Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
Biotechnology Center, TU Dresden, Dresden, Germany.
Elife. 2020 Jul 9;9:e54930. doi: 10.7554/eLife.54930.
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 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.
细胞的正确定位对于发育的许多方面都是至关重要的。通过在胞质分裂过程中定向细胞分裂轴，子细胞的位置可以被指定。分裂过程中旋转的肌动球蛋白流被暗示在指定和重新定向细胞分裂轴方面发挥作用，但这种重新定向事件有多普遍，以及它们是如何被控制的，仍然不清楚。我们跟踪了胚胎发育的前九次分裂，并证明在早期 AB 谱系中系统地出现了手性反向旋转流，但在早期 P/EMS 谱系细胞分裂中没有出现。将我们的实验与薄膜活性手性流体理论相结合，我们确定了一种机制，在手性反向旋转肌动球蛋白流仅在 AB 谱系中产生，并表明它们驱动谱系特异性纺锤体倾斜和细胞重定向事件。总之，我们的工作揭示了早期发育中手性形态发生的物理过程。
