DNA甲基化和组蛋白修饰在兔早期胚胎的动态分析

Dynamics of Histone Modifiers and DNA Methylation in Rabbit Embryos

胚胎发育过程伴随着遗传学与表观遗传学不断变化,表观重编程完整性直接影响胚胎发育能力。孤雌胚胎发育可能与表观重编程不完全密切相关。然而,当前关于兔早期胚胎发育的表观遗传研究鲜有报道。研究拟确定兔早期胚胎中DNA甲基化与组蛋白修饰动态分布,比较这些表观修饰在体内受精胚胎与孤雌胚胎的差异。结果表明:体内受精胚胎与孤雌胚胎均呈现较高H3K4me2和泛乙酰化丰度,而较低H3K27me2和巴豆酰化丰度。四细胞到囊胚时期,孤雌胚胎5-甲基胞嘧啶(5mC)含量高于体内受精胚胎。二细胞到桑椹胚时期,孤雌胚胎5-羟甲基胞嘧啶(5hmC)水平高于体内受精胚胎。培养基添加维生素C并没有显著改善孤雌胚胎DNA甲基化状态,而应用5-Aza-dC处理58 h能够降低5mC和5hmC水平,说明使用化合物进行适当处理可以改善孤雌胚胎的表观修饰水平。

Embryonic development is accompanied by changes in genetics and epigenetics,and reprogramming integrity directly affects embryonic developmental capacity.To enrich the knowledge about epigenetic modification in rabbit embryos,the dynamic distribution of histone modifiers,5-methyl-cytidine and 5-hydroxymethylcytosin were analyzed between in vivo and parthenogenetic rabbit embryos.Results of the present study indicated that the intensity of both H3 K4 me2 and pan-acetylation signals was maintained at a high level in both in vivo and parthenogenetic embryos.The signal of H3 K27 me2 and histone lysine crotonylation was weak or even undetectable at the early stage,but all these signals turned up at the blastocyst stage.The signal intensity of 5-methyl-cytidine stayed at a higher level in parthenogenetic embryos than that of in vivo embryos from 4-cell to blastocyst stage.And there was a significant weaker signal intensity of 5-hydroxymethylcytosin from2-cell to morula stage in parthenogenetic embryos when compared with the in vivo embryos.The signal intensity of both 5 mC and 5 hmC in the parthenogenetic embryos was not significantly affected with vitamin C treatment.And the signal intensity of both 5 mC and 5 hmC in the parthenogenetic embryos at the morula stage was not significantly reduced after 5-aza-dC treatment for 58 h following activation.The epigenetic modification in parthenogenetic embryos could be modulated with proper compounds treatments.