Coat Color Roan Shows Association with KIT Variants and No Evidence of Lethality in Icelandic Horses.
Abstract: Roan (Rn) horses show a typical seasonal change of color. Their body is covered with colored and white hair. We performed a descriptive statistical analysis of breeding records of Icelandic horses to challenge the hypothesis of roan being lethal in utero under homozygous condition. The roan to non-roan ratio of foals from roan × roan matings revealed homozygous roan Icelandic horses to be viable. Even though roan is known to be inherited in a dominant mode and epistatic to other coat colors, the causative mutation is still unknown. Nevertheless, an association between roan phenotype and the KIT gene was shown for different horse breeds. In the present study, we identified KIT variants by Sanger sequencing, and show that KIT is also associated with roan in the Icelandic horse breed.
Publication Date: 2020-06-22 PubMed ID: 32580410PubMed Central: PMC7348759DOI: 10.3390/genes11060680Google Scholar: Lookup
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- Journal Article
Summary
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This research investigates the genetic factors responsible for the unique coat color exhibited by Roan horses, primarily those of the Icelandic breed. The study refutes earlier beliefs that the roan color phenotype could lead to in utero fatalities when inherited in a homozygous state. It also points out an association between the roan coat color and the KIT gene.
Objective and Methodology
The aim of the research was to unravel the genetics behind the unique coat color seen in roan horses, with a focus on the Icelandic breed. Roan horses have a distinct coat color, characterized by a mix of colored and white hair. To debunk the hypothesis that this trait might be lethal in utero when present in its homozygous form, the authors performed a statistical analysis on Icelandic horse breeding records. They specifically examined the ratio of roan to non-roan foals resulting from roan × roan matings.
Findings
- The analysis revealed that homozygous roan Icelandic horses are viable, debunking the hypothesis that the roan color assortment is lethal in utero when exhibited in its homozygous form.
- This finding was significant as the roan trait is inherited dominantly and is often ‘epistatic’—it masks the effects of other coat color genes. Yet, the specific genetic mutation causing the roan phenotype remained unknown.
- However, the researchers found an association between the roan phenotype and the KIT gene. The KIT gene has been associated with color patterns in various horse breeds, but its link with the roan phenotype in Icelandic horses was hitherto unknown.
- The authors identified variations in the KIT gene through Sanger sequencing, indicating the role of this gene in contributing to the roan coat color in the Icelandic horse breed.
Significance
The study thus sheds light on the genetic underpinnings of the unique roan coat color in horses, especially in the Icelandic breed. By debunking a long-standing hypothesis and pointing out the role of the KIT gene, the research paves the way for more in-depth genetic studies on coat color variation in horses. This can have substantial implications in the world of horse breeding, genetics, and veterinary science.
Cite This Article
APA
Voß K, Tetens J, Thaller G, Becker D.
(2020).
Coat Color Roan Shows Association with KIT Variants and No Evidence of Lethality in Icelandic Horses.
Genes (Basel), 11(6).
https://doi.org/10.3390/genes11060680 Publication
Researcher Affiliations
- Institute of Animal Breeding and Husbandry, University of Kiel, Olshausenstraße 40, 24098 Kiel, Germany.
- Institute of Animal Breeding and Husbandry, University of Kiel, Olshausenstraße 40, 24098 Kiel, Germany.
- Institute of Animal Breeding and Husbandry, University of Kiel, Olshausenstraße 40, 24098 Kiel, Germany.
- Institute of Genome Biology, Leibniz Institute for Farm Animal Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
MeSH Terms
- Animals
- Breeding
- Color
- Genes, Lethal / genetics
- Hair Color / genetics
- Horse Diseases / genetics
- Horse Diseases / pathology
- Horses / genetics
- Mutation / genetics
- Phenotype
- Proto-Oncogene Proteins c-kit / genetics
Conflict of Interest Statement
The authors declare no conflict of interest.
References
This article includes 39 references
- Castle W.E.. The Abc of color inheritance in horses.. Genetics 1948;33:22–35.
- Hintz H.F., Van Vleck L.D.. Lethal dominant roan in horses.. J. Hered. 1979;70:145–146.
- Andersson L., Sandberg K.. A linkage group composed of three coat color genes and three serum protein loci in horses.. J. Hered. 1982;73:91–94.
- Sponenberg D.P., Harper H.T., Harper A.L.. Direct evidence for linkage of roan and extension loci in Belgian horses.. J. Hered. 1984;75:413–414.
- Marklund S., Moller M., Sandberg K., Andersson L.. Close association between sequence polymorphism in the KIT gene and the roan coat color in horses.. Mamm. Genome. 1999;10:283–288.
