OMIA 001199-9793 : Coat colour, extension in Equus asinus

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 , , coyote , reindeer , Geoffroy's cat , Kodkod , Colocolo , Arabian camel , Mongolian gerbil

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

Mendelian trait/disorder: yes

Mode of inheritance: Autosomal Recessive

Considered a defect: no

Key variant known: yes

Year key variant first reported: 2014

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: Abitbol et al. (2014) "used a panel of 124 donkeys to identify a recessive missense c.629T>C variant in MC1R that showed a perfect association with the red coat colour. This variant leads to a methionine to threonine substitution at position 210 in the protein . . . , [a location in which] methionine 210 is highly conserved among vertebrate melanocortin receptors. Abitbol et al. (2014) proposed "to name the c.629T>C allele in donkeys the e allele". FN is grateful to Corinne Benavides for informing him of this paper describing red coat colour in donkeys, and a likely causal variant.

Breeds: miniature donkey, Normand.

Associated gene:

Symbol Description Species Chr Location OMIA gene details page Other Links
MC1R melanocortin 1 receptor (alpha melanocyte stimulating hormone receptor) Equus asinus - no genomic information (-..-) MC1R Homologene, Ensembl, NCBI gene

Variants

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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.

Breed(s) Variant Phenotype Gene Allele Type of Variant Reference Sequence Chr. g. or m. c. or n. p. Verbal Description EVA ID Year Published PubMed ID(s) Acknowledgements
miniature donkey Normand Red coat colour MC1R e missense c.629T>C p.M210T 2014 25155046

Reference


2014 Abitbol, M., Legrand, R., Tiret, L. :
A missense mutation in melanocortin 1 receptor is associated with the red coat colour in donkeys. Anim Genet 45:878-80, 2014. Pubmed reference: 25155046. DOI: 10.1111/age.12207.

Edit History


  • Created by Frank Nicholas on 22 Jul 2018
  • Changed by Frank Nicholas on 22 Jul 2018