Center for Regenerative Therapies Dresden (CRTD.
Development. 2012 Aug;139(15):2663-9. doi: 10.1242/dev.075242. Epub 2012 Jun 28.
In the Drosophila testis, germline stem cells (GSCs) and somatic cyst stem cells (CySCs) are arranged around a group of postmitotic somatic cells, termed the hub, which produce a variety of growth factors contributing to the niche microenvironment that regulates both stem cell pools. Here we show that CySC but not GSC maintenance requires Hedgehog (Hh) signalling in addition to Jak/Stat pathway activation. CySC clones unable to transduce the Hh signal are lost by differentiation, whereas pathway overactivation leads to an increase in proliferation. However, unlike cells ectopically overexpressing Jak/Stat targets, the additional cells generated by excessive Hh signalling remain confined to the testis tip and retain the ability to differentiate. Interestingly, Hh signalling also controls somatic cell populations in the fly ovary and the mammalian testis. Our observations might therefore point towards a higher degree of organisational homology between the somatic components of gonads across the sexes and phyla than previously appreciated.
在果蝇的睾丸中，生殖干细胞（GSCs）和体腔干细胞（CySCs）围绕着一群有丝分裂后体细胞，称为中心体，这些体细胞产生多种生长因子，有助于调节干细胞池的小生境微环境。在这里，我们表明 CySC 的维持不仅需要 Hedgehog（Hh）信号通路，还需要 Jak/Stat 通路的激活。不能转导 Hh 信号的 CySC 克隆会通过分化丢失，而通路的过度激活会导致增殖增加。然而，与异位过表达 Jak/Stat 靶标的细胞不同，过多的 Hh 信号产生的额外细胞仍然局限于睾丸顶端，并保持分化能力。有趣的是，Hh 信号通路也控制着果蝇卵巢和哺乳动物睾丸中的体细胞群。因此，我们的观察结果可能表明，两性和各门类动物的性腺体成分在组织同源性方面比以前认为的要高。
