E Locus (Extension)

For an overview of dog coat color hierarchy continue to the article Introduction into coat color in dogs.

The expression of E locus is affected by MC1R gene that is located on the canine chromosome 5. Within E locus, the allele as stated below are known:

• E – dominant, original so-called wild type allele (non-mutated form), allows the dog to produce a pigment called Eumelanin, i.e., dark brown to black melanin. To obtain this coat colour, the dog must have genotype E/E or E/e.
• e – recessive allele caused by mutation c.916C>T, and results in loss of function of MC1R-gene, is responsible for production of yellow pigment called Pheomelanin, i.e., resulting in bright red to yellow coat colour. The e/e genotype is the most recessive one, but epistatic, i.e., prevents the expression of the loci K and A.

If the allele is dominant, the offspring must inherit this allele only from one parent to get this coat colour. The recessive e allele is expressed if it is inherited from each parent.

.

Other alleles on locus E that are not determined by this test:

• EM – melanistic mask, production of black pigment eumelanin, faced-localized → for more information about this allele and for ordering the test continue here.
• EH – sable colour in English and American Cocker Spaniels → to find more information about this allele and ordering the test continue here.
• EG – grizzle colour in Saluki breed and domino colour in Afghan Hounds → for more information about this allele and for ordering the test continue here.

.

Other alleles known at E locus, however not tested in Genomia laboratory:

• In Australian Cattle dogs, e1 and e2 alleles that cause pale red colour has been discovered.
• e3 or e-del allele has been described in Nordic breeds (e.g., Siberian husky). If a dog bears two such alleles or one of these alleles and one e-allele, then the coat colour expression can vary from yellow or red colouring to more subtle differences as apricot, cream and white.

.

What is the relationship of E-locus to A and K loci? Continue and have a look at the dominance hierarchy of allele affecting the coat colour in dogs.