DNA methylation and expression of proopiomelanocortin (POMC) gene in the hypothalamus of three-week-old chickens show sex-specific differences

Increased availability and improved sequence annotation of the chicken (Gallus gallus f. domestica) genome have sparked interest in the bird as a model system to investigate translational embryonic development and health/disease outcomes. However, the epigenetics of this bird genome remain unclear. The aim of this study was to determine the levels of gene expression and DNA methylation at the proopiomelanocortin (POMC) gene in the hypothalamus of 3-week-old chickens. POMC is a key player in the control of the stress response, food intake, and metabolism. DNA methylation of the promoter, CpG island, and gene body regions of POMC were measured. Our data illustrate the pattern, variability, and functionality of DNA methylation for POMC expression in the chicken. Our findings show correlation of methylation pattern and gene expression along with sex-specific differences in POMC. Overall, these novel data highlight the promising potential of the chicken as a model and also the need for breeders and researchers to consider sex ratios in their studies.