OMIA:001199-494514 : Coat colour, extension in Vulpes lagopus (Arctic fox)

In other species: lorises , coyote , 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

Categories: Pigmentation phene

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

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal recessive

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2005

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.

Inheritance: As summarised by Yan et al. (2013), "According to their coat colour phenotype in winter, arctic fox (Alopex lagopus) are divided naturally into two colour morphs: the white and blue, named polar fox and blue fox respectively . . . . The two coat colours are determined by different alleles at the E locus, where the ‘blue’ allele Ed is dominant over the ‘white’ one E (Adalsteinsson et al. 1987)."

Mapping: Tietgen et al. (2021): "Using a whole-genome approach, we identified the MC1R gene as the sole causal gene underlying Arctic fox Vulpes lagopus fur colour."

Molecular basis: The blue (Ed) allele is a haplotype comprising two missense variants (p.Gly5Cys and p.Phe280Cys) (Våge et al., 2005)

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
MC1R Vulpes lagopus - no genomic information (-..-) MC1R Ensembl


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WARNING! Inclusion of a variant in this table does not automatically mean that it should be used for DNA testing. Anyone contemplating the use of any of these variants for DNA testing should examine critically the relevant evidence (especially in breeds other than the breed in which the variant was first described). If it is decided to proceed, the location and orientation of the variant sequence should be checked very carefully.

Since October 2021, OMIA includes a semiautomated lift-over pipeline to facilitate updates of genomic positions to a recent reference genome position. These changes to genomic positions are not always reflected in the ‘acknowledgements’ or ‘verbal description’ fields in this table.

OMIA Variant ID Breed(s) Variant Phenotype Gene Allele Type of Variant Source of Genetic Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
262 Blue coat colour MC1R Ed missense Naturally occurring variant p.[(G5C);(F280C)] The blue (Ed) allele is a haplotype comprising two missense variants (p.Gly5Cys and p.Phe280Cys) (Våge et al., 2005) 2005 15982782

Cite this entry

Nicholas, F. W., Tammen, I., & Sydney Informatics Hub. (2021). OMIA:001199-494514: Online Mendelian Inheritance in Animals (OMIA) [dataset].


Note: the references are listed in reverse chronological order (from the most recent year to the earliest year), and alphabetically by first author within a year.

2022 Ji, R.L., Tao, Y.X. :
Melanocortin-1 receptor mutations and pigmentation: Insights from large animals. Prog Mol Biol Transl Sci 189:179-213, 2022. Pubmed reference: 35595349. DOI: 10.1016/bs.pmbts.2022.03.001.
2021 Tietgen, L., Hagen, I.J., Kleven, O., Bernardi, C.D., Kvalnes, T., Norén, K., Hasselgren, M., Wallén, J.F., Angerbjörn, A., Landa, A., Eide, N.E., Flagstad, Ø., Jensen, H. :
Fur colour in the Arctic fox: genetic architecture and consequences for fitness. Proc Biol Sci 288:20211452, 2021. Pubmed reference: 34583587. DOI: 10.1098/rspb.2021.1452.
2016 Liu, Z., Gong, Y., Feng, M., Duan, L., Li, Y., Li, X. :
Genetic variations of the coding region of the melanocortin receptor 1 (MC1R) gene in the fox. Vet Dermatol 27:135-e36, 2016. Pubmed reference: 27072328. DOI: 10.1111/vde.12303.
2013 Nowacka-Woszuk, J., Salamon, S., Gorna, A., Switonski, M. :
Missense polymorphisms in the MC1R gene of the dog, red fox, arctic fox and Chinese raccoon dog. J Anim Breed Genet 130:136-41, 2013. Pubmed reference: 23496014. DOI: 10.1111/jbg.12005.
Switonski, M., Mankowska, M., Salamon, S. :
Family of melanocortin receptor (MCR) genes in mammals-mutations, polymorphisms and phenotypic effects. J Appl Genet 54:461-72, 2013. Pubmed reference: 23996627. DOI: 10.1007/s13353-013-0163-z.
2005 Vage, DI., Fuglei, E., Snipstad, K., Beheim, J., Landsem, VM., Klungland, H. :
Two cysteine substitutions in the MC1R generate the blue variant of the Arctic fox (Alopex lagopus) and prevent expression of the white winter coat. Peptides 26:1814-7, 2005. Pubmed reference: 15982782. DOI: 10.1016/j.peptides.2004.11.040.
1987 Adalsteinsson, S., Hersteinsson, P., Gunnarsson, E. :
Fox colors in relation to colors in mice and sheep Journal of Heredity 78:235-237, 1987. Pubmed reference: 3624844.

Edit History

  • Created by Frank Nicholas on 18 Jul 2010
  • Changed by Frank Nicholas on 10 Aug 2011
  • Changed by Frank Nicholas on 12 Oct 2011
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  • Changed by Frank Nicholas on 08 Dec 2013
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  • Changed by Frank Nicholas on 30 Mar 2020
  • Changed by Imke Tammen2 on 03 Oct 2021