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  • 1.
    Fallahsharoudi, Amir
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Løtvedt, Pia
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. AVIAN Behavioural Genomics and Physiology Group, IFM Biology, Linköping University, 58183, Linköping, Sweden..
    Beltéky, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Altimiras, Jordi
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Changes in pituitary gene expression may underlie multiple domesticated traits in chickens.2019In: Heredity, ISSN 0018-067X, E-ISSN 1365-2540, Vol. 122, no 2, p. 195-204Article in journal (Refereed)
    Abstract [en]

    Domesticated animals share a unique set of morphological and behavioral traits, jointly referred to as the domesticated phenotype. Striking similarities amongst a range of unrelated domesticated species suggest that similar regulatory mechanisms may underlie the domesticated phenotype. These include color pattern, growth, reproduction, development and stress response. Although previous studies have focused on the brain to find mechanisms underlying domestication, the potential role of the pituitary gland as a target of domestication is highly overlooked. Here, we study gene expression in the pituitary gland of the domesticated White Leghorn chicken and its wild ancestor, the Red Junglefowl. By overlapping differentially expressed genes with a previously published list of functionally important genes in the pituitary gland, we narrowed down to 34 genes. Amongst them, expression levels of genes with inhibitory function on pigmentation (ASIP), main stimulators of metabolism and sexual maturity (TSHB and DIO2), and a potential inhibitor of broodiness (PRLR), were higher in the domesticated breed. Additionally, expression of 2 key inhibitors of the stress response (NR3C1, CRHR2) was higher in the domesticated breed. We suggest that changes in the transcription of important modulatory genes in the pituitary gland can account not only for domestication of the stress response in domestic chickens, but also for changes in pigmentation, development, and reproduction. Given the pivotal role of the pituitary gland in the regulation of multiple shared domesticated traits, we suggest that similar changes in pituitary transcriptome may contribute to the domesticated phenotype in other species as well.

  • 2.
    Hedlund, Louise
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Whittle, Rosemary
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Effects of commercial hatchery processing on short- and long-term stress responses in laying hens2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 2367Article in journal (Refereed)
    Abstract [en]

    In commercial egg production, chicks are exposed to a potentially stressful procedure during their first day of life. Here, we investigated how this procedure affects the chickens in a short-as well as long-term perspective by conducting two behaviour tests and measuring corticosterone (CORT) and sex hormone levels at different time points. These results were compared with a group of control chickens from the same hatchery and incubator that did not go through the commercial hatchery routine. Chickens were continuously weighed, egg production data was collected and feather scoring was performed. We found that chicks have a significant increase in CORT during the hatchery process, which implies they are exposed to stress. During first weeks of life, these chicks were more fearful, had a higher CORT reactivity during restraint and weighed more than control chicks. Later in life, hatchery treated chickens had more feather damages and injuries on combs and wattles, a faster onset of egg laying and higher levels of estradiol. We conclude that processing at the commercial hatchery was a stressful event with short-and long-term effects on behaviour and stress reactivity, and potentially also positive effects on production. The results are relevant for a large number of individuals, since the chicken is by far the globally most common farm animal.

  • 3.
    Cardoso-Moreira, Margarida
    et al.
    Heidelberg Univ ZMBH, Germany; Univ Lausanne, Switzerland.
    Halbert, Jean
    Univ Lausanne, Switzerland.
    Valloton, Delphine
    Univ Lausanne, Switzerland.
    Velten, Britta
    European Mol Biol Lab, Germany.
    Chen, Chunyan
    Chinese Acad Sci, Peoples R China; Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Shao, Yi
    Chinese Acad Sci, Peoples R China; Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Liechti, Angelica
    Univ Lausanne, Switzerland.
    Ascencao, Kelly
    Univ Lausanne, Switzerland.
    Rummel, Coralie
    Univ Lausanne, Switzerland.
    Ovchinnikova, Svetlana
    Heidelberg Univ ZMBH, Germany.
    Mazin, Pavel V.
    Skolkovo Inst Sci and Technol, Russia; RAS, Russia; HSE Univ, Russia.
    Xenarios, Ioannis
    Univ Lausanne, Switzerland.
    Harshman, Keith
    Univ Lausanne, Switzerland.
    Mort, Matthew
    Cardiff Univ, Wales.
    Cooper, David N.
    Cardiff Univ, Wales.
    Sandi, Carmen
    Ecole Polytech Fed Lausanne, Switzerland.
    Soares, Michael J.
    Univ Kansas, MO USA; Childrens Mercy, MO USA.
    Ferreira, Paula G.
    Univ Porto, Portugal; Univ Porto, Portugal.
    Afonso, Sandra
    Univ Porto, Portugal.
    Carneiro, Miguel
    Univ Porto, Portugal; Univ Porto, Portugal.
    Turner, James M. A.
    Francis Crick Inst, England.
    VandeBerg, John L.
    Univ Texas Rio Grande Valley, TX USA; Univ Texas Rio Grande Valley, TX USA; Univ Texas Rio Grande Valley, TX USA; Univ Texas Rio Grande Valley, TX USA; Univ Texas Rio Grande Valley, TX USA; Univ Texas Rio Grande Valley, TX USA.
    Fallahshahroudi, Amir
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behr, Ruediger
    Leibniz Inst Primate Res DPZ, Germany; DZHK German Ctr Cardiovasc Res, Germany.
    Lisgo, Steven
    Newcastle Univ, England.
    Lindsay, Susan
    Newcastle Univ, England.
    Khaitovich, Philipp
    Skolkovo Inst Sci and Technol, Russia; Chinese Acad Sci, Peoples R China; Univ Chinese Acad Sci, Peoples R China.
    Huber, Wolfgang
    European Mol Biol Lab, Germany.
    Baker, Julie
    Stanford Univ, CA 94305 USA.
    Anders, Simon
    Heidelberg Univ ZMBH, Germany.
    Zhang, Yong E.
    Chinese Acad Sci, Peoples R China; Chinese Acad Sci, Peoples R China; Chinese Acad Sci, Peoples R China.
    Kaessmann, Henrik
    Heidelberg Univ ZMBH, Germany.
    Gene expression across mammalian organ development2019In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 571, no 7766, p. 505-+Article in journal (Refereed)
    Abstract [en]

    The evolution of gene expression in mammalian organ development remains largely uncharacterized. Here we report the transcriptomes of seven organs (cerebrum, cerebellum, heart, kidney, liver, ovary and testis) across developmental time points from early organogenesis to adulthood for human, rhesus macaque, mouse, rat, rabbit, opossum and chicken. Comparisons of gene expression patterns identified correspondences of developmental stages across species, and differences in the timing of key events during the development of the gonads. We found that the breadth of gene expression and the extent of purifying selection gradually decrease during development, whereas the amount of positive selection and expression of new genes increase. We identified differences in the temporal trajectories of expression of individual genes across species, with brain tissues showing the smallest percentage of trajectory changes, and the liver and testis showing the largest. Our work provides a resource of developmental transcriptomes of seven organs across seven species, and comparative analyses that characterize the development and evolution of mammalian organs.

  • 4.
    Fogelholm, Jesper
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Inkabi, Samuel
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Höglund, Andrey
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Abbey-Lee, Robin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Johnsson, Martin
    Univ Edinburgh, Scotland; Swedish Univ Agr Sci, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Henriksen, Rie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Genetical Genomics of Tonic Immobility in the Chicken2019In: Genes, ISSN 2073-4425, E-ISSN 2073-4425, Vol. 10, no 5, article id 341Article in journal (Refereed)
    Abstract [en]

    Identifying the molecular mechanisms of animal behaviour is an enduring goal for researchers. Gaining insight into these mechanisms enables us to gain a greater understanding of behaviour and their genetic control. In this paper, we perform Quantitative Trait Loci (QTL) mapping of tonic immobility behaviour in an advanced intercross line between wild and domestic chickens. Genes located within the QTL interval were further investigated using global expression QTL (eQTL) mapping from hypothalamus tissue, as well as causality analysis. This identified five candidate genes, with the genes PRDX4 and ACOT9 emerging as the best supported candidates. In addition, we also investigated the connection between tonic immobility, meat pH and struggling behaviour, as the two candidate genes PRDX4 and ACOT9 have previously been implicated in controlling muscle pH at slaughter. We did not find any phenotypic correlations between tonic immobility, struggling behaviour and muscle pH in a smaller additional cohort, despite these behaviours being repeatable within-test.

  • 5.
    Sundman, Ann-Sofie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    van Poucke, Enya
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Svensson Holm, Ann-Charlotte
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Olsen Faresjö, Åshild
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Theodorsson, Elvar
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Chemistry. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Chemistry.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Roth, Lina
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Long-term stress levels are synchronized in dogs and their owners2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 7391Article in journal (Refereed)
    Abstract [en]

    This study reveals, for the first time, an interspecific synchronization in long-term stress levels. Previously, acute stress, has been shown to be highly contagious both among humans and between individuals of other species. Here, long-term stress synchronization in dogs and their owners was investigated. We studied 58 dog-human dyads and analyzed their hair cortisol concentrations (HCC) at two separate occasions, reflecting levels during previous summer and winter months. The personality traits of both dogs and their owners were determined through owner-completed Dog Personality Questionnaire (DPQ) and human Big Five Inventory (BFI) surveys. In addition, the dogs activity levels were continuously monitored with a remote cloud-based activity collar for one week. Shetland sheepdogs (N = 33) and border collies (N = 25), balanced for sex, participated, and both pet dogs and actively competing dogs (agility and obedience) were included to represent different lifestyles. The results showed significant interspecies correlations in long-term stress where human HCC from both summer and winter samplings correlated strongly with dog HCC (summer: N = 57, chi(2) = 23.697, P amp;lt; 0.001, beta = 0.235; winter: N = 55, chi(2) = 13.796, P amp;lt; 0.001, beta = 0.027). Interestingly, the dogs activity levels did not affect HCC, nor did the amount of training sessions per week, showing that the HCC levels were not related to general physical activity. Additionally, there was a seasonal effect in HCC. However, although dogs personalities had little effects on their HCC, the human personality traits neuroticism, conscientiousness, and openness significantly affected dog HCC. Hence, we suggest that dogs, to a great extent, mirror the stress level of their owners.

