Epigenetic mechanisms play essential roles in determining distinct cell fates during the development of multicellular organisms. Histone proteins represent crucial epigenetic components that help specify cell identities. Previous work has demonstrated that during the asymmetric cell division of Drosophila male germline stem cells (GSCs), histones H3 and H4 are asymmetrically inherited, such that pre-existing (old) histones are segregated towards the self-renewing GSC whereas newly synthesized (new) histones are enriched towards the differentiating daughter cell. In order to further understand the molecular mechanisms underlying this striking phenomenon, two key questions must be answered: when and how old and new histones are differentially incorporated by sister chromatids, and how epigenetically distinct sister chromatids are specifically recognized and segregated. Here, we discuss recent advances in our understanding of the molecular mechanisms and cellular bases underlying these fundamental and important biological processes responsible for generating two distinct cells through one cell division.

中文翻译：

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不对称分裂干细胞中的不对称组蛋白遗传。

表观遗传机制在确定多细胞生物发育过程中不同的细胞命运中起着至关重要的作用。组蛋白代表重要的表观遗传成分，可帮助确定细胞身份。先前的研究表明，在果蝇雄性种系干细胞（GSCs）的不对称细胞分裂过程中，组蛋白H3和H4不对称地遗传，因此先前存在的（旧）组蛋白被隔离到自我更新的GSC上，而新合成的（新）组蛋白向分化的子细胞富集。为了进一步了解这种惊人现象的分子机制，必须回答两个关键问题：姐妹染色单体何时以及如何差异结合新旧组蛋白，以及如何在表观遗传学上区分姐妹染色单体，以及如何对其进行分离。在这里，我们讨论了对这些分子机制和细胞基础的了解的最新进展，这些分子机制和细胞基础是这些基本和重要的生物学过程的基础，这些过程通过一个细胞分裂产生两个不同的细胞。