2004/11/24 by Christopher J.D. Mau, P. A. Poncet, B. Bucher +2 · 3 citations
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #melanin and skin pigmentation #Genetic and phenotypic traits in livestock #Garlic and Onion Studies
paper · doi:10.1111/j.1439-0388.2004.00481.x
openalex publication_date 2004/11/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Summary Dominant white coat colour ( W ) is a depigmentation syndrome, known in miscellaneous species. When homozygous in the horse (similar in mice), the mutation responsible for the white phenotype is lethal in a very early stage of gestation. It seems, that the action of the dominant white allele is not always fully penetrant, resulting occasionally in spotted look alike offspring. These horses resemble a coat colour pattern known as sabino spotting. So far, it is not known whether dominant white ( W ) and sabino spotting ( S ) share a common genetic background. In this study, a pedigree consisting of 87 horses segregating for dominant white ( W ) was used to genetically localize the horse ( W )‐locus. Microsatellite ASB23 was found linked to ( W ), which allowed us to map dominant white to a region on horse chromosome 3q22. Tyrosine kinase receptor ( KIT ) was previously mapped to this same chromosome region (3q21–22). KIT and its ligand ( KITLG ) are responsible for the normal function of melanogenesis, haematopoiesis and gametogenesis. So far, sequence analysis of different KIT gene fragments did not lead to new polymorphisms, except for a SNP detected in KIT intron 3 ( KITSNPIn3 ). Additional microsatellites from ECA3q ( TKY353 and LEX7 ), together with KITSNPIn3 allowed us to state more precisely the ( W )‐mutation. The positional results and comparative functional data strongly suggest that KIT encodes for the horse ( W )‐locus.