Fine Tuning of Histone Demethylase KDM6A/B Improves the Development of Nuclear Transfer Embryo

Despite the success of the production of animals by somatic cell nuclear transfer (SCNT) in many species, the method is limited by a low efficiency. After zygotic genome activation (ZGA), a large number of endogenous retroviruses (ERVs) are expressed, including the murine endogenous retrovirus-L (MuERVL/MERVL). In this study, we generated a series of MERVL-reporter mouse strains to detect the ZGA event in embryos. We found that the majority of SCNT embryos exhibited ZGA failure, and histone H3 lysine 27 trimethylation (H3K27me3) prevented SCNT reprogramming. Overexpression of the H3K27me3-specific demethylase KDM6A, but not KDM6B, improved the efficiency of SCNT. Conversely, knockdown KDM6B not only facilitate ZGA, but also impede ectopic Xist expression in SCNT reprogramming. Furthermore, the knockdown of KDM6B increased the rate of SCNT-derived Duchenne muscular dystrophy embryonic stem cell establishment, indicate that these results not only provide insight into the mechanisms underlying failures of SCNT, but also may extend the applications of SCNT.