Dog Coat Color - E Locus (Cream; e2) – Australian Cattle Dog

Acronym:	E Locus (e2)
Gene:	MC1R
Mutation:	c.-432G>C
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 variant of MC1R that has been described in Australian Cattle dogs causes a cream color phenotype due to loss-of-function protein. Dogs carrying that mutation are usually creamy white and have pink irides, noses, and lips.

The cream color in Australian Cattle dogs has an autosomal recessive mode of inheritance meaning only dogs with two mutated variants of e will show cream coat color. If the dog is carrying just one mutated gene and the other one is E or ancient red (e^A) variant, the dog will show normal or red ochre coat color. If the dog carries some other recessive variant of the MC1R gene such as apricot or yellow, the coat color is likely to be their mix. 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:

Brancalion, L., Haase, B., Wade, C. M. (2022). Canine coat pigmentation genetics: a review. Animal genetics, 53(1), 3–34. https://doi.org/10.1111/age.13154

Dürig, N., Letko, A., Lepori, V., Hadji Rasouliha, S., Loechel, R., Kehl, A., Hytönen, M. K., Lohi, H., Mauri, N., Dietrich, J., Wiedmer, M., Drögemüller, M., Jagannathan, V., Schmutz, S. M., Leeb, T. (2018). Two MC1R loss-of-function alleles in cream-coloured Australian Cattle Dogs and white Huskies. Animal genetics, 49(4), 284–290. https://doi.org/10.1111/age.12660