| 1. |
- Staiger, E. A., et al.
(författare)
-
The evolutionary history of the DMRT3 'Gait keeper' haplotype
- 2017
-
Ingår i: Animal Genetics. - : WILEY. - 0268-9146 .- 1365-2052. ; 48:5, s. 551-559
-
Tidskriftsartikel (refereegranskat)abstract
- A previous study revealed a strong association between the DMRT3:Ser301STOP mutation in horses and alternate gaits as well as performance in harness racing. Several follow-up studies have confirmed a high frequency of the mutation in gaited horse breeds and an effect on gait quality. The aim of this study was to determine when and where the mutation arose, to identify additional potential causal mutations and to determine the coalescence time for contemporary haplotypes carrying the stop mutation. We utilized sequences from 89 horses representing 26 breeds to identify 102 SNPs encompassing the DMRT3 gene that are in strong linkage disequilibrium with the stop mutation. These 102 SNPs were genotyped in an additional 382 horses representing 72 breeds, and we identified 14 unique haplotypes. The results provided conclusive evidence that DMRT3: Ser301STOP is causal, as no other sequence polymorphisms showed an equally strong association to locomotion traits. The low sequence diversity among mutant chromosomes demonstrated that they must have diverged from a common ancestral sequence within the last 10 000 years. Thus, the mutation occurred either just before domestication or more likely some time after domestication and then spread across the world as a result of selection on locomotion traits.
|
|
| 2. |
- Abebe Abiye, Shenkut, et al.
(författare)
-
Genetic diversity of five local Swedish chicken breeds detected by microsatellite markers
- 2015
-
Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- This study aimed at investigating the genetic diversity, relationship and population structure of 110 local Swedish chickens derived from five breeds (Gotlandshona, Hedemorahona, Olandsk dvarghona, Skansk blommehona, and Bohuslan-Dals svarthona, in the rest of the paper the shorter name Svarthona is used) using 24 microsatellite markers. In total, one hundred thirteen alleles were detected in all populations, with a mean of 4.7 alleles per locus. For the five chicken breeds, the observed and expected heterozygosity ranged from 0.225 to 0.408 and from 0.231 to 0.515, with the lowest scores for the Svarthona and the highest scores for the Skansk blommehona breeds, respectively. Similarly, the average within breed molecular kinship varied from 0.496 to 0.745, showing high coancestry, with Skansk blommehona having the lowest and Svarthona the highest coancestry. Furthermore, all breeds showed significant deviations from Hardy-Weinberg expectations. Across the five breeds, the global heterozygosity deficit (FIT) was 0.545, population differentiation index (F-ST) was 0.440, and the global inbreeding of individuals within breed (F-IS) was 0.187. The phylogenetic relationships of chickens were examined using neighbor-joining trees constructed at the level of breeds and individual samples. The neighbor-joining tree constructed at breed level revealed two main clusters, with Hedemorahona and Olandsk dvarghona breeds in one cluster, and Gotlandshona and Svarthona breeds in the second cluster leaving the Skansk blommehona in the middle. Based on the results of the STRUCTURE analysis, the most likely number of clustering of the five breeds was at K = 4, with Hedemorahona, Gotlandshona and Svarthona breeds forming their own distinct clusters, while Olandsk dvarghona and Skansk blommehona breeds clustered together. Losses in the overall genetic diversity of local Swedish chickens due to breeds extinction varied from -1.46% to -6.723%. The results of the current study can be used as baseline genetic information for genetic conservation program, for instance, to control inbreeding and to implement further genetic studies in local Swedish chickens.
|
|
| 3. |
- Ablondi, Michela, et al.
