Wenfan Ke, Ph.D., Postdoctoral Fellow (Schedl Laboratory), Department of Molecular Biology, Princeton University
As in humans, female fruit flies (Drosophila melanogaster) have two ovaries which are responsible for making the eggs (oocytes) that are needed for the generation of future offspring. In the fruit fly, each ovary contains about 15-20 germ-line stem cells. Those stem cells go through a series of divisions, becoming more and more mature, while confined in a linear channel (the germarium); this image shows some of the 12-16 such channels that make up the ovary. This linear assembly line from stem cell to mature oocyte provides investigators with a unique opportunity to study this important step-wise differentiation process. In this ovary from a mutant fly, the oocytes fail to differentiate properly. The animal is sterile. Studying the mechanism of action of such mutations has led to a virtual gold mine of basic information about the biology underlying stem cell behavior and the intricate process of cell differentiation.