PPARGC1A and obesity due to melanocortin 4 receptor deficiency: To investigate the role of dietary fat, purified dietary Q, and ROE in determining Pgc-1α DNA methylation in skeletal muscle in association with HFD-induced obesity and insulin resistance and elaborate on how these epigenetic effects associate with splice variant expression, we used diet-induced obese C57BL/6J mice as a model system.