  • 6.
    Nunez-Leon, Daniel
    et al.
    Univ Zurich, Switzerland.
    Aguirre-Fernandez, Gabriel
    Univ Zurich, Switzerland.
    Steiner, Andrea
    Univ Zurich, Switzerland.
    Nagashima, Hiroshi
    Niigata Univ, Japan.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Stoeckli, Esther
    Univ Zurich, Switzerland.
    Schneider, Richard A.
    Univ Calif San Francisco, CA 94143 USA.
    Sanchez-Villagra, Marcelo R.
    Univ Zurich, Switzerland.
    Morphological diversity of integumentary traits in fowl domestication: Insights from disparity analysis and embryonic development2019In: Developmental Dynamics, ISSN 1058-8388, E-ISSN 1097-0177Article, review/survey (Refereed)
    Abstract [en]

    The domestication of the fowl resulted in a large diversity of integumental structures in chicken breeds. Several integumental traits have been investigated from a developmental genetics perspective. However, their distribution among breeds and their developmental morphology remain unexplored. We constructed a discrete trait-breed matrix and conducted a disparity analysis to investigate the variation of these structures in chicken breeds; 20 integumental traits of 72 chicken breeds and the red junglefowl were assessed. The analyses resulted in slight groupings of breed types comparable to standard breed classification based on artificial selection and chicken type use. The red junglefowl groups together with bantams and European breeds. We provide new data on the red junglefowl and four chicken breeds, demonstrating where and when variation arises during embryonic development. We document variation in developmental timing of the egg tooth and feather formation, as well as other kinds of developmental patterning as in the anlagen of different type of combs. Changes in epithelial-mesenchymal signaling interactions may drive the highly diverse integument in chickens. Experimental and comparative work has revealed that the cranial neural crest mesenchyme mediates its interactions with the overlying epithelium and is the likely source of patterning that generates diversity in integumental structures.

  • 7.
    Pértille, Fábio
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Univ Sao Paulo, Brazil.
    Da Silva, Vinicius H.
    Wageningen Univ and Res, Netherlands; Netherlands Inst Ecol NIOO KNAW, Netherlands; Swedish Univ Agr Sci, Sweden.
    Johansson, Anna M.
    Swedish Univ Agr Sci, Sweden.
    Lindström, Tom
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Coutinho, Luiz L.
    Univ Sao Paulo, Brazil.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Guerrero Bosagna, Carlos
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Mutation dynamics of CpG dinucleotides during a recent event of vertebrate diversification2019In: Epigenetics, ISSN 1559-2294, E-ISSN 1559-2308Article in journal (Refereed)
    Abstract [en]

    DNA methylation in CpGs dinucleotides is associated with high mutability and disappearance of CpG sites during evolution. Although the high mutability of CpGs is thought to be relevant for vertebrate evolution, very little is known on the role of CpG-related mutations in the genomic diversification of vertebrates. Our study analysed genetic differences in chickens, between Red Junglefowl (RJF; the living closest relative to the ancestor of domesticated chickens) and domesticated breeds, to identify genomic dynamics that have occurred during the process of their domestication, focusing particularly on CpG-related mutations. Single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) between RJF and these domesticated breeds were assessed in a reduced fraction of their genome. Additionally, DNA methylation in the same fraction of the genome was measured in the sperm of RJF individuals to identify possible correlations with the mutations found between RJF and the domesticated breeds. Our study shows that although the vast majority of CpG-related mutations found relate to CNVs, CpGs disproportionally associate to SNPs in comparison to CNVs, where they are indeed substantially under-represented. Moreover, CpGs seem to be hotspots of mutations related to speciation. We suggest that, on the one hand, CpG-related mutations in CNV regions would promote genomic flexibility in evolution, i.e., the ability of the genome to expand its functional possibilities; on the other hand, CpG-related mutations in SNPs would relate to genomic specificity in evolution, thus, representing mutations that would associate with phenotypic traits relevant for speciation.

  • 8.
    Tälle, Malin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Wiréhn, Lotten
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR.
    Ellström, Daniel
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Hjerpe, Mattias
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR.
    Huge-Brodin, Maria
    Linköping University, Department of Management and Engineering, Logistics & Quality Management. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Lindström, Tom
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Schmid Neset, Tina
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR.
    Wennergren, Uno
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Metson, Genevieve
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Biology. Linköping University, Faculty of Science & Engineering.
    Synergies and Trade-Offs for Sustainable Food Production in Sweden: An Integrated Approach2019In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 11, no 3, article id 601Article in journal (Refereed)
    Abstract [en]

    The production of food can have large impacts on sustainable development in relation to various socio-ecological dimensions, like climate change, the environment, animal welfare, livestock epidemiology, and the economy. To achieve a sustainable food production system in Sweden, an integrated approach that considers all five of these dimensions, and all parts of the food production chain, is necessary. This paper systematically reviewed the literature related to food production in Sweden, especially in association with resource distribution and recycling logistics, and identified potential sustainability interventions and assessed their effects according to the five dimensions. Participation of stakeholders across the food production chain contributed with the focus of the literature search and subsequent synthesis. In general, there were synergies between the sustainability interventions and their effect on climate change and the environment, while there often were trade-offs between effects on the economy and the other dimensions. Few interventions considered effects on animal welfare or livestock epidemiology and few studies dealt with resource distribution and recycling logistics. This indicates that there is a need for future research that considers this in particular, as well as research that considers the whole food production chain and all dimensions at once, and investigates effects across multiple scales.

  • 9.
    Fallahshahroudi, Amir
    et al.
    Uppsala Univ, Sweden.
    Sorato, Enrico
    Reneco Int Wildlife Consultants, U Arab Emirates.
    Altimiras, Jordi
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    The Domestic BCO2 Allele Buffers Low-Carotenoid Diets in Chickens: Possible Fitness Increase Through Species Hybridization2019In: Genetics, ISSN 0016-6731, E-ISSN 1943-2631, Vol. 212, no 4, p. 1445-1452Article in journal (Refereed)
    Abstract [en]

    Domestic animals are adapted to conditions vastly different from those of their wild ancestors, and this is particularly true for their diets. The most numerous of all domestic species, the chicken, originated from the Red Junglefowl (RJF), a native of subtropical forests in Southeast Asia. Surprisingly however, in domestic chicken breeds, a common haplotype of the beta-carotene oxygenase 2 (BCO2) gene, which is involved in carotenoid metabolism, is introgressed from a related species, the Gray Junglefowl, and has been under strong selective pressure during domestication. This suggests that a hybridization event may have conferred a fitness advantage on chickens carrying the derived allele. To investigate the possible biological function of the introgressed BCO2 allele in chicken, we introgressed the ancestral BCO2 allele into domestic White Leghorn chickens. We measured gene expression as well as carotenoid accumulation in skin and eggs of chickens carrying either the ancestral or the derived BCO2 allele. The derived haplotype was associated with down-regulation of BCO2 in skin, muscle, and adipose tissue, but not in liver or duodenum, indicating that carotenoid accumulation occurred in the tissues with reduced gene expression. Most importantly, we found that hens with the derived BCO2 genotype were capable of allocating stored carotenoids to their eggs, suggesting a functional benefit through buffering any shortage in the diet during egg production. Nevertheless, it is of interest that loss of function mutations in BCO2 gene are prevalent in other domesticates including cows, rabbits, and sheep, and, given the importance of carotenoids in development, reproduction, and immunity, it is possible that derived BCO2 alleles may provide a general mechanism in multiple domestic species to deal with higher demand for carotenoids in an environment with carotenoid shortage in the diet.

  • 10.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    2 - Genetics and genomics of animal welfare2018In: Advances in Agricultural Animal Welfare / [ed] Joy A. Mench, Woodhead Publishing , 2018, p. 25-48Chapter in book (Other academic)
    Abstract [en]

    Behavior and welfare are closely dependent on the underlying genetics, yet so far this connection has been poorly investigated. Using domestication as a model, this chapter outlines the fundamentals of genetic inheritance, and explains some central concepts such as linkage, pleiotropy, epistasis, and heritability. It then outlines the essential approaches to finding single genes associated with specific behavioral- and welfare-related traits. These are split into top-down and bottom-up approaches, depending on whether the phenotype or genotype is the starting point for analysis. Finally, the novel field of epigenetics and its importance for welfare science are covered.

  • 11.
    Katajamaa, Rebecca
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Larsson, Lovisa H.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Lundberg, Pauline
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Sorensen, Ida
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Activity, social and sexual behaviour in Red Junglefowl selected for divergent levels of fear of humans2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 9, article id e0204303Article in journal (Refereed)
    Abstract [en]

    The domesticated phenotype is a set of behavioural, morphological and physiological traits that is common for domesticated species. Previous research has found that selection for tameness only can give rise to correlated selection responses that resemble the domesticated phenotype. It has therefore been suggested that tameness may drive the domesticated phenotype as correlated traits. We selected Red Junglefowl for divergent levels of fear of human for eight generations and assessed possible correlated selection responses in other behaviours in semi-natural settings. Behavioural studies were carried out on birds from generations six to eight, and at different ages, in order to study possible effects on general activity, social behaviour and male courtship behaviour. We found that the differences between selection lines changed with age. Adult low fear birds were generally more active and high fear males showed a more intense courtship behaviour. Our study shows that several behaviours can be modified through correlated selection responses by selection on reduced fear of humans only, emphasising the putative role of tameness as a driver of domestication related phenotypes.

