Visualization of spatiotemporal activation of Notch signaling : live monitoring and significance in neural development and Hematopoiesis

Notch信号在中枢神经系统发育过程中以上下文依赖的方式决定细胞命运中起着各种关键作用。然而，其确切的生理作用及其靶细胞的定位仍不清楚。为了解决虹膜问题，我们开发了一个新的报告系统，使用荧光蛋白金星来评估rbp - j介导的Notch信号靶基因在活细胞和组织中的激活。我们的记者系统显示。Notch信号在体外神经球起始多能神经干细胞和体内胚胎前脑的放射状胶质细胞中被选择性激活。此外，Notch信号的激活发生在胶质形成过程中，并且在星形胶质发育的早期阶段是必需的。与这些结局一致的是，Notch信号的持续激活抑制了gmap阳性星形胶质细胞的分化。因此，我们的rbp - j依赖的活报告系统的开发，在Notch激活时被激活，以及阶段依赖的功能获得分析，使我们能够进一步了解Notch信号在哺乳动物中枢神经系统发育中的复杂性。

Notch signaling plays various key roles in cell fate determination during CNS development in a context-dependent fashion. However, its precise physiological role and the localization of its target cells remain unclear. To address iris issue, we developed a new reporter system for assessing the RBP-J-mediated activation of Notch signaling target genes in living cells and tissues using a fluorescent protein Venus. Our reporter system revealed. that Notch signaling is selectively activated in neurosphere-initiating multipotent neural stem cells in vitro and in radial glia in the embryonic forebrain in vivo. Furthermore, the activation of Notch signaling occurs during gliogenesis and is required in the early stage of astroglial development. Consistent with these Endings, the persistent activation of Notch signaling inhibits the differentiation of GFAP-positive astrocytes. Thus, the development of our RBP-J-dependent live reporter system, which is activated upon Notch activation, together with a stage-dependent gain-of-function analysis allowed us to gain further insight into the complexity of Notch signaling in mammalian CNS development.