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

In other species: cattle , dog , horse , red fox , pig , sheep , jaguar , jaguarundi , American black bear , woolly mammoth , domestic cat , rabbit , domestic guinea pig , goat , Arctic fox , rock pocket mouse , oldfield mouse , gray squirrel , lesser earless lizard , little striped whiptail , water buffalo , domestic yak , alpaca , , reindeer , Geoffroy's cat , Kodkod , Colocolo , ass , Arabian camel , Mongolian gerbil

Possibly relevant human trait(s) and/or gene(s) (MIM number): 266300

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; also 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.

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.

Reference


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