Germ cell proliferation and differentiation are also controlled by the DELTA/NOTCH and RAS/MAPK signaling pathways, but in contrast to the vulva, the germ cells do not follow a fixed cell lineage. Rather, the decision whether a meiotic germ cell enters oogenesis or undergoes apoptosis is made in a stochastic manner.
The phenomenon of germ cell apoptosis is a physiological process, which ensures that enough but not too many germ cells are available for oocytes production. Germ cell development thus serves as a model to study cell homeostasis in a self-renewing organ. We are investigating how the RAS/MAPK pathway activates the pro-apoptotic cascade in germ cells fated to die.