Dominant Black K Locus | Seal | Brindle
Coat colors in mammals is achieved by the production of two pigments, eumelanin aka black, and pheomelanin aka red or yellow. Most of the time, these 2 pigments are controlled by MC1R and Agouti genes. Coat color research in dogs has shown that a third gene, Dominant Black, K locus is involved. This gene produces either dominant black, brindle, and fawn color. The Seal Color is also somehow produced involving this gene.
K/K 2 copies of dominant black, dog will be visibly trindle, seal, or brindle
K/N 1 copy of dominant black, dog will be visibly trindle, seal, or brindle
N/N Dog does not have the dominant black mutation