Mouse ooplasm confers context-specific reprogramming capacity

Enucleated oocytes have the remarkable ability to reprogram somatic nuclei back to totipotency. Here we investigate genome-scale DNA methylation patterns after nuclear transfer and identify specific targets for DNA demethylation as well as NT specific limitations. We find that the ooplasm can confer similar demethylation patterns in both processes except at some repetitive element classes and that germ-line associated promoters are specifically targeted in NT. Comparison of DNA methylation patterns in murine fertilization and somatic cell nuclear transfer