State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University, Shanghai, 200438, China.
Shanghai Chenshan Plant Science Research Center, Chinese Academy of Sciences, Chenshan Botanical Garden, Shanghai, 201602, China.
New Phytol. 2019 Oct;224(1):229-241. doi: 10.1111/nph.16014. Epub 2019 Jul 24.
Faithful chromosome segregation is required for both mitotic and meiotic cell divisions and is regulated by multiple mechanisms including the anaphase-promoting complex/cyclosome (APC/C), which is the largest known E3 ubiquitin-ligase complex and has been implicated in regulating chromosome segregation in both mitosis and meiosis in animals. However, the role of the APC/C during plant meiosis remains largely unknown. Here, we show that Arabidopsis APC8 is required for male meiosis. We used a combination of genetic analyses, cytology and immunolocalisation to define the function of AtAPC8 in male meiosis. Meiocytes from apc8-1 plants exhibit several meiotic defects including improper alignment of bivalents at metaphase I, unequal chromosome segregation during anaphase II, and subsequent formation of polyads. Immunolocalisation using an antitubulin antibody showed that APC8 is required for normal spindle morphology. We also observed mitotic defects in apc8-1, including abnormal sister chromatid segregation and microtubule morphology. Our results demonstrate that Arabidopsis APC/C is required for meiotic chromosome segregation and that APC/C-mediated regulation of meiotic chromosome segregation is a conserved mechanism among eukaryotes.
有丝分裂和减数分裂都需要忠实的染色体分离，这是由多种机制调控的，包括后期促进复合物/周期蛋白（APC/C），它是已知最大的 E3 泛素连接酶复合物，已被牵涉到在动物的有丝分裂和减数分裂中调控染色体分离。然而，APC/C 在植物减数分裂中的作用在很大程度上仍然未知。在这里，我们表明拟南芥 APC8 是减数分裂所必需的。我们使用遗传分析、细胞学和免疫定位的组合来定义 AtAPC8 在雄性减数分裂中的功能。apc8-1 植物的减数分裂细胞表现出几种减数分裂缺陷，包括在中期 I 时二价体不正确排列、后期 II 时染色体不均匀分离，以及随后形成多联体。使用抗微管蛋白抗体的免疫定位显示 APC8 是正常纺锤体形态所必需的。我们还观察到 apc8-1 中的有丝分裂缺陷，包括异常的姐妹染色单体分离和微管形态。我们的结果表明，拟南芥 APC/C 是减数分裂染色体分离所必需的，并且 APC/C 介导的减数分裂染色体分离的调节是真核生物中的一种保守机制。
