A gene containing 954 bp which encodes the melanocyte-1-receptor, a protein that contains 317 amino acids. The dominant allele (D) encodes a protein that stimulates the production of black melanin. The recessive allele (d) encodes an isoform (q.v.) which differs from the D protein by 4 amino acid substitutions. Mice homozygous for d are light colored. In Chaetodipus intermedius (q.v.) the D allele is found in those races of mice that live among the dark rocks of ancient lava flows. Mice living in areas of light-colored rocks and sand are homozygous for the d allele. See Chronology, 2003, Nachman, Hoekstra, D'Agostino; adaptive melanism, melanin.
Subjects: Genetics and Genomics.