DNMT1 associates with the DNA replication fork and functions as a hemi-methylase responsible for maintaining correct methylation patterns on DNA replication.

The DNA of vertebrates contains tissue-specific patterns of methylated cytosine residues. These methylation patterns are transmitted by clonal inheritance through the strong preference of mammalian DNA (cytosine-5)-methyltransferase for hemimethylated DNA.

Methylation patterns are established during early embryogenesis and gametogenesis, although little is known of the molecular mechanisms that control sequence-specific de novo methylation and demethylation.

See also

 DNMTs (DNA methyltransferases)