  • 12.
    Bélteky, Johan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Agnvall, Beatrix
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bektic, Lejla
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Höglund, Andrey
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Guerrero Bosagna, Carlos
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Epigenetics and early domestication: differences in hypothalamic DNA methylation between red junglefowl divergently selected for high or low fear of humans2018In: Genetics Selection Evolution, ISSN 0999-193X, E-ISSN 1297-9686, Vol. 50, article id 13Article in journal (Refereed)
    Abstract [en]

    Background: Domestication of animals leads to large phenotypic alterations within a short evolutionary time-period. Such alterations are caused by genomic variations, yet the prevalence of modified traits is higher than expected if they were caused only by classical genetics and mutations. Epigenetic mechanisms may also be important in driving domesticated phenotypes such as behavior traits. Gene expression can be modulated epigenetically by mechanisms such as DNA methylation, resulting in modifications that are not only variable and susceptible to environmental stimuli, but also sometimes transgenerationally stable. To study such mechanisms in early domestication, we used as model two selected lines of red junglefowl (ancestors of modern chickens) that were bred for either high or low fear of humans over five generations, and investigated differences in hypothalamic DNA methylation between the two populations. Results: Twenty-two 1-kb windows were differentially methylated between the two selected lines at p amp;lt; 0.05 after false discovery rate correction. The annotated functions of the genes within these windows indicated epigenetic regulation of metabolic and signaling pathways, which agrees with the changes in gene expression that were previously reported for the same tissue and animals. Conclusions: Our results show that selection for an important domestication-related behavioral trait such as tameness can cause divergent epigenetic patterns within only five generations, and that these changes could have an important role in chicken domestication.

  • 13.
    Johnsson, Martin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Univ Edinburgh, England; Swedish Univ Agr Sci, Sweden.
    Henriksen, Rie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Swedish Univ Agr Sci, Sweden.
    Höglund, Andrey
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Swedish Univ Agr Sci, Sweden.
    Fogelholm, Jesper
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Swedish Univ Agr Sci, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Swedish Univ Agr Sci, Sweden.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Swedish Univ Agr Sci, Sweden.
    Genetical genomics of growth in a chicken model2018In: BMC Genomics, ISSN 1471-2164, E-ISSN 1471-2164, Vol. 19, article id 72Article in journal (Refereed)
    Abstract [en]

    Background: The genetics underlying body mass and growth are key to understanding a wide range of topics in biology, both evolutionary and developmental. Body mass and growth traits are affected by many genetic variants of small effect. This complicates genetic mapping of growth and body mass. Experimental intercrosses between individuals from divergent populations allows us to map naturally occurring genetic variants for selected traits, such as body mass by linkage mapping. By simultaneously measuring traits and intermediary molecular phenotypes, such as gene expression, one can use integrative genomics to search for potential causative genes. Results: In this study, we use linkage mapping approach to map growth traits (N = 471) and liver gene expression (N = 130) in an advanced intercross of wild Red Junglefowl and domestic White Leghorn layer chickens. We find 16 loci for growth traits, and 1463 loci for liver gene expression, as measured by microarrays. Of these, the genes TRAK1, OSBPL8, YEATS4, CEP55, and PIP4K2B are identified as strong candidates for growth loci in the chicken. We also show a high degree of sex-specific gene-regulation, with almost every gene expression locus exhibiting sex-interactions. Finally, several trans-regulatory hotspots were found, one of which coincides with a major growth locus. Conclusions: These findings not only serve to identify several strong candidates affecting growth, but also show how sex-specificity and local gene-regulation affect growth regulation in the chicken.

  • 14.
    Johnsson, Martin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Univ Edinburgh, Scotland; Swedish Univ Agr Sci, Sweden.
    Henriksen, Rie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Fogelholm, Jesper
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Höglund, Andrey
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Genetics and Genomics of Social Behavior in a Chicken Model2018In: Genetics, ISSN 0016-6731, E-ISSN 1943-2631, Vol. 209, no 1, p. 209-221Article in journal (Refereed)
    Abstract [en]

    The identification of genes affecting sociality can give insights into the maintenance and development of sociality and personality. In this study, we used the combination of an advanced intercross between wild and domestic chickens with a combined QTL and eQTL genetical genomics approach to identify genes for social reinstatement, a social and anxiety-related behavior. A total of 24 social reinstatement QTL were identified and overlaid with over 600 eQTL obtained from the same birds using hypothalamic tissue. Correlations between overlapping QTL and eQTL indicated five strong candidate genes, with the gene TTRAP being strongly significantly correlated with multiple aspects of social reinstatement behavior, as well as possessing a highly significant eQTL.

  • 15.
    Agnvall, Beatrix
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bélteky, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Katajamaa, Rebecca
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Is evolution of domestication driven by tameness? A selective review with focus on chickens2018In: Applied Animal Behaviour Science, ISSN 0168-1591, E-ISSN 1872-9045, Vol. 205, p. 227-233Article in journal (Refereed)
    Abstract [en]

    Domestication of animals offers unique possibilities to study evolutionary changes caused by similar selection pressures across a range of species. Animals from separate genera tend to develop a suite of phenotypic alterations referred to as "the domesticated phenotype". This involves changes in appearance, including loss of pigmentation, and alterations in body size and proportions. Furthermore, effects on reproduction and behaviour are typical. It is hypothesized that this recurring phenotype may be secondary effects of the increased tameness that is an inevitable first step in the domestication of any species. We first provide a general overview of observations and experiments from different species and then review in more detail a project attempting to recreate the initial domestication of chickens. Starting from an outbred population of Red Junglefowl, ancestors of all modem chickens, divergent lines were selected based on scores in a standardized fear-of-human test applied to all birds at 12 weeks of age. Up to the eighth selected generation, observations have been made on correlated effects of this selection on various phenotypes. The fear score had a significant heritability and was genetically correlated to several other behavioural traits. Furthermore, low-fear birds were larger at hatch, grew faster, laid larger eggs, had a modified metabolism and increased feed efficiency, had modified social behaviour and reduced brain size. Selection affected gene expression and DNA-methylation in the brains, but the genetic and epigenetic effects were not specifically associated with stress pathways. Further research should be focused on unraveling the genetic and epigenetic mechanisms underlying the correlated side-effects of reduced fear of humans.

  • 16.
    Stange, Madlen
    et al.
    Univ Zurich, Switzerland.
    Nunez-Leon, Daniel
    Univ Zurich, Switzerland.
    Sanchez-Villagra, Marcelo R.
    Univ Zurich, Switzerland.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wilson, Laura A. B.
    Univ New South Wales, Australia.
    Morphological variation under domestication: how variable are chickens?2018In: Royal Society Open Science, E-ISSN 2054-5703, Vol. 5, no 8, article id 180993Article in journal (Refereed)
    Abstract [en]

    The process of domestication has long fascinated evolutionary biologists, yielding insights into the rapidity with which selection can alter behaviour and morphology. Previous studies on dogs, cattle and pigeons have demonstrated that domesticated forms show greater magnitudes of morphological variation than their wild ancestors. Here, we quantify variation in skull morphology, modularity and integration in chickens and compare those to the wild fowl using three-dimensional geometric morphometrics and multivariate statistics. Similar to other domesticated species, chickens exhibit a greater magnitude of variation in shape compared with their ancestors. The most variable part of the chicken skull is the cranial vault, being formed by dermal and neural crest-derived bones, its form possibly related to brain shape variation in chickens, especially in crested breeds. Neural crest-derived portions of the skull exhibit a higher amount of variation. Further, we find that the chicken skull is strongly integrated, confirming previous studies in birds, in contrast to the presence of modularity and decreased integration in mammals.

  • 17.
    Persson, Mia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Sundman, Ann-Sofie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Hallden, Lise-Lotte
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Trottier, Agaia J.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Sociality genes are associated with human-directed social behaviour in golden and Labrador retriever dogs2018In: PeerJ, ISSN 2167-8359, E-ISSN 2167-8359, Vol. 6, article id e5889Article in journal (Refereed)
    Abstract [en]

    Background: Dogs have human-directed social skills that allow them to communicate and cooperate with humans. We have previously identified two loci on chromosome 26 associated with human contact-seeking behaviors during an unsolvable problem task in laboratory beagles (Persson et A, 2016). The aim of the present study was to verify the single nucleotide polymorphisms (SNPs) in additional dog breeds. We also studied how the allele frequencies have changed during domestication and recent selection. Methods: Dogs of two breeds, 61 golden retrievers and 100 Labrador retrievers, were phenotyped and genotyped, and 19 wolves were genotyped. The Labrador retrievers were divided into common and field type by pedigree data to make it possible to study the effects of recent selection. All dogs were tested in an unsolvable problem task where human-directed social behaviors were scored. DNA from dogs (buccal swabs) and wolves (blood or brain tissue) was analyzed for genotype on two of the previously identified SNP markers, BICF2G630798942 (SNP1) and BICF2S23712114 (SNP2), by pyrosequencing. Results: There was genetic variation for SNP1 in both dog breeds whereas the wolves were fixed for this polymorphism, and for SNP2 there was variation in both dogs and wolves. For both SNPs, Labrador retriever types differed significantly in allele frequencies. We found associations between SNPs and human-directed social behavior in both dog breeds. In golden retrievers, SNP I was associated with physical contact variables, for example, with the duration of physical contact with the owner (F-2,F-56 = 4.389, p = 0.017). SNP2 was associated with several behavioral variables in both breeds, among others owner gazing frequency in both golden retrievers (F-2,F-55 = 6.330, p = 0.003) and Labradors (F-1,F-93 = 5.209, p = 0.025). Discussion: Our results verify the association between the previously identified SNPs and human-directed social behavior scored in an unsolvable problem task. Differences in allele frequencies suggest that these loci have been affected by selection. The results indicate that these genomic regions are involved in human-directed social behavior in not only beagles but in other dog breeds as well. We hypothesize that they may have been important during dog domestication.

