Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.
Department of Pathology, University of Southern California, Keck School of Medicine, Los Angeles, United States.
Elife. 2017 Oct 10;6:e23279. doi: 10.7554/eLife.23279.
Both oriented cell divisions and cell rearrangements are critical for proper embryogenesis and organogenesis. However, little is known about how these two cellular events are integrated. Here we examine the linkage between these processes in chick limb cartilage. By combining retroviral-based multicolor clonal analysis with live imaging, the results show that single chondrocyte precursors can generate both single-column and multi-column clones through oriented division followed by cell rearrangements. Focusing on single column formation, we show that this stereotypical tissue architecture is established by a pivot-like process between sister cells. After mediolateral cell division, N-cadherin is enriched in the post-cleavage furrow; then one cell pivots around the other, resulting in stacking into a column. Perturbation analyses demonstrate that planar cell polarity signaling enables cells to pivot in the direction of limb elongation via this N-cadherin-mediated coupling. Our work provides new insights into the mechanisms generating appropriate tissue architecture of limb skeleton.
定向细胞分裂和细胞重排对于胚胎发生和器官发生至关重要。然而，人们对这两个细胞事件如何整合知之甚少。在这里，我们检查了鸡翅膀软骨中这两个过程之间的联系。通过将基于逆转录病毒的多色克隆分析与实时成像相结合，结果表明单个软骨细胞前体可以通过定向分裂和细胞重排产生单柱和多柱克隆。关注单柱形成，我们表明这种典型的组织结构是通过姐妹细胞之间的枢轴样过程建立的。在中侧细胞分裂后，N-钙粘蛋白在分裂沟后富集；然后一个细胞围绕另一个细胞枢转，导致堆叠成一个柱。扰动分析表明，通过这种 N-钙粘蛋白介导的偶联，平面细胞极性信号使细胞能够沿着肢体伸长的方向枢转。我们的工作为生成适当的肢体骨骼组织结构的机制提供了新的见解。
