Linkage and Segregation Analysis of Black and Brindle Coat Color in Domestic Dogs

摘要: Mutations of pigment type switching have provided basic insight into melanocortin physiology and evolutionary adaptation. In all vertebrates that been studied to date, two key genes, Agouti Melanocortin 1 receptor (Mc1r), encode a ligand-receptor system controls the switch between synthesis red–yellow pheomelanin vs. black–brown eumelanin. However, in domestic dogs, historical studies based on pedigree segregation analysis suggested type-switching is more complicated fundamentally different from other mammals. Using genomewide linkage scan Labrador × greyhound cross segregating for black, yellow, brindle coat colors, we demonstrate controlled by an additional gene, K locus. Our results reveal three alleles with dominance order black (KB) > (kbr) yellow (ky), whose genetic map position dog chromosome 16 distinct predicted location pigmentation genes. Interaction Mc1r epistatic variation at or relationship depends being tested. These findings suggest molecular model new component signaling pathway how coat-color patterns pigmentary diversity shaped recent selection.