Overexpression of MBD3 Improves Reprogramming of Cloned Pig Embryos.

Methyl-CpG-binding domain protein 3 () is a core component of the nucleosome remodeling and deacetylase (NuRD) complex, which is crucial for pluripotent stem cell differentiation and embryonic development. was shown to play important roles in transcription factor-induced somatic cell reprogramming. Expression level of was demonstrated to be higher in somatic cell nuclear transfer-generated cloned pig embryos than in fertilization-derived porcine embryos. However, the functions of in nuclear transfer-mediated somatic cell reprogramming are unknown. In this study, was overexpressed in cloned pig embryos, and the effects of overexpression on gene transcription, DNA methylation, and developmental competence of cloned pig embryos were analyzed. Results indicated that overexpression of in cloned pig embryos not only increased blastocyst rate and number of cells per blastocyst but also upregulated mRNA expression levels and decreased the DNA methylation of , , and genes to the levels close to those in fertilization-produced pig embryos. These findings suggest that overexpression of improves reprogramming of cloned pig embryos.