  • 18.
    Zidar, Josefina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Balogh, Alexandra
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Stockholm Univ, Sweden.
    Favati, Anna
    Stockholm Univ, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Leimar, Olof
    Stockholm Univ, Sweden.
    Sorato, Enrico
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Lovlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    The relationship between learning speed and personality is age- and task-dependent in red junglefowl2018In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 72, no 10, article id UNSP 168Article in journal (Refereed)
    Abstract [en]

    Cognition is fundamental to animals lives and an important source of phenotypic variation. Nevertheless, research on individual variation in animal cognition is still limited. Further, although individual cognitive abilities have been suggested to be linked to personality (i.e., consistent behavioral differences among individuals), few studies have linked performance across multiple cognitive tasks to personality traits. Thus, the interplays between cognition and personality are still unclear. We therefore investigated the relationships between an important aspect of cognition, learning, and personality, by exposing young and adult red junglefowl (Gallus gallus) to multiple learning tasks (discriminative, reversal, and spatial learning) and personality assays (novel arena, novel object, and tonic immobility). Learning speed was not correlated across learning tasks, and learning speed in discrimination and spatial learning tasks did not co-vary with personality. However, learning speed in reversal tasks was associated with individual variation in exploration, and in an age-dependent manner. More explorative chicks learned the reversal task faster than less explorative ones, while the opposite association was found for adult females (learning speed could not be assayed in adult males). In the same reversal tasks, we also observed a sex difference in learning speed of chicks, with females learning faster than males. Our results suggest that the relationship between cognition and personality is complex, as shown by its task- and age-dependence, and encourage further investigation of the causality and dynamics of this relationship.Significance statementIn the ancestor of todays chickens, the red junglefowl, we explored how personality and cognition relate by exposing both chicks and adults to several learning tasks and personality assays. Our birds differed in personality and learning speed, while fast learners in one task did not necessarily learn fast in another (i.e., there were no overall smarter birds). Exploration correlated with learning speed in the more complex task of reversal learning: faster exploring chicks, but slower exploring adult females, learned faster, compared to less explorative birds. Other aspects of cognition and personality did not correlate. Our results suggest that cognition and personality are related, and that the relationship can differ depending on task and age of the animal.

  • 19.
    Buller, Henry
    et al.
    Univ Exeter, England.
    Blokhuis, Harry
    Swedish Univ Agr Sci, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Keeling, Linda
    Swedish Univ Agr Sci, Sweden.
    Towards Farm Animal Welfare and Sustainability2018In: Animals, ISSN 2076-2615, E-ISSN 2076-2615, Vol. 8, no 6, article id 81Article, review/survey (Refereed)
    Abstract [en]

    As farm animal welfare becomes an increasingly important component of contemporary global livestock production, animal welfare science and animal welfare policy-making need to find new ways of entering global debates over food security and sustainability. In this paper, we explore the means by which both animal welfare science and policy should articulate with these emerging global debates. Having first established the important gains in animal welfare policy and the maturity of animal welfare science, we identify and explore the potential impact of these current debates and argue that they have the potential for profound change in our understanding of, and our response to, the welfare of animals. We conclude the paper with a number of possible recommendations for how a scientifically informed, sustainable animal welfare policy might flourish.

  • 20.
    Sundman, Ann-Sofie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Persson, Mia
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Grozelier, Anna
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Halldén, Lise-Lotte
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Roth, Lina
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Understanding of human referential gestures is not correlated to human-directed social behaviour in Labrador retrievers and German shepherd dogs2018In: Applied Animal Behaviour Science, ISSN 0168-1591, E-ISSN 1872-9045, Vol. 201, p. 46-53Article in journal (Refereed)
    Abstract [en]

    Dogs are known to excel in interspecific communication with humans and both communicate with humans and follow human communicative cues. Two tests commonly used to test these skills are, firstly, the problem-solving paradigm, and, secondly, following human referential signals, for example pointing. The aim of the present study was to investigate whether dogs that seek more human contact in an unsolvable problem-solving paradigm also better understand human communicative cues in a pointing test. We also assessed between- and within-breed variation in both tests. 167 dogs were tested and were of the breeds German shepherd dog and Labrador retriever. The Labradors were separated into the two selection lines: common type (bred for show and pet) and field type (bred for hunting). A principal component analysis of behaviours during the problem solving revealed four components: Passivity, Experimenter Contact, Owner Contact and Eye Contact. We analysed the effect of these components on success rate in the pointing test and we found no effect for three of them, while a negative correlation was found for Owner Contact (F(1,147) = 6.892; P = 0.010). This was only present in common-typed Labradors. We conclude that the ability to follow a pointing cue does not predict the propensity for human-directed social behaviour in a problem-solving situation and suggest that the two tests measure different aspects of human-directed social behaviour in dogs.

  • 21.
    Zidar, Josefina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Balogh, Alexandra
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology.
    Favati, Anna
    Stockholm University, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Leimar, Olof
    Stockholm University, Sweden.
    Lovlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    A comparison of animal personality and coping styles in the red junglefowl2017In: Animal Behaviour, ISSN 0003-3472, E-ISSN 1095-8282, Vol. 130, p. 209-220Article in journal (Refereed)
    Abstract [en]

    There is an increased focus in biology on consistent behavioural variation. Several terms are used to describe this variation, including animal personality and coping style. Both terms describe between individual consistency in behavioural variation; however, they differ in the behavioural assays typically used, the expected distribution of response variables, and whether they incorporate variation in behavioural flexibility. Despite these differences, the terms are often used interchangeably. We conducted experiments using juvenile and adult red junglefowl, Gallus gallus, as subjects to explore the degree to which animal personality and coping styles overlap. We demonstrate that animal personality and coping styles can be described in this species, and that shyer individuals had more flexible responses, as expected for coping styles. Behavioural responses from both personality and coping style assays had continuous distributions, and were not clearly separated into two types. Behavioural traits were not correlated and, hence, there was no evidence of a behavioural syndrome. Further, behavioural responses obtained in personality assays did not correlate with those from coping style tests. Animal personality and coping styles are therefore not synonymous in the red junglefowl. We suggest that the terms animal personality and coping style are not equivalent and should not be used interchangeably. (C) 2017 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

  • 22.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behaviour genetics, evolution and domestication2017In: The ethology of domestic animals: an introcuctory text / [ed] Per Jensen, wallingford: CABI Publishing, 2017, 3, p. 11-25Chapter in book (Other academic)
  • 23.
    Agnvall, Beatrix
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bélteky, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Brain size is reduced by selectionfor tameness in Red Junglefowl–correlated effects in vital organs2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, article id 3306Article in journal (Refereed)
    Abstract [en]

    During domestication animals have undergone changes in size of brain and other vital organs. We hypothesize that this could be a correlated effect to increased tameness. Red Junglefowl (ancestors of domestic chickens) were selected for divergent levels of fear of humans for five generations. The parental (P0) and the fifth selected generation (S5) were culled when 48–54 weeks old and the brains were weighed before being divided into telencephalon, cerebellum, mid brain and optic lobes. Each single brain part as well as the liver, spleen, heart and testicles were also weighed. Brains of S5 birds with high fear scores (S5 high) were heavier both in absolute terms and when corrected for body weight. The relative weight of telencephalon (% of brain weight) was significantly higher in S5 high and relative weight of cerebellum was lower. Heart, liver, testes and spleen were all relatively heavier (% of body weight) in S5 high. Hence, selection for tameness has changed the size of the brain and other vital organs in this population and may have driven the domesticated phenotype as a correlated response.

  • 24.
    Løtvedt, Pia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Fallahshahroudi, Amir
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bektic, Lejla
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Altimiras, Jordi
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Chicken domestication changes expression of stress-related genes in brain, pituitary and adrenals2017In: Neurobiology of stress, ISSN 2352-2895, Vol. 7, p. 113-121Article in journal (Refereed)
    Abstract [en]

    Domesticated species have an attenuated behavioral and physiological stress response compared to their wild counterparts, but the genetic mechanisms underlying this change are not fully understood. We investigated gene expression of a panel of stress response-related genes in five tissues known for their involvement in the stress response: hippocampus, hypothalamus, pituitary, adrenal glands and liver of domesticated White Leghorn chickens and compared it with the wild ancestor of all domesticated breeds, the Red Junglefowl. Gene expression was measured both at baseline and after 45 min of restraint stress. Most of the changes in gene expression related to stress were similar to mammals, with an upregulation of genes such as FKBP5, C-FOS and EGR1 in hippocampus and hypothalamus and StAR, MC2R and TH in adrenal glands. We also found a decrease in the expression of CRHR1 in the pituitary of chickens after stress, which could be involved in negative feedback regulation of the stress response. Furthermore, we observed a downregulation of EGR1 and C-FOS in the pituitary following stress, which could be a potential link between stress and its effects on reproduction and growth in chickens. We also found changes in the expression of important genes between breeds such as GR in the hypothalamus, POMC and PC1 in the pituitary and CYP11A1 and HSD3B2 in the adrenal glands. These results suggest that the domesticated White Leghorn may have a higher capacity for negative feedback of the HPA axis, a lower capacity for synthesis of ACTH in the pituitary and a reduced synthesis rate of corticosterone in the adrenal glands compared to Red Junglefowl. All of these findings could explain the attenuated stress response in the domesticated birds.

  • 25.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Den missförstådda hunden2017Book (Other (popular science, discussion, etc.))
  • 26.
    Pertille, Fabio
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. University of Sao Paulo, Brazil.
    Brantsaeter, Margrethe
    Norwegian University of Life Science, Norway.
    Nordgreen, Janicke
    Norwegian University of Life Science, Norway.
    Lehmann Coutinho, Luiz
    University of Sao Paulo, Brazil.
    Janczak, Andrew M.
    Norwegian University of Life Science, Norway.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Guerrero Bosagna, Carlos
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    DNA methylation profiles in red blood cells of adult hens correlate with their rearing conditions2017In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 220, no 19, p. 3579-3587Article in journal (Refereed)
    Abstract [en]

    Stressful conditions are common in the environment where production animals are reared. Stress in animals is usually determined by the levels of stress-related hormones. A big challenge, however, is in determining the history of exposure of an organism to stress, because the release of stress hormones can show an acute (and recent) but not a sustained exposure to stress. Epigenetic tools provide an alternative option to evaluate past exposure to long-termstress. Chickens provide a unique model to study stress effects in the epigenome of red blood cells (RBCs), a cell type of easy access and nucleated in birds. The present study investigated whether two different rearing conditions in chickens can be identified by looking at DNA methylation patterns in their RBCs later in life. These conditions were rearing in open aviaries versus in cages, which are likely to differ regarding the amount of stress they generate. Our comparison revealed 115 genomic windows with significant changes in RBC DNA methylation between experimental groups, which were located around 53 genes and within 22 intronic regions. Our results set the ground for future detection of long-term stress in live production animals by measuring DNA methylation in a cell type of easy accessibility.

