Authors : HuiMin Wang, XuDong Ao, ZhenFei Wang, Na Zhang, HaiXia Gao, HaiDong Bai, YongLi Yue and HaiQuan Yu
Abstract: To elucidate the epigenetic regulation of methylated CpG binding protein (MBD1) gene expression and its effect on other developmental genes, the expression of MBD1 and the DNA methylation status of its regulatory region were investigated in differentiated bovine tissues, during oocyte maturation and in the preimplantation embryo. Firstly, MBD1 gene expression was analyzed by RT-PCR in bovine heart, liver, kidney, testis and ovary and at different stages of oocyte maturation and embryonic development. Dynamic changes in DNA methylation in the regulatory region of MBD1 were detected by bisulfite-sequencing and chromosome immunoprecipitation was used to investigate the relationship between MBD1 and the pluripotency genes Nanog, Oct4 and H1foo or the maternal gene ZAR1. The results showed that the transcription level of the MBD1 gene was lower in heart and kidney and the DNA methylation levels of the MBD1 regulatory region were also lower in heart and kidney than in liver, testis and ovary. The transcription level of MBD1 incresed stably during the in vitro maturation of oocytes but began to decline dramatically from the 4 cells embryo stage. However, the DNA methylation levels of the MBD1 regulatory region were identical during either oocyte maturation or embryonic development. MBD1 protein spatiotemporally binded to the promoter regions of the pluripotency genes Nanog and Oct4 and the maternal genes ZAR1 and H1foo. These results indicated that during the bovine preimplantation embryo stages from the germinal vesicle oocyte to the blastocyst, transcription of MBD1 was not controled by the mechanism of promoter DNA methylation and MBD1 protein may participates in the transcriptional regulation of some key developmental regulatory genes.
HuiMin Wang, XuDong Ao, ZhenFei Wang, Na Zhang, HaiXia Gao, HaiDong Bai, YongLi Yue and HaiQuan Yu, 2013. Epigenetic Regulation of Methylated CpG Binding Protein MBD1 and its Effect on Developmental Gene Expression in the Bovine Embryo. Journal of Animal and Veterinary Advances, 12: 1597-1604.