OsMLH1 interacts with OsMLH3 to regulate synapsis and interference-sensitive crossover formation during meiosis in rice  

作　　者：Xiaodong Xin Xingwang Li Junkai Zhu Xiaobin Liu Zhenghu Chu Jiali Shen Changyin Wu 

机构地区：[1]National Key Laboratory of Crop Genetic Improvement,National Center of Plant Gene Research(Wuhan),Huazhong Agricultural University,Wuhan 430070,China [2]Jiangsu Kingearth Seed Co.,Ltd.,Yangzhou 225012,China

出　　处：《Journal of Genetics and Genomics》2021年第6期485-496,共12页遗传学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(31630054,31425018,31821005);Program for Chinese Outstanding Talents in Agricultural Scientific Research。

摘　　要：Meiotic recombination is essential for reciprocal exchange of genetic information between homologous chromosomes and their subsequent proper segregation in sexually reproducing organisms. MLH1 and MLH3 belong to meiosis-specific members of the Mut L-homolog family, which are required for normal level of crossovers(COs) in some eukaryotes. However, their functions in plants need to be further elucidated.Here, we report the identification of Os MLH1 and reveal its functions during meiosis in rice. Using CRISPRCas9 approach, two independent mutants, Osmlh1-1 and Osmlh1-2, are generated and exhibited significantly reduced male fertility. In Osmlh1-1, the clearance of PAIR2 is delayed and partial ZEP1 proteins are not loaded into the chromosomes, which might be due to the deficient in resolution of interlocks at late zygotene. Thus, Os MLH1 is required for the assembly of synapsis complex. In Osmlh1-1, CO number is dropped by ~53% and the distribution of residual COs is consistent with predicted Poisson distribution,indicating that Os MLH1 is essential for the formation of interference-sensitive COs(class I COs). Os MLH1 interacts with Os MLH3 through their C-terminal domains. Mutation in Os MLH3 also affects the pollen fertility. Thus, our experiments reveal that the conserved heterodimer Mut Lg(Os MLH1-Os MLH3) is essential for the formation of class I COs in rice.

关 键 词：MEIOSIS CROSSOVER OsMLH1 OsMLH3 RICE 

分 类 号：S511[农业科学—作物学]