Genetic control of programmed cell death in the Caenorhabditis elegans hermaphrodite germline

Development of the nematode Caenorhabditis elegans is highly reproducible a nd the fate of every somatic cell has been reported, We describe here a pre viously uncharacterized cell fate in C. elegans: we show that germ cells, w hich in hermaphrodites can differentiate into sperm and oocytes, also under go apoptotic cell death, In adult hermaphrodites, over 300 germ cells die, using the same apoptotic execution machinery (ced-3, ced-4 and ced-9) as th e previously described 131 somatic cell deaths, However, this machinery is activated by a distinct pathway, as loss of egl-1 function, which inhibits somatic cell death, does not affect germ cell apoptosis. Germ cell death re quires ras/MAPK pathway activation and is used to maintain germline homeost asis. We suggest that apoptosis eliminates excess germ cells that acted as nurse cells to provide cytoplasmic components to maturing oocytes.