The A-locus regulates the distribution of light and dark pigment. Common names for colours...plus
The A locus is responsible for a number of common coat patterns in the dog. Expression of the A-locus requires any combination of two ky or kbr alleles at the K locus, and at least one E or EM allele at the E locus. The Agouti gene and its variations determine the coat colours fawn / sable (Ay), wild type (aw), tan points (at), and recessive black (a). Ay is dominant to Aw, Aw is dominant to at, at is dominant to a.
HeredityAy > Aw > at > a
about one week after arrival of the sample in the lab