The Agouti Signaling Protein (ASIP) gene interacts with the MC1R gene to control red and black pigment switching in dogs, affecting amount, type, and distribution of the two pigments.
Several gene variants are known to produce dilute coloration in dogs. Colors are lightened (diluted) to paler shades as a result of the variants' effects on pigmentation.
The Dominant Black gene (K Locus) affects pigment switching between eumelanin (black) and phaeomelanin (red or yellow) by interacting with the Agouti and MC1R genes.
White spotting patterns that occur in many dog breeds do not have a uniform genetic basis, and the genetics are complex. In piebald/parti/random white spotting, the extent of white pattern expression varies, and markings are often asymmetrical.
