Chemical tracking of DNMT1-specific activity during mESC ground state transition using RRBS

DNA methylation results from the collective performance of three AdoMet-dependent DNA methyltransferases (DNMTs), whose catalytic interplay and temporal dynamics remain poorly elucidated. In this study, we generated a Dnmt1 knock-in mESC line with a N1580A mutation at a single allele, while retaining a functioning wild-type protein.

The heterozygous DNMT1 N1580A knock-in line, together with the DNMT1 wild-type, homozygous N1580A knock-in, and knockout mouse embryonic stem cells were subsequently assessed for genome-wide CpG methylation levels using whole-genome bisulfite sequencing. Next, monoallelic DNMT1 N1580A KI cells underwent electroporation using the synthetic cofactor analogue Ado-6-azide and genomic targets unique to DNMT1 were subsequently assessed with Dnmt-TOP-seq.