DNA甲基化在奶牛金黄色葡萄球菌性乳房炎中的调控

摘要

The aim of this study was to study the change of DNA methylation around STAT5-binding region in the far upstream promoter and its effect on gene expression of the bovine CSN1S1 during Staphylococcus aureus mastitis in dairy cattle. The methylation status of the promoter and the expression of CSN1S1 mRNA were detected by the bisulphite modification technique and the real-time quantitative PCR at 0,12,24,36 and 196 h after intramammary inoculation with Staphylococcus aureus. The result showed that the level of methylation gradually increased with time within 24 h,while the expression of CSN1S1 mRNA were significantly down-regulated in infected mammary tissue(P<0. 01), at 36 and 196 h after infection, the methylation status and gene expression levels were no significant difference from that at 24 h. The results suggest that DNA re-methylation of mammary tissue can be caused by Staphylococcus aureus mastitis, DNA re-methylation may be a general regulation of the acute phase of bovine mastitis.%旨在研究CSN1S1基因启动子区上游STAT5结合区域的DNA甲基化在奶牛金黄色葡萄球菌性乳房炎中的变化及其对CSN1S1基因表达的调控.本研究利用亚硫酸氢盐修饰和荧光定量PCR法检测受金黄色葡萄球菌侵染后12、24、36和196 h乳腺组织CSN1S1基因启动子区上游甲基化程度及CSN1S1基因表达量.结果,24 h内在细菌侵染的乳腺组织中甲基化程度随着时间的延长而增加；而CSN1S1基因表达量则显著降低(P＜0.01),而在侵染后36和196 h,甲基化程度和基因表达水平与24 h无显著差异.结果表明,奶牛金黄色葡萄球菌性乳房炎能够促使乳腺组织DNA再甲基化,DNA再甲基化可能是奶牛乳房炎急性期的一种普遍调控.