Arabidopsis Cell Division Cycle 20.1 Is Required for Normal Meiotic Spindle Assembly and Chromosome Segregation
Arabidopsis Cell Division Cycle 20.1 Is Required for Normal Meiotic Spindle Assembly and Chromosome Segregation
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拟南芥细胞分裂周期 20.1 是正常减数分裂纺锤体组装和染色体分离所必需的。
DOI：
10.1105/tpc.15.00834
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发表时间：
2015-12-01
期刊：
影响因子：
11.6
通讯作者：
Wang, Yingxiang
中科院分区：
文献类型：
--
作者：
Niu, Baixiao;Wang, Liudan;Wang, Yingxiang
细胞分裂需要合适的纺锤体组装；纺锤体组装检查点（SAC）监测纺锤体是否正常并正确连接到着丝点。SAC蛋白通过影响CDC20（细胞分裂周期20）功能调节有丝分裂染色体分离。然而，CDC20是否调控减数分裂纺锤体组装和适当的同源分离尚不清楚。在这里，我们发现拟南芥CDC20.1基因在减数分裂和雄性生殖中是不可或缺的。我们证明cdc20.1减数分裂染色体不同步排列和不均匀分离，中期I纺锤体有异常形态。通过比较野生型和cdc20.1的减数分裂阶段在不同时间点的分布，可以发现cdc20.1减数分裂过程从早期到后期i的延迟。此外，cdc20.1减数分裂细胞中出现了由极光激酶介导的组蛋白H3磷酸化标记的异常分布，这表明cdc20.1在减数分裂染色体分离中调节极光定位。减数分裂特异性敲低At-Aurora1表达，导致与CDC20.1类似的减数分裂染色体分离缺陷，进一步证明CDC20.1和Aurora在功能上相关。综上所述，这些结果表明CDC20.1在sac依赖性减数分裂染色体分离中起关键作用。
Cell division requires proper spindle assembly; a surveillance pathway, the spindle assembly checkpoint (SAC), monitors whether the spindle is normal and correctly attached to kinetochores. The SAC proteins regulate mitotic chromosome segregation by affecting CDC20 (Cell Division Cycle 20) function. However, it is unclear whether CDC20 regulates meiotic spindle assembly and proper homolog segregation. Here, we show that the Arabidopsis thaliana CDC20.1 gene is indispensable for meiosis and male fertility. We demonstrate that cdc20.1 meiotic chromosomes align asynchronously and segregate unequally and the metaphase I spindle has aberrant morphology. Comparison of the distribution of meiotic stages at different time points between the wild type and cdc20.1 reveals a delay of meiotic progression from diakinesis to anaphase I. Furthermore, cdc20.1 meiocytes exhibit an abnormal distribution of a histone H3 phosphorylation mark mediated by the Aurora kinase, providing evidence that CDC20.1 regulates Aurora localization for meiotic chromosome segregation. Further evidence that CDC20.1 and Aurora are functionally related was provided by meiosis-specific knockdown of At-Aurora1 expression, resulting in meiotic chromosome segregation defects similar to those of cdc20.1. Taken together, these results suggest a critical role for CDC20.1 in SAC-dependent meiotic chromosome segregation.