Epimutations are associated with CHROMOMETHYLASE 3-induced de novo DNA methylation
Epimutations are associated with CHROMOMETHYLASE 3-induced de novo DNA methylation
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DOI：
10.7554/elife.47891
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发表时间：
2019-07
期刊：
影响因子：
7.7
通讯作者：
Jered M. Wendte;Yinwen Zhang;Lexiang Ji;Xiuling Shi;R. Hazarika;Yadollah Shahryary;F. Johannes;
中科院分区：
文献类型：
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作者：
Jered M. Wendte;Yinwen Zhang;Lexiang Ji;Xiuling Shi;R. Hazarika;Yadollah Shahryary;F. Johannes;
在许多植物物种中，转录基因的一个子集的特征是严格的CG背景DNA甲基化，称为基因体甲基化（gbM）。建立gbM的机制尚不清楚，但天然没有gbM的开花植物物种缺乏DNA甲基转移酶CMT3，其维持CHG（H = A，C或T）而不是CG甲基化在组成型异染色质。在这里，我们确定了gbM建立的机制基础，通过表达CMT3在一个物种自然缺乏CMT3。CMT3表达通过表达基因上从头CHG甲基化的进展重建gbM，随后是即使在CMT3转基因丢失后也可以遗传的CG甲基化的积累。因此，gbM可能起源于通过促进常染色质和异染色质的途径同时靶向基因座，其引发基因以CG DNA甲基化的形式形成稳定遗传的表突变。
In many plant species, a subset of transcribed genes are characterized by strictly CG-context DNA methylation, referred to as gene body methylation (gbM). The mechanisms that establish gbM are unclear, yet flowering plant species naturally without gbM lack the DNA methyltransferase, CMT3, which maintains CHG (H = A, C, or T) and not CG methylation at constitutive heterochromatin. Here, we identify the mechanistic basis for gbM establishment by expressing CMT3 in a species naturally lacking CMT3. CMT3 expression reconstituted gbM through a progression of de novo CHG methylation on expressed genes, followed by the accumulation of CG methylation that could be inherited even following loss of the CMT3 transgene. Thus, gbM likely originates from the simultaneous targeting of loci by pathways that promote euchromatin and heterochromatin, which primes genes for the formation of stably inherited epimutations in the form of CG DNA methylation.