OMIA:001199-9614 : Coat colour, extension in Canis latrans (coyote)

In other species: lorises , dog , red fox , American black bear , domestic cat , jaguar , ass (donkey) , horse , Przewalski's horse , pig , Arabian camel , reindeer , taurine cattle , indicine cattle (zebu) , goat , sheep , rabbit , Mongolian gerbil , domestic guinea pig , domestic yak , fallow deer , alpaca , gray squirrel , raccoon dog , antarctic fur seal , woolly mammoth , rock pocket mouse , oldfield mouse , lesser earless lizard , Geoffroy's cat , jaguarundi , Colocolo , little striped whiptail , water buffalo , Arctic fox

Categories: Pigmentation phene

Links to possible relevant human trait(s) and/or gene(s) in OMIM: 266300 (trait) , 155555 (gene)

Mendelian trait/disorder: unknown

Considered a defect: no

Key variant is published: no

Cross-species summary: The extension locus encodes the melanocyte-stimulating hormone receptor (MSHR; now known as MC1R). This receptor controls the level of tyrosinase within melanocytes. Tyrosinase is the limiting enzyme involved in synthesis of melanins: high levels of tyrosinase result in the production of eumelanin (dark colour, e.g. brown or black), while low levels result in the production of phaeomelanin (light colour, e.g. red or yellow). When melanocyte-stimulating hormone (MSH) binds to its receptor, the level of tyrosinase is increased, leading to production of eumelanin. The wild-type allele at the extension locus corresponds to a functional MSHR, and hence to dark pigmentation in the presence of MSH. As explained by Schneider et al. (PLoS Genet 10(2): e1004892; 2015), "The most common causes of melanism (black coat) mutations are gain-of-function alterations in MC1R, or loss-of function alterations in ASIP, which encodes Agouti signaling protein, a paracrine signaling molecule that inhibits MC1R signaling". Mutations in MC1R have been associated with white colouring in several species.

Molecular basis: By comparing the sequence at three coat-colour genes (MC1R, ASIP, and CBD103) in all-white and coloured coyotes from Newfoundland, Brockerville et al. (2013) provided data strongly implicating one or both of two mutations (P159Q or R306Ter) in the MC1R gene as being causative of white coat colour in these coyotes. Further work is required to confirm a causal mutation.

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2013). OMIA:001199-9614: Online Mendelian Inheritance in Animals (OMIA) [dataset].


2013 Brockerville, R.M., McGrath, M.J., Pilgrim, B.L., Marshall, H.D. :
Sequence analysis of three pigmentation genes in the Newfoundland population of Canis latrans links the Golden Retriever Mc1r variant to white coat color in coyotes. Mamm Genome 24:134-41, 2013. Pubmed reference: 23297074. DOI: 10.1007/s00335-012-9443-x.

Edit History

  • Created by Frank Nicholas on 06 Feb 2013
  • Changed by Frank Nicholas on 05 Aug 2013