Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine and the Penn Institute for Regenerative Medicine, Philadelphia, PA 19104-6048, USA.
Development. 2011 May;138(9):1687-96. doi: 10.1242/dev.057364.
To function properly, tissue-specific stem cells must reside in a niche. The Drosophila testis niche is one of few niches studied in vivo. Here, a single niche, comprising ten hub cells, maintains both germline stem cells (GSC) and somatic stem cells (CySC). Here, we show that lines is an essential CySC factor. Surprisingly, lines-depleted CySCs adopted several characteristics of hub cells, including the recruitment of new CySCs. This led us to examine the developmental relationship between CySCs and hub cells. In contrast to a previous report, we did not observe significant conversion of steady-state CySC progeny to hub fate. However, we found that these two cell types derive from a common precursor pool during gonadogenesis. Furthermore, lines mutant embryos exhibited gonads containing excess hub cells, indicating that lines represses hub cell fate during gonadogenesis. In many tissues, lines acts antagonistically to bowl, and we found that this is true for hub specification, establishing bowl as a positively acting factor in the development of the testis niche.
为了正常运作，组织特异性干细胞必须存在于特定的微环境中。果蝇睾丸微环境是少数在体内研究过的微环境之一。在这里，一个由十个枢纽细胞组成的单一微环境维持着生殖干细胞（GSC）和体干细胞（CySC）。在这里，我们表明 Lines 是 CySC 的一个必需因子。令人惊讶的是，Lines 耗尽的 CySCs 采用了几个枢纽细胞的特征，包括招募新的 CySCs。这促使我们研究 CySCs 和枢纽细胞之间的发育关系。与之前的报告相反，我们没有观察到稳态 CySC 后代向枢纽命运的显著转化。然而，我们发现这两种细胞类型在性腺发生过程中来自于一个共同的前体细胞池。此外，Lines 突变体胚胎的性腺中含有过多的枢纽细胞，表明 Lines 在性腺发生过程中抑制了枢纽细胞命运。在许多组织中，Lines 与 bowl 呈拮抗作用，我们发现这在枢纽细胞的特化中也是如此，从而确立了 bowl 在睾丸微环境发育中的正向作用因子。
