Insulin and Target of rapamycin signaling orchestrate the development of ovarian niche-stem cell units in Drosophila
Insulin and Target of rapamycin signaling orchestrate the development of ovarian niche-stem cell units in Drosophila
复制标题
DOI：
10.1242/dev.093773
复制
发表时间：
2013-10-15
期刊：
影响因子：
4.6
通讯作者：
Gilboa, Lilach
中科院分区：
文献类型：
--
作者：
Gancz, Dana;Gilboa, Lilach
组织特异性干细胞及其利基被组织成对外部提示做出反应的功能单元，以维持器官的动态平衡。胰岛素和雷帕霉素靶标(Tor)信号传递控制成体壁龛和干细胞的外部信号。这些途径是否在器官发生过程中建立生态位干细胞单元中发挥了作用还很少被探索。我们发现，在果蝇幼虫发育过程中，胰岛素样受体(INR)和Tor都参与了果蝇卵巢生态位和生殖系干细胞(GSCs)的建立。TOR和INR是细胞自主性地为体细胞壁龛和GSCs的前体增殖所必需的。这些途径也促进了顶丝(体细胞壁龛的一部分)的形成。值得注意的是，INR而不是Tor信号非自主地促进原始生殖细胞(PGC)分化。该途径的体细胞衰减延缓了PGC的分化，而它的激活导致了PGC的早熟分化。我们还表明，INR介导的PGC分化不依赖于躯体蜕皮激素信号，但进一步分化为包囊需要蜕皮激素的输入。这些结果表明，Tor和INR信号通过影响细胞数量和分化，积极参与卵巢壁龛和干细胞的形成。Tor和INR对体细胞和原核细胞的双重影响确保了这两个细胞群体的协调发展。我们的工作进一步确定了生殖细胞分化调控的新步骤，证明了在大理石表达之后，囊泡的形成需要额外的激素输入。
Tissue-specific stem cells and their niches are organized into functional units that respond to external cues in order to maintain organ homeostasis. Insulin and Target of rapamycin (Tor) signaling mediate external cues that control adult niches and stem cells. Whether these pathways play a role in the establishment of niche-stem cell units during organogenesis has been little explored. We show that during larval development both Insulin-like receptor (InR) and Tor participate in the establishment of ovarian niches and germline stem cells (GSCs) in Drosophila melanogaster. Tor and InR are required cell-autonomously for the proliferation of precursors for both somatic niches and GSCs. These pathways also promote the formation of terminal filaments (part of the somatic niche). Significantly, InR, but not Tor, signaling non-autonomously promotes primordial germ cell (PGC) differentiation. Somatic attenuation of the pathway retards PGC differentiation, whereas its activation results in their precocious differentiation. We also show that InR-mediated PGC differentiation is independent of somatic ecdysone signaling, but that further differentiation into cysts requires an ecdysone input. These results demonstrate that Tor and InR signaling actively participate in the formation of ovarian niches and stem cells by affecting both cell numbers and differentiation. The dual influence of Tor and InR on both somatic cells and PGCs ensures that these two cell populations develop coordinately. Our work further identifies a novel step in the regulation of germ cell differentiation by demonstrating that following bag of marbles expression, cyst formation requires an additional hormonal input.