Despite successful cloning of many mammalian species, the cloning efficiency is extremely low compared to that of IVF raising the possibility of the existence of epigenetic barrier preventing successful cloning.
Materials and methods
Using comparative transcriptome analysis comparing transcriptomes of IVF and SCNT embryos and that of donor cells, we identified epigenetic barrier and find a simple way to over come the barrier.
We identified that the Suv39h deposited H3K9me3 in somatic cells is an epigenetic barrier preventing zygotic genome activation and thus preventing successful development of the SCNT embryos. We find that by injecting mRNA encoding a H3K9me3 demethylase can overcome this epigenetic barrier to achieve high efficient cloning.
Suv39h deposited H3K9me3 in somatic cell is an epigenetic barrier for SCNT, which can be overcome by injecting mRNA of Kdm4d into the one-cell embryo to achieve high efficient cloning.