Dynamic CpG and non-CpG methylation of the Peg1/Mest gene in the mouse oocyte and preimplantation embryo
Dynamic CpG and non-CpG methylation of the Peg1/Mest gene in the mouse oocyte and preimplantation embryo
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DOI：
10.1074/jbc.m501749200
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发表时间：
2005-05-20
影响因子：
4.8
通讯作者：
Pàldi, A
中科院分区：
文献类型：
--
作者：
Imamura, T;Kerjean, A;Pàldi, A
在体细胞组织中，印迹Peg1/Mest基因的CpG岛在母体等位基因上甲基化。我们在新鲜排卵的卵母细胞、体外老化的卵母细胞和植入前胚胎中检测了CpG和非CpG岛差异甲基化位点的甲基化。CpG甲基化模式在新排卵的卵母细胞中是异质的，尽管它们都在中期II中被抑制。在短时间体外培养后，Peg1/Mest发生超甲基化，而长时间体外培养导致部分卵母细胞发生去甲基化。非cpg甲基化也以特定阶段的方式发生。在CpG位点完全甲基化的等位基因上，这种修饰被发现，并且在双细胞期胚胎和囊胚中减少。这些观察结果表明，在这个位点建立甲基化印记的过程比以前认为的更加动态。
In somatic tissues, the CpG island of the imprinted Peg1/Mest gene is methylated on the maternal allele. We have examined the methylation of CpG and non-CpG sites of this differentially methylated CpG island in freshly ovulated oocytes, in vitro aged oocytes, and preimplantation embryos. The CpG methylation pattern was heterogeneous in freshly ovulated oocytes, despite the fact that they all were arrested in metaphase II. After short in vitro culture, Peg1/Mest became hyper-methylated, whereas prolonged in vitro culture resulted in demethylation in a fraction of oocytes. Non-CpG methylation also occurred in a stage-specific manner. On alleles that were fully methylated at CpG sites, this modification was found, and it became reduced in two-cell stage embryos and blastocysts. These observations suggest that the process of establishment of the methylation imprint at this locus is more dynamic than previously thought.