2017年6月16日，中国农业科学院蔬菜花卉研究所甘蓝青花菜研究团队在期刊genes（2023IF=3.5，Q2）上发表了题为“Comparative Analysis of Genome Wide DNA Methylation Profiles for the Genic Male Sterile Cabbage Line 01-20S and Its Maintainer Line”的研究论文。论文第一作者是韩风庆博士和张小丽博士，通讯作者是吕红豪研究员。
甲基化修饰在多种生物过程中起着重要作用。一些研究报告了水稻和小麦等雄性不育植物的甲基化模式发生了变化，但对全球甲基化特征及其在甘蓝(Brassica Oleracea)雄性不育系中的可能作用知之甚少。本研究采用单碱基分辨测序技术(single-base-resolution bisulfite sequencing，BS-Seq)对甘蓝雄性不育系01-20S及其近等基因可育系01-20F的胞嘧啶甲基化模式和甲基化程度进行了鉴定。类似的甲基化模式也有，但在局部位置观察到了一些变化。总共检测到505个差异甲基化基因组区域(differentially methylated genomic regions，DMR)和106个DMR相关基因。发现了9个与花粉发育相关的基因，并通过定量逆转录聚合酶链式反应(qRT-PCR)进一步验证。
其中，4个在01-20S被下调。特别是，Bol039180(转化酶/果胶甲酯酶抑制蛋白家族蛋白)可能参与了果胶的降解，并可能在01-20S的花粉分离缺陷中发挥重要作用。这项研究有助于更好地了解DNA甲基化变化及其在甘蓝核不育中的可能作用。
Figure 1. DNA methylation patterns of 01-20F (F) and 01-20S (S). (a) The cytosine methylation level
(mC) percentage for each sequence context; (b) Levels of CG, CHG and CHH methylation in the whole
cabbage genome.
Figure 2. Genomic methylation levels of 01-20F and 01-20S. (a) Global DNA methylation patterns of
01-20F and 01-20S; (b) DNA methylation levels in nine chromosomes; (c) Methylcytosines density in
chromosome 8 and 9. The blue dots represent methylcytosine density . The smoothed lines represent
the methylcytosine density of the three contexts.
Figure 3. Gene expression and DNA methylation patterns of differentially methylated genomic
regions (DMR)-associated genes involved in pollen development. (a) Expression analysis of nine
genes related to pollen development; (b) DNA methylation at specific sites of four genes by bisulfite
sequencing (BS-seq). The asterisk indicates a significant difference between F and S (* p-value < 0.05;
** p-value < 0.01).
