CG methylation

CG methylation refers to the addition of a methyl group (a small chemical group) to cytosine bases when they are followed by guanine bases in DNA. This chemical modification typically occurs in gene regions and can influence gene activity without changing the DNA sequence itself. In many organisms, especially mammals, CG methylation is a key mechanism for regulating gene expression, turning genes on or off, and maintaining cellular identity. It plays a vital role in development, gene silencing, and genomic stability, functioning as an important epigenetic marker that affects how our genes behave.