a protein illustrated to have roles in melanogenesis in humans, mice, and medaka, though the specific action is not known. Mutations in the human Matp gene result in several distinct forms of Oculocutaneous albinism, Type IV as well as normal variations in skin and hair color. Mice affected by a condition homologous to cream, called underwhite, exhibit irregularly shaped melanosomes, which are the organelles within melanocytes that directly produce pigment. The first descriptions of the dosage-dependent genetic control of the palomino coat color occurred early on in equine coat color inheritance research. However, the distinction between Dun and Cream remained poorly understood until Stefan Adalsteinsson wrote Inheritance of the palomino color in Icelandic horses in 1974. The mutation responsible, a single nucleotide polymorphism in Exon 2 resulting in an aspartic acid-to-asparagine substitution (N153D), was located and described in 2003 by a research team in France. Cream phenotypes C/C homozygous wildtype. Visually, the horse may be any color other than the cream dilute shades of palomino, buckskin, smoky black, cremello, perlino, smoky cream, and so on. CCr/C heterozygous. The colors most commonly associated with this genotype are palomino, buckskin, and smoky black, though the phenotype may vary depending on other factors. Any pheomelanin in the coat is diluted to yellow or gold, and the eyes and skin are often slightly lighter than unaffected horses. CCr/CCr homozygous. The colors most commonly associated with this genotype are cremello, perlino, and smoky cream. Regardless, the coat will be cream- or ivory-colored, and the skin a rosy-pink. The eyes are pale blue. Champagne Champagne is a gene that controls the saturation or dilution of pigment in the coat. Unlike Cream, Champagne is not strongly dosage-dependent, and affects both types of pigment equally. Champagne differs from Dun in that it affects the color of the coat, skin, and eyes, and in that the unaffected condition is the wildtype. Horses with the dominant CH allele (CH/CH or CH/ch genotype) exhibit hypomelanism of the body coat, such that phaeomelanin is diluted to gold and eumelanin is diluted to tan. Affected horses are born with blue eyes which darken to amber, green, or light brown, and bright pink skin which acquires darker freckling with maturity. The difference in phenotype between the homozygous (CH/CH) and heterozygous (CH/ch) horse may be subtle, in that the coat of the homozygote may be a shade lighter, with less mottling. Horses with the homozygous