  • 27.
    Zidar, Josefina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Sorato, Enrico
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Malmqvist, Ann-Marie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jansson, Emelie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Rosher, Charlotte
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Faculty of Life Sciences, University of Manchester, Manchester, UK.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Favati, Anna
    Department of Zoology, Stockholm University, Stockholm, Sweden.
    Løvlie, Hanne
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Early experience affects adult personality in the red junglefowl: a role for cognitive stimulation?2017In: Behavioural Processes, ISSN 0376-6357, E-ISSN 1872-8308, Vol. 134, p. 78-86Article in journal (Refereed)
    Abstract [en]

    Despite intense research efforts, biologists are still puzzled by the existence of animal personality. While recent studies support a link between cognition and personality, the directionality of this relationship still needs to be clarified. Early-life experiences can affect adult behaviour, and among these, cognitive stimulation has been suggested theoretically to influence personality. Yet, the influence of early cognitive stimulation has rarely been explored in empirical investigations of animal behaviour and personality. We investigated the effect of early cognitive stimulation on adult personality in the red junglefowl (Gallus gallus). To this end, we assessed adult behaviour across a number of personality assays and compared behaviour of individuals previously exposed to a series of learning tasks as chicks, with that of control individuals lacking this experience. We found that individuals exposed to early stimulation as adults were more vigilant and performed fewer escape attempts in personality assays. Other behaviours describing personality traits in the fowl were not affected. We conclude that our results support the hypothesis that early stimulation can affect aspects of adult behaviour and personality, suggesting a hitherto underappreciated causality link between cognition and personality. Future research should aim to confirm these findings and resolve their underlying dynamics and proximate mechanisms.

  • 28.
    Beltéky, Johan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Eklund, Beatrix
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Gene expression of behaviorally relevant genes in the cerebral hemisphere changes after selection for tameness in Red Junglefowl.2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 5, article id e0177004Article in journal (Refereed)
    Abstract [en]

    The process of domestication in animals has led to alterations in behavior, physiology and phenotypic traits, changes that may be driven by correlations with reduced fear of humans. We used Red Junglefowl, ancestors of all domesticated chickens selected for either high or low fear of humans for five generations to study the effects of selection on gene transcription in the cerebral hemisphere, which is heavily involved in behaviour control. A total of 24 individuals from the parental generation as well as from the fifth selected generation were used. Twenty-two genes were significantly differentially expressed at p < 0.05 after false discovery rate (FDR) correction. Those genes that were upregulated in the low fearful animals were found to be involved in neural functions. Gene ontology and pathway analysis revealed enrichment for terms associated with behavioural processes. We conclude that five generations of divergent selection for high or low tameness has significantly changed gene expression patterns in the cerebral hemisphere in the Red Junglefowl population used here, which could underlie a range of changes in the domestic phenotype.

  • 29.
    Fallahshahroudi, Amir
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    de Kock, Neil
    Department of Chemistry, BMC, Analytical Chemistry and Neurochemistry, University of.
    Johnsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bektic, Lejla
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Ubhayasekera, S J Kumari A
    Department of Chemistry, BMC, Analytical Chemistry and Neurochemistry, University of.
    Bergquist, Jonas
    Department of Chemistry, BMC, Analytical Chemistry and Neurochemistry, University of.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Genetic and Targeted eQTL Mapping Reveals Strong Candidate Genes Modulating the Stress Response During Chicken Domestication.2017In: G3: Genes, Genomes, Genetics, ISSN 2160-1836, E-ISSN 2160-1836, Vol. 7, no 2Article in journal (Refereed)
    Abstract [en]

    The stress response has been largely modified in all domesticated animals, offering a strong tool for genetic mapping. In chickens, ancestral Red Junglefowl react stronger both in terms of physiology and behavior to a brief restraint stress than domesticated White Leghorn, demonstrating modified functions of the hypothalamic-pituitary-adrenal (HPA) axis. We mapped quantitative trait loci (QTL) underlying variations in stress-induced hormone levels using 232 birds from the 12th generation of an advanced intercross between White Leghorn and Red Junglefowl, genotyped for 739 genetic markers. Plasma levels of corticosterone, dehydroepiandrosterone (DHEA), and pregnenolone (PREG) were measured using LC-MS/MS in all genotyped birds. Transcription levels of the candidate genes were measured in the adrenal glands or hypothalamus of 88 out of the 232 birds used for hormone assessment. Genes were targeted for expression analysis when they were located in a hormone QTL region and were differentially expressed in the pure breed birds. One genome-wide significant QTL on chromosome 5 and two suggestive QTL together explained 20% of the variance in corticosterone response. Two significant QTL for aldosterone on chromosome 2 and 5 (explaining 19% of the variance), and one QTL for DHEA on chromosome 4 (explaining 5% of the variance), were detected. Orthologous DNA regions to the significant corticosterone QTL have been previously associated with the physiological stress response in other species but, to our knowledge, the underlying gene(s) have not been identified. SERPINA10 had an expression QTL (eQTL) colocalized with the corticosterone QTL on chromosome 5 and PDE1C had an eQTL colocalized with the aldosterone QTL on chromosome 2. Furthermore, in both cases, the expression levels of the genes were correlated with the plasma levels of the hormones. Hence, both these genes are strong putative candidates for the domestication-induced modifications of the stress response in chickens. Improved understanding of the genes associated with HPA-axis reactivity can provide insights into the pathways and mechanisms causing stress-related pathologies.

  • 30.
    Lind, Olle
    et al.
    Lund University, Sweden.
    Milton, Ida
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Andersson, Elin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Roth, Lina
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    High visual acuity revealed in dogs2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 12, article id e0188557Article in journal (Refereed)
    Abstract [en]

    Humans have selectively bred and used dogs over a period of thousands of years, and more recently the dog has become an important model animal for studies in ethology, cognition and genetics. These broad interests warrant careful descriptions of the senses of dogs. Still there is little known about dog vision, especially what dogs can discriminate in different light conditions. We trained and tested whippets, pugs, and a Shetland sheepdog in a two-choice discrimination set-up and show that dogs can discriminate patterns with spatial frequencies between 5.5 and 19.5 cycle per degree (cpd) in the bright light condition (43 cd m(-2)). This is a higher spatial resolution than has been previously reported although the individual variation in our tests was large. Humans tested in the same set-up reached acuities corresponding to earlier studies, ranging between 32.1 and 44.2 cpd. In the dim light condition (0.0087 cd m(-2)) the acuity of dogs ranged between 1.8 and 3.5 cpd while in humans, between 5.9 and 9.9 cpd. Thus, humans make visual discrimination of objects from roughly a threefold distance compared to dogs in both bright and dim light.

  • 31.
    Persson, Mia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Trottier, Agaia J.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bélteky, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Roth, Lina
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Intranasal oxytocin and a polymorphism in the oxytocin receptor gene are associated with human-directed social behavior in golden retriever dogs2017In: Hormones and Behavior, ISSN 0018-506X, E-ISSN 1095-6867, Vol. 95, p. 85-93Article in journal (Refereed)
    Abstract [en]

    The oxytocin system may play an important role in dog domestication from the wolf. Dogs have evolved unique human analogue social skills enabling them to communicate and cooperate efficiently with people. Genomic differences in the region surrounding the oxytocin receptor (OXTR) gene have previously been associated with variation in doge communicative skills. Here we have utilized the unsolvable problem paradigm to investigate the effects of oxytocin and OXTR polymorphisms on human-directed contact seeking behavior in 60 golden retriever dogs. Human-oriented behavior was quantified employing a previously defined unsolvable problem paradigm. Behaviors were tested twice in a repeated, counterbalanced design, where dogs received a nasal dose of either oxytocin or saline 45 min before each test occasion. Buccal DNA was analysed for genotype on three previously identified SNP-markers associated with OXTR. The same polymorphisms were also geno-typed in 21 wolf blood samples to explore potential genomic differences between the species. Results showed that oxytocin treatment decreased physical contact seeking with the experimenter and one of the three polymorphisms was associated with degree of physical contact seeking with the owner. Dogs with the AA-genotype at this locus increased owner physical contact seeking in response to oxytocin while the opposite effect was found in GG-genotype individuals. Hence, intranasal oxytocin treatment, an OXTR polymorphism and their interaction are associated with doge human-directed social skills, which can explain previously described breed differences in oxytocin response. Genotypic variation at the studied locus was also found in wolves indicating that it was present even at the start of dog domestication.

  • 32.
    Fallahsharoudi, Amir
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    de Kock, Neil
    Department of Chemistry e Biomedical Center, Analytical Chemistry and Neurochemistry - BMC, 75124 Uppsala, Sweden.
    Johnsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bektic, Lejla
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Ubhayasekera, S J Kumari A
    Department of Chemistry e Biomedical Center, Analytical Chemistry and Neurochemistry - BMC, 75124 Uppsala, Sweden.
    Bergquist, Jonas
    Department of Chemistry e Biomedical Center, Analytical Chemistry and Neurochemistry - BMC, 75124 Uppsala, Sweden.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    QTL mapping of stress related gene expression in a cross between domesticated chickens and ancestral red junglefowl.2017In: Molecular and Cellular Endocrinology, ISSN 0303-7207, E-ISSN 1872-8057, Vol. 446, p. 52-58, article id S0303-7207(17)30090-4Article in journal (Refereed)
    Abstract [en]

    Domestication of animals is associated with numerous alterations in physiology, morphology, and behavior. Lower reactivity of the hypothalamic-pituitary-adrenal (HPA) axis and reduced fearfulness is seen in most studied domesticates, including chickens. Previously we have shown that the physiological stress response as well as expression levels of hundreds of genes in the hypothalamus and adrenal glands are different between domesticated White Leghorn and the progenitor of modern chickens, the Red Junglefowl. To map genetic loci associated with the transcription levels of genes involved in the physiological stress response, we conducted an eQTL analysis in the F12 generation of an inter-cross between White Leghorn and Red Junglefowl. We selected genes for further studies based on their known function in the regulation of the HPA axis or sympathoadrenal (SA) system, and measured their expression levels in the hypothalamus and the adrenal glands after a brief stress exposure (physical restraint). The expression values were treated as quantitative traits for the eQTL mapping. The plasma levels of corticosterone were also assessed. We analyzed the correlation between gene expression and corticosterone levels and mapped eQTL and their potential effects on corticosterone levels. The effects on gene transcription of a previously found QTL for corticosterone response were also investigated. The expression levels of the glucocorticoid receptor (GR) in the hypothalamus and several genes in the adrenal glands were correlated with the post-stress levels of corticosterone in plasma. We found several cis- and trans-acting eQTL for stress-related genes in both hypothalamus and adrenal. In the hypothalamus, one eQTL for c-FOS and one QTL for expression of GR were found. In the adrenal tissue, we identified eQTL for the genes NR0B1, RGS4, DBH, MAOA, GRIN1, GABRB2, GABRB3, and HSF1. None of the found eQTL were significant predictors of corticosterone levels. The previously found QTL for corticosterone was associated with GR expression in hypothalamus. Our data suggests that domestication related modification in the stress response is driven by changes in the transcription levels of several modulators of the HPA and SA systems in hypothalamus and adrenal glands and not by changes in the expression of the steroidogenic genes. The presence of eQTL for GR in hypothalamus combined with the negative correlation between GR expression and corticosterone response suggests GR as a candidate for further functional studies regarding modification of stress response during chicken domestication.

