An epigenetic switch ensures transposon repression upon dynamic loss of DNA methylation in embryonic stem cells.

ABSTRACT: DNA methylation is extensively remodeled during mammalian gametogenesis and embryogenesis. Most transposons become hypomethylated, raising the question of their regulation in the absence of DNA methylation. To reproduce a rapid and extensive demethylation, we subjected mouse ES cells to chemically defined hypomethylating culture conditions. Surprisingly, we observed two phases of transposon regulation. After an initial burst of de-repression, various transposon families were efficiently re-silenced. This was accompanied by a reconfiguration of the repressive chromatin landscape: while H3K9me3 was stable, H3K9me2 globally disappeared and H3K27me3 accumulated at transposons. Interestingly, we observed that H3K9me3 and H3K27me3 occupy different transposon families or different territories wit

SUBMITTER: Walter M 

PROVIDER: S-EPMC4769179 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature