Like many stem cell systems, the Caenorhabditis elegans germ line contains a self-renewing germ cell population that is maintained by a niche. Although the exact cellular mechanism for self-renewal is not yet known, three recent studies shed considerable light on the cell cycle behavior of germ cells, including a support for significant and plastic renewal potential. This review brings together the results of the three recent cell-based studies, places them in the context of previous work, and discusses future perspectives for the field. Developmental Dynamics 236:3343–3357, 2007. © 2007 Wiley-Liss, Inc.