Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706.
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706.
Mol Biol Cell. 2019 Jul 1;30(14):1757-1769. doi: 10.1091/mbc.E19-03-0164. Epub 2019 May 8.
Stem cell maintenance by niche signaling is a common theme across phylogeny. In the gonad, the broad outlines of germline stem cell (GSC) regulation are the same for both sexes: GLP-1/Notch signaling from the mesenchymal distal tip cell niche maintains GSCs in the distal gonad of both sexes and does so via two key stem cell regulators, SYGL-1 and LST-1. Yet most recent analyses of niche signaling and GSC regulation have focused on XX hermaphrodites, an essentially female sex making sperm in larvae and oocytes in adults. Here we focus on GSC regulation in XO males. Sexual dimorphism of niche architecture, reported previously, suggested that the molecular responses to niche signaling or numbers of GSCs might also be sexually distinct. Remarkably, this is not the case. This work extends our understanding of the sexually dimorphic niche architecture, but also demonstrates that the dimorphic niches drive a similar molecular response and maintain a similar number of GSCs in their stem cell pools.
龛信号维持干细胞是贯穿整个进化的一个普遍主题。在性腺中，生殖干细胞（GSC）的调控大致相同：间质远端顶端细胞龛的 GLP-1/Notch 信号从两性的远端性腺中维持 GSC，并通过两个关键的干细胞调节因子，SYGL-1 和 LST-1 来实现。然而，最近对龛信号和 GSC 调控的分析主要集中在 XX 雌雄同体上，这是一种基本上是雌性的性别，在幼虫中产生精子，在成体中产生卵子。在这里，我们专注于 XO 雄性的 GSC 调控。先前报道的龛结构的性二态性表明，龛信号的分子反应或 GSC 的数量也可能具有性别差异。值得注意的是，事实并非如此。这项工作扩展了我们对性二态龛结构的理解，但也表明，这种二态龛结构驱动了类似的分子反应，并在其干细胞库中维持了类似数量的 GSC。
