question: What is the role of 5hmC (5 hydroxy-methyl-Cytocine) in differentiation?
answer: The balance between 5hmC and 5mC in the genome is linked with cell-differentiation processes such as pluripotency and lineage commitment. Tet1-mediated antagonism of CpG methylation imparts differential maintenance of DNA methylation status at Tet1 targets, ultimately contributing to mESC differentiation and the onset of embryonic development. By mapping DNA methylation and hydroxymethylation at base resolution, we find that deletion of Tet2 causes extensive loss of 5hmC at enhancers, accompanied by enhancer hypermethylation, reduction of enhancer activity, and delayed gene induction in the early steps of differentiation.