遗传 ›› 2009, Vol. 31 ›› Issue (4): 387-392.doi: 10.3724/SP.J.1005.2009.00387

• 研究报告 • 上一篇    下一篇

小鼠四倍体早期胚胎基因组甲基化模式

员新旭1;冯书堂1;潘登科1;窦红伟1, 2;牟玉莲1;李奎1
  

  1. 1. 中国农业科学院北京畜牧兽医研究所, 畜禽遗传资源与利用农业部重点开放实验室, 北京 100193;
    2. 甘肃农业大学动物医学院产科室, 兰州 730070
  • 收稿日期:2008-10-23 修回日期:2008-11-27 出版日期:2009-04-10 发布日期:2009-04-10
  • 通讯作者: 李奎

DNA methylation patterns of mouse tetraploid embryos

YUN Xin-Xu1;FENG Shu-Tang1;PAN Deng-Ke1;DOU Hong-Wei1, 2;MU Yu-Lian1;LI Kui1   

  1. 1. Key Laboratory for Farm Animal Genetic Resourses and Utilization of Ministry of Agriculture of China, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
    2. Department of Obstetric, College of Veterinary Medecine, Gansu Agricultural University, Lanzhou 730070, China
  • Received:2008-10-23 Revised:2008-11-27 Online:2009-04-10 Published:2009-04-10
  • Contact: LI Kui

摘要: 利用小鼠抗5-甲基胞嘧啶(5MeC)单克隆抗体检测了体外培养小鼠四倍体早期胚胎的基因组甲基化模式。结果表明: 利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程, 在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样, 呈现高度甲基化状态; 在细胞核开始融合的时候, 甲基化水平急速下降, 在细胞核完全融合的时候甲基化水平达到最低点; 随着胚胎继续分裂, 胚胎甲基化水平逐渐增加, 在桑葚胚期甲基化水平最高; 但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别, 这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。因此, 小鼠体外培养四倍体胚胎的甲基化模式是不正常的, 这可能是四倍体小鼠难以发育到妊娠足月的原因之一。这是对小鼠四倍体早期胚胎基因组甲基化模式的首次报道。

关键词: 小鼠, 四倍体胚胎, 甲基化, 抗5-甲基胞嘧啶抗体

Abstract: In the present study, the DNA methylation patterns of in vitro-derived mouse tetraploid embryos were investi-gated by immunofluorescence staining with an antibody against 5-methylcytosine (5MeC). Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cyto-plasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methy-lation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribu-tion of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass (ICM) than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts. So the DNA methylation patterns of mouse tetraploid embryos are aberrant, which may lead to subsequent de-velopmental failure and embryo death. This is the first report on the methylation patterns of in vitro-derived mouse tetraploid embryos.