Proper positioning of cells is essential for many aspects of development. Daughter cell positions can be specified via orienting the cell division axis during cytokinesis. Rotatory actomyosin flows during division have been implied in specifying and reorienting the cell division axis, but how general such reorientation events are, and how they are controlled, remains unclear. We followed the first nine divisions of Caenorhabditis elegans embryo development and demonstrate that chiral counter-rotating flows arise systematically in early AB lineage, but not in early P/EMS lineage cell divisions. Combining our experiments with thin film active chiral fluid theory we identify a mechanism by which chiral counter-rotating actomyosin flows arise in the AB lineage only, and show that they drive lineage-specific spindle skew and cell reorientation events. In conclusion, our work sheds light on the physical processes that underlie chiral morphogenesis in early development.

中文翻译：

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细胞谱系依赖性手性肌动球蛋白流驱动早期秀丽隐杆线虫发育中的细胞重排

细胞的正确定位对于发育的许多方面都是必不可少的。子细胞位置可以通过在胞质分裂期间定向细胞分裂轴来指定。分裂过程中的旋转肌动球蛋白流动暗示了细胞分裂轴的指定和重新定向，但这种重新定向事件有多普遍，以及它们是如何控制的，仍不清楚。我们跟踪了秀丽隐杆线虫胚胎发育的前九个分裂，并证明手性反向旋转流在早期 AB 谱系中系统地出现，但在早期 P/EMS 谱系细胞分裂中没有。将我们的实验与薄膜活性手性流体理论相结合，我们确定了手性反向旋转肌动球蛋白流仅在 AB 谱系中出现的机制，并表明它们驱动谱系特异性纺锤体偏斜和细胞重新定向事件。