硒缺乏对鸡肌肉组织DNA甲基化水平的影响

Effect of selenium deficiency on DNA methylation in muscle tissue of chickens

选取健康1日龄雏鸡200只,随机分为2组,低硒组(饲料硒含量为0.033 mg·kg-1)和对照组(饲料硒含量为0.15 mg·kg-1),分别于0、15、25、35、45、55日龄取胸肌、翅肌、腿肌组织,高效液相色谱法检测DNA总甲基化水平,实时荧光定量PCR方法检测DNA甲基转移酶1(DNMT1)、DNA甲基转移酶3A(DNMT3A)、DNA甲基转移酶3B(DNMT3B)mRNA表达水平。结果表明,DNA总甲基化水平整体呈降低趋势,低硒组与对照组相比DNMT1、DNMT3A mRNA表达量先增加后减少,DNMT3B各组均低于正常组并且随日龄增加组内呈降低趋势。硒缺乏可导致鸡肌肉组织DNA甲基化水平降低。

The aim of this study was to investigate the effects of selenium（Se） deficiency on the DNA methylation in the muscle tissue of chickens.Two hundred 1-day-old chickens were randomly allocated to two groups.The low-Se group was fed a Se-deficient basal diet（containing 0.033 mg.kg-1Se）.Control group was fed a medium-Se diet（containing 0.15 mg.kg-1）.Breast muscle,flight muscle and Leg muscle was collected when the chickens were 15,25,35,45 and 55 days old.DNA methylation levels were detected by HPLC,while the expression levels of DNA-methyltransferase 1（DNMT1） DNA-methyltransferase 3A（DNMT3A） and DNA-methyltransferase 3B（DNMT3B） mRNA were deter-mined by real-time PCR.The total levels of DNA methylation were decreasing.Selenium deficiency group expression of DNMT1,DNMT3A mRNA increased compared with control group and then it expression decreased.The expression of DNMT3B in each group was lower than the control group with age increased.Selenium can down-regulate the levels of DNA methylation in chicken muscle tissue.