8 - Sex and Death in the Caenorhabditis elegans Germ Line

Abstract

This chapter provides a rough portrait of the mechanisms that control cell fate in the developing germ line. Two factors have combined to make Caenorhabditis elegans a leading system for studying programmed cell death. First, these deaths can be studied in living animals. Second, many mutations that affect programmed deaths are viable and easy to identify. After germ cells have entered meiosis and begun to differentiate as sperm or oocytes, some face a final cell fate decision. Direct observation reveals that many cells that appear committed to oogenesis choose instead to undergo programmed cell deaths. These suicides are not observed during the process of spermatogenesis. One attractive theory is that these dying germ cells function as nurse cells, producing material for use in developing oocytes. Because they resemble developing oocytes in all other respects, it is likely that the only cell fate decision required to control this process involves determining which of these differentiating germ cells will become oocytes and which will die.