| 1. |
- Brunberg, Emma, et al.
(författare)
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A missense mutation in PMEL17 is associated with the Silver coat color in the horse
- 2006
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Ingår i: BMC Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 7, s. 46-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The Silver coat color, also called Silver dapple, in the horse is characterized by dilution of the black pigment in the hair. This phenotype shows an autosomal dominant inheritance. The effect of the mutation is most visible in the long hairs of the mane and tail, which are diluted to a mixture of white and gray hairs. Herein we describe the identification of the responsible gene and a missense mutation associated with the Silver phenotype. Results: Segregation data on the Silver locus (Z) were obtained within one half-sib family that consisted of a heterozygous Silver colored stallion with 34 offspring and their 29 non-Silver dams. We typed 41 genetic markers well spread over the horse genome, including one single microsatellite marker (TKY284) close to the candidate gene PMEL17 on horse chromosome 6 (ECA6q23). Significant linkage was found between the Silver phenotype and TKY284 (theta = 0, z = 9.0). DNA sequencing of PMEL17 in Silver and non-Silver horses revealed a missense mutation in exon 11 changing the second amino acid in the cytoplasmic region from arginine to cysteine (Arg618Cys). This mutation showed complete association with the Silver phenotype across multiple horse breeds, and was not found among non-Silver horses with one clear exception; a chestnut colored individual that had several Silver offspring when mated to different non-Silver stallions also carried the exon 11 mutation. In total, 64 Silver horses from six breeds and 85 non-Silver horses from 14 breeds were tested for the exon 11 mutation. One additional mutation located in intron 9, only 759 bases from the missense mutation, also showed complete association with the Silver phenotype. However, as one could expect to find several non-causative mutations completely associated with the Silver mutation, we argue that the missense mutation is more likely to be causative. Conclusion: The present study shows that PMEL17 causes the Silver coat color in the horse and enable genetic testing for this trait.
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| 2. |
- Brunberg, Emma, et al.
(författare)
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Behavioural and Brain Gene Expression Profiling in Pigs during Tail Biting Outbreaks – Evidence of a Tail Biting Resistant Phenotype
- 2013
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Abnormal tail biting behaviour is a major welfare problem for pigs receiving the behaviour, as well as an indication of decreased welfare in the pigs performing it. However, not all pigs in a pen perform or receive tail biting behaviour and it has recently been shown that these ‘neutral’ pigs not only differ in their behaviour, but also in their gene expression compared to performers and receivers of tail biting in the same pen. To investigate whether this difference was linked to the cause or a consequence of them not being involved in the outbreak of tail biting, behaviour and brain gene expression was compared with ‘control’ pigs housed in pens with no tail biting. It was shown that the pigs housed in control pens performed a wider variety of pig-directed abnormal behaviour (belly nosing 0.95±1.59, tail in mouth 0.31±0.60 and ‘other‘ abnormal 1.53±4.26; mean±S.D) compared to the neutral pigs (belly nosing 0.30±0.62, tail in mouth 0.13±0.50 and “other“ abnormal 0.42±1.06). With Affymetrix gene expression arrays, 107 transcripts were identified as differently expressed (p<0.05) between these two categories of pigs. Several of these transcripts had already been shown to be differently expressed in the neutral pigs when they were compared to performers and receivers of tail biting in the same pen in an earlier study. Hence, the different expression of these genes cannot be a consequence of the neutral pigs not being involved in tail biting behaviour, but rather linked to the cause contributing to why they were not involved in tail biting interactions. These neutral pigs seem to have a genetic and behavioural profile that somehow contributes to them being resistant to performing or receiving pig-directed abnormal behaviour, such as tail biting, even when housed in an environment that elicits that behaviour in other pigs.
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| 3. |
- Brunberg, Emma, et al.
(författare)
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Brain gene expression differences are associated with abnormal tail biting behavior in pigs
- 2013
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Ingår i: Genes, Brain and Behavior. - : Wiley. - 1601-1848 .- 1601-183X. ; 12:2, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about gene expression in animals involved in abnormal behaviors can contribute to the understanding of underlying biological mechanisms. This study aimed to explore the motivational background to tail biting, an abnormal injurious behavior and severe welfare problem in pig production. Affymetrix microarrays were used to investigate gene expression differences in the hypothalamus and prefrontal cortex of pigs performing tail biting, pigs receiving bites to the tail and neutral pigs who were not involved in the behavior. In the hypothalamus, 32 transcripts were differentially expressed (P<0.05) when tail biters were compared with neutral pigs, 130 when comparing receiver pigs with neutrals, and two when tail biters were compared with receivers. In the prefrontal cortex, seven transcripts were differently expressed in tail biters when compared with neutrals, seven in receivers vs. neutrals and none in the tail biters vs. receivers. In total, 19 genes showed a different expression pattern in neutral pigs when compared with both performers and receivers. This implies that the functions of these may provide knowledge about why the neutral pigs are not involved in tail biting behavior as performers or receivers. Among these 19 transcripts were genes associated with production traits in pigs (PDK4), sociality in humans and mice (GTF2I) and novelty seeking in humans (EGF). These are in line with hypotheses linking tail biting with reduced back fat thickness and explorative behavior.
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| 4. |
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| 5. |
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| 6. |
- Brunberg, Emma, et al.
