Polycomb-group histone methyltransferase CLF is required for proper somatic recombination in Arabidopsis  

作　　者：Na Chen Wang-Bin Zhou Ying-Xiang Wang Ai-Wu Dong Yu Yu 

机构地区：[1]State Key Laboratory of Genetic Engineering, Institute of Plant Biology, School of Life Sciences, Fudan University

出　　处：《Journal of Integrative Plant Biology》2014年第6期550-558,共9页植物学报（英文版）

基　　金：supported by the National Basic Research Program of China (973 Program, grants nos. 2012CB910500 and 2011CB944600);the National Natural Science Foundation of China (31371304)

摘　　要：Homologous recombination （HR） is a key process during meiosis in reproductive cells and the DNA damage repair process in somatic cells. Although chromatin structure is thought to be crucial for HR, only a smal number of chromatin modifiers have been studied in HR regulation so far. Here, we investigated the function of CURLY LEAF （CLF）, a Polycomb-group （PcG） gene responsible for histone3 lysine 27 trimethylation （H3K27me3）, in somatic and meiotic HR in Arabidopsis thaliana. Although fluorescent protein reporter assays in pol en and seeds showed that the frequency of meiotic cross-over in the loss-of-function mutant clf-29 was not significantly different from that in wild type, there was a lower frequency of HR in clf-29 than in wild type under normal conditions and under bleomycin treatment. The DNA damage levels were comparable between clf-29 and wild type, even though several DNA damage repair genes （e.g. ATM, BRCA2a, RAD50, RAD51, RAD54,and PARP2） were expressed at lower levels in clf-29. Under bleomycin treatment, the expression levels of DNA repair genes were similar in clf-29 and wild type, thus CLF may also regulate HR via other mechanisms. These findings expand the current knowledge of PcG function and contribute to general interests of epigenetic regulation in genome stability regulation.Homologous recombination （HR） is a key process during meiosis in reproductive cells and the DNA damage repair process in somatic cells. Although chromatin structure is thought to be crucial for HR, only a smal number of chromatin modifiers have been studied in HR regulation so far. Here, we investigated the function of CURLY LEAF （CLF）, a Polycomb-group （PcG） gene responsible for histone3 lysine 27 trimethylation （H3K27me3）, in somatic and meiotic HR in Arabidopsis thaliana. Although fluorescent protein reporter assays in pol en and seeds showed that the frequency of meiotic cross-over in the loss-of-function mutant clf-29 was not significantly different from that in wild type, there was a lower frequency of HR in clf-29 than in wild type under normal conditions and under bleomycin treatment. The DNA damage levels were comparable between clf-29 and wild type, even though several DNA damage repair genes （e.g. ATM, BRCA2a, RAD50, RAD51, RAD54,and PARP2） were expressed at lower levels in clf-29. Under bleomycin treatment, the expression levels of DNA repair genes were similar in clf-29 and wild type, thus CLF may also regulate HR via other mechanisms. These findings expand the current knowledge of PcG function and contribute to general interests of epigenetic regulation in genome stability regulation.

关 键 词：ARABIDOPSIS CLF DNA repair homologous recombination MEIOSIS 

分 类 号：Q946[生物学—植物学]