- Brooks S.A., Lear T.L., Adelson D.L., Bailey E.. A chromosome inversion near the KIT gene and the Tobiano spotting pattern in horses.. Cytogenet Genome Res. 2007;119:225–230.
- Brooks S.A., Bailey E.. Exon skipping in the KIT gene causes a Sabino spotting pattern in horses.. Mamm. Genome. 2005;16:893–902.
- Haase B., Jude R., Brooks S.A., Leeb T.. An equine chromosome 3 inversion is associated with the tobiano spotting pattern in German horse breeds.. Anim. Genet. 2008;39:306–309.
- Haase B., Brooks S.A., Tozaki T., Burger D., Poncet P.A., Rieder S., Hasegawa T., Penedo C., Leeb T.. Seven novel KIT mutations in horses with white coat colour phenotypes.. Anim. Genet. 2009;40:623–629.
- Ezoe K., Holmes S.A., Ho L., Bennett C.P., Bolognia J.L., Brueton L., Burn J., Falabella R., Gatto E.M., Ishii N.. Novel mutations and deletions of the KIT (steel factor receptor) gene in human piebaldism.. Am. J. Hum. Genet. 1995;56:58–66.
- De Sepulveda P., Peyrieras N., Panthier J.J.. Instability at the W/c-kit locus in mice: Analysis of melanocyte cell lines derived from reversion spots.. Oncogene 1994;9:2655–2661.
- Duttlinger R., Manova K., Berrozpe G., Chu T.Y., DeLeon V., Timokhina I., Chaganti R.S., Zelenetz A.D., Bachvarova R.F., Besmer P.. The Wsh and Ph mutations affect the c-kit expression profile: c-kit misexpression in embryogenesis impairs melanogenesis in Wsh and Ph mutant mice.. Proc. Natl. Acad. Sci. USA. 1995;92:3754–3758.
- Geissler E.N., Ryan M.A., Housman D.E.. The dominant-white spotting (W) locus of the mouse encodes the c-kit proto-oncogene.. Cell 1988;55:185–192.
- Grilz-Seger G., Reiter S., Neuditschko M., Wallner B., Rieder S., Leeb T., Jagannathan V., Mesaric M., Cotman M., Pausch H.. A genome-wide association analysis in noriker horses identifies a SNP associated with roan coat color.. J. Equine Vet. Sci. 2020;88:102950.
- Sponenberg D.P., Bellone R.R.. Equine Color Genetics.. 4th ed. John Wiley & Sons; Hoboken, NJ, USA: 2017.
- Yokohama M., Nozawa K.. An additional analysis on lethality of roan allele in Hokkaido native horses.. J. Agri. Sci. Tokyo Univ. Agric. 2004;49:147–149.
- Yokohama M., Nomura H., Yasuhara T., Nozawa K.. Lethal dominant roan is not found in Hokkaido native horses.. J. Agric. Sci. 2002;47:98–101.
- Miller S.A., Dykes D.D., Polesky H.F.. A simple salting out procedure for extracting DNA from human nucleated cells.. Nucleic Acids Res. 1988;16:1215.
- Purcell S., Neale B., Todd-Brown K., Thomas L., Ferreira M.A., Bender D., Maller J., Sklar P., De Bakker P.I., Daly M.J.. PLINK: A tool set for whole-genome association and population-based linkage analyses.. Am. J. Hum. Genet. 2007;81:559–575.
- Thiruvenkadan A.K., Kandasamy N., Panneerselvam S.. Coat colour inheritance in horses.. Livest. Sci. 2008;117:109–129.
- Terry R.B., Archer S., Brooks S., Bernoco D., Bailey E.. Assignment of the appaloosa coat colour gene (LP) to equine chromosome 1.. Anim. Genet. 2004;35:134–137.
- Sponenberg D.P., Carr G., Simak E., Schwink K.. The inheritance of the leopard complex of spotting patterns in horses.. J. Hered. 1990;81:323–331.
- Neves A.P., Schwengber E.B., Albrecht F.F., Isola J.V., De Salles van der Linden L.. Beyond fifty shades: The genetics of horse colors.. In: Abubakar M., editor. Trends and Advances in Veterinary Genetics. IntechOpen; London, UK: 2017.
- Garcia-Ruiz A., Wiggans G.R., Ruiz-Lopez F.J.. Pedigree verification and parentage assignment using genomic information in the Mexican Holstein population.. J. Dairy Sci. 2019;2:1806–1810.
- Sanders K., Bennewitz J., Kalm E.. Wrong and missing sire information affects genetic gain in the Angeln dairy cattle population.. J. Dairy Sci. 2006;89:315–321.
