神经祖细胞不对称分裂中纺锤体取向与细胞皮层极性的偶联机制

The Coupling Mechanisms of Spindle Orientation and Cell Cortical Polarity in Asymmetric Cell Divisions of Neural Progenitors

神经祖细胞的不对称分裂是神经发生的必要环节。近年来关于不对称分裂的研究,为果蝇及哺乳动物中枢神经系统发育期间神经祖细胞的分化机制提供了新的理解。在这一分裂模式中,纺锤体作为细胞结构的支架,受到细胞皮层极性信号的引导而改变取向,保证底部细胞命运决定子(cell fate determinants)的不对称分配。G蛋白亚基、各种接头蛋白及微管相关蛋白组成极性蛋白复合体,在纺锤体取向改变中发挥了有序的调节作用。现在细胞和分子水平探讨不对称分裂纺锤体与细胞皮层极性偶联这一标志性事件。

Asymmetric cell division of neural progenitor cells functions as a prerequisite for neurogenesis. Elegant studies in this field over recent years have shed new light on the pathways whereby neural progenitor cells differentiate during the development of Drosophila and mammalian central nervous system. The orientation of mitotic spindle, a key cellular scaffold, is induced by cell cortical polarity, and therefore ensures preferential distributions of cell fate determinants in the basal part. This process is sequentially regulated by polarized protein complexes consisting of G-protein subunits, distinct adaptor proteins and microtubule-associated proteins. Here we discuss the coupling of spindle orientation and cell cortical polarity, a hallmark of this unique pattern of cell division, on both cellular and molecular levels.