Table of Contents
International Journal of Evolutionary Biology
Volume 2014 (2014), Article ID 475981, 7 pages
http://dx.doi.org/10.1155/2014/475981
Review Article

DNA Methylation, Epigenetics, and Evolution in Vertebrates: Facts and Challenges

Laboratory of Molecular Evolution, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy

Received 31 July 2013; Revised 11 November 2013; Accepted 23 November 2013; Published 16 January 2014

Academic Editor: Y. Satta

Copyright © 2014 Annalisa Varriale. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

DNA methylation is a key epigenetic modification in the vertebrate genomes known to be involved in biological processes such as regulation of gene expression, DNA structure and control of transposable elements. Despite increasing knowledge about DNA methylation, we still lack a complete understanding of its specific functions and correlation with environment and gene expression in diverse organisms. To understand how global DNA methylation levels changed under environmental influence during vertebrate evolution, we analyzed its distribution pattern along the whole genome in mammals, reptiles and fishes showing that it is correlated with temperature, independently on phylogenetic inheritance. Other studies in mammals and plants have evidenced that environmental stimuli can promote epigenetic changes that, in turn, might generate localized changes in DNA sequence resulting in phenotypic effects. All these observations suggest that environment can affect the epigenome of vertebrates by generating hugely different methylation patterns that could, possibly, reflect in phenotypic differences. We are at the first steps towards the understanding of mechanisms that underlie the role of environment in molding the entire genome over evolutionary times. The next challenge will be to map similarities and differences of DNA methylation in vertebrates and to associate them with environmental adaptation and evolution.