TÁMOP-4.1.2-08/1/A-2009-0011 DNA methylation Covalent modifications of cytosine nucleotides of CpG dinucleotides Majority of methylated CpG dinucleotides are present in heterochromatic region Promoter CpG islands DNA methyltransferases (Dnmts)DNA methylation is controlled by DNA methyltransferases (Dnmts) –Dnmt1: methylation of hemimethylated CpG sites –Dnmt3a and Dnmt3b: de novo symmetric methylation of DNA during embryonic development and differentiation gene silencingFunction: methylation in mammals is required for gene silencing genomic imprinting (NB.
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