E Locus - Ea (Ancient Red) - Spitz and Scent Hound Type

Acronym:	Ea locus
Gene:	MC1R
Mutation:	g.63694349C>T
Inheritance:	Autosomal Recessive
Sample type:	CHS (Cheek Swab), WBE (Whole Blood EDTA)

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Genetics and characteristics

Coat color in dogs is an important characteristic along with hair length, growth pattern, and curl. Coat color is determined by the expression of two melanin pigments, eumelanin (black/brown) and pheomelanin (yellow/red). The Melanocortin 1 Receptor (MC1R) plays a central role in the regulation of coat color determination in various species, including dogs, and is commonly referred to as the E (extension) Locus. It represents the key signaling molecule on melanocytes inducing expression of enzymes responsible for eumelanin synthesis Previously, there have been reported few variants of the MC1R gene that are causing different color phenotypes with different inheritance patterns. Those variants include phenotypes such as E^m (melanistic mask), E^g (grizzle/domino), e^A (ancient red) and e^1-3 (recessive apricot/yellow/red, cream, white) in dogs. A point mutation variant of MC1R that has been described in Spitz and Scent Hound dogs causes a red color phenotype called ancient red (e^A) or red ochre color.

The ancient red color in Spitz and Scent Hound dogs has a complex inheritance pattern, involving several genes, but the most important is the MC1R gene. This mutation is recessive to the E variant (which allows dark pigment) and dominant to the e allele (red/apricot/cream). If the dog carries an ancient red variant and dominant E variant, its coat will be dark-colored. If the dog carries a recessive e variant and an e^A variant or both e^A variants, it will result in an ancient red coat pattern. Genetic testing can identify carriers and help breeders in future mating pairs selection.

 

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Results Reported As

 

 

 

 

 

 

 

 

 

 

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References:

Newton, J. M., Wilkie, A. L., He, L., Jordan, S. A., Metallinos, D. L., Holmes, N. G., Jackson, I. J., Barsh, G. S. (2000). Melanocortin 1 receptor variation in the domestic dog. Mammalian genome : official journal of the International Mammalian Genome Society, 11(1), 24–30. https://doi.org/10.1007/s003350010005

Anderson, H., Honkanen, L., Ruotanen, P., Mathlin, J., Donner, J. (2020). Comprehensive genetic testing combined with citizen science reveals a recently characterized ancient MC1R mutation associated with partial recessive red phenotypes in dog. Canine medicine and genetics, 7(1), 16. https://doi.org/10.1186/s40575-020-00095-7