小分子RNA决定果蝇生殖干细胞命运的分子机制研究

The fate determination of Drosophila germline stem cells regulated by small RNAs

生殖干细胞是具有自我更新能力的一群生殖细胞,充当配子生成的源泉。果蝇生殖干细胞的特征在于通过不对称分裂产生两个子代细胞,一个通过自我更新维持干细胞特性,另一个则进行分化。生殖干细胞的命运受其周围的微环境——"干细胞niche"控制,而"niche"的功能又通过干细胞的外源和内源信号间的相互作用来完成。小分子RNA通过复杂的RNAi途径调控基因的表达。大量证据表明生殖干细胞的维持和分化需要小分子RNA参与,小分子RNA生成的紊乱会导致干细胞的"丢失"或"未分化"。该文综述了小分子RNA对果蝇生殖干细胞命运调控的研究进展,并讨论新发现的小分子RNA在生殖干细胞命运决定中的相关功能。

The Germline stem cell（GSC） is the special type of adult stem cells that has the unique capacity to self-renew as well as function as the source of gametogenesis that can pass genetic information to the next generation.In Drosophila,a GSC undergoes self-renewal and asymmetric division to produce two daughter cells with distinct fate： one self-renewal cell and the other differentiated cell.The asymmetric division of GSCs is tightly controlled by the stromal cells（also called microenviroment or niche）,which regulate the fate of GSCs through the integra-tion of both extrinsic and intrinsic signaling at multiple levels.Increasingly complex networks of small RNAs act through RNA interference pathway to regulate gene expression.Recent studies suggest that both self-renewal and differentiation of GSCs require intricate spatiotemporal expression of a wide repertoire of small regulatory RNAs.Misregulation of these small RNAs gives rise to either ＂lose＂ or ＂over-proliferation＂ of GSCs.Here,we will review recent progresses made toward understanding roles of small regulatory RNAs in the fate determina-tion of GSCs and discuss the potential involvement of newly discovered classes of small RNAs in the fate determination of GSCs.