Chen Ting-An, Lin Kun-Yang, Yang Shun-Min, Tseng Chen-Yuan, Wang Yu-Ting, Lin Chi-Hung, Luo Lichao, Cai Yu, Hsu Hwei-Jan
Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
Faculty of Science, University of South Bohemia, České Budějovice, Czechia.
Front Cell Dev Biol. 2022 Apr 19;10:877047. doi: 10.3389/fcell.2022.877047. eCollection 2022.
Morphogen-mediated signaling is critical for proper organ development and stem cell function, and well-characterized mechanisms spatiotemporally limit the expression of ligands, receptors, and ligand-binding cell-surface glypicans. Here, we show that in the developing ovary, canonical Wnt signaling promotes the formation of somatic escort cells (ECs) and their protrusions, which establish a physical permeability barrier to define morphogen territories for proper germ cell differentiation. The protrusions shield germ cells from Dpp and Wingless morphogens produced by the germline stem cell (GSC) niche and normally only received by GSCs. Genetic disruption of EC protrusions allows GSC progeny to also receive Dpp and Wingless, which subsequently disrupt germ cell differentiation. Our results reveal a role for canonical Wnt signaling in specifying the ovarian somatic cells necessary for germ cell differentiation. Additionally, we demonstrate the morphogen-limiting function of this physical permeability barrier, which may be a common mechanism in other organs across species.
形态发生素介导的信号传导对于器官的正常发育和干细胞功能至关重要，并且已充分表征的机制在时空上限制了配体、受体和配体结合细胞表面硫酸乙酰肝素蛋白聚糖的表达。在这里，我们表明，在发育中的卵巢中，经典Wnt信号传导促进体细胞护送细胞（ECs）及其突起的形成，这些突起建立了一个物理渗透屏障，以定义形态发生素区域，从而实现生殖细胞的正常分化。这些突起保护生殖细胞免受生殖系干细胞（GSC）微环境产生的Dpp和无翅形态发生素的影响，而这些形态发生素通常仅被GSCs接收。EC突起的基因破坏使GSC后代也能接收Dpp和无翅形态发生素，随后扰乱生殖细胞分化。我们的结果揭示了经典Wnt信号传导在指定生殖细胞分化所需的卵巢体细胞中的作用。此外，我们证明了这种物理渗透屏障的形态发生素限制功能，这可能是跨物种其他器官中的一种常见机制。
