麻疯树杂交子代与亲本间基因组DNA甲基化分析

张辰笈　邹枚伶　夏志强　孙倩　江思容　王文泉

摘  要：為揭示麻疯树（Jatropha curcas）杂交子代与亲本间基因组甲基化变化规律，以1组亲缘关系较远且差异较大的亲本杂交构建的麻疯树遗传群体为材料，采用AFSM技术挖掘麻疯树DNA甲基化位点，比较不同材料的甲基化水平，对其进行功能分析。结果表明：共检测出537 234个甲基化位点，杂交子代DNA甲基化水平（0.29）显著低于2个亲本（0.39和0.35）。对不同全甲基化水平的样品进行功能分析，结果发现均富集于催化活性和蛋白结合，而相对于mCCGG全甲基化水平，CmCGG全甲基化水平样品还富集于大分子复合物、细胞器等细胞组分，以及发育过程、生物过程、细胞过程、代谢过程等生物学过程。这对于进一步从表观遗传学角度揭示麻疯树维持必要的遗传稳定性形成的内在机制具有重要意义。

关键词：麻疯树;甲基化;遗传群体

中图分类号：Q943      文献标识码：A

Analysis of Genomic DNA Methylation Between Progenies and Parents for Jatropha curcas

ZHANG Chenji1，2， ZOU Meiling2， XIA Zhiqiang1，2，3， SUN Qian2，4， JIANG Sirong2，5， WANG Wenquan1，2，3，5*

1. Hainan University， Haikou， Hainan 570228， China; 2. Institute of Tropical Biosciences and Biotechnology， Chinese Academy of Tropical Agricultural Sciences， Haikou， Hainan 571101， China; 3. Tropical Bio-omics and Big-Data Center， Chinese Academy of Tropical Agricultural Sciences， Haikou， Hainan 571101， China; 4. Guangxi University， Nanning， Guangxi 530004， China; 5. Nanjing Agricultural University， Nanjing， Jiangsu 210095， China

Abstract： In order to reveal the changes of genomic methylation between the progeny of Jatropha curcas and the parents， a group of J. curcas genetic groups constructed by crossing a group of distantly related parents with large differences was used as the test materials. The AFSM technology was used to mine the DNA methylation sites of J. curcas， to compare the methylation levels of different materials， and to perform functional analysis. In this study， a total of 537 234 methylated sites were identified. The DNA methylation level in the hybrid offsprings was significantly lower than that in J. curcas parents （0.29 for offsprings， 0.39 and 0.35 for the parents， respectively）. Functional analysis for J. curcas genes with different fully methylation levels revealed that all were tended to exhibit the enrichment of catalytic activity and protein binding. Compared with the mCCGG full methylation level， CmCGG full methylation level samples were also enriched in macromolecular complexes， organelles cellular components， and enriched in biological processes included development， biological， cellular and metabolic processes. This is of great significance for further revealing the inherent mechanism of maintaining the necessary genetic stability of J. curcas from the perspective of epigenetics.

Keywords： Jatropha curcas; methylation; genetic population

DOI： 10.3969/j.issn.1000-2561.2021.03.002

DNA甲基化（DNA methylation）是一种在植物杂种优势、环境适应性、生长发育等方面意义重大的表观遗传修饰标记[1-3]。DNA甲基化是指胞嘧啶中的5位碳原子上通过DNA甲基转移酶的作用，增加一个新的甲基基团，构成5-甲基胞嘧啶（5mC）的过程[4]。研究发现，DNA甲基化可以改变基因组的功能[3]，对种子萌发、花期调控、移栽表现等都有很大影响[5]，另外，DNA甲基化修饰可以通过调节基因表达，在植物生长发育中发挥重要作用。随着DNA甲基化的研究不断深入，越来越多的学者证实DNA甲基化在杂种优势形成过程也发挥着至关重要的作用，双亲基因组的组合可导致杂种基因组的不稳定性、表观遗传以及基因表达变化，影响杂种中表型的变化[6]。……