“…DNA methylation is a feature shared by all vertebrates and by many, but not all, non-vertebrate organisms. In vertebrates, up to 90% of all CG dinucleotides, which tend to be interspersed across the genome, are methylated, with the exception of unmethylated islands (Bogdanovi c et al, 2016;Long et al, 2013). These regions are relatively rich in CG dinucleotides, especially in mammals (CpG islands), and often overlap with regulatory sequences (Bogdanovic and Gomez-Skarmeta, 2014).…”