Notch signaling controls germline stem cell niche formation in the Drosophila ovary
Notch signaling controls germline stem cell niche formation in the Drosophila ovary
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DOI：
10.1242/dev.003392
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发表时间：
2007-03-15
期刊：
影响因子：
4.6
通讯作者：
Xie, Ting
中科院分区：
文献类型：
--
作者：
Song, Xiaoqing;Call, Gerald B.;Xie, Ting
干细胞可以自我更新并产生分化的细胞，已被证明是由周围的微环境或在几个成年组织中的小生境控制的。然而，它仍然在很大程度上是未知的，什么构成了一个功能生态位，以及如何控制生态位的形成。在果蝇卵巢中，生殖干细胞（GSC），这是相邻的帽细胞和其他两种细胞类型，已被证明是维持在小生境。在这项研究中，我们表明，Notch信号控制GSC生态位的形成和维持，帽细胞有助于确定果蝇卵巢中的生态位大小。扩增的Notch激活导致形成更多的帽细胞和更大的小生境，其支持更多的GSC，而在小生境形成期间损害Notch信号传导减少帽细胞数量和小生境大小，并因此减少GSC数量。此外，位于远离其正常位置的小生境仍然可以通过维持高的局部BMP信号传导和抑制正常GSC中的bam来充分维持GSC自我更新。最后，成年人Notch功能的丧失导致GSC小生境的快速丧失，包括帽细胞和GSC。我们的研究结果表明，Notch信号是重要的GSC生态位的形成和维持，帽细胞有助于确定生态位的大小和功能。
Stem cells, which can self-renew and generate differentiated cells, have been shown to be controlled by surrounding microenvironments or niches in several adult tissues. However, it remains largely unknown what constitutes a functional niche and how niche formation is controlled. In the Drosophila ovary, germline stem cells (GSCs), which are adjacent to cap cells and two other cell types, have been shown to be maintained in the niche. In this study, we show that Notch signaling controls formation and maintenance of the GSC niche and that cap cells help determine the niche size in the Drosophila ovary. Expanded Notch activation causes the formation of more cap cells and bigger niches, which support more GSCs, whereas compromising Notch signaling during niche formation decreases the cap cell number and niche size and consequently the GSC number. Furthermore, the niches located away from their normal location can still sufficiently sustain GSC self-renewal by maintaining high local BMP signaling and repressing bam as in normal GSCs. Finally, loss of Notch function in adults results in rapid loss of the GSC niche, including cap cells and thus GSCs. Our results indicate that Notch signaling is important for formation and maintenance of the GSC niche, and that cap cells help determine niche size and function.