  • 33.
    Warnefors, Maria
    et al.
    Heidelberg University of ZMBH, Germany.
    Mossinger, Katharina
    Heidelberg University of ZMBH, Germany.
    Halbert, Jean
    University of Lausanne, Switzerland.
    Studer, Tania
    Heidelberg University of ZMBH, Germany.
    VandeBerg, John L.
    University of Texas Rio Grande Valley, TX 78520 USA.
    Lindgren, Isa
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Fallahshahroudi, Amir
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Kaessmann, Henrik
    Heidelberg University of ZMBH, Germany.
    Sex-biased microRNA expression in mammals and birds reveals underlying regulatory mechanisms and a role in dosage compensation2017In: Genome Research, ISSN 1088-9051, E-ISSN 1549-5469, Vol. 27, no 12, p. 1961-1973Article in journal (Refereed)
    Abstract [en]

    Sexual dimorphism depends on sex-biased gene expression, but the contributions of microRNAs (miRNAs) have not been globally assessed. We therefore produced an extensive small RNA sequencing data set to analyze male and female miRNA expression profiles in mouse, opossum, and chicken. Our analyses uncovered numerous cases of somatic sex-biased miRNA expression, with the largest proportion found in the mouse heart and liver. Sex-biased expression is explained by miRNA-specific regulation, including sex-biased chromatin accessibility at promoters, rather than piggybacking of intronic miRNAs on sex-biased protein-coding genes. In mouse, but not opossum and chicken, sex bias is coordinated across tissues such that autosomal testis-biased miRNAs tend to be somatically male-biased, whereas autosomal ovary-biased miRNAs are female-biased, possibly due to broad hormonal control. In chicken, which has a Z/W sex chromosome system, expression output of genes on the Z Chromosome is expected to be male-biased, since there is no global dosage compensation mechanism that restores expression in ZW females after almost all genes on the W Chromosome decayed. Nevertheless, we found that the dominant liver miRNA, miR-122-5p, is Z-linked but expressed in an unbiased manner, due to the unusual retention of a W-linked copy. Another Z-linked miRNA, the male-biased miR-2954-3p, shows conserved preference for dosage-sensitive genes on the Z Chromosome, based on computational and experimental data from chicken and zebra finch, and acts to equalize male-to-female expression ratios of its targets. Unexpectedly, our findings thus establish miRNA regulation as a novel gene-specific dosage compensation mechanism.

  • 34.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    The study of animal behaviour and its applications2017In: The ethnology of domestic animals: an introcuctory text / [ed] Per Jensen, Wallingford: CABI Publishing, 2017, p. 3-10Chapter in book (Other academic)
  • 35.
    Karlsson, Anna-Carin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Fallahsharoudi, Amir
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Johnsen, Hanna
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Hagenblad, Jenny
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Andersson, Leif
    Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    A domestication related mutation in the thyroid stimulating hormonereceptor gene (TSHR) modulates photoperiodic response andreproduction in chickens2016In: General and Comparative Endocrinology, ISSN 0016-6480, E-ISSN 1095-6840, Vol. 228, p. 69-78Article in journal (Refereed)
    Abstract [en]

    The thyroid stimulating hormone receptor gene (TSHR) has been suggested to be a ‘‘domestication locus”in the chicken. A strong selective sweep over TSHR in domestic breeds together with significant effects ofa mutation in the gene on several domestication related traits, indicate that the gene has been importantfor chicken domestication. TSHR plays a key role in the signal transduction of seasonal reproduction,which is characteristically less strict in domestic animals. We used birds from an advanced intercross linebetween ancestral Red Junglefowl (RJF) and domesticated White Leghorn (WL) to investigate effects ofthe mutation on reproductive traits as well as on TSHB, TSHR, DIO2 and DIO3 gene expression duringaltered day length (photoperiod). We bred chickens homozygous for either the mutation (d/d) or wildtype allele (w/w), allowing assessment of the effect of genotype at this locus while also controlling forbackground variation in the rest of the genome. TSHR gene expression in brain was significantly lowerin both d/d females and males and d/d females showed a faster onset of egg laying at sexual maturity thanw/w. Furthermore, d/d males showed a reduced testicular size response to decreased day length, andlower levels of TSHB and DIO3 expression. Additionally, purebred White Leghorn females kept under naturalshort day length in Sweden during December had active ovaries and lower levels of TSHR and DIO3expression compared to Red Junglefowl females kept under similar conditions. Our study indicates thatthe TSHR mutation affects photoperiodic response in chicken by reducing dependence of seasonal reproduction,a typical domestication feature, and may therefore have been important for chickendomestication.

  • 36.
    Foyer, Pernilla
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering. Department of Military Studies, Military-Technology Division, Swedish Defence University, Stockholm, Sweden.
    Svedberg, Anna-Maria
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Nilsson, Emma
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wilsson, Erik
    Swedish Armed Forces Dog Training Unit, Märsta, Sweden.
    Olsen Faresjö, Åshild
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Behavior and cortisol responses of dogs evaluated in a standardized temperament test for military working dogs2016In: Journal of Veterinary Behavior: Clinical Applications and Research, ISSN 1558-7878, E-ISSN 1878-7517, Vol. 11, p. 7-12Article in journal (Refereed)
    Abstract [en]

    Military and police working dogs are often exposed to stressful or threatening events, and an improper response, e.g., fear, may implicate both reduced working efficiency and welfare. Therefore, identifying individuals that display a favorable response to potentially threatening situations is of great interest. In the present study, we investigated behavior responses of 85 prospective military working dogs in 4 subtests in a standardized temperament test used to select working dogs for the Swedish Armed Forces. Our goal was to evaluate behavioral responses in specific subtests and cortisol responses of candidate dogs. After dogs were rated as approved or nonapproved based on the test leader’s assessment of the full test result, we independently analyzed video recordings of 4 subtests. In addition, for 37 dogs, we analyzed pretest and posttest salivary cortisol levels. Dogs which were approved by the test leader for further training scored higher in the video recordings on emotionality and, in particular, fear-related behavior during a subset of the test and had higher levels of cortisol both before and after the test, than nonapproved dogs. Although this may actually reflect the desired traits, it could also indicate a bias in the selection procedure, which may pose limitations on the attempts to recruit the most suitable working dogs.

  • 37.
    Willems, Els
    et al.
    KU Leuven, Department of Biosystems, Laboratory of Livestock Physiology, Kasteelpark Arenberg 30 box 2456, 3001 Leuven, Belgium.
    Guerrero-Bosagna, Carlos
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Decuypere, Eddy
    KU Leuven, Department of Biosystems, Laboratory of Livestock Physiology, Kasteelpark Arenberg 30 box 2456, 3001 Leuven, Belgium.
    Janssens, Steven
    KU Leuven, Department of Biosystems, Research Group Livestock Genetics, Kasteelpark Arenberg 30 box 2456, 3001 Leuven, Belgium.
    Buyse, Johan
    KU Leuven, Department of Biosystems, Laboratory of Livestock Physiology, Kasteelpark Arenberg 30 box 2456, 3001 Leuven, Belgium.
    Buys, Nadine
    KU Leuven, Department of Biosystems, Research Group Livestock Genetics, Kasteelpark Arenberg 30 box 2456, 3001 Leuven, Belgium.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Everaert, Nadia
    4University of Liège, Gembloux Agro-Bio Tech, Precision Livestock and Nutrition Unit, Passage des Déportés 2, 5030 Gembloux, Belgium.
    Differential Expression of Genes and DNA Methylation associated with Prenatal Protein Undernutrition by Albumen Removal in an avian model2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6Article in journal (Refereed)
    Abstract [en]

    Previously, long-term effects on body weight and reproductive performance have been demonstrated in the chicken model of prenatal protein undernutrition by albumen removal. Introduction of such persistent alterations in phenotype suggests stable changes in gene expression. Therefore, a genome-wide screening of the hepatic transcriptome by RNA-Seq was performed in adult hens. The albumen-deprived hens were created by partial removal of the albumen from eggs and replacement with saline early during embryonic development. Results were compared to sham-manipulated hens and non-manipulated hens. Grouping of the differentially expressed (DE) genes according to biological functions revealed the involvement of processes such as 'embryonic and organismal development' and 'reproductive system development and function'. Molecular pathways that were altered were 'amino acid metabolism', 'carbohydrate metabolism' and 'protein synthesis'. Three key central genes interacting with many DE genes were identified: UBC, NR3C1, and ELAVL1. The DNA methylation of 9 DE genes and 3 key central genes was examined by MeDIP-qPCR. The DNA methylation of a fragment (UBC_3) of the UBC gene was increased in the albumen-deprived hens compared to the non-manipulated hens. In conclusion, these results demonstrated that prenatal protein undernutrition by albumen removal leads to long-term alterations of the hepatic transcriptome in the chicken.

