胞质分裂（一个母细胞分裂成两个分开的子细胞的过程）机制的研究，经常关注的是可收缩的肌动球蛋白环在细胞（球体）赤道上的作用。Ewa Paluch及其同事则是研究胞质分裂过程中细胞两极的肌动球蛋白皮层的机械作用。
他们发现，一个可收缩的两极皮层的存在，使得胞质分裂成为一个具有固有不稳定性的过程，它能导致收缩环的位置不准。他们提出，形成分裂中的细胞的两极的膜泡，能通过释放皮层的收缩性来稳定其位置。
这些发现揭示了一个正在分裂中的细胞在形状上的一个固有的不稳定性，也显示了可帮助限制形状不稳定性的一个新机制。
生物探索推荐英文论文摘要：
Polar actomyosin contractility destabilizes the position of the cytokinetic furrow
Cytokinesis, the physical separation of daughter cells at the end of mitosis, requires precise regulation of the mechanical properties of the cell periphery. Although studies of cytokinetic mechanics mostly focus on the equatorial constriction ring a contractile actomyosin cortex is also present at the poles of dividing cells. Whether polar forces influence cytokinetic cell shape and furrow positioning remains an open question. Here we demonstrate that the polar cortex makes cytokinesis inherently unstable. We show that limited asymmetric polar contractions occur during cytokinesis, and that perturbing the polar cortex leads to cell shape oscillations, resulting in furrow displacement and aneuploidy. A theoretical model based on a competition between cortex turnover and contraction dynamics accurately accounts for the oscillations. We further propose that membrane blebs, which commonly form at the poles of dividing cells5 and whose role in cytokinesis has long been enigmatic, stabilize cell shape by acting as valves releasing cortical contractility. Our findings reveal an inherent instability in the shape of the dividing cell and unveil a novel, spindle-independent mechanism ensuring the stability of cleavage furrow positioning.
