Genetics and characteristics
The dominant Em allele of MC1R is responsible for the localized distribution of eumelanin on the muzzle that resembles a darkened mask in a pheomelanic (ay) background. The melanistic mask caused by one copy of this allele is only visible on dogs that are fawn or brindle. The mask can be black, liver, blue, or isabella on the muzzle and sometimes the ears. Dogs that are solid black, brown, or blue do not have a mask that is distinguishable from their body color. However, dogs that fade to grey with age do show their mask for a time. Similarly, dogs that have white muzzles do not produce melanin in that area of the body and so they may not exhibit a mask, even if they carry this allele.
Results Reported As
Test Result |
Interpretation of test result |
|
|
|
|
|
|
|
|
|
References:
Newton, J.M., Wilkie, A.L., He, L., Jordan, S.A., Metallinos, D.L., Holmes, N.G., Jackson, I.J., and Barsh, G.S. (2000). Melanocortin 1 receptor variation in the domestic dog. Mamm. Genome 11, 24–30.
Schmutz, S.M., and Berryere, T.G. (2007). Genes affecting coat colour and pattern in domestic dogs: a review. Anim. Genet. 38, 539–549.
Schmutz, S.M., Berryere, T.G., Ellinwood, N.M., Kerns, J.A., and Barsh, G.S. (2003). MC1R Studies in Dogs With Melanistic Mask or Brindle Patterns. J Hered 94, 69–73.