母鸡叶酸缺乏对子代MTHFD2和TYMS基因甲基化和表达水平的影响

为探究母鸡叶酸缺乏对子代与叶酸代谢相关的MTHFD2和TYMS基因甲基化模式和基因表达水平的影响,利用亚硫酸盐测序和定量PCR方法进行测定。结果表明:1)亲代叶酸缺乏对子代MTHFD2基因启动子区甲基化没有影响,该基因启动子区16个CpG位点不存在甲基化;2)子代TYMS基因ATG下游8个CpG位点甲基化主要发生在第2、3、4和5位点,但这4个CpG位点的甲基化比率在对照组和叶酸缺乏组之间均未达到差异显著水平(P0.05);并且TYMS总体甲基化水平在对照组和叶酸缺乏组之间差异也不显著(P0.05);3)母鸡叶酸缺乏可引起子代肝脏组织MTHFD2和TYMS基因表达水平均显著增加(P0.05)。综上所述,亲代叶酸缺乏对子代MTHFD2和TYMS基因表达水平发生作用,但未对基因甲基化比率造成影响,表明DNA甲基化模式由多个因素决定,可能存在叶酸以外的其他调控机制。

Effects of folate deficiency in hen on the methylation and expression levels of MTHFD2 and TYMS genes of its progeny

By using bisulfite sequencing and quantitative PCR methods, the effects of folate deficiency in hens on the methylation patterns and expression levels of MTHFD2 and TYMS of its progeny were studied. The results indicated that:1) Parental folate deficiency had no effect on the promoter region methylation of MTHFD2 and there were no methylation among 16 CpG sites of MTHFD2 promoter; 2) Methylation of downstream at ATG of TYMS (including 8 CpG sites) in progeny occurred mainly in the 2nd, 3rd, 4th and 5th sites. However, the methylation ratio of these 4 CpG sites showed no significant difference between the control and folate deficiency groups (P>0.05), and there was also no significant difference in the total methylation levels of TYMS either (P>0.05); 3) The expression levels of MTHFD2 and TYMS genes in liver tissues of hens progeny were significantly increased (P<0.05). Taken together, the expression levels of MTHFD2 and TYMS genes in hen''s progeny were influenced under folate deficiency, but it didn''t affect the methylation ratio. These results indicated that DNA methylation patterns were determined by several factors, and other regulatory mechanisms might be existed.