  • 38.
    Ericsson, Maria
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Domestication and ontogeny effects on the stress response inyoung chickens (Gallus gallus)2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 6_35818Article in journal (Refereed)
    Abstract [en]

    Domestication is thought to increase stress tolerance. The connection between stressor exposure,glucocorticoids and behavioural responses has been studied in adults, where domestication effectsare evident. Early stress exposure may induce detrimental effects both in short-and long term.Previous research has reported a lack of glucocorticoid response in newly hatched chickens (Gallusgallus), whereas others have found opposite results. Hence it remains unclear whether the HPA-axis isfunctional from hatch, and if domestication has affected the early post-hatch ontogeny of the stressresponse. Our aims were to investigate the early ontogeny of the HPA-axis and characterize behaviouraland hormonal stress responses in ancestral Red Junglefowl and in two domestic layer strains. Plasmacorticosteone and behavioural responses before and after physical restraint was measured on dayone, nine, 16 and 23 post hatch. The results showed significant increases of corticosterone after stressin all three breeds at all the different ages. The HPA-response decreased with age and was lower inRed Junglefowl. Behavioural responses also decreased with age, and tended to be stronger in RedJunglefowl. In summary, the HPA-axis is reactive from day one, and domestication may have affectedits development and reactivity, alongside with related behaviour responses.

  • 39.
    Bélteky, Johan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Agnvall, Beatrix
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Johnsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Domestication and tameness: brain geneexpression in red junglefowl selected for less fear of humans suggests effects on reproduction and immunology2016In: Royal Society Open Science, E-ISSN 2054-5703, no 3, article id 160033Article in journal (Refereed)
    Abstract [en]

    The domestication of animals has generated a set of phenotypicmodifications, affecting behaviour, appearance, physiologyand reproduction, which are consistent across a range ofspecies. We hypothesized that some of these phenotypes couldhave evolved because of genetic correlation to tameness,an essential trait for successful domestication. Starting froman outbred population of red junglefowl, ancestor of alldomestic chickens, we selected birds for either high or lowfear of humans for five generations. Birds from the fifthselected generation (S5) showed a divergent pattern of growthand reproduction, where low fear chickens grew larger andproduced larger offspring. To examine underlying geneticmechanisms, we used microarrays to study gene expressionin thalamus/hypothalamus, a brain region involved in fearand stress, in both the parental generation and the S5. Whileparents of the selection lines did not show any differentiallyexpressed genes, there were a total of 33 genes with adjustedp-values below 0.1 in S5. These were mainly related to spermfunction,immunological functions, with only a few known tobe relevant to behaviour. Hence, five generations of divergentselection for fear of humans produced changes in hypothalamicgene expression profiles related to pathways associated withmale reproduction and to immunology. This may be linked to the effects seen on growth and size of offspring. These results support the hypothesis thatdomesticated phenotypes may evolve because of correlated effects related to reduced fear of humans.

  • 40.
    Agnvall, Beatrix
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Effects of Divergent Selection for Fear of Humans on Behaviour in Red Junglefowl2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 11, p. 1-12Article in journal (Refereed)
    Abstract [en]

    Domestication has caused a range of similar phenotypic changes across taxa, relating to physiology, morphology and behaviour. It has been suggested that this recurring domesticated phenotype may be a result of correlated responses to a central trait, namely increased tameness. We selected Red Junglefowl, the ancestors of domesticated chickens, during five generations for reduced fear of humans. This caused a marked and significant response in tameness, and previous studies have found correlated effects on growth, metabolism, reproduction, and some behaviour not directly selected for. Here, we report the results from a series of behavioural tests carried out on the initial parental generation (P0) and the fifth selected generation (S5), focusing on behaviour not functionally related to tameness, in order to study any correlated effects. Birds were tested for fear of humans, social reinstatement tendency, open field behaviour at two different ages, foraging/exploration, response to a simulated aerial predator attack and tonic immobility. In S5, there were no effects of selection on foraging/exploration or tonic immobility, while in the social reinstatement and open field tests there were significant interactions between selection and sex. In the aerial predator test, there were significant main effects of selection, indicating that fear of humans may represent a general wariness towards predators. In conclusion, we found only small correlated effects on behaviours not related to the tameness trait selected for, in spite of them showing high genetic correlations to fear of humans in a previous study on the same population. This suggests that species-specific behaviour is generally resilient to changes during domestication.

  • 41.
    Johnsson, Martin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Williams, Michael J
    Institutionen för neurovetenskap, Uppsala universitet.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Genetical Genomics of Behavior: A novel chicken genomic model for anxiety behavior2016In: Genetics, ISSN 0016-6731, Vol. 202, no 1, p. 327+-Article in journal (Refereed)
    Abstract [en]

    The identification of genetic variants responsible for behavioral variation is an enduring goal in biology, with wide-scale ramifications, ranging from medical research to evolutionary theory on personality syndromes. Here, we use for the first time a large-scale genetical genomics analysis in the brain of the chicken to identify genes affecting anxiety as measured by an open field test. We combine quantitative trait locus (QTL) analysis in 572 individuals and expression QTL (eQTL) analysis in 129 individuals from an advanced intercross between domestic chickens and Red Junglefowl. We identify ten putative quantitative trait genes affecting anxiety behavior. These genes were tested for an association in the mouse Heterogenous Stock anxiety (open field) dataset and human GWAS datasets for bipolar disorder, major depressive disorder and schizophrenia. Although comparisons between species are complex, associations were observed for four of the candidate genes in mouse, and three of the candidate genes in humans. Using a multi-model approach we have therefore identified a number of putative quantitative trait genes affecting anxiety behavior, principally in the chicken but also with some potentially translational effects as well. This study demonstrates that the chicken is an excellent model organism for the genetic dissection of behavior.

  • 42.
    Persson, Mia
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Roth, Lina
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Batakis, Petros
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Genomic Regions Associated With Interspecies Communication in Dogs Contain Genes Related to Human Social Disorders2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 33439Article in journal (Refereed)
    Abstract [en]

    Unlike their wolf ancestors, dogs have unique social skills for communicating and cooperating with humans. Previously, significant heritabilities for human-directed social behaviors have been found in laboratory beagles. Here, a Genome-Wide Association Study identified two genomic regions associated with dog's human-directed social behaviors. We recorded the propensity of laboratory beagles, bred, kept and handled under standardized conditions, to initiate physical interactions with a human during an unsolvable problem-task, and 190 individuals were genotyped with an HD Canine SNP-chip. One genetic marker on chromosome 26 within the SEZ6L gene was significantly associated with time spent close to, and in physical contact with, the human. Two suggestive markers on chromosome 26, located within the ARVCF gene, were also associated with human contact seeking. Strikingly, four additional genes present in the same linkage blocks affect social abilities in humans, e.g., SEZ6L has been associated with autism and COMT affects aggression in adolescents with ADHD. This is, to our knowledge, the first genome-wide study presenting candidate genomic regions for dog sociability and inter-species communication. These results advance our understanding of dog domestication and raise the use of the dog as a novel model system for human social disorders.

  • 43.
    Roth, Lina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Olsen Faresjö, Åshild
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences.
    Theodorsson, Elvar
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Chemistry.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Hair cortisol varies with season and lifestyle and relates to human interactions in German shepherd dogs2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, no 19631Article in journal (Refereed)
    Abstract [en]

    It is challenging to measure long-term endocrine stress responses in animals. We investigated whether cortisol extracted from dog hair reflected the levels of activity and stress long-term, during weeks and months. Hair samples from in total 59 German shepherds were analysed. Samples for measuring cortisol concentrations were collected at three occasions and we complemented the data with individual scores from the Canine Behavioural Assessment and Research Questionnaire (C-BARQ). Generalised linear mixed model (GLMM) results showed that hair cortisol varied with season and lifestyle: competition dogs had higher levels than companion, and professional working dogs, and levels were higher in January than in May and September. In addition, a positive correlation was found between the cortisol levels and the C-BARQ score for stranger-directed aggression (r = 0.31, P = 0.036). Interestingly, the factor "playing often with the dog" (r = -0.34, P = 0.019) and "reward with a treat/toy when the dog behaves correctly" (r = -0.37, P = 0.010) correlated negatively with cortisol levels, suggesting that positive human interactions reduce stress. In conclusion, hair cortisol is a promising method for revealing the activity of the HPA-axis over a longer period of time, and human interactions influence the cortisol level in dogs.

  • 44.
    Pértille, Fábio
    et al.
    1Animal Biotechnology Laboratory, Animal Science and Pastures Department, University of São Paulo (USP)/Luiz de Queiroz College of Agriculture (ESALQ), Piracicaba, São Paulo, Brazil.
    Guerrero-Bosagna, Carlos
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    da Silva, Vinicius Henrique
    1Animal Biotechnology Laboratory, Animal Science and Pastures Department, University of São Paulo (USP)/Luiz de Queiroz College of Agriculture (ESALQ), Piracicaba, São Paulo, Brazil.
    Boschiero, Clarissa
    1Animal Biotechnology Laboratory, Animal Science and Pastures Department, University of São Paulo (USP)/Luiz de Queiroz College of Agriculture (ESALQ), Piracicaba, São Paulo, Brazil..
    da Silva Nunes, José de Ribamar
    1Animal Biotechnology Laboratory, Animal Science and Pastures Department, University of São Paulo (USP)/Luiz de Queiroz College of Agriculture (ESALQ), Piracicaba, São Paulo, Brazil..
    Corrêa Ledur, Mônica
    Brazilian Agricultural Research Corporation (EMBRAPA) Swine & Poultry, Concórdia, Santa Catarina, Brazil.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Lehmann Coutinho, Luiz
    1Animal Biotechnology Laboratory, Animal Science and Pastures Department, University of São Paulo (USP)/Luiz de Queiroz College of Agriculture (ESALQ), Piracicaba, São Paulo, Brazil.
    High-throughput and Cost-effective Chicken Genotyping Using Next-Generation Sequencing2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 26929Article in journal (Refereed)
    Abstract [en]

    Chicken genotyping is becoming common practice in conventional animal breeding improvement.Despite the power of high-throughput methods for genotyping, their high cost limits large scale use inanimal breeding and selection. In the present paper we optimized the CornellGBS, an efficient and costeffectivegenotyping by sequence approach developed in plants, for its application in chickens. Herewe describe the successful genotyping of a large number of chickens (462) using CornellGBS approach.Genomic DNA was cleaved with the PstI enzyme, ligated to adapters with barcodes identifyingindividual animals, and then sequenced on Illumina platform. After filtering parameters were applied,134,528 SNPs were identified in our experimental population of chickens. Of these SNPs, 67,096 hada minimum taxon call rate of 90% and were considered ‘unique tags’. Interestingly, 20.7% of theseunique tags have not been previously reported in the dbSNP. Moreover, 92.6% of these SNPs wereconcordant with a previous Whole Chicken-genome re-sequencing dataset used for validation purposes.The application of CornellGBS in chickens showed high performance to infer SNPs, particularly inexonic regions and microchromosomes. This approach represents a cost-effective (~US$50/sample)and powerful alternative to current genotyping methods, which has the potential to improve wholegenomeselection (WGS), and genome-wide association studies (GWAS) in chicken production.

