Sammanfattning

The roan coat color in horses is characterized by dispersed white hair and dark points. This phenotype segregates in a broad range of horse breeds, while the underlying genetic background is still unknown. Previous studies mapped the roan locus to the KIT gene on equine chromosome 3 (ECA3). However, this association could not be validated across different horse breeds. Performing a genome-wide association analysis (GWAS) in Noriker horses, we identified a single nucleotide polymorphism (SNP) (ECA3:g.79,543.439 A > G) in the intron 17 of the KIT gene. The G -allele of the top associated SNP was present in other roan horses, namely Quarter Horse, Murgese, Slovenian, and Belgian draught horse, while it was absent in a panel of 15 breeds, including 657 non-roan horses. In further 379 gray Lipizzan horses, eight animals exhibited a heterozygous genotype (A/G). Comparative whole-genome sequence analysis of the KIT region revealed two deletions in the downstream region (ECA3:79,533,217_79,533,224deITCGTCTTC; ECA3:79,533,282_79,533,285deITTCT) and a 3 bp deletion combined with 17 bp insertion in intron 20 of KIT (ECA3:79,588,128_79,588,130delinsTTATCTCTA-TAGTAGTT). Within the Noriker sample, these loci were in complete linkage disequilibrium (LD) with the identified top SNP. Based upon pedigree information and historical records, we were able to trace back the genetic origin of roan coat color to a baroque gene pool. Furthermore, our data suggest allelic heterogeneity and the existence of additional roan alleles in ponies and breeds related to the English Thoroughbred. In order to study the roan phenotype segregating in those breeds, further association and verification studies are required. (C) 2020 Elsevier Inc. All rights reserved.

Nyckelord

Roan; Horse; Coat color; KIT; GWAS; Genetic marker

Publicerad i

Journal of Equine Veterinary Science
2020, Volym: 88, artikelnummer: 102950
Utgivare: ELSEVIER SCIENCE INC

SLU författare

• Lindgren, Gabriella

  • Institutionen för husdjurens biovetenskaper, Sveriges lantbruksuniversitet
    
  • Katholieke Universiteit Leuven

UKÄ forskningsämne

Genetik och förädling


Publikationens identifierare

DOI: https://doi.org/10.1016/j.jevs.2020.102950

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/105364