Fig. 2.—

Variation of genomic DNA methylation patterns in different species. The methylomes of invertebrates and vertebrates are drastically different as the former typically harbor much lower levels of DNA methylation than the latter. Limited amount of DNA methylation in invertebrate genomes is found in a subset of genes, and very rarely in promoters. In contrast, vertebrate genomes are heavily methylated across the board, although some variation exists in different taxa. Plant genomes generally have methylated transposable elements and some gene bodies. Recent studies showed that gene body methylation is lacking in some of the plant lineages.