Epigenetic modification of the cytosine base of DNA by its methylation introduced the
possibility that beyond the inherent information contained within the nucleotide sequence
there was an additional layer of information added to the underlying genetic code. DNA
methylation has been implicated in a wide range of biological functions, including an
essential developmental role in the reprogramming of germ cells and early embryos, the
repression of endogenous retrotransposons, and a generalized role in gene expression …

The DNA methylation field has matured from a phase of discovery and genomic
characterization to one seeking deeper functional understanding of how this modification
contributes to development, ageing and disease. In particular, the past decade has seen
many exciting mechanistic discoveries that have substantially expanded our appreciation for
how this generic, evolutionarily ancient modification can be incorporated into robust
epigenetic codes. Here, we summarize the current understanding of the distinct DNA …