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- Andersson, Lisa, et al.
(författare)
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The same ELA class II risk factors confer equine insect bite hypersensitivity in two distinct populations
- 2012
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Ingår i: Immunogenetics. - : Springer Science and Business Media LLC. - 0093-7711 .- 1432-1211. ; 64:3, s. 201-208
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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.
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- Arvelius, Per, et al.
(författare)
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Does the Swedish Armed Forces’ temperament test give information on genetic differences between dogs?
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- With the purpose to select breeders and dogs for training, all German Shepherd dogs in the Swedish Armed Forces (SAF) breeding program go through a temperament test. During the test, the dog's behavioural responses are rated with two different methods. In a previous study, using PCA on the test items, five and three underlying behavioural dimensions from each rating method were defined. Three of the dimensions correlated significantly to training success. Using test results from 873 dogs, we estimated heritabilities of, and genetic correlations between, the 38 test items plus the eight underlying behavioural dimensions. Parameters were estimated using a linear animal model including fixed effects of sex, educational level, test age and interaction between test year and test arena, and random effect of litter, genetic effect of the individual and residual. Heritabilities ranged from 0.00 to 0.28 (SE=0.05- 0.10), which is similar to what has been reported in previous studies on traits defined and measured in a comparable way. Genetic correlations were high (rg=0.92-0.98, SE=0.08-0.12) between dimensions derived from each registration method and defined as confidence, engagement and aggressiveness, but relatively weak between these dimensions within registration method (rg=0.00-0.45, SE=0.29-0.41). Our results imply that the test measures three separate behavioural dimensions and that the SAF temperament test as a whole is possible to utilize for selection of dogs for breeding, but also that some test items should be measured differently to be meaningful for selection purposes. Furthermore, aggregating variables based on a PCA performed on phenotypic data might be sub-optimal when defining dimensions for breeding purposes.
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- Arvelius, Per, et al.
(författare)
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Genetic analysis of a temperament test as a tool to select against everyday life fearfulness in Rough Collie
- 2014
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Ingår i: Journal of Animal Science. - : Oxford University Press (OUP). - 0021-8812 .- 1525-3163. ; 92, s. 4843-4855
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Tidskriftsartikel (refereegranskat)abstract
- Fear-related problems are common among Rough Collies in Sweden. Annually, on average, >200 Rough Collies are subjected to the dog mentality assessment (DMA), a temperament test during which 33 behavioral reactions are rated. Previous research has shown that a dog's DMA result can be condensed into 5 underlying personality traits. The aim of the study was to evaluate if it is possible to use the DMA for selection for temperament in Swedish Rough Collies, in particular to decrease everyday life fearfulness. We also wanted to compare 2 methods to compute the personality traits: summated scales (SS) and factor scores (FS). The DMA data for 2,953 Rough Collies were used to estimate genetic parameters for the 5 personality traits (both SS and FS), using a linear animal model including fixed effects of sex, year and month of test, and random effects of litter, judge, test occasion, genetic effect of the individual, and residual. Age at test was included as linear and quadratic regressions. The DMA personality trait heritability estimates ranged from 0.13 to 0.25. The SS showed greater or equal heritability estimates compared with the FS. To validate the DMA, data on everyday life behavior of 1,738 Rough Collies were collected using an extended version of the Canine Behavioral Assessment and Research Questionnaire. Each dog's questionnaire result was condensed into 18 underlying behavioral subscales. Genetic parameters for the subscales were estimated using a linear animal model, including a fixed effect of sex and random genetic effect of the individual and residual. Age when the questionnaire was completed was included as linear and quadratic regressions. Heritability estimates for the questionnaire subscales were 0.06 to 0.36. There were high and significant genetic correlations between DMA personality traits and questionnaire subscales. For instance, the DMA personality trait Curiosity/Fearlessness correlated strongly genetically to the questionnaire subscale Non-social fear (-0.70), DMA Sociability to Stranger-directed interest (0.87) and Stranger-directed fear (-0.80), DMA Playfulness to Human-directed play interest (0.63), and DMA Chase-proneness to Chasing (0.73). We could not detect any obvious difference in validity between DMA SS and FS. We conclude that the DMA is an effective tool for selection of breeding animals with the goal to decrease everyday life fearfulness among Swedish Rough Collies. The DMA can also be used for breeding for other traits. The SS method seems to perform at least as good the FS method.
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- Arvelius, Per, et al.
(författare)
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Good Possibilities to Select Against Fearfulness in Rough Collie
- 2014
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Fear-related problems are common among Swedish Rough Collies. Genetic analyses were performed on 4 composite behavioral traits based on 2953 Rough Collie results from a temperament test. Heritabilities ranged from 0.13-0.25. Validation of the test was done using a dog owner questionnaire, which generated information about everyday life behavior for 1738 Rough Collies. There were high and significant genetic correlations between traits measured in the test, and the everyday life behavior of the dogs as described by the owners. For instance, Curiosity/fearlessness in the test was negatively genetically correlated with Nonsocial fear in the questionnaire (-0.70, SE 0.10). We conclude that data from the analyzed test is possible to use for selection to decrease everyday life fearfulness in the Swedish Rough Collie population.
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- Arvelius, Per, et al.
(författare)
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The Swedish Armed Forces temperament test gives information on genetic differences among dogs
- 2014
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Ingår i: Journal of Veterinary Behavior: Clinical Applications and Research. - : Elsevier BV. - 1558-7878 .- 1878-7517. ; 9, s. 281-289
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Tidskriftsartikel (refereegranskat)abstract
- With the dual purpose of selecting both breeding animals and dogs for training, all German shepherd dogs in the Swedish Armed Forces (SAF) breeding program are subjected to a temperament test. During the test, the dog's behavioral responses are rated with 2 different methods. In a previous study, using Principal Components Analysis (PCA) on the test items, 5 and 3 underlying behavioral dimensions from each rating method were defined. Three of the dimensions were reported to correlate significantly to training success. Using the test results from 873 dogs, we estimated heritabilities of, and genetic correlations among, the 38 test items and the 8 underlying behavioral dimensions. Parameters were estimated using a mixed linear animal model including fixed effects of sex, training level, test age and test year-location combination, and random effects of litter, genetic effect of the individual, and residual. Heritabilities ranged from 0.00 to 0.28 (standard error [SE] = 0.05-0.10), which is similar to what has been reported in previous studies of traits defined and measured in a comparable way. Genetic correlations were high (r(g) = 0.92-0.98, SE = 0.08-0.12) between dimensions derived from each rating method and defined as either confidence, engagement, or aggressiveness, but relatively weak among these dimensions within rating method (r(g) = 0.00-0.45, SE = 0.29-0.41). Our results imply that the test measures 3 separate behavioral dimensions and that the SAF temperament test as a whole is possible to use for selection of dogs for breeding, but also that some test items should be measured differently to be meaningful for genetic selection purposes. Furthermore, aggregating variables based on a PCA performed on phenotypic data might be suboptimal when defining dimensions for breeding purposes; taking genetic parameters into consideration resulted in generally higher heritabilities for the dimensions. (C) 2014 Elsevier Inc. All rights reserved.
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