Methylation patterns in 5' terminal regions of pluripotency-related genes in bovine in vitro fertilized and cloned embryos

作     者：Jie Lan Song Hua Hailin Zhang Yongli Song Jun Liu Yong Zhang 

作者机构：Key Laboratory of Animal Reproductive Physiology & Embryo Technology Institution of biotechnology College of Veterinary Medicine Northwest A & F University Yangling 712100 China 

出 版 物：《Journal of Genetics and Genomics》 (遗传学报（英文版）)

年 卷 期：2010年第37卷第5期

页      面：297-304页

核心收录：

学科分类：0710[理学-生物学] 1001[医学-基础医学(可授医学、理学学位)] 07[理学] 08[工学] 09[农学] 071007[理学-遗传学] 0901[农学-作物学] 0836[工学-生物工程] 090102[农学-作物遗传育种] 

基　　金：supported by the Key Scientific and Technological Special Program for the Culture of Disease-resistance Transgenic Cattle Species(No.2008ZX08007-004) Government of China 

主　　题：bovine DNA methylation Fgf4 Nanog Oct4 Rex1 Sox2 

摘      要：In order to investigate DNA methylation profiles of five pluripotency-related genes （Oct4, Sox2, Nanog, Rexl and Fgf4） during bovine maternal to zygotic transition （MZT） in both in vitro fertilized （IVF） and nuclear transfer （NT） embryos, sodium bisulfite sequencing method was used to detect DNA methylation levels, accompanied by the statistical analysis of embryo developmental rates. The results showed that Oct4, Nanog, Rexl and Fgf4 were respectively demethylated by 25.22% （P 〈 0.01）, 3.84% （P 〉 0.05）, 31.82% （P 〈 0.01） and 10% （P 〉 0.05） while Sox2 retained unmethylafion during MZT in IVF embryos. By contrast, Oct4 and Rexl respectively underwent demethylation by 23.04% （P 〈 0.01） and 6.02% （P 〉 0.05）, and, reversely, Sox2, Nanog and Fgf4 respectively experienced remethylation by 0.84% （P 〉 0.05）, 5.39% （P 〉 0.05） and 5.46% （P 〉 0.05） during MZT in NT embryos. Interestingly, the CpG 14 site of Sox2 was specifically methylated in both 8-cell and morula NT embryos. In addition, the development of blastocysts between IVF and NT embryos showed no significant difference. DNA methylation analysis showed that only Oct4 and Sox2 underwent the correct methylation reprogramming process, which may be responsible for the development of blastocysts of NT embryos to a certain extent. In conclusion, the five genes respectively experienced demethylation to different extents and incomplete DNA methylation reprogramming during bovine MZT in both IVF and NT embryos, suggesting that they may be used as indicators for bovine embryo developmental competence.