(författare)
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Evidence for a link between tail biting and central monoamine metabolism in pigs (Sus scrofa domestica)
- 2015
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Ingår i: Physiology and Behavior. - : Elsevier BV. - 0031-9384 .- 1873-507X. ; 143, s. 151-157
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Tidskriftsartikel (refereegranskat)abstract
- Tail biting in pigs is a major welfare problem within the swine industry. Even though there is plenty of information on housing and management-related risk factors, the biological bases of this behavioral problem are poorly understood. The aim of this study was to investigate a possible link between tail biting, based on behavioral recordings of pigs during an ongoing outbreak, and certain neurotransmitters in different brain regions of these pigs. We used a total of 33 pigs at a farm with a long-standing problem of tail biting. Three equally big behavioral phenotypic groups, balanced for gender and age were selected, the data thus consisting of 11 trios of pigs. Two of the pigs in each trio originated from the same pen: one tail biter (TB) and one tail biting victim (V). A control (C) pig was selected from a pen without significant tail biting in the same farm room. We found an effect of tail biting behavioral phenotype on the metabolism of serotonin and dopamine, with a tendency for a higher 5-HIAA level in the prefrontal cortex (PFC) of TB compared to the other groups, while V pigs showed changes in both serotonin and dopamine metabolism in the striatum (ST) and limbic cortex (LC). Trp:BCAA and Trp:LNAA correlated positively with serotonin and 5-HIAA in the PFC, but only in TB pigs. Furthermore, in both ST and LC, several of the neurotransmitters and their metabolites correlated positively with the frequency of bites received by the pig. This is the first study indicating a link between brain neurotransmission and tail biting behavior in pigs with TB pigs showing a tendency for increased PFC serotonin metabolism and V pigs showing several changes in central dopamine and serotonin metabolism in their ST and LC, possibly due to the acute stress caused by being bitten.
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| 7. |
- Brunberg, Emma, et al.
(författare)
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Feather pecking behavior in laying hens : Hypothalamic gene expression in birds performing and receiving pecks
- 2011
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Ingår i: Poultry Science. - : Elsevier BV. - 0032-5791 .- 1525-3171. ; 90:6, s. 1145-1152
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Tidskriftsartikel (refereegranskat)abstract
- Feather pecking (FP) is a welfare and economic problem in the egg production sector. Beak trimming, the current method used to reduce FP, is also criticized. The present study used gene expression to explore the biological mechanisms underlying this behavior, which could lead to a greater understanding of the cause and a tool to mitigate the problem. White Leghorn hens performing and receiving FP, as well as neutral control birds, were identified on a commercial farm. Hypothalamic RNA from 11 peckers, 10 victims, and 10 controls was hybridized onto GeneChip Chicken Genome Arrays (Affymetrix Inc., Santa Clara, CA) to compare gene expression profiles in the different groups. Eleven transcripts corresponding to 10 genes differed significantly between the 3 groups (adjusted P < 0.05). Eight of these transcripts differed in the peckers compared with the controls, 1 was upregulated in the victims compared with the controls, and 6 differed significantly in the peckers compared with the victims. Additionally, 5 transcripts showed a trend (adjusted P < 0.1) to differ in the pecker-victim comparison. Some of the products of the differently expressed genes are involved in disorders, such as intestinal inflammation and insulin resistance, which fit well with the previously proposed hypothesis that FP is an abnormal foraging behavior. Other findings may also support the proposal that FP is linked to immune mechanisms and may serve as an animal model for obsessive compulsive disorder in humans. In conclusion, this study provides a gene list that may be useful in further research on the mechanisms behind FP.
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| 8. |
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| 9. |
- Brunberg, Emma, et al.
(författare)
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Icelandic horses with the Silver coat colour show altered behaviour in a fear reaction test
- 2013
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Ingår i: Applied Animal Behaviour Science. - : Elsevier BV. - 0168-1591 .- 1872-9045. ; 146, s. 72-78
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Tidskriftsartikel (refereegranskat)abstract
- The colour of a horse's coat has long been discussed to reflect its temperament. One opinion is that Silver coloured horses are nervous, difficult to handle and react more strongly to different fear stimuli. The objective with the present study was to investigate if mutations associated with the Silver coat colour affect fear reactions in Icelandic horses. The hypothesis was that horses with the Silver mutation Arg618Cys in PMEL show stronger fear reactions than horses without the mutation (e.g. Black/Brown or Chestnut horses). Twenty-seven Icelandic horses (nine Silver, nine Chestnuts and nine Black/Brown) matched for sire, were exposed to the fear stimulus (a suddenly moving plastic bag) while feeding from a container. The test was repeated five times and behavioural responses and latency to return to the feed container were recorded. All horses were genotyped for the Silver mutation. The proportion of Silver horses that were hesitant to approach the test set-up before each trial was significantly higher (P < 0.05) than the proportion of non-Silver horses and this difference was most pronounced before the first two trials. No differences in reaction vigour or latency to resume feeding were found between the differently coloured horses. The results suggest that Silver horses are more cautious in novel situations rather than more reactive in fearful situations. One likely explanation for this difference is that the Silver mutation is associated with multiple congenital ocular anomalies (MCOA) syndrome and visual impairment. Furthermore, offspring (regardless of coat colour) from sires with a Best Linear Unbiased Prediction (BLUP, an index indicating which traits a horse will pass on to its offspring) value above 100 for the temperament trait 'Spirit', showed a greater fear reaction (P < 0.01) and reacted for a longer time (P < 0.01) than horses from sires with a lower (<100) index. These results indicate that horses with a high BLUP value for 'Spirit' seem to express stronger fear reactions. Breeding for Silver coat colour and the 'Spirit' trait, as it is currently defined, may need to be reconsidered if these results are confirmed in a larger cohort. (c) 2013 Elsevier B.V. All rights reserved.
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