what is a CpG methylation site
Cytosines in CpG dinucleotides can be methylated to form 5-methylcytosine. In mammals, methylating the cytosine within a gene can change its expression, a mechanism that is part of a larger field of science studying gene regulation that is called epigenetics.Enzymes that add a methyl group are called DNA methyltransferases. In mammals, 70% to 80% of CpG cytosines are methylated.Unmethylated CpG dinucleotide sites can be detected by Toll-like receptor 9 (TLR 9) on plasmacytoid dendritic cells, monocytes, natural killer (NK) cells, and B cells in humans.n mammals, methylating the cytosine within a gene can change its expression, a mechanism that is part of a larger field of science studying gene regulation that is called epigenetics. Enzymes that add a methyl group are called DNA methyltransferases. In mammals, 70% to 80% of CpG cytosines are methylated.