DNA demethylation affects imprinted gene expression in maize endosperm

第一作者：Qiang Xu

第一单位：华中农业大学

通讯作者：Qing Li

 Abstarct 

背景+问题：DNA demethylation occurs in many species and is involved in diverse biological processes. However, the occurrence and role of DNA demethylation in maize remain unknown. 

DNA去甲基化在许多物种中都有发生，参与多种生物学过程。然而，DNA去甲基化在玉米中的发生和作用仍不清楚。

主要研究：We analyze loss-of-function mutants of two major genes encoding DNA demethylases. 

本文中，作者分析了两个编码DNA去甲基酶的主要基因的功能缺失突变体。

结果1-DNA去甲基化与胚乳基因表达：No significant change in DNA methylation has been detected in these mutants. However, we detect increased DNA methylation levels in the mutants around genes and some transposons. The increase in DNA methylation is accompanied by alteration in gene expression, with a tendency to show downregulation, especially for the genes that are preferentially expressed in endosperm. 

在这些突变体中，作者未检测到明显的DNA甲基化变化。然而，作者发现突变体中某些基因和一些转座子周边的DNA甲基化水平升高。DNA甲基化的增加伴随着基因表达的变化，通常表现出下调表达的趋势，尤其是对于那些在胚乳中高表达的基因。

结果2-DNA去甲基化与印记基因表达：Imprinted expression of both maternally and paternally expressed genes changes in F₁ hybrid with the mutant as female and the wild-type as male parental line, but not in the reciprocal hybrid. This alteration in gene expression is accompanied by allele-specific DNA methylation differences, suggesting that removal of DNA methylation of the maternal allele is required for the proper expression of these imprinted genes.

在突变体为母本、野生型为父本获得的F1代杂种中，母系和父系表达基因的印记表达都发生了改变，但在反交获得的杂种中没有变化。这种基因表达的改变伴随着等位基因特异性DNA甲基化差异，表明母系等位基因DNA甲基化的去除是这些印记基因正确表达所必需的。

结果3-DNA去甲基化与TFs结合靶基因：Finally, we demonstrate that hypermethylation in the double mutant is associated with reduced binding of transcription factor to its target, and altered gene expression. 

最后，作者发现双突变体中的超甲基化与转录因子结合其靶基因的减少以及基因表达的改变有关。

结论：Our results suggest that active removal of DNA methylation is important for transcription factor binding and proper gene expression in maize endosperm.

本文的研究结果表明，活跃的DNA甲基化去除对于玉米胚乳中转录因子结合和基因的正确表达非常重要。

** 李青 **

doi: https://doi.org/10.1186/s13059-022-02641-x

Journal: Genome Biology

Published date: March 09, 2022