LOOKING AT OOGENESIS

The analysis of oogenesis in Drosophila has proved to be invaluable in dissecting diverse cell biological processes. Oogenesis requires carefully regulated interactions between the germline-derived nurse cells and oocyte, and the somatically derived follicle cell populations. This chapter describes the commonly used techniques applied for examining the ovarian tissue. These techniques are particularly useful for determining the phenotype of mutations, as a first step in characterizing the function of a gene required during oogenesis. The ovary is ideal for the study of cell biology since relatively few cell types are involved and their morphology and behavior are well characterized. The nurse cells are synthetically active and they have a complex and dynamic cytoskeleton. The somatic follicle cells are polarized secretory epithelial cells that undergo cellular rearrangements as they carry out their various migrations around the developing oocyte. To examine the egg chambers, ovaries need to be dissected out of adult flies. To stimulate egg production, females are fed a wet yeast paste before dissecting them. The optimal amount of time for yeast feeding can be 24–48 hr but should be determined empirically for each mutant line. The goal is to obtain ovaries as healthy as possible to avoid assigning nonspecific consequences of undernourishment to the mutant phenotype description. © 1994, Elsevier Science Publishers, B.V. All rights reserved.