| 1. |
- Axling, Johanna, et al.
(författare)
-
Use of diagnostic reports to estimate prevalence and distribution of skeletal lesions in young Thoroughbreds
- 2016
-
Ingår i: Veterinary Journal. - : Elsevier BV. - 1090-0233 .- 1532-2971. ; 214, s. 72-76
-
Tidskriftsartikel (refereegranskat)abstract
- Diagnostic reports written to assist stud managers in the sale of young Thoroughbreds have not previously been used as a data source for the study of skeletal lesions. However, analyses of these reports may provide efficient and cost-effective insights into the prevalence and distribution of skeletal lesions within a population. Diagnostic reports written by veterinarians were acquired from Thoroughbred stud managers in Australia and New Zealand. The reports were based on approximately 1300 sets of weanling and yearling radiographs taken between 2002 and 2007. The prevalence and anatomical distribution of skeletal lesions in weanlings (299 horses) and yearlings (1004 horses) were determined from these reports. Overall, 69.9% of weanlings and 64.5% of yearlings were reported as having one or more skeletal lesions. Diagnostic reports in weanlings were a strong indication of what was likely to be seen in subsequent yearling reports. These diagnostic reports are typically used by stud managers in the sales process and the potential drawback is that some categories of skeletal lesions may be under-reported. However, there was substantial agreement between the prevalence and distribution of several skeletal lesions reported in this study and those previously reported from direct evaluation of radiographs for Australian and New Zealand Thoroughbred yearlings. Strong agreement was found for osteophytes, enthesiophytes and other modelling in the hocks, and for lesions in the hind fetlocks and stifles. This indicates that written diagnostic reports are a useful and a reliable source of data for the study of some skeletal lesions in young Thoroughbred horses. (C) 2016 Elsevier Ltd. All rights reserved.
|
|
| 2. |
- Da Silva, Vinicius, et al.
(författare)
-
Copy number variations associated with insect bite hypersensitivity in Friesian horses
- 2016
-
Ingår i: Annual meeting of the European Association for Animal Production. - 1382-6077. ; , s. 286-286
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Copy number variations (CNVs) are the largest source of genetic variation that has been identified in the equine genome so far. CNV-based GWAS could therefore facilitate detection of genetic variation for traits of interest. The aim of our study was to identify, characterize and associate CNVs in Friesian horses with insect bite hypersensitivity (IBH), a common equine allergy to insects that causes intense itch and seriously reduces welfare. After pre-processing of raw intensity signals from 670,796 SNPs for 138 cases and 131 controls, CNVs were identified using PennCNV and merged into CNV regions (CNVRs) using CNVRuler. A SNP-based GWAS performed beforehand (chi squared test with 1df) showed a clear association between the ELA region on ECA20 and IBH in Friesian horses. Regions identified on ECA9, 11 and 20 have rather consistently been associated with IBH across equine breeds investigated so far. Currently, the CNV analysis is at an early stage and different strategies to improve the SNP array overall signal quality are being tested. The preliminary CNV-based GWAS, which analysed gains and losses separately by logistic regression, indicated a loss in the ELA region significantly more frequent in affected horses. CNVRs significantly associated with IBH could point to genes involved in this complex polygenic disease. Our study will increase the knowledge on CNVs in horses and will highlight which genes and pathways are affected by CNVs. Moreover, it will facilitate in our attempt to improve selection against IBH.
|
|
| 3. |
- Da Silva, Vinicius, et al.
(författare)
-
Copy number variations in Friesian horses and genetic risk factors for insect bite hypersensitivity
- 2018
-
Ingår i: BMC Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 19
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Many common and relevant diseases affecting equine welfare have yet to be tested regarding structural variants such as copy number variations (CNVs). CNVs make up a substantial proportion of total genetic variability in populations of many species, resulting in more sequence differences between individuals than SNPs. Associations between CNVs and disease phenotypes have been established in several species, but equine CNV studies have been limited. Aim of this study was to identify CNVs and to perform a genome-wide association (GWA) study in Friesian horses to identify genomic loci associated with insect bite hypersensitivity (IBH), a common seasonal allergic dermatitis observed in many horse breeds worldwide.Results: Genotypes were obtained using the Axiom (R) Equine Genotyping Array containing 670,796 SNPs. After quality control of genotypes, 15,041 CNVs and 5350 CNV regions (CNVRs) were identified in 222 Friesian horses. Coverage of the total genome by CNVRs was 11.2% with 49.2% of CNVRs containing genes. 58.0% of CNVRs were novel (i.e. so far only identified in Friesian horses). A SNP- and CNV-based GWA analysis was performed, where about half of the horses were affected by IBH. The SNP-based analysis showed a highly significant association between the MHC region on ECA20 and IBH in Friesian horses. Associations between the MHC region on ECA20 and IBH were also detected based on the CNV-based analysis. However, CNVs associated with IBH in Friesian horses were not often in close proximity to SNPs identified to be associated with IBH.Conclusions: CNVs were identified in a large sample of the Friesian horse population, thereby contributing to our knowledge on CNVs in horses and facilitating our understanding of the equine genome and its phenotypic expression. A clear association was identified between the MHC region on ECA20 and IBH in Friesian horses based on both SNP- and CNV-based GWA studies. These results imply that MHC contributes to IBH sensitivity in Friesian horses. Although subsequent analyses are needed for verification, nucleotide differences, as well as more complex structural variations like CNVs, seem to contribute to IBH sensitivity. IBH should be considered as a common disease with a complex genomic architecture.
|
|
| 4. |
- Fegraeus, Kim, et al.
