Insights into Epigenome Evolution from Animal and Plant Methylomes.

4 years ago

Insights into Epigenome Evolution from Animal and Plant Methylomes.

Soojin V Yi

Evolutionary studies of DNA methylation begin to provide insights into the underlying forces governing the variation of genomic DNA methylation across different species. Comparisons of gross levels of DNA methylation between distantly related species indicate that the size of the genome and the level of genomic DNA methylation are positively correlated. In plant genomes, this can be reliably explained by the contents of repetitive sequences, while the underlying driver of this correlation is less clear in animal genomes. On a shorter timescale, population-level comparisons of genomic DNA methylation demonstrate that genetic variation can explain variation of DNA methylation to some degree. The amount of DNA methylation variation that has been attributed to genetic variation in the human population studies so far is substantially lower than that from Arabidopsis population studies, but this disparity might reflect the differences in the computational and experimental techniques used. The effect of genetic variation on DNA methylation has been directly examined in mammalian experimental systems, revealing several causative factors that govern DNA methylation. On the other hand, studies from Arabidopsis have furthered our understanding of spontaneous mutations of DNA methylation, termed 'epimutations'. Arabidopsis has an extremely high rate of spontaneous epimutations, which may play a major role in shaping the global DNA methylation landscape in this genome. Key missing information includes the prevalence of spontaneous epimutations in other lineages, in particular animal genomes, and how population-level variation of DNA methylation leads to species-level differences.

Publisher URL: http://doi.org/10.1093/gbe/evx203

DOI: 10.1093/gbe/evx203