Close association between sequence polymorphism in the KIT gene and the roan coat color in horses.
Abstract: The roan coat color in horses is controlled by a dominant allele that is lethal in the homozygous condition. Phenotypic similarities to some pigmentation disorders in human and mouse, combined with comparative mapping data, identified KIT, encoding the mast cell growth factor receptor, as a major candidate gene for the roan locus (Rn). Rn has previously been mapped to equine linkage group (LG) II. In this study, LGII was expanded with KIT and PDGFRA (platelet-derived growth factor receptor alpha) by use of RFLP and linkage analysis. Moreover, highly significant linkage disequilibrium between Rn and a KIT TaqI RFLP, representing a synonymous substitution in exon 19, was revealed. There was a strong KIT-Rn association in most breeds. Almost the complete KIT-encoding sequence was determined by sequence analysis of RT-PCR products. Comparison of horse KIT cDNA sequences, representing three different alleles (two different rn and one Rn), revealed five sequence polymorphisms and several mRNA splice variants, but none of these proved to be specifically associated with Rn. An insertion of a partial (79 bp) LINE1-element between exons 1 and 2, leading to a frameshift, represented about 30% of KIT transcripts in the Belgian roan horse used for the sequence analysis. However, an association between this L1 splice insertion and the roan phenotype was not verified when testing additional unrelated roan and non-roan horses from different breeds. The study strengthens the hypothesis that the roan coat color is controlled by KIT, but further analyses are needed to reveal the causative mutation(s).
Publication Date: 1999-03-02 PubMed ID: 10051325DOI: 10.1007/s003359900987Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research explores a strong association between sequence variation in the KIT gene and the roan coat color in horses. However, the study could not identify the exact mutations responsible for this trait and stressed the need for additional analysis.
Understanding the Research Problem
- The study seeks to understand the genetic factors contributing to the color of a horse’s coat, specifically the roan pattern. The roan color is a mixture of white and colored hairs, and its expression is controlled by a dominant allele that is lethal if it occurs in pairs (homozygous condition).
- The researchers focused on the KIT gene, which is involved in pigmentation, and its possible involvement in the expression of the roan coat color.
Methods of the Study
- The researchers expanded the linkage group II (LGII) with KIT and PDGFRA genes, using RFLP and linkage analysis. Linkage groups are clusters of genes that tend to be inherited together.
- Sequence analysis of RT-PCR products led to the determination of almost the complete KIT-encoding sequence in horses.
- In total, three different alleles of the horse KIT gene were compared, displaying five sequence polymorphisms along with several mRNA splice variants. However, none of these were found to be directly linked with the expression of the roan coat color (Rn).
Key Findings
- A certain TaqI RFLP in the KIT gene, indicating a synonymous substitution in exon 19, was found in strong linkage disequilibrium with the roan coat color. Linkage disequilibrium refers to a non-random association of alleles at different loci, indicating that these variations are often inherited together.
- A specific insertion of a partial LINE1-element (a type of transposable element) occurring between exons 1 and 2 and causing a frameshift, was detected in about 30% of the KIT transcripts from the Belgian roan horse under study. However, this insertion was not observed to be associated with the roan coat phenotype upon further testing with other horses.
Conclusions and Implications
- Despite not identifying direct mutations corresponding with the roan coat color, the research reinforced the hypothesis that the KIT gene plays a significant role in control over this trait.
- The researchers highlighted the need for continued analysis and investigation to finally decipher the precise genetic mutations giving rise to the roan coat color in horses.
Cite This Article
APA
Marklund S, Moller M, Sandberg K, Andersson L.
(1999).
Close association between sequence polymorphism in the KIT gene and the roan coat color in horses.
Mamm Genome, 10(3), 283-288.
https://doi.org/10.1007/s003359900987 Publication
Researcher Affiliations
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Box 597, S-751 24 Uppsala, Sweden.