(författare)
-
An endothelial regulatory module links blood pressure regulation with elite athletic performance
- 2024
-
Ingår i: PLOS Genetics. - : Public Library of Science (PLoS). - 1553-7390 .- 1553-7404. ; 20:6
-
Tidskriftsartikel (refereegranskat)abstract
- The control of transcription is crucial for homeostasis in mammals. A previous selective sweep analysis of horse racing performance revealed a 19.6 kb candidate regulatory region 50 kb downstream of the Endothelin3 (EDN3) gene. Here, the region was narrowed to a 5.5 kb span of 14 SNVs, with elite and sub-elite haplotypes analyzed for association to racing performance, blood pressure and plasma levels of EDN3 in Coldblooded trotters and Standardbreds. Comparative analysis of human HiCap data identified the span as an enhancer cluster active in endothelial cells, interacting with genes relevant to blood pressure regulation. Coldblooded trotters with the sub-elite haplotype had significantly higher blood pressure compared to horses with the elite performing haplotype during exercise. Alleles within the elite haplotype were part of the standing variation in pre-domestication horses, and have risen in frequency during the era of breed development and selection. These results advance our understanding of the molecular genetics of athletic performance and vascular traits in both horses and humans.
|
|
| 5. |
- Fegraeus, K. Jaderkvist, et al.
(författare)
-
Different DMRT3 Genotypes Are Best Adapted for Harness Racing and Riding in Finnhorses
- 2015
-
Ingår i: Journal of Heredity. - : Oxford University Press (OUP). - 0022-1503 .- 1465-7333. ; 106:6, s. 734-740
-
Tidskriftsartikel (refereegranskat)abstract
- Previous studies showed a positive effect of the DMRT3 "gait keeper" mutation on harness racing performance in Standardbreds, French-, and Nordic trotters. The mutation has also been shown to influence riding traits in multiple breeds. This study investigated the effect of the DMRT3 mutation on harness racing performance and riding traits in Finnhorses. Finnhorses used for harness racing (n = 180) and for riding (n = 59) were genotyped for the DMRT3 mutation. For the trotters the genotypes were evaluated for association with racing performance (number of starts, victories, placings, earnings, and race times). At 3-6 years of age the AA genotype was superior compared with the CA and CC genotypes. The AA horses had a significantly higher proportion of victories (P = 1.4 x 10(-6)) and placings (P = 4.1 x 10(-7)), better race times (P = 0.01), and earned more money (P = 0.009) compared with C-horses. For the Finnhorses used for riding the owners answered a questionnaire to score how well the horse performed the gaits walk, trot, and canter on a scale from 1 to 6. These scores were tested for association with the DMRT3 genotypes. Although AA horses were more successful as racehorses, the CC and CA horses appear more adapted for classical riding disciplines. The AA horses received significantly lower gait scores compared with C-horses for the majority of gaits. Except for rhythm in extended canter (P = 0.05), there were no significant differences between CA and CC horses. This study shows that there are different optimal genotypes for different disciplines and the DMRT3 mutation clearly influences gaits and performance in Finnhorses.
|
|
| 6. |
- Felkel, S., et al.
(författare)
-
Asian horses deepen the MSY phylogeny
- 2018
-
Ingår i: Animal Genetics. - : WILEY. - 0268-9146 .- 1365-2052. ; 49:1, s. 90-93
-
Tidskriftsartikel (refereegranskat)abstract
- Humans have shaped the population history of the horse ever since domestication about 5500years ago. Comparative analyses of the Y chromosome can illuminate the paternal origin of modern horse breeds. This may also reveal different breeding strategies that led to the formation of extant breeds. Recently, a horse Y-chromosomal phylogeny of modern horses based on 1.46Mb of the male-specific Y (MSY) was generated. We extended this dataset with 52 samples from five European, two American and seven Asian breeds. As in the previous study, almost all modern European horses fall into a crown group, connected via a few autochthonous Northern European lineages to the outgroup, the Przewalski's Horse. In total, we now distinguish 42 MSY haplotypes determined by 158 variants within domestic horses. Asian horses show much higher diversity than previously found in European breeds. The Asian breeds also introduce a deep split to the phylogeny, preliminarily dated to 5527 +/- 872years. We conclude that the deep splitting Asian Y haplotypes are remnants of a far more diverse ancient horse population, whose haplotypes were lost in other lineages.
|
|
| 7. |
- Felkel, Sabine, et al.
