Genome-wide DNA methylation in Tibetan chicken and Chahua chicken embryos

In this study, methylated DNA immunoprecipitation and high-throughput sequencing (MeDIP-seq) was used to provide an atlas of DNA methylomes in the heart tissue of hypoxic highland Tibetan and lowland Chahua chicken embryos.A total of 31.2 gigabases (Gb) of sequence data were generated from six MeDIP-seq libraries. We identified 1049 differentially methylated regions (DMRs) and 695 related differentially methylated genes (DMGs) between the two chicken breeds. The DMGs were involved in vascular smooth muscle contraction, VEGF signaling pathway, calcium signaling pathway, and other hypoxia related pathways. Five candidate genes that had low methylation (EDNRA, EDNRB, BMPR1B, BMPRII, and ITGA2) might have key regulatory functions for hypoxia adaptation in Tibetan chicken embryos. Our study provides significant explanations for the functions of genes and their epigenetic regulation for hypoxic adaptation in Tibetan chickens. Overall design: we use MeDIP-seq to generate an atlas of DNA methylomes in heart tissue of hypoxic chicken embryos to investigate the difference in DNA methylation between Tibetan chickens and their lowland counterparts.