UC Davis School of Veterinary Medicine Veterinary Genetics Laboratory
SERVICES
Dog Coat Color Agouti Test

Agouti

Order this test on MyVGL

The Agouti Signaling Protein (ASIP) gene interacts with the MC1r gene to control red and black pigment switching in most mammals including dogs. Dog coat color is further complicated by the interaction of other genes that restrict agouti expression such as the dominant black gene – Beta-Defensin 103. There are 4 known alleles (variants) of agouti listed here with corresponding color pattern in order of dominance: fawn/ sable (ay) yellow to red with some dorsal black tipped hairs, wild sable (aw) banded hairs of yellow and black as in seen in wolves and coyotes, black-and-tan (at) black dorsal hairs with tan hair on cheeks, eyebrows and undersides, and recessive black (a) all black as seen in some herding dogs.  The Eurasier dog breed has all 4 alleles while some breeds are fixed for only one variant such as the Norwegian Elkhound for wild sable and the Beagle for black-and-tan. For many breeds, there are 2 or 3 alleles possible and it may be advantageous for breeders to predict the possible colors of offspring resulting from specific matings.  The agouti test is also useful to help determine the color of dogs that have white patterns that may obscure the distribution of the colored pigment.

The Veterinary Genetics Lab offers a test for agouti to assist breeders/owners to determine the agouti alleles present in their dogs. This test will help determine possible coat color outcomes from specific matings. Results are reported as:

ay / ay   Homozygous for fawn/ sable.

ay / aDog is fawn and carries wild sable.

ay / at  Dog is fawn and carries black-and-tan.

ay / a  Dog is fawn and carries recessive black.

aw/ aw  Homozygous for wild-sable.

aw/ at  Dog is wild-sable and carries black-and-tan.

aw/ a   Dog is wild-sable and carries recessive black.

at/ at  Homozygous for black-and-tan.

at/ a  Dog is black-and-tan and carries recessive black.

a/a   Homozygous for recessive black.

References:

Berryere TG, JA Kerns, GS Barsh and SM Schmutz. Association of an Agouti allele with fawn or sable coat color in domestic dogs. Mammalian Genome 16: 262-272 (2005)

Kerns JA, J Newton, TG Berryere, EM Rubin, JF Cheng, SM Schmutz and GS Barsch. Characterization of the dog Agouti gene and a nonagouti mutation in German Shepard Dogs. Mammalian Genome 15:798-808 (2004).

Dreger DL and SM Schmutz. A SINE insertion causes the black-and-tan and saddle tan phenotypes in domestic dogs. Journal of Heredity 102(S1):S11-S18 (2011).

Veterinary Genetics Laboratory, Tel 530-752-2211, Email VGL