双胚苗水稻来源的单倍体、二倍体及其杂交F1的DNA甲基化位点分析  

DNA Methylation Site Analysis of Haploid, Diploid, and Hybrids in Twin-Seedling Rice

作　　者：吴绍华[1,2] 张红宇[1] 薛晶晶[1] 徐培洲[1] 吴先军[1] 

机构地区：[1]四川农业大学水稻研究所,西南作物基因资源与遗传改良教育部重点实验室,四川成都611130 [2]中国热带农业科学院橡胶研究所,海南儋州571737

出　　处：《作物学报》2013年第1期50-59,共10页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(30971618,30771157)资助

摘　　要：全基因组倍增或多倍化,伴随着基因丢失和二倍化进程,被认为是植物进化的重要推动力量。DNA甲基化与miRNA的表观遗传调控机制在植物生长发育及进化过程中起着重要的作用。本文采用MSAP(甲基化敏感扩增多态性)技术分析同一双胚苗水稻来源的单倍体、二倍体及其杂交F1的基因组DNA5'-CCGG位点胞嘧啶的甲基化及遗传特点。对部分甲基化位点进行切胶、回收、测序及功能注释,并结合miRNA靶基因预测探讨特定甲基化位点的遗传特点及其与miRNA的相关性。16对选择性扩增引物在双亲及杂交F1中共检测了462个DNA甲基化位点,杂交F1甲基化水平平均为43.20%,与双亲相近(单倍体为46.75%,二倍体为41.99%)。TargetFinder软件分析发现其中的7个甲基化位点基因序列上存在1～4个miRNA的结合位点,这些基因的功能注释包括逆转录转座子蛋白、ras相关蛋白、H2A/H2B/H3/H4核心组蛋白等。同时,探讨了逆转录转座子在植物进化中的作用。研究结果为进一步阐明水稻基因组倍增过程中DNA甲基化与miRNA的关系提供了参考。Whole-genome duplication or polyploidy, followed by gene loss and diploidization has long been recognized as an important evolutionary force in plants. Epigenetic mechanism, such as DNA methylation and miRNA, plays an important role in plant growth and development, and may also change its regulation pattern to adapt genomic duplication in new species. In this study, the DNA cytosine methylation at the 5＇-CpCpGpG sites was analyzed by MSAP （methylation-sensitive amplification poly- morphism） method in haploid, diploid and their hybrids derived from twin-seedling rice. And also, the relationships between DNA methylation and miRNA were investigated by sequencing the methylated DNA fragments and predicting the targets of miRNA. A total of 462 DNA methylated sites were detected. The hybrid＇s methylation level was 43.20% and a little different from that of its parents （haploid, 46.75%; diploid, 41.99%）. TargetFinder was used to find that seven methylated genes matched in sequence of rice database had 1-4 binding sites of miRNAs. The annotation indicated that the genes might include retrotransposon protein, ras-related protein and core histone H2A/H2B/H3/H4 domain containing protein. Most of the genes were annotated as retrotrans- posons and their functions in evolution were discussed. The results might help us to understand the relationships between DNA methylation and miRNA in rice genome duplication.

关 键 词：双胚苗水稻 单倍体 DNA甲基化 MSAP miRNA 

分 类 号：S511[农业科学—作物学]