利用拟南芥杂交组合研究siRNA与等位基因DNA甲基化调控中的联系

近年来，越来越多的实验结果表明，表观遗传因子，如DNA甲基化、小RNA、组蛋白修饰等在杂种优势形成中起到重要作用，然而对于这些表观遗传因子在F。中遗传调控方式的认识仍很有限．本实验室先前工作曾以拟南芥C24和Ler两种生态型及其正反交子一代为材料，运用新一代测序方法获得该杂交组合中DNA甲基化及小RNA单碱基分辨率的全基因组图谱．本文进一步对这批数据中的等位基因DNA甲基化水平进行分析，区分DNA甲基化遗传过程中的顺式与反式调控方式，并发现这两种调控方式均有重要的贡献．研究发现，siRNA与DNA甲基化的两种调控方式有密切联系，尤其在DNA甲基化的反式调控中，Fl中DNA甲基化变化程度越大，该区域内siRNA富集程度越强，二者可能存在某种调控机制．通过等位基因表观遗传组的分析研究杂交过程中DNA甲基化和小RNA遗传调控的规律，为更好地理解杂种优势机制提供了帮助．

Allelic DNA Methylation Analysis in Arabidopsis Hybrids Associated with siRNA

Recently, accumulating evidence suggests that epigenetic factors including DNA methylation, small RNA and histone modifications may play important roles in hybrid vigor in plants. However, knowledge about the mechanism of these epigenetic factors in hybrids is still limited. Based on genome-wide DNA methylation and small RNA maps of Arabidopsis thaliana Ler and C24 ecotypes and their reciprocal F~ hybrids in previous work, we further analyzed allelic specific DNA methylation. Our study indicated that both trans- and cis-factors play roles in DNA methylation regulations in hybrids. In addition, we found that siRNAs correlate with DNA methylation trans-regulations. High degree trans-regulation DNA methylation is significantly concurrent with enriched siRNA regions. Our study analyzed DNA methylation regulations associated with siRNAs in hybrids, and shed light on understanding the mechanism of hybrid vigor.