2-3 hours, allowing analysis of cell behavior in wild type and mutant egg chambers2. Several methods for imaging older egg chambers have been reported, but culturing of stage 8 and 9 egg chambers has not been possible, perhaps because at these stages egg chambers grow fast and are highly sensitive to poor nutrient conditions. Previous methods have been used to study cytoplasmic streaming3, RNA localization4 and for late epithelial morphogenetic movements5. In contrast to these approaches, our method has been optimized to support maintenance and growth of earlier egg chambers. Although we have so far only applied this technique to border cell migration, it may well prove adaptable to the study of other early processes in oogenesis