Project description:In this new study, we analyzed the blood transcriptome of horses housed individually that were first examined for their behavior, health and microbiota. We performed differential and regression analyzes of gene expression to unveil the molecular pathways related to the behavioural changes associated with housing horses in individual boxes. This study shows that aggressiveness towards humans and stereotypies are behavioural indicators that covary with physiological alterations.
Project description:The improvement of horse welfare through housing conditions has become a real issue in recent years and have highlighted the detrimental effect of individual housing of horses on their health and behaviour. In this new study, we analysed the blood transcriptome of 45 sport horses housed individually that were previously examined for their behaviour and gut microbiota. We performed differential and regression analyses of gene expression, followed by downstream bioinformatic analyses, to unveil the molecular pathways related to the behavioural changes associated with welfare impairment in these sport horses. We found that aggressiveness towards humans was the behavioural indicator the most correlated to blood gene expression and that the pathways involved belonged mainly to systemic inflammation. In contrast, the correlations between genes, alert postures and unresponsiveness towards the environment were weak. When blood gene expression profiling was combined with faecal microbiota of a sub-population of horses, stereotypies came out as the most correlated to blood gene expression. This study shows that aggressiveness towards humans and stereotypies are behavioural indicators that covary with physiological alterations. Further studies are needed regarding the biological correlates of unresponsiveness to the environment and alert postures.
Project description:Equine hepacivirus (EqHV) is the closest genetic relative of hepatitis C virus (HCV) and shares features of genome organization, hepatotropism, persistent infection, and the ability to cause liver disease. As such, EqHV studies are important both in order to understand equine liver disease, and as an outbred animal model for HCV pathogenesis and immune responses. Here, we characterize the natural history and immune response to EqHV infection. Seven horses were experimentally inoculated with EqHV, monitored for 6 months, and challenge inoculated with the same, and subsequently a divergent EqHV inoculum. Clearance was the primary outcome (6 of 7) and was associated with subclinical hepatitis characterized by lymphocytic infiltrate and individual hepatocyte necrosis. Seroconversion was delayed and antibody titers waned slowly. Resolving horses developed non-sterilizing immunity resulting in short duration of infection upon challenge. Unlike those observed in acutely HCV-infected patients, peripheral blood mononuclear cell responses in horses were minimal, although EqHV specific T-cells were identified. In contrast, an interferon stimulated gene signature was detected in the liver during EqHV infection, which is similar to acute HCV in humans. EqHV, similarly to HCV, is stimulated by direct binding of the liver-specific microRNA, miR-122. Surprisingly, we found that EqHV infection sequesters enough miR-122 to functionally affect gene regulation in the liver. This RNA-based mechanism thus could have consequences for pathology. Conclusion: EqHV infection in horses typically has an acute resolving course, and the immune response attenuates subsequent infections lasting for at least a year. This could have important implications to achieve the first goal of an HCV vaccine; to prevent chronicity while accepting acute resolving infection after challenge.
Project description:Social experience influences multiple behaviors of many animal species, including aggression. Social isolation often increases aggressiveness. To investigater the molecular basis of social influences on aggressiveness, we performed comparative gene expression profiling on heads from 6-day-old, single-housed, more aggressive and group-housed, less aggressive male flies. Keywords: social experience
Project description:Horses are mainly housed in individual boxes. This housing system is reported to be highly detrimental with regard to welfare and could trigger the expression of four behavioural indicators of a compromised welfare state: stereotypies, aggressiveness toward humans, unresponsiveness to the environment, and stress-related behaviours. The aim of this study was to identify housing and management factors that could alleviate the detrimental effects of individual boxes on welfare. A total of 187 horses were observed over 50 days by scan sampling. The impact of 12 factors was investigated on the expression of the four behavioural indicators in three different analyses. The results show that the majority of factors tested did not influence the expression of the behavioural indicators. Only three (straw bedding, a window opening onto the external environment, and a reduced quantity of concentrated feed) would have beneficial, although limited, effects. Furthermore, the longer the horses spent in individual boxes, the more likely they were to express unresponsiveness to the environment. To preserve the welfare of horses, it seems necessary to allow free exercise, interactions with conspecifics, and fibre consumption as often as possible, to ensure the satisfaction of the species' behavioural and physiological needs.
Project description:The purpose of this experiment was to further our understanding of gene expression in the central nervous system (thalamus and cerebrum) after exposure to West Nile virus. To that end, three different analyses were performed. The first examined differences in gene expression between horses not vaccinated and exposed to WNV and normal control horses (exposure). The second examined differences in gene expression between horses not vaccinated and exposed to WNV and horses vaccinated and exposed to WNV (survival). And the third examined differences between the nonvaccinated cerebrum and nonvaccinated thalamus of horses exposed to WNV (location). Six conditions- Gene expression in the thalamus and cerebrum of three different groups of horses (Non-vaccinated horses exposed to West Nile virus, Vaccinated horses exposed to West Nile virus, normal horses not exposed to West Nile virus). Biological replicates- 6 normal cerebrums, 6 normal thalamus, 6 vaccinated and exposed cerebrums, 6 vaccinated and exposed thalamus, 6 non-vaccinated and exposed cerebrum, 6 non-vaccinated and exposed thalamus.
Project description:The purpose of this experiment was to further our understanding of gene expression in the central nervous system (thalamus and cerebrum) after exposure to West Nile virus. To that end, three different analyses were performed. The first examined differences in gene expression between horses not vaccinated and exposed to WNV and normal control horses (exposure). The second examined differences in gene expression between horses not vaccinated and exposed to WNV and horses vaccinated and exposed to WNV (survival). And the third examined differences between the nonvaccinated cerebrum and nonvaccinated thalamus of horses exposed to WNV (location).