Germline immortality
In contrast to somatic cells, which exist for only one generation, germ cells proliferate through successive generations. These cells are maintained through a microenvironment, referred to as a stem cell niche, which maintains mitotic-arrested cells. The proliferative fate of these stem cells are controlled in these niches through cellular architecture and secreted factors. In C. elegans, the equivalent of the stem cell niche for the immortal germline cells is provided by the distal tip cell (DTC) and its gonad arm processes. Germ line DNA-damage checkpoints are key monitors of processes involved in germ cell immortality.