MeSH Terms
- Alternative Splicing
- Amino Acid Sequence
- Animals
- Base Sequence
- Cloning, Molecular
- DNA
- Hair Color / genetics
- Horses / genetics
- Humans
- Molecular Sequence Data
- Polymerase Chain Reaction
- Polymorphism, Restriction Fragment Length
- Proto-Oncogene Proteins c-kit / chemistry
- Proto-Oncogene Proteins c-kit / genetics
- Sequence Homology, Amino Acid
Citations
This article has been cited 15 times.- Novak TE, Bailey NP, Stevison LS. Genetic characterization of Macaca arctoides: A highlight of key genes and pathways.. Primates 2023 Jul;64(4):451-462.
- Bartolomé E, Perdomo-González DI, Ripollés-Lobo M, Valera M. Basal Reactivity Evaluated by Infrared Thermography in the "Caballo de Deporte Español" Horse Breed According to Its Coat Color.. Animals (Basel) 2022 Sep 21;12(19).
- Derks MFL, Steensma M. Review: Balancing Selection for Deleterious Alleles in Livestock.. Front Genet 2021;12:761728.
- Xu J, Fu Y, Hu Y, Yin L, Tang Z, Yin D, Zhu M, Yu M, Li X, Zhou Y, Zhao S, Liu X. Whole genome variants across 57 pig breeds enable comprehensive identification of genetic signatures that underlie breed features.. J Anim Sci Biotechnol 2020 Dec 3;11(1):115.
- Voß K, Tetens J, Thaller G, Becker D. Coat Color Roan Shows Association with KIT Variants and No Evidence of Lethality in Icelandic Horses.. Genes (Basel) 2020 Jun 22;11(6).
- Jivanji S, Worth G, Lopdell TJ, Yeates A, Couldrey C, Reynolds E, Tiplady K, McNaughton L, Johnson TJJ, Davis SR, Harris B, Spelman R, Snell RG, Garrick D, Littlejohn MD. Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle.. Genet Sel Evol 2019 Nov 8;51(1):62.
- Grilz-Seger G, Druml T, Neuditschko M, Mesarič M, Cotman M, Brem G. Analysis of ROH patterns in the Noriker horse breed reveals signatures of selection for coat color and body size.. Anim Genet 2019 Aug;50(4):334-346.
- Andersson L. Domestic animals as models for biomedical research.. Ups J Med Sci 2016;121(1):1-11.
- Jiang L, Campagne C, Sundström E, Sousa P, Imran S, Seltenhammer M, Pielberg G, Olsson MJ, Egidy G, Andersson L, Golovko A. Constitutive activation of the ERK pathway in melanoma and skin melanocytes in Grey horses.. BMC Cancer 2014 Nov 21;14:857.
- Fontanesi L, Vargiolu M, Scotti E, Latorre R, Faussone Pellegrini MS, Mazzoni M, Asti M, Chiocchetti R, Romeo G, Clavenzani P, De Giorgio R. The KIT gene is associated with the english spotting coat color locus and congenital megacolon in Checkered Giant rabbits (Oryctolagus cuniculus).. PLoS One 2014;9(4):e93750.
- Jackling FC, Johnson WE, Appleton BR. The genetic inheritance of the blue-eyed white phenotype in alpacas (Vicugna pacos).. J Hered 2014 Nov-Dec;105(6):847-57.
- Li S, Wang C, Yu W, Zhao S, Gong Y. Identification of genes related to white and black plumage formation by RNA-Seq from white and black feather bulbs in ducks.. PLoS One 2012;7(5):e36592.
- Hayes BJ, Pryce J, Chamberlain AJ, Bowman PJ, Goddard ME. Genetic architecture of complex traits and accuracy of genomic prediction: coat colour, milk-fat percentage, and type in Holstein cattle as contrasting model traits.. PLoS Genet 2010 Sep 23;6(9):e1001139.
- Haase B, Brooks SA, Schlumbaum A, Azor PJ, Bailey E, Alaeddine F, Mevissen M, Burger D, Poncet PA, Rieder S, Leeb T. Allelic heterogeneity at the equine KIT locus in dominant white (W) horses.. PLoS Genet 2007 Nov;3(11):e195.
- Brooks SA, Bailey E. Exon skipping in the KIT gene causes a Sabino spotting pattern in horses.. Mamm Genome 2005 Nov;16(11):893-902.
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