Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA.
Curr Biol. 2011 Mar 22;21(6):485-91. doi: 10.1016/j.cub.2011.02.002. Epub 2011 Mar 3.
Animal development requires tight integration between the processes of proliferative growth and epithelial morphogenesis, both of which play out at the level of individual cells. In this respect, not only must polarized epithelial cells assume complex morphologies, these distinct forms must be radically and repeatedly transformed to permit mitosis. A dramatic illustration of this integration between epithelial morphogenesis and cell proliferation is interkinetic nuclear migration (IKNM), wherein the nuclei of pseudostratified epithelial cells translocate to the apical epithelial surface to execute cell division. IKNM is widely considered a hallmark of pseudostratified vertebrate neuroepithelia, and prior investigations have proposed both actomyosin- and microtubule-dependent mechanisms for apical localization of the mitotic nucleus. Here, using comparative functional analysis in arthropod and cnidarian systems (Drosophila melanogaster and Nematostella vectensis), we show that actomyosin-dependent IKNM is likely to be a general feature of mitosis in pseudostratified epithelia throughout Eumetazoa. Furthermore, our studies suggest a mechanistic link between IKNM and the fundamental process of mitotic cell rounding.
动物的发育需要增殖生长和上皮形态发生过程的紧密整合，这两个过程都在单个细胞的水平上发挥作用。在这方面，极化的上皮细胞不仅必须呈现出复杂的形态，而且这些不同的形态必须被彻底和反复地改变以允许有丝分裂。上皮形态发生和细胞增殖之间这种整合的一个显著例子是核周运动（IKNM），其中假复层上皮细胞的核迁移到上皮表面的顶端以进行细胞分裂。IKNM 被广泛认为是假复层脊椎动物神经上皮的标志，先前的研究提出了肌动球蛋白和微管依赖性机制，用于有丝分裂核的顶端定位。在这里，我们使用节肢动物和刺胞动物系统（黑腹果蝇和 Nematostella vectensis）的比较功能分析，表明肌动球蛋白依赖性 IKNM 可能是整个后生动物中假复层上皮有丝分裂的一个普遍特征。此外，我们的研究还表明 IKNM 与有丝分裂细胞变圆的基本过程之间存在机制联系。