- Visscher P.M., Woolliams J.A., Smith D., Williams J.L.. Estimation of pedigree errors in the UK dairy population using microsatellite markers and the impact on selection.. J. Dairy Sci. 2002;85:2368–2375.
- Ron M., Domochovsky R., Golik M., Seroussi E., Ezra E., Shturman C., Weller J.I.. Analysis of vaginal swabs for paternity testing and marker-assisted selection in cattle.. J. Dairy Sci. 2003;86:1818–1820.
- Seyedabadi H.R., Savar Sofla S.. Microsatellite analysis for parentage verification and genetic characterization of the Turkmen horse population.. Kafkas Univ. Vet. Fak. 2017;23:467–471.
- Sereno F., Sereno J.R.B., Vega-Pla J.L., Delado J.V.. DNA testing for parentage verification in a conservation nucleus of Pantaneiro horse.. Genet. Mol. Biol. 2008;31:64–67.
- Wright S.. Color inheritance in mammals: VI, Cattle—Explanation of reds, roans, whites in short-horns long a matter of dispute—Annlysis shows that only a single pair of mendelian factors can be involved aside from minor variations—Colors in general determined by combination of independent sets of allelomorphs and not by polygamous factors—Dun the dilute form of black.. J. Hered. 1917;8:521–527.
- Babcock E.B., Clausen R.E.. Genetics in Relation to Agriculture.. McGraw-Hill; New York, NY, USA: 1918.
- Butaye R.. Inheritance of coat colour in Belgian horses.. Vlaams Dier. Tijdshrift. 1974;43:464–486.
- Wagner H.J., Reissmann M.. New polymorphism detected in the horse MC1R gene.. Anim. Genet. 2000;31:289–290.
- Haase B., Brooks S.A., Schlumbaum A., Azor P.J., Bailey E., Alaeddine F., Mevissen M., Burger D., Poncet P.A., Rieder S.. Allelic heterogeneity at the equine KIT locus in dominant white (W) horses.. PLoS Genet. 2007;3:e195.
- Reissmann M., Musa L., Zakizadeh S., Ludwig A.. Distribution of coat-color-associated alleles in the domestic horse population and Przewalski’s horse.. J. Appl. Genet. 2016;57:519–525.
- Clark L.A., Wahl J.M., Rees C.A., Murphy K.E.. Retrotransposon insertion in SILV is responsible for merle patterning of the domestic dog.. Proc. Natl. Acad. Sci. USA. 2006;103:1376–1381.
- Martin P.M., Palhiere I., Ricard A., Tosser-Klopp G., Rupp R.. Genome wide association study identifies new loci associated with undesired coat color phenotypes in Saanen Goats.. PLoS ONE. 2016;11:e0152426.
- Jivanji S., Worth G., Lopdell T.J., Yeates A., Couldrey C., Reynolds E., Tiplady K., McNaughton L., Johnson T.J.J., Davis S.R.. Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle.. Genet. Sel. Evol. 2019;51:62.
- Hong E.P., Park J.W.. Sample size and statistical power calculation in genetic association studies.. Genom. Inform. 2012;10:117–122.
Citations
This article has been cited 5 times.- Everts RE, Caron R, Foster G, McLoone K, Simiele L, Martin K, Brooks SA, Lafayette C. Identification of a Novel Haplotype Associated with Roan Coat Color in American Quarter Horses. Animals (Basel) 2025 Aug 14;15(16).
- Everts RE, Caron R, Foster G, McLoone K, Martin K, Brooks SA, Lafayette C. Identification of Two Genetic Haplotypes Associated with the Roan Coat Color in the American Quarter Horse and Other Equine Breeds. Animals (Basel) 2025 Jun 9;15(12).
- Liu X, Peng Y, Zhang X, Wang X, Chen W, Kou X, Liang H, Ren W, Khan MZ, Wang C. Coloration in Equine: Overview of Candidate Genes Associated with Coat Color Phenotypes. Animals (Basel) 2024 Jun 17;14(12).
- Durward-Akhurst SA, Marlowe JL, Schaefer RJ, Springer K, Grantham B, Carey WK, Bellone RR, Mickelson JR, McCue ME. Predicted genetic burden and frequency of phenotype-associated variants in the horse. Sci Rep 2024 Apr 10;14(1):8396.
- Dong H, Dong Z, Wang F, Wang G, Luo X, Lei C, Chen J. Whole Genome Sequencing Provides New Insights Into the Genetic Diversity and Coat Color of Asiatic Wild Ass and Its Hybrids. Front Genet 2022;13:818420.
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