Does methylation increase gene expression?

Methylation, the transfer of a methyl group (―CH3) to an organic compound. Methyl groups may be transferred through addition reactions or substitution reactions; in either case, the methyl group takes the place of a hydrogen atom on the compound. ... Biological methylation occurs in various ways.

Presently, the exact role of methylation in gene expression is unknown, but it appears that proper DNA methylation is essential for cell differentiation and embryonic development. Moreover, in some cases, methylation has observed to play a role in mediating gene expression

DNA methylation regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factor(s) to DNA. During development, the pattern of DNA methylation in the genome changes as a result of a dynamic process involving both de novo DNA methylation and demethylation.

Evidence suggests that DNA methylation of the gene body is associated with a higher level of gene expression in dividing cells. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.

 

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