| 1. |
|
|
| 2. |
|
|
| 3. |
- Andersson, Lisa, et al.
(författare)
-
The same ELA class II risk factors confer equine insect bite hypersensitivity in two distinct populations
- 2012
-
Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 64:3, s. 201-208
-
Tidskriftsartikel (refereegranskat)abstract
- Insect bite hypersensitivity (IBH) is a chronic allergic dermatitis common in horses. Affected horses mainly react against antigens present in the saliva from the biting midges, Culicoides ssp, and occasionally black flies, Simulium ssp. Because of this insect dependency, the disease is clearly seasonal and prevalence varies between geographical locations. For two distinct horse breeds, we genotyped four microsatellite markers positioned within the MHC class II region and sequenced the highly polymorphic exons two from DRA and DRB3, respectively. Initially, 94 IBH-affected and 93 unaffected Swedish born Icelandic horses were tested for genetic association. These horses had previously been genotyped on the Illumina Equine SNP50 BeadChip, which made it possible to ensure that our study did not suffer from the effects of stratification. The second population consisted of 106 unaffected and 80 IBH-affected Exmoor ponies. We show that variants in the MHC class II region are associated with disease susceptibility (p(raw)=2.34x10(-5)), with the same allele (COR112:274) associated in two separate populations. In addition, we combined microsatellite and sequencing data in order to investigate the pattern of homozygosity and show that homozygosity across the entire MHC class II region is associated with a higher risk of developing IBH (p=0.0013). To our knowledge this is the first time in any atopic dermatitis suffering species, including man, where the same risk allele has been identified in two distinct populations.
|
|
| 4. |
- Siguroardottir, Heiorun, et al.
(författare)
-
The genetics of gaits in Icelandic horses goes beyond DMRT3, with RELN and STAU2 identified as two new candidate genes
- 2023
-
Ingår i: Genetics Selection Evolution. - : Springer Nature. - 0999-193X .- 1297-9686. ; 55:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: In domesticated animals, many important traits are complex and regulated by a large number of genes, genetic interactions, and environmental influences. The ability of Icelandic horses to perform the gait 'pace' is largely influenced by a single mutation in the DMRT3 gene, but genetic modifiers likely exist. The aim of this study was to identify novel genetic factors that influence pacing ability and quality of the gait through a genome-wide association study (GWAS) and correlate new findings to previously identified quantitative trait loci (QTL) and mutations.Results: Three hundred and seventy-two Icelandic horses were genotyped with the 670 K+ Axiom Equine Genotyping Array, of which 362 had gait scores from breeding field tests. A GWAS revealed several SNPs on Equus caballus chromosomes (ECA) 4, 9, and 20 that were associated (p < 1.0 x 10(-5)) with the breeding field test score for pace. The two novel QTL on ECA4 and 9 were located within the RELN and STAU2 genes, respectively, which have previously been associated with locomotor behavior in mice. Haplotypes were identified and the most frequent one for each of these two QTL had a large favorable effect on pace score. The second most frequent haplotype for the RELN gene was positively correlated with scores for tolt, trot, gallop, and canter. Similarly, the second most frequent haplotype for the STAU2 gene had favorable effects on scores for trot and gallop. Different genotype ratios of the haplotypes in the RELN and STAU2 genes were also observed in groups of horses with different levels of pacing ability. Furthermore, interactions (p < 0.05) were detected for the QTL in the RELN and STAU2 genes with the DMRT3 gene. The novel QTL on ECA4, 9, and 20, along with the effects of the DMRT3 variant, were estimated to account jointly for 27.4% of the phenotypic variance of the gait pace.Conclusions: Our findings provide valuable information about the genetic architecture of pace beyond the contribution of the DMRT3 gene and indicate genetic interactions that contribute to the complexity of this trait. Further investigation is needed to fully understand the underlying genetic factors and interactions.
|
|
| 5. |
|
|
| 6. |
- Velie, Brandon, et al.
(författare)
-
Frequencies of polymorphisms in myostatin vary in Icelandic horses according to the use of the horses
- 2015
-
Ingår i: Animal Genetics. - : Wiley. - 0268-9146 .- 1365-2052. ; 46, s. 467-468
-
Tidskriftsartikel (refereegranskat)abstract
- The recent association of the myostatin gene (MSTN) with best race distance has provided valuable insight into the influence of MSTN on racing performance. However, the importance of MSTN in horses is unlikely to be limited to racing performance. First described in mice, the effects of mutations in MSTN have long been associated with heavily muscled cattle. In cattle, some of the morphological variability between breeds can be attributed to MSTN and its effects on muscle fiber development. As such, it is highly probable that MSTN polymorphisms influence not only racing performance, but also the general use of a horse or breed. This variability would likely be reflected in the genotype frequencies of horses used for specific purposes, as certain genotypes would undoubtedly yield more desirable phenotypes. The aim of this study was to explore this idea by estimating the genotype frequencies of three SNPs in MSTN in the Icelandic horse breed, a breed traditionally used for both meat production and riding.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
