Miranda directs Prospero to a daughter cell during Drosophila asymmetric divisions
Miranda directs Prospero to a daughter cell during Drosophila asymmetric divisions
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DOI：
10.1038/37641
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发表时间：
1997-12-11
期刊：
影响因子：
64.8
通讯作者：
Matsuzaki, F
中科院分区：
文献类型：
--
作者：
IkeshimaKataoka, H;Skeath, JB;Matsuzaki, F
不对称细胞分裂是在许多发育过程中普遍使用的一种过程，用于从单个祖细胞产生两个命运不同的细胞。细胞分裂过程中命运决定因子的不对称传递等内在机制以及细胞间相互作用的外在机制，都可以介导不对称分裂（1 - 3）。在果蝇中枢神经系统的胚胎发育过程中，被称为成神经细胞的神经干细胞进行不对称分裂，产生另一个多能性的成神经细胞和一个发育潜能更受限的神经节母细胞（GMC）。内在机制促进成神经细胞的不对称分裂：例如，转录因子Prospero定位于有丝分裂成神经细胞的基底细胞皮质，然后专门分离进入从成神经细胞基底侧长出的GMC（4 - 6）。在GMC中，Prospero转移到细胞核，在那里它在姐妹细胞之间建立差异基因表达。在此我们报道了一个基因miranda的鉴定，它编码一种新的蛋白质，这种蛋白质在有丝分裂的成神经细胞中与Prospero共定位，将Prospero束缚在有丝分裂成神经细胞的基底皮质，引导Prospero进入GMC，并在GMC内将Prospero从细胞皮质释放。因此，miranda通过在神经干细胞分裂过程中调节转录因子仅不对称地分离到一个子细胞中，从而在姐妹细胞之间产生内在差异。
Asymmetric cell division is a general process used in many developmental contexts to create two differently fated cells from a single progenitor cell. Intrinsic mechanisms like the asymmetric transmission of tell-fate determinants during cell division, and extrinsic cell-interaction mechanisms, can mediate asymmetric divisions(1-3). During embryonic development of the Drosophila central nervous system, neural stem cells called neuroblasts divide asymmetrically to produce another multipotent neuroblast and a ganglion mother cell (GMC) of more restricted developmental potential. Intrinsic mechanisms promote asymmetric division of neuroblasts: for example, the transcription factor Prospero localizes to the basal cell cortex of mitotic neuroblasts and then segregates exclusively into the GMC, which buds off from the basal side of the neuroblast(4-6). In the GMC, Prospero translocates to the nucleus, where it establishes differential gene expression between sibling cells. Here we report the identification of a gene, miranda, which encodes a new protein that co-localizes with Prospero in mitotic neuroblasts, tethers Prospero to the basal cortex of mitotic neuroblasts, directing Prospero into the GMC, and releases Prospero from the cell cortex within GMCs. miranda thus creates intrinsic differences between sibling cells by mediating the asymmetric segregation of a transcription factor into only one daughter cell during neural stem-cell division.