Shape Transformation of the Nuclear Envelope during Closed Mitosis.
Shape Transformation of the Nuclear Envelope during Closed Mitosis.
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DOI：
10.1016/j.bpj.2016.10.004
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发表时间：
2016-11
影响因子：
3.4
通讯作者：
Qian Zhu;Fan Zheng;Allen P. Liu;J. Qian;Chuanhai Fu;Yuan Lin
中科院分区：
文献类型：
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作者：
Qian Zhu;Fan Zheng;Allen P. Liu;J. Qian;Chuanhai Fu;Yuan Lin
在较低等的真核生物如粟酒裂殖酵母的有丝分裂过程中，核膜的形态发生了很大的变化。然而，哪些物理参数在控制NE的形状演变中是重要的，以及分裂染色体/微管中的缺陷如何反映在这些参数中，是尚未解决的基本问题。在这项研究中，我们表明，在遗传缺陷细胞染色体分离不当导致膜束缚或不对称分裂，在野生型细胞中形成两个相等大小的子核。我们推测，向极力传递到核膜通过其物理接触分离的姐妹染色单体在两个纺锤体极。一个理论模型的开发，以预测的NE的形态演变的关键因素，如所做的工作，由向极力和弯曲和表面能量存储在膜中已被考虑在内。有趣的是，预测的相图，总结了核形状对负载传输区域的大小的依赖性，以及极-极距离与表面积的关系，都与我们的实验观察定量一致，这表明该模型捕捉到了封闭有丝分裂中所涉及的基本物理。
The nuclear envelope (NE) in lower eukaryotes such asSchizosaccharomyces pombeundergoes large morphology changes during closed mitosis. However, which physical parameters are important in governing the shape evolution of the NE, and how defects in the dividing chromosomes/microtubules are reflected in those parameters, are fundamental questions that remain unresolved. In this study, we show that improper separation of chromosomes in genetically deficient cells leads to membrane tethering or asymmetric division in contrast to the formation of two equal-sized daughter nuclei in wild-type cells. We hypothesize that the poleward force is transmitted to the nuclear membrane through its physical contact with the separated sister chromatids at the two spindle poles. A theoretical model is developed to predict the morphology evolution of the NE where key factors such as the work done by the poleward force and bending and surface energies stored in the membrane have been taken into account. Interestingly, the predicted phase diagram, summarizing the dependence of nuclear shape on the size of the load transmission regions, and the pole-to-pole distance versus surface area relationship all quantitatively agree well with our experimental observations, suggesting that this model captures the essential physics involved in closed mitosis.