Yamanaka Ken-Ichi, Yamashita Kyoko, Khatun Hafiza, Wada Yasuhiko, Tatemoto Hideki, Sakatani Miki, Takenouchi Naoki, Takahashi Masashi, Watanabe Shinya
Faculty of Agriculture, Saga University, Saga, Japan.
The United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan.
Anim Sci J. 2018 Oct;89(10):1406-1414. doi: 10.1111/asj.13086. Epub 2018 Jul 31.
Epigenetic reprogramming confers totipotency even during somatic cell nuclear transfer (SCNT), which has been used to clone various animal species. However, as even apparently healthy cloned animals sometimes have aberrant epigenetic status, the harmful effects of these defects could be passed onto their offspring. This is one of the biggest obstacles for the application of cloned animals for livestock production. Here, we investigated the DNA methylation status of four developmentally regulated genes (PEG3, XIST, OCT4, and NANOG) in sperms from a cloned and a non-cloned bull, and blastocysts obtained by in vitro fertilization using those sperms and SCNT. We found no differences in the methylation status of the above genes between cloned and non-cloned bull sperms. Moreover, the methylation status was also similar in blastocysts obtained with cloned and non-cloned bull sperms. In contrast, the methylation status was compromised in the SCNT blastocysts. These results indicate that sperm from cloned bulls would be adequately reprogrammed during spermatogenesis and, thus, could be used to produce epigenetically normal embryos. This study highlights the normality of cloned bull offspring and supports the application of cloned cattle for calf production.
表观遗传重编程即使在体细胞核移植（SCNT）过程中也能赋予全能性，体细胞核移植已被用于克隆各种动物物种。然而，由于即使是看起来健康的克隆动物有时也有异常的表观遗传状态，这些缺陷的有害影响可能会传递给它们的后代。这是克隆动物应用于畜牧生产的最大障碍之一。在这里，我们研究了一头克隆公牛和一头非克隆公牛精子中四个发育调控基因（PEG3、XIST、OCT4和NANOG）的DNA甲基化状态，以及使用这些精子通过体外受精和体细胞核移植获得的囊胚中的DNA甲基化状态。我们发现克隆公牛和非克隆公牛精子中上述基因的甲基化状态没有差异。此外，使用克隆公牛和非克隆公牛精子获得的囊胚中的甲基化状态也相似。相比之下，体细胞核移植囊胚中的甲基化状态受到损害。这些结果表明，克隆公牛的精子在精子发生过程中会被充分重编程，因此可用于产生表观遗传正常的胚胎。这项研究突出了克隆公牛后代的正常性，并支持克隆牛用于犊牛生产。
