The zinc finger protein DCM1 is required for male meiotic cytokinesis by preserving callose in rice

First author: Chao Zhang; Affiliations: Institute of Genetics and Developmental Biology, Chinese Academy of Sciences (中国科学院遗传与发育生物学研究所): Beijing, China

Corresponding author: Zhukuan Cheng 

Meiotic cytokinesis (减数分裂的胞质分裂) influences the fertility and ploidy of gametes (配子). However, limited information is available on the genetic control of meiotic cytokinesis in plants. Here, we identified a rice mutant with low male fertility, defective callose in meiosis 1 (dcm1). The pollen grains of dcm1 are proved to be defective in exine (花粉粒外壁) formation. Meiotic cytokinesis is disrupted in dcm1, resulting in disordered spindle (纺锤体) orientation during meiosis II and formation of pollen grains with varied size and DNA content. We demonstrated that meiotic cytokinesis defect in dcm1 is caused by prematurely (过早地) dissolution of callosic plates (胼胝质板). Furthermore, peripheral callose surrounding the dcm1 pollen mother cells (PMCs) also disappeared untimely (不合时宜地) around pachytene (粗线期). The DCM1 protein contains five tandem CCCH motifs and interacts with nuclear poly (A) binding proteins (PABNs) in nuclear speckles (核散斑体). The expression profiles of genes related to callose synthesis and degradation are significantly modified in dcm1. Together, we propose that DCM1 plays an essential role in male meiotic cytokinesis by preserving callose from prematurely dissolution in rice.

减数分裂的胞质分裂影响配子的育性和倍性。然而，对于植物中有关减数分裂的胞质分裂的遗传调控机制我们还所知甚少。本文中，作者鉴定了一个雄性育性较低的水稻突变体，叫做dcm1。该突变体的花粉粒在花粉粒外壁的形成方面存在缺陷。在dcm1突变体中，减数分裂的胞质分裂被破坏，导致了减数分裂II期的纺锤体方向混乱，并形成了不同大小和DNA含量的花粉粒。dcm1突变体中减数分裂的胞质分裂缺陷是由胼胝质板过早解体所导致的。此外，dcm1突变体花粉母细胞周围所包裹的胼胝质同样在粗线期提前消失。DCM1蛋白包含5个串联的CCCH基序，在核散斑体中与PABN蛋白互作。与胼胝质合成和降解相关的基因表达谱在dcm1突变体中发生显著的变化。综上，作者在本文中提出水稻DCM1通过防止胼胝质过早降解而在雄性减数分裂的胞质分裂中发挥重要作用。

通讯：程祝宽  (http://sourcedb.genetics.cas.cn/zw/zjrck/200907/t20090721_2130988.html)

个人简介：1987年，扬州大学农学系，农学学士；1990年，扬州大学农学系，作物遗传育种硕士；1999年，中国科学院遗传研究所，理学博士；1999-2002年，美国Wisconsin-Madison大学，博士后。

研究方向：植物减数分裂的遗传调控机制。

doi: https://doi.org/10.1371/journal.pgen.1007769

Journal: PLOS Genetics

Published date: 12 November, 2018