Fig. 1

Inheritance of the basic coat colour loci. Locus E affects the distribution of eumelanin and pheomelanin. In dogs, there are three alleles with specific dominance (E^m > E > e). E^m is responsible for melanistic mask and e is responsible for recessive red. The K locus is hypostatic for the E locus, and there are also three alleles with a specific hierarchy (K > K^br > k). The K allele is responsible for dominant black and K^br is responsible for brindle colour. Locus A has four alleles, and the dominance of these alleles is A^y > A^w > A^t > a. Allele A^y is responsible for fawn or sable colour. Allele A^w represents wild colouration, which is ancestral. Allele A^t represents black and tan or saddle and tan colouration, and allele a is responsible for recessive black. Alleles E and k are wild-type, and coat colour is under the control of hypostatic loci