Structural analysis and haplotype diversity in swine LEP and MC4R genes.

Knowledge about structural variation of candidate genes could be important to improve breeding selection scheme and preserve genetic variability in livestock species. Leptin (LEP) and melanocortin-4 receptor (MC4R) genes are involved in the energetic pathway and are obvious candidate genes for fatness. By sequencing LEP and MC4R genes in 72 pigs belonging to lean (Large White and Duroc), fat (Meishan and Casertana) breeds and also Wild Boar, 98 polymorphic sites, of which 91 were novel, were found in the Leptin sequence while only the previously described mutation was found in the MC4R gene. A total of 18 LEP haplotypes were observed and their distribution was unequal among the breeds. The phylogenetic analysis showed two haplotype branches distinguishing between lean and fat breeds.