Replication protein A large subunit (RPA1a) limits chiasma formation during rice meiosis.
Replication protein A large subunit (RPA1a) limits chiasma formation during rice meiosis.
复制标题
DOI：
10.1093/plphys/kiab365
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发表时间：
2021-08
期刊：
影响因子：
7.4
通讯作者：
Yongjie Miao;Wenqing Shi;Hongjun Wang;Z. Xue;Hanli You;Fanfan Zhang;Guijie Du;Ding Tang;Yafei Li;Yi Shen;Zhukuan Cheng
中科院分区：
文献类型：
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作者：
Yongjie Miao;Wenqing Shi;Hongjun Wang;Z. Xue;Hanli You;Fanfan Zhang;Guijie Du;Ding Tang;Yafei Li;Yi Shen;Zhukuan Cheng
复制蛋白A（RPA）是一种单链DNA结合蛋白，在同源重组中起重要作用。然而，由于RPA的缺失会导致哺乳动物的胚胎死亡，RPA在减数分裂中的确切功能仍不清楚。本研究利用CRISPR/Cas9技术构建了rpa 1a突变体，并探讨了其在水稻减数分裂中的功能。在rpa 1a中，与野生型一样，在中期I形成12个二价体，但在后期I始终观察到染色体片段化。荧光原位杂交分析表明，这些片段化是由于重组中间体未能解决。重要的是，突变体具有高度升高的交叉数，并且RPA 1a的缺失可以完全恢复zmm（对于ZIP 1 -4、MSH 4/5和MER 3）突变体背景中的12个二价形成。蛋白质-蛋白质相互作用分析表明，RPA 1a与甲磺酸甲酯和UV敏感的81（以及范可尼贫血互补群M-Bloom综合征蛋白同源物（RECQ 4A）-拓扑异构酶3 α-RecQ介导的基因组不稳定性1）形成复合物，调节交叉形成和重组中间体的加工。因此，我们的数据建立了一个关键的作用，RPA 1a在促进重组中间体的准确分辨率和限制冗余的交叉形成在水稻减数分裂。
Replication protein A (RPA), a single-stranded DNA-binding protein, plays essential role in homologous recombination. However, because deletion of RPA causes embryonic lethality in mammals, the exact function of RPA in meiosis remains unclear. In this study, we generated an rpa1a mutant using CRISPR/Cas9 technology and explored its function in rice (Oryza sativa) meiosis. In rpa1a, 12 bivalents were formed at metaphase I, just like in wild-type, but chromosome fragmentations were consistently observed at anaphase I. Fluorescence in situ hybridization assays indicated that these fragmentations were due to the failure of the recombination intermediates to resolve. Importantly, the mutant had a highly elevated chiasma number, and loss of RPA1a could completely restore the 12 bivalent formations in the zmm (for ZIP1-4, MSH4/5, and MER3) mutant background. Protein-protein interaction assays showed that RPA1a formed a complex with the methyl methansulfonate and UV sensitive 81 (and the Fanconi anemia complementation group M-Bloom syndrome protein homologs (RECQ4A)-Topoisomerase3α-RecQ-mediated genome instability 1 complex to regulate chiasma formation and processing of the recombination intermediates. Thus, our data establish a pivotal role for RPA1a in promoting the accurate resolution of recombination intermediates and in limiting redundant chiasma formation during rice meiosis.