A missense mutation in the gene for melanocyte-stimulating hormone receptor (MCIR) is associated with the chestnut coat color in horses
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The melanocyte-stimulating hormone receptor gene (MCIR) is the major candidate gene for the chestnut coat color in horses since it is assumed to be controlled by an allele at the extension locus. MCIR sequences were PCR amplified from chestnut (e/e) and non-chestnut (EI-) horses. A single-strand conformation polymorphism was found that showed a complete association to the chestnut coat color among 144 horses representing 12 breeds. Sequence analysis revealed a single missense mutation (83Ser → Phe) in the MCIR allele associated with the chestnut color. The substitution occurs in the second transmembrane region, which apparently plays a key role in the molecule since substitutions associated with coat color variants in mice and cattle as well as red hair and fair skin in humans are found in this part of the molecule. We propose that the now reported mutation is likely to be the causative mutation for the chestnut coat color. The polymorphism can be detected with a simple PCR-RFLP test, since the mutation creates a TaqI restriction site in the chestnut allele.
KeywordsCystic Fibrosis Transmembrane Conductance Regulator Coat Color Chestnut Horse Fair Skin Icelandic Horse
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- Johansson, M., Marklund, L., Sandberg, K., Andersson, L. (1994). Cosegregation between the chestnut coat colour in horses and polymorphisms at the melanocyte stimulating hormone (MSH) receptor locus. Anim. Genet. 25 (suppl):35.Google Scholar
- Johansson Moller, M., Chaudhary, R., Hellmén, E., Höyheim, B., Chowdhary, B., Andersson, L. (1996). Pigs with the dominant white coat color phenotype carry a duplication of the KIT gene encoding the mast/ stem cell growth factor receptor. Mamm. Genome, in press.Google Scholar
- Klungland, H., Våge, D.I., Gomez-Raya, L., Adalsteinsson, S., Lien, S. (1995). The role of melanocyte-stimulating hormone (MSH) receptor in bovine coat color determination. Mamm. Genome 6, 636–639.Google Scholar
- Kumar, S., Tamura, K., Nei, M. (1993). MEGA: Molecular Evolutionary Genetics Analysis, version 1.0. (University Park, Pa.: The Pennsylvania State University.)Google Scholar