Institut Pasteur, CNRS UMR3738, Paris, France.
Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Cell Division and Neurogenesis, Ecole Normale Supérieure, CNRS, Inserm, PSL Université Paris, Paris, France.
Nat Commun. 2022 Aug 25;13(1):4999. doi: 10.1038/s41467-022-32685-3.
Neural stem cells (NSCs) live in an intricate cellular microenvironment supporting their activity, the niche. Whilst shape and function are inseparable, the morphogenetic aspects of niche development are poorly understood. Here, we use the formation of a glial niche to investigate acquisition of architectural complexity. Cortex glia (CG) in Drosophila regulate neurogenesis and build a reticular structure around NSCs. We first show that individual CG cells grow tremendously to ensheath several NSC lineages, employing elaborate proliferative mechanisms which convert these cells into syncytia rich in cytoplasmic bridges. CG syncytia further undergo homotypic cell-cell fusion, using defined cell surface receptors and actin regulators. Cellular exchange is however dynamic in space and time. This atypical cell fusion remodels cellular borders, restructuring the CG syncytia. Ultimately, combined growth and fusion builds the multi-level architecture of the niche, and creates a modular, spatial partition of the NSC population. Our findings provide insights into how a niche forms and organises while developing intimate contacts with a stem cell population.
神经干细胞 (NSCs) 生活在一个复杂的细胞微环境中，这个微环境支持着它们的活动，即龛位。虽然形状和功能是不可分割的，但龛位发育的形态发生方面还知之甚少。在这里，我们利用胶质龛位的形成来研究获得建筑复杂性的过程。果蝇的皮层胶质细胞 (CG) 调节神经发生，并在 NSCs 周围构建一个网状结构。我们首先表明，单个 CG 细胞生长得非常大，能够包裹几个 NSC 谱系，采用精细的增殖机制，将这些细胞转化为富含细胞质桥的合胞体。CG 合胞体进一步通过定义明确的细胞表面受体和肌动蛋白调节剂进行同源细胞-细胞融合。然而，细胞交换在空间和时间上是动态的。这种非典型的细胞融合重塑了细胞边界，重构了 CG 合胞体。最终，细胞的生长和融合共同构建了龛位的多层次结构，并为 NSC 群体创建了一个模块化、空间分隔的分区。我们的研究结果提供了关于龛位如何在与干细胞群体形成密切联系的同时形成和组织的见解。
