Bai Guang-Yu, Song Si-Hang, Zhang Yu-Wei, Huang Xiang, Huang Xing-Wei, Sun Rui-Zhen, Lei Lei
Department of Histology and Embryology,Harbin Medical University,Harbin 150081,China.
Zygote. 2018 Feb;26(1):24-32. doi: 10.1017/S0967199417000673. Epub 2017 Dec 14.
Somatic cell nuclear transfer (SCNT) is an important technique for life science research. However, most SCNT embryos fail to develop to term due to undefined reprogramming defects. Here, we show that abnormal Xi occurs in somatic cell NT blastocysts, whereas in female blastocysts derived from cumulus cell nuclear transfer, both X chromosomes were inactive. H3K27me3 removal by Kdm6a mRNA overexpression could significantly improve preimplantation development of NT embryos, and even reached a 70.2% blastocyst rate of cleaved embryos compared with the 38.5% rate of the control. H3K27me3 levels were significantly reduced in blastomeres from cloned blastocysts after overexpression of Kdm6a. qPCR indicated that rDNA transcription increased in both NT embryos and 293T cells after overexpression of Kdm6a. Our findings demonstrate that overexpression of Kdm6a improved the development of cloned mouse embryos by reducing H3K27me3 and increasing rDNA transcription.
体细胞核移植（SCNT）是生命科学研究中的一项重要技术。然而，由于存在不明的重编程缺陷，大多数SCNT胚胎无法发育至足月。在此，我们发现体细胞NT囊胚中出现了异常的失活X染色体（Xi），而在源自卵丘细胞核移植的雌性囊胚中，两条X染色体均处于失活状态。通过过表达Kdm6a去除H3K27me3可显著改善NT胚胎的植入前发育，与对照组38.5%的囊胚率相比，经卵裂的胚胎囊胚率甚至达到了70.2%。过表达Kdm6a后，克隆囊胚的卵裂球中H3K27me3水平显著降低。定量PCR表明，过表达Kdm6a后，NT胚胎和293T细胞中的核糖体DNA（rDNA）转录均增加。我们的研究结果表明，过表达Kdm6a通过降低H3K27me3和增加rDNA转录，改善了克隆小鼠胚胎的发育。
