The hypothalamus is a key area of the brain for appetite regulation. More specifically, there are two neuronal circuits, in the arcuate nucleus of the hypothalamus, that are important in both nutritional status and regulating energy homeostasis. One neuronal circuit contains the anorexigenic neuropeptides, including pro-opiomelanocortin (POMC), and the other circuit contains orexigenic peptides such as neuropeptide Y .
Pro-opiomelanocortin is a prohormone that codes for many different peptides including adrenocorticotrophin (ACTH), alpha melanocyte stimulating hormone (α-MSH), beta melanocyte stimulating hormone (β-MSH), gamma melanocyte stimulating hormone (γ-MSH), and β-endorphin (β-END) some of which are involved in the appetite pathway . The main POMC encoded anorectic peptide responsible for reductions in food intake and appetite is αMSH which reduces appetite when bound to melanocortin 4-receptor (MC4R) or melanocortin 3-receptor (MC3R); γ and β MSH also reduce appetite but not to the same magnitude as α-MSH.
The prohormone POMC undergoes many post-translational cleavages as it passes through the Golgi bodies via the regulated secretory pathway (RSP) . POMC is cleaved by prohormone convertases (PC1 and PC2) to produce the range of bioactive peptides [2, 4, 5]. The prohormone convertases (PC) cleave at the eight pairs, and one quadruplet, of basic amino acids contained within POMC .
The importance of POMC in the appetite pathway has made it a strong candidate gene for obesity in humans and carcass traits in livestock. Mutations in POMC in humans have been associated with obesity [6, 7]. In beef cattle Thue and Buchanan  discovered POMC c.288C>T and mapped it to BTA 11: this SNP does not alter the amino acid - it remains a serine. This area is known to harbour a quantitative trait locus (QTL) affecting carcass weight and average daily gain . Buchanan et al.  found an association between POMC c.288C>T with ship weight and hot carcass weight (HCW) in 256 Charolais cross steers.
The value of beef is currently determined based on lean meat yield and the extent of marbling. Consequently, it is important to study genes that are part of the appetite pathway and that may ultimately affect carcass composition. Since an association between POMC c.288C>T with hot carcass weight and shipping weight had already been established , it was important validate this association in another population.