E Locus (MC1R)
The E Locus determines if and where a dog can produce dark (black or brown) hair. Dogs with two copies of
the recessive e allele do not produce dark hairs at all, and will be “red” over their entire body.
The shade of red, which can range from a deep copper to yellow/gold to cream, is dependent on other genetic
factors including the Intensity (I) Locus, which has yet to be genetically mapped. In addition to
determining if a dog can develop dark hairs at all, the E Locus can give a dog a black “mask” or “widow’s
peak,” unless the dog has overriding coat color genetic factors. Dogs with one or two copies of the
Em allele usually have a melanistic mask (dark facial hair as commonly seen in the German Shepherd
and Pug). Dogs with no copies of Em but one or two copies of the Eg allele usually have a
melanistic "widow's peak" (dark forehead hair as commonly seen in the Afghan Hound and Borzoi, where it is
called either “grizzle” or “domino”).
Learn More: http://www.doggenetics.co.uk/masks.html
Citations: Schmutz et al 2003,Dreger and Schmutz 2010,Ollivier et al 2017
K Locus (CBD103)
The K Locus KB allele “overrides” the A Locus, meaning that it prevents the A Locus
genotype from affecting coat color. For this reason, the KB allele is referred to as the
“dominant black” allele. As a result, dogs with at least one KB allele will usually have
solid black or brown coats (or red/cream coats if they are ee at the E Locus) regardless of their
genotype at the A Locus, although several other genes could impact the dog’s coat and cause other patterns,
such as white spotting. Dogs with the kyky genotype will show a coat color
pattern based on the genotype they have at the A Locus.
Learn More: http://www.doggenetics.co.uk/black.htm
Citations: Candille et al 2007
A Locus (ASIP)
The A Locus controls switching between black and red pigment in hair cells, but it will only be expressed
in dogs that are not ee at the E Locus and are kyky at the K Locus.
Sable (also called “Fawn”) dogs have a mostly or entirely red coat with some interspersed black hairs.
Agouti (also called “Wolf Sable”) dogs have red hairs with black tips, mostly on their head and back. Black
and tan dogs are mostly black or brown with lighter patches on their cheeks, eyebrows, chest, and legs.
Recessive black dogs have solid-colored black or brown coats.
Learn More: http://www.doggenetics.co.uk/tan.html
Citations: Berryere et al 2005,Dreger and Schmutz 2011
D Locus (MLPH)
Dogs with two copies of the d allele will have all black pigment lightened (“diluted”) to gray, or
brown pigment lightened to lighter brown in their hair, skin, and sometimes eyes. There are many
breed-specific names for these dilute colors, such as “blue”, “charcoal”, “fawn”, “silver”, and “Isabella”.
Note that dilute dogs have a higher incidence of Color Dilution Alopecia, especially in certain breeds. Dogs
with one copy of the d allele will not be dilute, but can pass the d allele on to their
Learn More: http://www.doggenetics.co.uk/dilutes.html
Citations: Drogemuller et al 2007,Bauer et al 2018
B Locus (TYRP1)
Dogs with two copies of the b allele produce brown pigment instead of black in both their hair and
skin. Dogs with one copy of the b allele will produce black pigment, but can pass the b allele
on to their puppies. E Locus ee dogs that carry two b alleles will have red or cream coats,
but have brown noses, eye rims, and footpads (sometimes referred to as "Dudley Nose" in Labrador
Retrievers). “Liver” or “chocolate” is the preferred color term for brown in most breeds; in the Doberman
Pinscher it is referred to as “red”.
Learn More: http://www.doggenetics.co.uk/liver.html
Citations: Schmutz et al 2002
Saddle Tan (RALY)
The "Saddle Tan" pattern causes the black hairs to recede into a "saddle" shape on the back, leaving a tan
face, legs, and belly, as a dog ages. The Saddle Tan pattern is characteristic of breeds like the Corgi,
Beagle, and German Shepherd. Dogs that have the II genotype at this locus are more likely to be
mostly black with tan points on the eyebrows, muzzle, and legs as commonly seen in the Doberman Pinscher and
the Rottweiler. This gene modifies the A Locus at allele, so dogs that do not express
at are not influenced by this gene.
Citations: Dreger et al 2013
M Locus (PMEL)
Merle coat patterning is common to several dog breeds including the Australian Shepherd, Catahoula Leopard
Dog, and Shetland Sheepdog, among many others. Merle arises from an unstable SINE insertion (which we term
the "M*" allele) that disrupts activity of the pigmentary gene PMEL, leading to mottled or patchy coat
color. Dogs with an M*m result are likely to be phenotypically merle or could be "phantom" merle,
that is, they have a merle allele that does not affect coat color. Dogs with an M*M* result are
likely to be phenotypically merle or double merle. Dogs with an mm result have no merle alleles and
are unlikely to have a merle coat pattern.
Note that Embark does not currently distinguish between
the recently described cryptic, atypical, atypical+, classic, and harlequin merle alleles. Our merle test
only detects the presence, but not the length of the SINE insertion. We do not recommend making breeding
decisions on this result alone. Please pursue further testing for allelic distinction prior to breeding
Learn More: http://www.doggenetics.co.uk/merle.html
Citations: Clark et al 2006