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) histories 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 chrometids are specifically recognized and segregated. Here, we discuss recent advances our under standing of the molecular mechanisms and cellular bases underlying these fund - one important biological processes responsible for generating two distinct cells through one cell division.
展开▼
机译:非对称网球拍或其他球拍-球拍的中线纵轴的每一侧都有不同宽度的拍头,且球拍的厚度不同。AB FR2691073A该球拍的手柄(4)沿球头的中纵轴排列。轴将头部分为左右两部分(7,8)。在垂直于轴线的每个侧向平面中,左侧部分(8)比右侧部分(7)宽。磁头左侧的最大厚度(L2)大于右侧的最小厚度(L3)。最大厚度大于手柄的厚度(L1),最小厚度小于此值。框架的左侧比右侧更厚。用途/优势-用于网球和类似运动的不对称球拍有利于将热量与地面成直角放置。 AN 93407774 TI内置磁罗经的滑雪杖-包括空心金属管(续)。带有塞子的指南针,用于覆盖wri附近的顶部开口