(författare)
-
Performance of Swedish Warmblood fragile foal syndrome carriers and breeding prospects
- 2022
-
Ingår i: Genetics Selection Evolution. - : Springer Science and Business Media LLC. - 0999-193X .- 1297-9686. ; 54
-
Tidskriftsartikel (refereegranskat)abstract
- Background Warmblood fragile foal syndrome (WFFS) is a monogenetic defect caused by a recessive lethal missense point mutation in the procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 gene (PLOD1, c.2032G>A). The majority of homozygous WFFS horses are aborted during gestation. Clinical signs of affected horses include fragile skin, skin and mucosa lacerations, hyperextension of the articulations, and hematomas. In spite of its harmful effect, a relatively high frequency of WFFS carriers has been found in Warmblood horses, suggesting a heterozygote advantage. Thus, in this study our aims were to: (1) estimate the frequency of WFFS carriers in the Swedish Warmblood breed (SWB), (2) estimate the effect of WFFS carrier genotype on performance traits in two SWB subpopulations bred for different disciplines, and (3) simulate the potential effects of balancing selection and different selection strategies on the frequency of carriers. Methods In total, 2288 SWB sport horses born between 1971 and 2020 were tested for the WFFS mutation and had estimated breeding values (EBV) for ten traditional evaluating and 50 linear descriptive traits. Results The frequency of WFFS carriers calculated from a pool of 511 randomly selected SWB horses born in 2017 was equal to 7.4% and ranged from 0.0 to 12.0% among the whole set of tested SWB horses, starting from 1971 till 2020. The effect of the WFFS carrier genotype was significant for several EBV mainly related to movements and dressage traits and especially for horses not bred for the show jumping discipline. Using simulation, we showed that balancing selection can maintain a recessive lethal allele in populations such as the SWB breed over generations and that the frequency is expected to slowly decrease in absence of balancing selection. Finally, we showed that selection against carrier sires can result in a more rapid decrease of the frequency of the mutant allele over time. Conclusion Further research is needed to confirm the apparent association between equine performance and the WFFS carrier genotype. Identification of such associations or new causative mutations for horse performance traits can serve as new tools in horse breeding to select for healthy, sustainable, and better performing horses.
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Ablondi, Michela, et al.
(författare)
-
Signatures of selection in the genome of Swedish warmblood horses selected for sport performance
- 2019
-
Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 20
-
Tidskriftsartikel (refereegranskat)abstract
- Background A growing demand for improved physical skills and mental attitude in modern sport horses has led to strong selection for performance in many warmblood studbooks. The aim of this study was to detect genomic regions with low diversity, and therefore potentially under selection, in Swedish Warmblood horses (SWB) by analysing high-density SNP data. To investigate if such signatures could be the result of selection for equestrian sport performance, we compared our SWB SNP data with those from Exmoor ponies, a horse breed not selected for sport performance traits. Results The genomic scan for homozygous regions identified long runs of homozygosity (ROH) shared by more than 85% of the genotyped SWB individuals. Such ROH were located on ECA4, ECA6, ECA7, ECA10 and ECA17. Long ROH were instead distributed evenly across the genome of Exmoor ponies in 77% of the chromosomes. Two population differentiation tests (F-ST and XP-EHH) revealed signatures of selection on ECA1, ECA4, and ECA6 in SWB horses. Conclusions Genes related to behaviour, physical abilities and fertility, appear to be targets of selection in the SWB breed. This study provides a genome-wide map of selection signatures in SWB horses, and ground for further functional studies to unravel the biological mechanisms behind complex traits in horses.
|
|
| 8. |
|
|
| 9. |
- Andersson, Lisa, et al.
(författare)
-
Augendefekte bei windfarbenen Pferden
- 2012
-
Ingår i: Eiðfaxi, Islandpferdemagazin. - 1023-3350. ; , s. 70-75
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
| 10. |
- Andersson, Lisa, et al.
(författare)
-
Augngallar í vindóttum hrossum
- 2012
-
Ingår i: Eiðfaxi, Icelandic horse Magazine. - 1023-3342. ; , s. 42-47
-
Tidskriftsartikel (populärvet., debatt m.m.)
|
|
