Knowledge Base

Panda White Spotting Dog - H354

White spotting in many animals is typically caused by a mutation to the tyrosine kinase receptor (KIT) gene. KIT plays a broad role in an animal's development and helps govern the formation of pigment-containing cells. In dogs there are several examples where a KIT mutation has been found to affect...

H-Locus (Harlequin)

The 20S proteasome β2 subunit (PSMB7) gene is responsible for the Harlequin coat pattern in Great Danes. This gene is also known as H-Locus. Harlequin is a pattern resulting from interaction of the Merle (M-locus) gene and the Harlequin (H-locus) gene on black pigment. The Harlequin gene can modify the Merle...

Coat Colour introduction Dogs

Dogs display a wide variety of coat colours and patterns. Classification of these colours can be confusing sometimes because different registries or associations may use different names for the same colour. In each dog two pigments are the basis for their coat colour: black pigment (eumelanin) and red/yellow/cream pigment (pheomelanin)....

S-Locus (Piebald)

The white spotting patterns that occur in many dog breeds do not have a uniform genetic basis. The Microphthalmia Associated Transcription Factor gene (MITF gene) is associated with many white spotting patterns. This gene is also known as the S-Locus. There are three major white spotting patterns described. One pattern...

E-Locus Dog - H632 / H734 / H791 / H783 / H784 / H818

Coat colour in dogs is controlled by a wide range of different genes working together. These genes are often referred to as ‘loci’. The Extension, or E-Locus, corresponds to the gene ‘melanocortin 1 receptor’ (MC1R), which is involved in the regulation of pigment production. Active MC1R causes a cell to...

Co-Locus (Cocoa)

The Hermansky-Pudlak syndrome 3 (HPS3) gene, also known as cocoa coat colour or co-locus is responsible for the brown colour in French Bulldogs. Mutations of the HPS3 gene interfere with the eumalin (black pigment) synthesis, which results in brown-pigmentation. The brown colour caused by the HPS3-variants is known to darken...

B-locus

The Tyrosinase-Related Protein 1 (TYRP1) gene, also known as Brown gene or B-Locus controls the dilution from black pigment to brown. The TYRP1 gene has no effect on the hair colour of dogs that are homozygous ee for the E-Locus as they do not have black pigment, but does have...

D-Locus Dog - H461 / H847 / H897

The Dilution, or D-Locus, corresponds to the gene for melanophilin, MLPH, which is involved in the distribution of pigment. Mutations of the D-Locus result in a ‘dilution’ that affects the eumelanin (black) and phaeomelanin (red/yellow) pigments in the coat. Affected dogs have a diluted or lighter coat coloration and nose,...

I-Locus

The MFSD12 gene, also known as I-Locus affects the expression of the pheomelanin (red) pigment. The MFSD12 gene has no effect on eumelanin (black) pigment, therefore the black coat and the black hair ends remain black. The mutation affects the pheomelanin in the entire coat resulting in a pure white...

A-Locus

The Agouti gene (ASIP gene) is responsible for the production of a protein that regulates the distribution of black pigment (eumelanin) within the hair shaft. This gene is also known as the A-locus and determines whether an animal expresses an agouti appearance, and if so what type, by controlling the...

K-Locus Dog (Dominant Black) - H819

The K-Locus (also known as the Dominant Black Locus) is one of the most fundamental factors in the development of a dog's coat colour. The K-Locus corresponds to the gene Beta-defensin 103 (CBD103). This gene affects pigment switching between eumelanin (black) and phaeomelanin (red or yellow) by interacting with the...

M-Locus (Merle)

The Silver gene (SILV gene), also called premelanosome protein (PMEL17 gene) is responsible for Merle. This gene is also known as M-Locus. Merle only dilutes eumelanin (black) pigment; dogs with two copies of the allele e (homozygous e/e) at E-Locus have no black pigment, thus do not express merle. Merle...

Saddle tan vs black-and-tan

The hnRNP associated with lethal yellow gene (RALY gene) defines whether tan points or saddle tan is expressed in Basset Hounds and Pembroke Welsh Corgi dogs. Black and tan colour is characterized by light colour on the muzzle, above the eyes (tan points) and on the undersides of the dog...

Albinism Dog - H393 / H715 / H751 / H894

Most genetically-determined coat colour traits are caused by various genes (mutated or otherwise) affecting the amount and distribution of melanin (pigment) in an animal's hairs and skin. Albinism, however, involves a general loss of pigment production. The traits described in this section are all forms of Oculocutaneous Albinism (OCA), an...

Roan-Ticked Dog - H763

The Ticking, or T-Locus, corresponds to the usherin gene (USH2A), which helps control the development of the dog’s coat pattern. T-Locus mutations in dogs cause the development of alternating areas of white and pigmented hairs, which can result in two distinct patterns: Ticked and Roan. A Ticked coat features dark,...

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