Methyl-CpG-binding domain protein 3 (MBD3) is a core component of the nucleosome remodeling and deacetylase (NuRD) complex, which is crucial for pluripotent stem cell differentiation and embryonic development. MBD3 was shown to play important roles in transcription factor-induced somatic cell reprogramming. Expression level of MBD3 was demonstrated to be higher in somatic cell nuclear transfer-generated cloned pig embryos than in fertilization-derived porcine embryos. However, the functions of MBD3 in nuclear transfer-mediated somatic cell reprogramming are unknown. In this study, MBD3 was overexpressed in cloned pig embryos, and the effects of MBD3 overexpression on gene transcription, DNA methylation, and in vitro developmental competence of cloned pig embryos were analyzed. Results indicated that overexpression of MBD3 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 NANOG, OCT4, and LINE1 genes to the levels close to those in in vivo fertilization-produced pig embryos. These findings suggest that overexpression of MBD3 improves reprogramming of cloned pig embryos.

中文翻译：

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MBD3的过表达改善了克隆猪胚的重编程。

甲基-CpG结合域蛋白3（MBD3）是核小体重塑和去乙酰化酶（NuRD）复合物的核心组成部分，对多能干细胞分化和胚胎发育至关重要。已显示MBD3在转录因子诱导的体细胞重编程中起重要作用。在体细胞核转移产生的克隆猪胚胎中，MBD3的表达水平高于受精猪胚胎。但是，MBD3在核转移介导的体细胞重编程中的功能尚不清楚。在这项研究中，MBD3在克隆的猪胚胎中过表达，并分析了MBD3的过表达对克隆的猪胚胎的基因转录，DNA甲基化和体外发育能力的影响。结果表明，克隆的猪胚胎中MBD3的过表达不仅增加了胚泡率和每个胚泡的细胞数，而且还上调了mRNA表达水平，并使NANOG，OCT4和LINE1基因的DNA甲基化水平降低至接近体内受精的水平。生产的猪胚胎。这些发现表明，MBD3的过表达改善了克隆的猪胚胎的重编程。