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- Velie, Brandon, et al.
(author)
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Frequencies of polymorphisms in myostatin vary in Icelandic horses according to the use of the horses
- 2015
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In: Animal Genetics. - : Wiley. - 0268-9146 .- 1365-2052. ; 46, s. 467-468
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Journal article (peer-reviewed)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.
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| 2. |
- Jäderkvist Fegraeus, Kim, et al.
(author)
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The DMRT3 'Gait keeper' mutation affects performance of Nordic and Standardbred trotters
- 2014
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In: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 92:10, s. 4279-4286
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Journal article (peer-reviewed)abstract
- In a previous study it was shown that a nonsense mutation in the DMRT3 gene alters the pattern of locomotion in horses and that this mutation has a strong positive impact on trotting performance of Standardbreds. One aim of this study was to test if racing performance and trotting technique in the Nordic (Coldblood) trotters are also influenced by the DMRT3 genotype. Another aim was to further investigate the effect of the mutation on performance in Standardbreds, by using a within-family analysis and genotype-phenotype correlations in a larger horse material than in the previous study. We genotyped 427 Nordic trotters and 621 Standardbreds for the DMRT3 nonsense mutation and a SNP in strong linkage disequilibrium with it. In Nordic trotters, we show that horses homozygous for the DMRT3 mutation (A) had significantly higher EBV for trotting performance traits than heterozygous (CA) or homozygous wild-type (CC) horses (P = 0.001). Furthermore, AA homozygotes had a higher proportion of victories and top 3 placings than horses heterozygous or homozygous wild-type, when analyzing performance data for the period 3 to 6 yr of age (P = 0.06 and P = 0.05, respectively). Another finding in the Nordic trotters was that the DMRT3 mutation influenced trotting technique (P = 2.1 x 10(-8)). Standardbred horses homozygous AA had significantly higher EBV for all traits than horses with at least 1 wild-type allele (CA and CC; P = 1.6 x 10(-16)). In a within-family analysis of Standardbreds, we found significant differences in several traits (e. g., earnings, P = 0.002; number of entered races, P = 0.004; and fraction of offspring that entered races, P = 0.002) among paternal half-sibs with genotype AA or CA sired by a CA stallion. For most traits, we found significant differences at young ages. For Nordic trotters, most of the results were significant at 3 yr of age but not for the older ages, and for the Standardbreds most of the results for the ages 3 to 5 were significant. For Nordic trotters, the proportion of victories and placings were the only traits that were significant for other ages than 3 yr.
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| 3. |
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| 4. |
- Andersson, Lisa, et al.
(author)
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SynchrogGait Learn about your horse´s natural ability for different gaits
- 2015
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Other publication (other academic/artistic)abstract
- Get help from the DNA-test SynchroGait® to learn about your horse's genetic potential for gaits. The test is very easy to use and by using information from the test, you are able to plan breeding to maximize the chances of getting offspring with the gaits that you prefer. It also provides valuable information for matching the right horse to the right rider and discipline and lays the foundation for a successful relationship between rider and horse.
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| 6. |
- Eriksson, Susanne, et al.
(author)
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Prevalence and genetic parameters for cryptorchidism in Swedish-born Icelandic horses
- 2015
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In: Livestock Science. - : Elsevier BV. - 1871-1413 .- 1878-0490. ; 180, s. 1-5
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Journal article (peer-reviewed)abstract
- Cryptorchidism is a defect in males where one or both testes fail to descend normally into the scrotum. If both testes are retained, the stallion will be infertile. There are few studies of the prevalence of the condition in horses based on field data, and heritability estimates for equine cryptorchidism are lacking. The objective of this study was to provide data on prevalence and heritability of cryptorchidism in Icelandic horses born in Sweden. A questionnaire was sent to breeders, asking whether or not stallions born at the farm had both testes present in the scrotum at the age of 1,6 and 12 months. Fixed effects were analysed using logistic regression and genetic parameters were estimated using linear animal models. Information about 595 yearling stallions born 1997-2011 was used in the analyses. Close to 9% of the yearlings did not have both testes in the scrotum. Probability of cryptorchidism in yearlings was significantly influenced by farm and time period of birth. Heritability estimates for cryptorchidism ranged from 0.12 to 0.32 (SE 0.08-0.12) on the observable scale, and from 0.35 to 0.96 (SE 0.24-0.40) when transformed to the underlying continuous scale. The results support that equine cryptorchidism is heritable. Further studies with more individuals included would be needed to confirm this. (C) 2015 Published by Elsevier B.V.
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| 8. |
- Jäderkvist Fegraeus, Kim, et al.
(author)
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A potential regulatory region near the EDN3 gene may control both harness racing performance and coat color variation in horses
- 2018
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In: Physiological Reports. - : Wiley. - 2051-817X. ; 6:10
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Journal article (peer-reviewed)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.
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