Al Khaled Y, Tierling S, Laqqan M, Lo Porto C, Hammadeh M E
Gynecology & Assisted Reproduction Laboratory, Department of Obstetrics, University of Saarland, Homburg, Germany.
FR8.3 Life Science, Department of Genetics & Epigenetics, Saarland University, Saarbrücken, Germany.
Andrologia. 2018 Feb;50(1). doi: 10.1111/and.12818. Epub 2017 May 14.
DNA methylation plays important roles in genome stability and regulation of gene expression. This study was designed to determine the influence of cigarette smoking on sperm DNA methylation. From a genome-wide survey on sperm samples, differentially methylated target CpGs should be selected and subjected to local deep bisulphite sequencing. Obtained methylation data are compared to sperm parameters and (ICSI) outcome. Similar to pilot study, samples were subjected to Infinium 450K BeadChip arrays to identify alterations in sperm DNA methylation between smokers and nonsmokers males. Routine testing on a significantly altered CpG site was performed on more samples using local deep bisulphite sequencing. Of approximately 485,000 CpG sites analysed, only seven CpGs were found to show a significant DNA methylation difference of >20% with the top six CpGs overlapping common SNP sites. The remaining CpG site (cg19455396) is located in intron 12 of the TAP2 gene. The results of deep bisulphite sequencing showed only a tendency towards hypomethylation in the smoking group. This study could not detect biologically relevant CpG positions that are altered in sperm DNA methylation on the influence of cigarette smoking beyond individual-specific effects that may be caused by other environmental factors.
DNA甲基化在基因组稳定性和基因表达调控中发挥着重要作用。本研究旨在确定吸烟对精子DNA甲基化的影响。通过对精子样本进行全基因组调查，应选择差异甲基化的目标CpG位点，并进行局部深度亚硫酸氢盐测序。将获得的甲基化数据与精子参数和（卵胞浆内单精子注射）结果进行比较。与初步研究类似，对样本进行Infinium 450K BeadChip芯片检测，以识别吸烟者和非吸烟者男性精子DNA甲基化的变化。使用局部深度亚硫酸氢盐测序对更多样本进行显著改变的CpG位点的常规检测。在分析的约485,000个CpG位点中，仅发现7个CpG位点的DNA甲基化差异显著>20%，其中前6个CpG位点与常见单核苷酸多态性位点重叠。其余的CpG位点（cg19455396）位于TAP2基因的第12内含子中。深度亚硫酸氢盐测序结果显示吸烟组仅呈现出低甲基化趋势。本研究未能检测到在吸烟影响下精子DNA甲基化发生改变的具有生物学相关性的CpG位点，超出了可能由其他环境因素引起的个体特异性效应。
