ELOVL2, FHL2 and PENK age-dependent DNA hypermethylation as a tool to infer age on forensic and ancient samples

The complex interaction between genetics and environment is mediated by epigenetics in a dynamic way. Epigenetics is a molecular mechanism that through reversible modification of cytosines and nuclear proteins is able to produce new phenotypes, relatively stable over time. These and other characteristics make this modification a perfect candidate for anthropological studies. Here we used Sequenom EpiTYPER assay (a single CpG resolution method) and we identified 3 regions, the CpG islands of ELOVL2, FHL2 and PENK genes, whose methylation level strongly correlates with chronological age. ELOVL2 displayed not only striking correlation levels, but also an almost ‘on-off’ methylation trend between the two extremes of life. These promising results can be exploited in two different fields of anthropological sciences: 1. Forensic applications. Epigenetic variability is an emerging tool for forensic applications, such as the identification of body fluid. Here we suggest the use of ELOVL2, FHL2 and PENK DNA methylation to assess the age of an individual on the basis of his blood traces found at a crime scene. 2. Ancient DNA studies. Epigenetics is a very informative and promising process to study evolution because it creates phenotypic diversity both within an individual and within population without genetic variation and because epigenetic variation could be transmitted through the germ line. However to perform this type of study tissue-specificity of epigenetic biomarkers should be considered. Here we discuss an experimental design to assess DNA methylation profile of teeth, the major source of DNA for studies on ancient DNA.