Evolutionary Role of DNA Methylation in Animal Genomes

Abstract

DNA methylation is a primary epigenetic mechanism involved in several regulatory and developmental processes. In this talk, I will focus on the molecular evolutionary role of DNA methylation. An important property of DNA methylation is its propensity to increase specific types of point mutations. Using this property, we have developed analytical tools to investigate influence of DNA methylation on genome evolution. We show that (i) DNA methylation causes different genomic regions to follow qualitatively different molecular clocks, (ii) influence regional variability of nucleotide composition, (iii) affected evolution of vertebrate promoters. Finally, (iv) our survey shows that the influence of DNA methylation on genome evolution is widespread in animal taxa. While the model invertebrate species Drosophila melanogaster and Caenorhabditis elegans lack DNA methylation, the genome of a social bee Apis mellifera exhibits an unmistakable signature of DNA methylation at sequence and functional level.