Seidel Hannah S, Smith Tilmira A, Evans Jessica K, Stamper Jarred Q, Mast Thomas G, Kimble Judith
Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States.
Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States.
Dev Biol. 2018 Oct 1;442(1):173-187. doi: 10.1016/j.ydbio.2018.07.013. Epub 2018 Jul 19.
Knowing how stem cells and their progeny are positioned within their tissues is essential for understanding their regulation. One paradigm for stem cell regulation is the C. elegans germline, which is maintained by a pool of germline stem cells in the distal gonad, in a region known as the 'progenitor zone'. The C. elegans germline is widely used as a stem cell model, but the cellular architecture of the progenitor zone has been unclear. Here we characterize this architecture by creating virtual 3D models of the progenitor zone in both sexes. We show that the progenitor zone in adult hermaphrodites is organized like a folded epithelium. The progenitor zone in males is not folded. Analysis of germ cell division shows that daughter cells are born side-by-side along the epithelial-like surface of the germline tissue. Analysis of a key regulator driving differentiation, GLD-1, shows that germ cells in hermaphrodites differentiate along a folded path, with previously described "steps" in GLD-1 expression corresponding to germline folds. Our study provides a three-dimensional view of how C. elegans germ cells progress from stem cell to overt differentiation, with critical implications for regulators driving this transition.
了解干细胞及其后代如何在组织中定位对于理解它们的调控至关重要。干细胞调控的一个范例是秀丽隐杆线虫的生殖系，它由远端性腺中一群生殖系干细胞维持，位于一个被称为“祖细胞区”的区域。秀丽隐杆线虫的生殖系被广泛用作干细胞模型，但祖细胞区的细胞结构一直不清楚。在这里，我们通过创建两性祖细胞区的虚拟三维模型来表征这种结构。我们表明，成年雌雄同体的祖细胞区组织成类似折叠上皮的结构。雄性的祖细胞区没有折叠。生殖细胞分裂分析表明，子细胞沿着生殖系组织的上皮样表面并排产生。对驱动分化的关键调节因子GLD-1的分析表明，雌雄同体中的生殖细胞沿着折叠路径分化，之前描述的GLD-1表达中的“步骤”对应于生殖系褶皱。我们的研究提供了一个三维视角，展示了秀丽隐杆线虫生殖细胞如何从干细胞发展到明显分化，这对驱动这种转变的调节因子具有关键意义。
