Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan 610065, China.
Sugashima Marine Biological Laboratory, Graduate School of Science, Nagoya University, Toba 517-0004, Japan.
Plant Cell. 2022 May 24;34(6):2120-2139. doi: 10.1093/plcell/koac069.
During development, both animals and plants exploit asymmetric cell division (ACD) to increase tissue complexity, a process that usually generates cells dissimilar in size, morphology, and fate. Plants lack the key regulators that control ACD in animals. Instead, plants have evolved two unique cytoskeletal structures to tackle this problem: the preprophase band (PPB) and phragmoplast. The assembly of the PPB and phragmoplast and their contributions to division plane orientation have been extensively studied. However, how the division plane is positioned off the cell center during asymmetric division is poorly understood. Over the past 20 years, emerging evidence points to a critical role for polarly localized membrane proteins in this process. Although many of these proteins are species- or cell type specific, and the molecular mechanism underlying division asymmetry is not fully understood, common features such as morphological changes in cells, cytoskeletal dynamics, and nuclear positioning have been observed. In this review, we provide updates on polarity establishment and nuclear positioning during ACD in plants. Together with previous findings about symmetrically dividing cells and the emerging roles of developmental cues, we aim to offer evolutionary insight into a common framework for asymmetric division-site determination and highlight directions for future work.
在发育过程中，动物和植物都利用不对称细胞分裂（ACD）来增加组织复杂性，这一过程通常会产生大小、形态和命运不同的细胞。植物缺乏控制动物 ACD 的关键调节因子。相反，植物已经进化出两种独特的细胞骨架结构来解决这个问题：前期带（PPB）和纺锤体。PPB 和纺锤体的组装及其对分裂面定向的贡献已得到广泛研究。然而，在不对称分裂过程中，细胞中心以外的分裂面是如何定位的，目前还知之甚少。在过去的 20 年中，新出现的证据表明极性定位的膜蛋白在这个过程中起着关键作用。尽管这些蛋白质中的许多都是物种或细胞类型特异性的，而且细胞不对称分裂的分子机制尚不完全清楚，但已经观察到了一些共同特征，如细胞形态变化、细胞骨架动力学和核定位。在这篇综述中，我们提供了关于植物 ACD 过程中极性建立和核定位的最新进展。结合之前关于对称分裂细胞的发现和新兴的发育线索的作用，我们旨在为不对称分裂位点确定的共同框架提供进化见解，并强调未来工作的方向。
