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. Mutations affecting the E-locus often result in a lightening of the coat, from black or brown to red, yellow or even white. This E-locus variant, designated as e^1, is a recessive mutation primarily observed in the Golden Retriever, Irish Setter and Labrador Retriever. Related variants are known to occur in the Husky and Australian Cattle Dog.
Affected dogs (e/e) typically have a fully red to yellow coat. Depending on the breed, this may be designated as apricot, cream, white, etc.
Coat colour is an intricate trait that involves a combination of multiple different genes. Testing for a range of different loci will give the most complete prediction of a dog's coat colour genetics.
Pubmed ID: 10602988
Omia ID: 1199
