CPT1A and obesity due to melanocortin 4 receptor deficiency: In chickens, PPARα mRNA expression was found to be negatively correlated with IMF from 0 to 8 w in thigh muscle tissue40. Carnitine palmitoyl transferase 2 (CPT2) is an enzyme required for mitochondrial long-chain fatty acid oxidation, and the loss of muscle CPT2led to accumulation of long-chain acylcarnitine and protected against diet-induced obesity and insulin resistance in mice41; Mitochondrial carnitine palmitoyl transferase 1a (CPT1A) in the liver mitochondrial outer membrane was found to catalyze the primary regulatory step in overall mitochondrial fatty acid oxidation42.