Epigenetic Pattern on the Human Y Chromosome is Evolutionarily Conserved

DNA methylation is very important for mammalian development. However, it is unclear whether the DNA methylation pattern is evolutionarily conserved. The Y-chromosome serves as a powerful tool for the study of human evolution because it is only transferred between males. In this study, based on deep-rooted pedigrees and the latest Y-chromosome phylogenetic tree, we performed epigenetic pattern analysis of Y-chromosome from 72 donors. By comparing their respective DNA methylation levels, we found that the DNA methylation pattern on the Y-chromosome was stable among family members and within haplogroups. Despite two haplogroup-specific methylation sites were found, they were both genotype-dependent. Moreover, with a remote divergence time, the African and Asian samples also had similar DNA methylation patterns. Our findings indicated that the DNA methylation pattern on Y-chromosome was conservative during human male history. Bisulphite converted DNA from the 74 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip.