title: Association analysis of KIT, MITF, and PAX3 variants with white markings in Spanish horses.
abstract: Several variants in the KIT, PAX3 and MITF genes have previously been associated with white markings in horses. In this study, we examined eight variants of these genes in 70 Menorca Purebred horses (PRMe, only black solid-coloured horses) and 70 Spanish Purebred horses (PRE, different coat colour patterns) that were scored for the extent of white markings. A maximum-likelihood chi-square test, logistic regression model and ridge regression analyses showed that a missense mutation (p.Arg682His) in KIT was associated with white facial markings (P < 0.05) and with total white markings (P < 0.05) in PRMe horses. The relative contribution of this variant to white markings in PRMe horses was estimated at 47.6% (head) and 43.4% (total score). In PRE horses, this variant was also associated with hindlimb scores (P < 0.05) with a relative contribution of 41.2%. The g.20147039C>T intronic variant located 29.9 kb downstream from the transcription start site of the MITF gene was associated with less white markings on forelimbs (P < 0.05) in PRMe horses, with a relative contribution of 63.9%, whereas in PRE horses this variant was associated with white facial markings (P < 0.05), with a relative contribution of 63.9%. No significant associations were found for PAX3 variants in these breeds. These results show that KIT and MITF variants are involved in the white marking patterns of both PRMe and PRE horses, providing breeders with an opportunity to use genetic testing to aid in breeding for their desired level of white markings.
authors.affiliation: Department Agro-Forestal Sciences, Seville University, 41013, Sevilla, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Negro
authors.affiliation: Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75123, Uppsala, Sweden.
authors.forename: F
authors.initials: F
authors.lastname: Imsland
authors.affiliation: Department Agro-Forestal Sciences, Seville University, 41013, Sevilla, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Valera
authors.affiliation: Department of Genetics, Cordoba University, 14071, Cordoba, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Molina
authors.affiliation: Department Agro-Forestal Sciences, Seville University, 41013, Sevilla, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Solé
authors.affiliation: Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 75123, Uppsala, Sweden.|Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, 75007, Uppsala, Sweden.|Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: L
authors.initials: L
authors.lastname: Andersson
mesh_terms: D000818:Animals; D001947:Breeding; D056726:Genetic Association Studies; D006200:Hair Color / Q000235:genetics*; D006736:Horses / Q000235:genetics*; D051739:Microphthalmia-Associated Transcription Factor / Q000235:genetics*; D008957:Models, Genetic; D000072041:PAX3 Transcription Factor / Q000235:genetics*; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D013030:Spain
chemical_list: D051739:Microphthalmia-Associated Transcription Factor; D000072041:PAX3 Transcription Factor; D019009:Proto-Oncogene Proteins c-kit
keywords: 
  SNP
  ; Menorca Purebred; Purebred; phenotypic variance; white spotting