  • 45.
    Foyer, Pernilla
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, The Institute of Technology. Swedish National Defence College, Stockholm, Sweden.
    Wilsson, Erik
    Swedish Armed Forces Dog Instruction Centre, Märsta, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Levels of maternal care in dogs affect adult off spring temperament2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6Article in journal (Refereed)
    Abstract [en]

    Dog puppies are born in a state of large neural immaturity; therefore, the nervous system is sensitive to environmental influences early in life. Early experiences, such as maternal care, have been shown to have a profound and lasting effect on the future behaviour and physiology of offspring in rodents and primates. We hypothesised that this would also be the case for dogs with important implications for the breeding of working dogs. In the present study, variation in the mother--‐offspring interactions of German Shepherd dogs within the Swedish breeding program for military working dogs was studied by video recording 22 mothers with their litters during the first three weeks postpartum. The aim was to classify mothers with respect to their level of maternal care and to investigate the effect of this care on pup behaviour in a standardised temperament test carried out at approximately 18 months of age. The results show that females differed consistently in their level of maternal care, which significantly affected the adult behaviour of the offspring, mainly with respect to behaviours classified as Physical and Social Engagement, as well as Aggression. Taking maternal quality into account in breeding programs may therefore improve the process of selecting working dogs.

  • 46.
    Ericsson, Maria
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Henriksen, Rie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Bélteky, Johan
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Sundman, Ann-Sofie
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Shionoya, Kiseko
    Linköping University, Department of Clinical and Experimental Medicine, Division of Cell Biology. Linköping University, Faculty of Medicine and Health Sciences.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Long-Term and Transgenerational Effects of Stress Experienced during Different Life Phases in Chickens (Gallus gallus)2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 4, article id e0153879Article in journal (Refereed)
    Abstract [en]

    Stress in animals causes not only immediate reactions, but may affect their biology for long periods, even across generations. Particular interest has been paid to perinatal stress, but also adolescence has been shown to be a sensitive period in mammals. So far, no systematic study has been performed of the relative importance of stress encountered during different life phases. In this study, groups of chickens were exposed to a six-day period of repeated stress during three different life phases: early (two weeks), early puberty (eight weeks) and late puberty (17 weeks), and the effects were compared to an unstressed control group. The short-term effects were assessed by behaviour, and the long-term and transgenerational effects were determined by effects on behavior and corticosterone secretion, as well as on hypothalamic gene expression. Short-term effects were strongest in the two week group and the eight week group, whereas long-term and transgenerational effects were detected in all three stress groups. However, stress at different ages affected different aspects of the biology of the chickens, and it was not possible to determine a particularly sensitive life phase. The results show that stress during puberty appears to be at least equally critical as the previously studied early life phase. These findings may have important implications for animal welfare in egg production, since laying hens are often exposed to stress during the three periods pinpointed here.

  • 47.
    Brunberg, Emma I
    et al.
    NORSØK – Norwegian Centre for Organic Agriculture, Tingvoll, Norway; NIBIO – Norwegian Institute for Bioeconomy Research, Tingvoll, Norway.
    Rodenburg, T Bas
    Behavioural Ecology Group, Wageningen University, Wageningen, Netherlands.
    Rydhmer, Lotta
    Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Kjaer, Joergen B
    Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Celle, Germany,.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Keeling, Linda J
    Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Omnivores Going Astray: A Review and New Synthesis of Abnormal Behavior in Pigs and Laying Hens2016In: Frontiers in veterinary science, ISSN 2297-1769, Vol. 3, p. 1-15, article id 57Article in journal (Refereed)
    Abstract [en]

    Pigs and poultry are by far the most omnivorous of the domesticated farm animals and it is in their nature to be highly explorative. In the barren production environments, this motivation to explore can be expressed as abnormal oral manipulation directed toward pen mates. Tail biting (TB) in pigs and feather pecking (FP) in laying hens are examples of unwanted behaviors that are detrimental to the welfare of the animals. The aim of this review is to draw these two seemingly similar abnormalities together in a common framework, in order to seek underlying mechanisms and principles. Both TB and FP are affected by the physical and social environment, but not all individuals in a group express these behaviors and individual genetic and neurobiological characteristics play an important role. By synthesizing what is known about environmental and individual influences, we suggest a novel possible mechanism, common for pigs and poultry, involving the brain-gut-microbiota axis.

  • 48.
    Johnsson, Martin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jonsson, Kenneth B
    Department of Surgical Sciences, Orthopaedics, Akademiska Sjukhuset, Uppsala University, Uppasla, Sweden.
    Andersson, Leif
    Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Quantitative trait locus and genetical genomics analysis identifies putatively causal genes for fecundity and brooding in the chicken2016In: G3: Genes, Genomes, Genetics, ISSN 2160-1836, E-ISSN 2160-1836, Vol. 6, no 2, p. 311-319Article in journal (Refereed)
    Abstract [en]

    Life history traits such as fecundity are important to evolution because they make up components of lifetime fitness. Due to their polygenic architectures, such traits are difficult to investigate with genetic mapping. Therefore, little is known about their molecular basis. One possible way toward finding the underlying genes is to map intermediary molecular phenotypes, such as gene expression traits. We set out to map candidate quantitative trait genes for egg fecundity in the chicken by combining quantitative trait locus mapping in an advanced intercross of wild by domestic chickens with expression quantitative trait locus mapping in the same birds. We measured individual egg fecundity in 232 intercross chickens in two consecutive trials, the second one aimed at measuring brooding. We found 12 loci for different aspects of egg fecundity. We then combined the genomic confidence intervals of these loci with expression quantitative trait loci from bone and hypothalamus in the same intercross. Overlaps between egg loci and expression loci, and trait–gene expression correlations identify 29 candidates from bone and five from hypothalamus. The candidate quantitative trait genes include fibroblast growth factor 1, and mitochondrial ribosomal proteins L42 and L32. In summary, we found putative quantitative trait genes for egg traits in the chicken that may have been affected by regulatory variants under chicken domestication. These represent, to the best of our knowledge, some of the first candidate genes identified by genome-wide mapping for life history traits in an avian species.

  • 49.
    Sundman, Ann-Sofie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Johnsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Similar recent selection criteria associated with different behavioural effects in two dog breeds2016In: Genes, Brain and Behavior, ISSN 1601-1848, E-ISSN 1601-183X, Vol. 15, no 8, p. 750-756Article in journal (Refereed)
    Abstract [en]

    Selection during the last decades has split some established dog breeds into morphologically and behaviourally divergent types. These breed splits are interesting models for behaviour genetics since selection has often been for few and well-defined behavioural traits. The aim of this study was to explore behavioural differences between selection lines in golden and Labrador retriever, in both of which a split between a common type (pet and conformation) and a field type (hunting) has occurred. We hypothesized that the behavioural profiles of the types would be similar in both breeds. Pedigree data and results from a standardized behavioural test from 902 goldens (698 common and 204 field) and 1672 Labradors (1023 and 649) were analysed. Principal component analysis revealed six behavioural components: curiosity, play interest, chase proneness, social curiosity, social greeting and threat display. Breed and type affected all components, but interestingly there was an interaction between breed and type for most components. For example, in Labradors the common type had higher curiosity than the field type (F1,1668 = 18.359; P < 0.001), while the opposite was found in goldens (F1,897 = 65.201; P < 0.001). Heritability estimates showed considerable genetic contributions to the behavioural variations in both breeds, but different heritabilities between the types within breeds was also found, suggesting different selection pressures. In conclusion, in spite of similar genetic origin and similar recent selection criteria, types behave differently in the breeds. This suggests that the genetic architecture related to behaviour differs between the breeds.

  • 50.
    Henriksen, Rie
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Johnsson, Martin
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Andersson, L
    Department of Medical Biochemistry and Microbiology, Uppsala University, Sweden.
    Jensen, Per
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    Wright, Dominic
    Linköping University, Department of Physics, Chemistry and Biology, Biology. Linköping University, Faculty of Science & Engineering.
    The domesticated brain: genetics of brain mass and brain structure in an avian species.2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6Article in journal (Refereed)
    Abstract [en]

    As brain size usually increases with body size it has been assumed that the two are tightly constrained and evolutionary studies have therefore often been based on relative brain size (i.e. brain size proportional to body size) rather than absolute brain size. The process of domestication offers an excellent opportunity to disentangle the linkage between body and brain mass due to the extreme selection for increased body mass that has occurred. By breeding an intercross between domestic chicken and their wild progenitor, we address this relationship by simultaneously mapping the genes that control inter-population variation in brain mass and body mass. Loci controlling variation in brain mass and body mass have separate genetic architectures and are therefore not directly constrained. Genetic mapping of brain regions indicates that domestication has led to a larger body mass and to a lesser extent a larger absolute brain mass in chickens, mainly due to enlargement of the cerebellum. Domestication has traditionally been linked to brain mass regression, based on measurements of relative brain mass, which confounds the large body mass augmentation due to domestication. Our results refute this concept in the chicken.

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