title: Associations between candidate gene markers at a quantitative trait locus on equine chromosome 4 responsible for osteochondrosis dissecans in fetlock joints of South German Coldblood horses.
abstract: A previously accomplished whole-genome scan for osteochondrosis (OC) and OC dissecans (OCD) in South German Coldblood horses using 250 microsatellite markers identified putative quantitative trait loci (QTL). A chromosome-wide significant QTL for fetlock OCD was found on Equus caballus chromosome (ECA) 4q at a relative position of 70.0-73.3 cM. The aim of this study was to analyze associations of single nucleotide polymorphisms (SNPs) in candidate genes for OC in this region. The association analysis included 32 affected and 64 unaffected horses. Three SNPs located in intron 8, intron 9, and 3'-untranslated region (UTR) of the acyloxyacyl hydrolase (AOAH) gene on ECA4q were significantly associated with OCD in fetlock joints. In order to control for systematic environmental and quantitative genetic effects, we employed a linear animal model. The association of the SNP (AJ543065:g.703A>G) in the 3'-UTR of exon 21 was confirmed in the animal model analysis and a significant additive genetic effect for fetlock OCD of 0.42 (P = 0.002) and a dominance effect of -0.32 (P = 0.03) was estimated. This is the first report on a marker in population-wide linkage disequilibrium with equine OCD in fetlock joints.
authors.affiliation: Institute for Animal Breeding and Genetics, University of Veterinary Medicine Hannover, Foundation, Bünteweg 17p, 30559 Hannover, Germany.
authors.forename: Catherine
authors.initials: C
authors.lastname: Wittwer
authors.forename: Claudia
authors.initials: C
authors.lastname: Dierks
authors.forename: Henning
authors.initials: H
authors.lastname: Hamann
authors.forename: Ottmar
authors.initials: O
authors.lastname: Distl
mesh_terms: D000818:Animals; D002874:Chromosome Mapping / Q000662:veterinary*; D005819:Genetic Markers; D006736:Horses / Q000235:genetics*; D007596:Joints / Q000473:pathology*; D016013:Likelihood Functions; D015810:Linkage Disequilibrium; D018895:Microsatellite Repeats / Q000235:genetics; D010007:Osteochondritis / Q000235:genetics* / Q000662:veterinary; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci
chemical_list: D005819:Genetic Markers