Dog

The B (brown) locus refers to different mutations in the TYRP1 gene causing the brown coat colour. In the Lancashire Heeler, a specific mutation (be) has been identified in addition to the classic mutations (bs, bd, bc) in the Locus-B test.

The B (brown) locus refers to different mutations in the TYRP1 gene causing the brown coat colour. In the Australian Shepherd, a specific mutation (b4) has been identified in addition to the classic mutations (bs, bd, bc) in the Locus-B test.

The locus E or extension refers to a mutation in the MC1R gene. Dogs with one or two dominant E alleles produce eumelanin (black pigment) while dogs with two copies of the e^1 allele will have a red or yellow coat. For dogs with at least one E allele, coat colour will be determined by other genes, including the A, B, D and K locus. Two other variants of this mutation were identified in 2018: the e^2 allele found in the Australian Cattle Dog (see DOG-LOCUS-E-CATTLEDOG) and the e^3 allele in the Husky (see DOG-LOCUS-E-HUSKY).

The E locus or extension refers to a mutation in the MC1R gene. For this test code, the mutation tested is the e^3 mutation. In the husky, dogs with two copies of the e^1 or e^3 alleles will have a white coat. For the e^1 allele and other breeds, see the following link:  DOG-LOCUS-E.

The E locus or extension refers to a mutation in the MC1R gene. For this test code, the mutation being tested is the e^2 mutation. In the Australian Cattle Dog, dogs with two copies of the e^1 or e^2 alleles or one copy of each allele will have a cream coat. For the e^1 allele and other breeds, see the following link: DOG-LOCUS-E.

Locus Em or melanin mask causes the black mask on the dog's face. This allele is dominant because only one copy is needed to express the mask phenotype. The mask can be tested for in any breed, but is most commonly found in the breeds listed below.

Locus K or dominant black has 3 variants KB, Kbr and ky. The KB allele prevents the expression of the A or agouti locus, the coat colour is then determined by the B and E locus. The coat colour of dogs that are ky/ky will be determined by the A locus. The Kbr variant is responsible for the brindle coat but the mutation has not yet been identified.

The locus D or dilution refers to a mutation in the MLPH gene that causes a diluted coat colour. This mutation dilutes black to blue, chocolate to lilac and yellow to champagne. The mutation tested is the d^1 mutation. For the breeds Chow Chow, Sloughi and Thai Ridgeback, the test to be performed is the DOG-LOCUS-D-CHOW test.

Locus S identifies piebald/white spotting patterns in dogs. A particular mutation within the MITF gene is linked to piebald spotting, though its impact varies across breeds. In breeds such as Collies and Boxers, this mutation exhibits dosage-dependent effects, where one copy produces partial white patterns and two copies result in more extensive white. Conversely, in other breeds, piebald spotting follows a recessive pattern, necessitating two copies for manifestation.

The locus D or dilution refers to a mutation in the MLPH gene that causes a diluted coat colour. This mutation dilutes black to blue, chocolate to lilac and yellow to champagne. The mutation tested is the d^2 mutation and is specific to the Chow Chow, Sloughi and Thai Ridgeback breeds. For the other breeds, the test to be performed is the DOG-LOCUS-D test.