Hu Qing, Li Yafei, Wang Hongjun, Shen Yi, Zhang Chao, Du Guijie, Tang Ding, Cheng Zhukuan
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Plant Cell. 2017 Jul;29(7):1697-1708. doi: 10.1105/tpc.17.00241. Epub 2017 Jul 10.
Homologous recombination plays a central role in guaranteeing chromosome segregation during meiosis. The precise regulation of the resolution of recombination intermediates is critical for the success of meiosis. Many proteins, including the RECQ DNA helicases (Sgs1/BLM) and Topoisomerase 3α (TOP3α), have essential functions in managing recombination intermediates. However, many other factors involved in this process remain to be defined. Here, we report the isolation of meiotic chromosome association 1 (MEICA1), a novel protein participating in meiotic recombination in rice (). Loss of MEICA1 leads to nonhomologous chromosome association, the formation of massive chromosome bridges, and fragmentation. MEICA1 interacts with MSH7, suggesting its role in preventing nonallelic recombination. In addition, MEICA1 has an anticrossover activity revealed by suppressing the defects of crossover formation in compared with that in , showing the similar function with its interacted protein TOP3α. Thus, our data establish two pivotal roles for MEICA1 in meiosis: preventing aberrant meiotic recombination and regulating crossover formation.
同源重组在确保减数分裂过程中的染色体分离方面发挥着核心作用。重组中间体分辨率的精确调控对于减数分裂的成功至关重要。许多蛋白质，包括RECQ DNA解旋酶（Sgs1/BLM）和拓扑异构酶3α（TOP3α），在处理重组中间体方面具有重要功能。然而，参与这一过程的许多其他因素仍有待确定。在这里，我们报告了减数分裂染色体关联蛋白1（MEICA1）的分离，它是一种参与水稻减数分裂重组的新型蛋白质。MEICA1的缺失会导致非同源染色体关联、大量染色体桥的形成以及染色体片段化。MEICA1与MSH7相互作用，表明其在防止非等位基因重组中的作用。此外，与[具体对照]相比，MEICA1通过抑制[具体实验对象]中交叉形成的缺陷而表现出反交叉活性，显示出与其相互作用蛋白TOP3α相似的功能。因此，我们的数据确定了MEICA1在减数分裂中的两个关键作用：防止异常减数分裂重组和调节交叉形成。
