Stem cell renewal in vivo often requires a specialised microenvironment, the stem cell niche. Niche cells provide self-renewal signals as well as structural and spatial cues to regulate stem cell maintenance and differentiation. Here, Pankaj Sahai-Hernandez and Todd Nystul () investigate the follicle stem cell (FSC) niche of the Drosophila ovary, providing evidence that the escort cells of the germarium - which surround germline cysts and support their development - are also key for FSC maintenance. Hedgehog (Hh) and Wingless (Wg) pathways are known to promote FSC self-renewal, and the distant terminal filament and cap cells were proposed to be the sources for these signals. However, the authors here show that escort cells are the essential source of Wg for FSC function, whereas Hh is produced from multiple somatic cell types - including escort cells - and acts on both FSCs and their progeny. Moreover, escort cells contact FSCs and likely provide a dynamic niche for their maintenance, revealing a new component of the niche and a new function for escort cells.
