Fig. 3. Enlarged view of the male and female germline stem cell (GSC) niches. In both the male and female GSC niches, GSCs are attached to the niche via DE-cadherin-rich cell-cell contacts. GSCs usually divide so that one daughter remains associated with the niche, and retains GSC identity, while the other daughter is displaced from the niche and enters gametogenesis. Signaling from the female niche (terminal filament and cap cells) uses the Tgfß signaling pathway to maintain GSCs and the Jak/Stat pathway to maintain the escort cell population. Signaling from the male niche (hub) uses both the Jak/Stat and Tgfß pathways to maintain the GSCs. Male: germ cells, dark blue; putative GSCs, light blue; hub cells, orange; cyst progenitor cells, light green; testis sheath, yellow. Female: germ cells, dark pink; GSCs, light pink; terminal filament cells, orange; cap cells, red; escort cells, light green; epithelial sheath, blue.