(författare)
-
The horse Y chromosome as an informative marker for tracing sire lines
- 2019
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Analysis of the Y chromosome is the best-established way to reconstruct paternal family history in humans. Here, we applied fine-scaled Y-chromosomal haplotyping in horses with biallelic markers and demonstrate the potential of our approach to address the ancestry of sire lines. We de novo assembled a draft reference of the male-specific region of the Y chromosome from Illumina short reads and then screened 5.8 million basepairs for variants in 130 specimens from intensively selected and rural breeds and nine Przewalski's horses. Among domestic horses we confirmed the predominance of a young'crown haplogroup' in Central European and North American breeds. Within the crown, we distinguished 58 haplotypes based on 211 variants, forming three major haplogroups. In addition to two previously characterised haplogroups, one observed in Arabian/Coldblooded and the other in Turkoman/Thoroughbred horses, we uncovered a third haplogroup containing Iberian lines and a North African Barb Horse. In a genealogical showcase, we distinguished the patrilines of the three English Thoroughbred founder stallions and resolved a historic controversy over the parentage of the horse 'Galopin', born in 1872. We observed two nearly instantaneous radiations in the history of Central and Northern European Y-chromosomal lineages that both occurred after domestication 5,500 years ago.
|
|
| 8. |
- Francois, Liesbeth, et al.
(författare)
-
Conformation Traits and Gaits in the Icelandic Horse are Associated with Genetic Variants in Myostatin (MSTN)
- 2016
-
Ingår i: Journal of Heredity. - : Oxford University Press (OUP). - 0022-1503 .- 1465-7333. ; 107:5, s. 431-437
-
Tidskriftsartikel (refereegranskat)abstract
- Many genes are known to have an influence on conformation and performance traits; however, the role of one gene, Myostatin (MSTN), has been highlighted in recent studies on horses. Myostatin acts as a repressor in the development and regulation of differentiation and proliferative growth of skeletal muscle. Several studies have examined the link between MSTN, conformation, and performance in racing breeds, but no studies have investigated the relationship in Icelandic horses. Icelandic horses, a highly unique breed, are known both for their robust and compact conformation as well as their additional gaits tolt and pace. Three SNPs (g.65868604G>T [PR8604], g.66493737C>T [PR3737], and g.66495826A>G [PR5826]) flanking or within equine MSTN were genotyped in 195 Icelandic horses. The SNPs and haplotypes were analyzed for association with official estimated breeding values (EBV) for conformation traits (n = 11) and gaits (n = 5). The EBV for neck, withers, and shoulders was significantly associated with both PR8604 and PR3737 (P < 0.05). PR8604 was also associated with EBV for total conformation (P = 0.05). These associations were all supported by the haplotype analysis. However, while SNP PR5826 showed a significant association with EBVs for leg stance and hooves (P < 0.05), haplotype analyses for these traits failed to fully support these associations. This study demonstrates the possible role of MSTN on both the form and function of horses from non-racing breeds. Further analysis of Icelandic horses as well as other non-racing breeds would be beneficial and likely help to completely understand the influence of MSTN on conformation and performance in horses.
|
|
| 9. |
|
|
| 10. |
- Jäderkvist Fegraeus, Kim, et al.
(författare)
-
A potential regulatory region near the EDN3 gene may control both harness racing performance and coat color variation in horses
- 2018
-
Ingår i: Physiological Reports. - : Wiley. - 2051-817X. ; 6:10
-
Tidskriftsartikel (refereegranskat)abstract
- The Swedish‐Norwegian Coldblooded trotter and the heavier North‐Swedish draught horse both descend from the North‐Swedish horse, but the Coldblooded trotters have been selected for racing performance while the North‐Swedish draught horse is mainly used for agricultural and forestry work. By comparing the genomes of Coldblooded trotters, North‐Swedish draught horses and Standardbreds for a large number of single‐nucleotide polymorphisms (SNPs), the aim of the study was to identify genetic regions that may be under selection for racing performance. We hypothesized that the selection for racing performance, in combination with unauthorized crossbreeding of Coldblooded trotters and Standardbreds, has created regions in the genome where the Coldblooded trotters and Standardbreds are similar, but differ from the North‐Swedish draught horse. A fixation index (Fst) analysis was performed and sliding window Delta Fst values were calculated across the three breeds. Five windows, where the average Fst between Coldblooded trotters and Standardbreds was low and the average Fst between Coldblooded trotters and North‐Swedish draught horses was high, were selected for further investigation. Associations between the most highly ranked SNPs and harness racing performance were analyzed in 400 raced Coldblooded trotters with race records. One SNP showed a significant association with racing performance, with the CC genotype appearing to be negatively associated. The SNP identified was genotyped in 1915 horses of 18 different breeds. The frequency of the TT genotype was high in breeds typically used for racing and show jumping while the frequency of the CC genotype was high in most pony breeds and draught horses. The closest gene in this region was the Endothelin3 gene (EDN3), a gene mainly involved in melanocyte and enteric neuron development. Both functional genetic and physiological studies are needed to fully understand the possible impacts of the gene on racing performance.
|
|
