He Li, Wu Wenwu, Zinta Gaurav, Yang Lan, Wang Dong, Liu Renyi, Zhang Huiming, Zheng Zhimin, Huang Huan, Zhang Qingzhu, Zhu Jian-Kang
Shanghai Center for Plant Stress Biology and Center of Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, 201602, Shanghai, China.
University of Chinese Academy of Sciences, 100049, Beijing, China.
Nat Commun. 2018 Jan 31;9(1):460. doi: 10.1038/s41467-018-02839-3.
Epigenetic variation has been proposed to facilitate adaptation to changing environments, but evidence that natural epialleles contribute to adaptive evolution has been lacking. Here we identify a retrotransposon, named "NMR19" (naturally occurring DNA methylation variation region 19), whose methylation and genomic location vary among Arabidopsis thaliana accessions. We classify NMR19 as NMR19-4 and NMR19-16 based on its location, and uncover NMR19-4 as an epiallele that controls leaf senescence by regulating the expression of PHEOPHYTIN PHEOPHORBIDE HYDROLASE (PPH). We find that the DNA methylation status of NMR19-4 is stably inherited and independent of genetic variation. In addition, further analysis indicates that DNA methylation of NMR19-4 correlates with local climates, implying that NMR19-4 is an environmentally associated epiallele. In summary, we discover a novel epiallele, and provide mechanistic insights into its origin and potential function in local climate adaptation.
表观遗传变异被认为有助于生物体适应不断变化的环境，但一直缺乏自然表观等位基因促进适应性进化的证据。在此，我们鉴定出一个逆转座子，命名为“NMR19”（自然发生的DNA甲基化变异区域19），其甲基化和基因组位置在拟南芥不同生态型间存在差异。我们根据其位置将NMR19分为NMR19 - 4和NMR19 - 16，并发现NMR19 - 4是一个通过调控脱镁叶绿酸脱镁 pheophorbide水解酶（PPH）的表达来控制叶片衰老的表观等位基因。我们发现NMR19 - 4的DNA甲基化状态能够稳定遗传且独立于遗传变异。此外，进一步分析表明NMR19 - 4的DNA甲基化与当地气候相关，这意味着NMR19 - 4是一个与环境相关的表观等位基因。总之，我们发现了一个新的表观等位基因，并对其起源以及在局部气候适应中的潜在功能提供了机制性见解。
