HAL ENVT (Ecole Nationale Vétérinaire de Toulouse)
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Impact de l'âge et du mode d'élevage (cage/sol) sur le méthylome sanguin de la poule
No full textMasterCe projet repose sur l'hypothèse que la méthylation de l'ADN, en tant que mécanisme de régulation génétique, est modulée par l'environnement d'élevage et le vieillissement des poules. En comparant deux types d'élevage (cage et sol) à deux âges (70 et 90 semaines), l'étude cherche à évaluer l'impact de ces facteurs à partir du méthylome sanguin de 1149 individus. Pour cela, ce projet utilise une méthode RRBS (Reduced Representation Bisulfite Sequencing) qui cible les îlots CpG présents sur le génome. Suite à un pipeline utilisant un outil dédié, BISCUIT, et une filtration adéquate de ces données, il en ressort 592 391 sites CpG uniques. Par la suite, une analyse différentielle a été réalisée à partir d'un package R, DSS, se basant sur un modèle multivarié avec interaction de nos deux facteurs, pour détecter des loci différentiellement méthylés (DML) et des régions différentiellement méthylées (DMR). Une analyse d'enrichissement (SEA, Singular Enrichment Analysis) a été effectuée sur les DML du facteur d'élevage. On retrouve pour le facteur d'élevage 225 DML hypométhylées, 169 DML hyperméthylées, 9 DMR hypométhylées et 3 DMR hyperméthylées. Dans ces DML, on en trouve 73 qui sont présents dans des gènes et 74 dans des promoteurs. Pour le facteur d'âge, on retrouve 22 DML dont 18 dans des gènes, et pour l'interaction entre ces facteurs, on trouve 2 DML présents dans 2 régions génomiques et 1 dans un promoteur. Les gènes VPS26A et SRA1 sortent significativement affectés par l'élevage en cage ou au sol, ainsi que d'autres gènes qui sont impliqués dans des fonctions biologiques essentielles, telles que le métabolisme, l'immunité, la minéralisation, le système nerveux et rétinien. Mots clefs : pipeline, méthylation, analyse différentielle, DMLThis project is based on the hypothesis that DNA methylation, as a mechanism of genetic regulation, is modulated by the rearing environment and the ageing of hens. By comparing two types of rearing (cage and floor) at two ages (70 and 90 weeks), the study seeks to assess the impact of these factors based on the blood methylome of 1,149 individuals. To do this, the project uses a RRBS (Reduced Representation Bisulfite Sequencing) method that targets CpG islands present in the genome. Following a pipeline using a dedicated tool, BISCUIT, and adequate filtering of this data, 592,391 unique CpG sites were identified. Subsequently, a differential analysis was performed using an R package, DSS, based on a multivariate model with interaction between our two factors, to detect differentially methylated loci (DMLs) and differentially methylated regions (DMRs). A Singular Enrichment Analysis (SEA) was performed on the DMLs of the breeding factor. For the breeding factor, there were 225 hypomethylated DMLs, 169 hypermethylated DMLs, 9 hypomethylated DMRs and 3 hypermethylated DMRs. Of these DMLs, 73 are found in genes and 74 in promoters. For the age factor, there were 22 DMLs, 18 of which are in genes, and for the interaction between these factors, there were 2 DMLs present in 2 genomic regions and 1 in a promoter. The VPS26A and SRA1 genes are significantly affected by cage or floor rearing, as are other genes involved in essential biological functions such as metabolism, immunity, mineralisation, and the nervous and retinal systems.</div
Participation à un atlas d’images scanners d’espèces de faune sauvage : mise en ligne de scanners bruts et légendés de plusieurs espèces de rapaces
No full textRaptors are critically endangered worldwide, yet they are commonly found in zoological institutions, where veterinarians often treat them. Therefore, having an advanced understanding of their general anatomy and morphological features is essential for providing adequate care. In recent decades, the democratization of computed tomography in veterinary medicine has proven particularly valuable for diagnosing common ailments in birds. This manuscript aims to bridge the gap between raptor anatomy education and the display of normal scan images, providing a valuable resource for students interested in avian imaging as well as for veterinarians in need of reference material. The images were provided by the ZooParc de Beauval. Additionally, this work is part of a larger project to create an online atlas of scan images, developed by the IMAIOS company.Les rapaces sont particulièrement menacés à l’échelle mondiale. Ce sont des espèces largement représentées en parc zoologique, que les vétérinaires sont souvent amenés à traiter. Par conséquent, une connaissance poussée de leur anatomie générale, et de leurs particularités morphologiques est essentielle pour une prise en charge adaptée. D’autre part, la démocratisation de la tomodensitométrie en médecine vétérinaire ces dernières décennies se révèle particulièrement pertinente pour le diagnostic de certaines affections aviaires. Ce manuscrit a pour objectif de concilier l’enseignement de l’anatomie des rapaces et la présentation d’images scanners normales afin de servir de support pédagogique aux étudiants intéressés par l’imagerie aviaire, mais également de servir de référence aux praticiens en activité. Il se base sur des images fournies par le ZooParc de Beauval et s’inscrit dans un projet plus vaste d’atlas d’images scanner en ligne porté par la société IMAIOS
Étude comparative des enjeux et conséquences de l’évolution virale sur la vaccination chez l’Homme et chez les carnivores domestiques
No full textViruses possess considerable genomic plasticity which can lead to the emergence of properties that enable viral immune escape. Vaccination is an essential means of tackling viral infections in human and veterinary medicine. This study aims to assess the challenges and consequences of viral evolution on vaccination in humans and domestic carnivores. While viral evolution is a factor of vaccine failure in human medicine, its consequences on domestic carnivores vaccination have so far been limited. Only the feline immunodeficiency virus (FIV) is sufficiently evolutionary to escape the immune response established post vaccination.Les virus possèdent une importante plasticité génomique pouvant être à l’origine de l’émergence de propriétés permettant leur échappement à la réponse immunitaire mise en place par l’hôte. La vaccination est un moyen de lutte primordial contre les infections virales en médecine humaine et vétérinaire. L’objectif de ce travail est d’évaluer les enjeux et les conséquences de l’évolution virale sur la vaccination chez l’Homme et chez les carnivores domestiques. Alors que l’évolution virale est un facteur d’échec à la vaccination en médecine humaine, ses conséquences sur la vaccination des carnivores domestiques sont à ce jour limitées. Seul le virus de l’immunodéficience féline (FIV) possède une capacité évolutive suffisamment importante pour échapper à l’immunité mise en place post-vaccination
Développement d’un nouveau scénario d’escape game pédagogique sur la gestion d’une Toxi-Infection Alimentaire Collective
No full textAs part of the "Food Hygiene 2" module at the Toulouse Veterinary School, a new escape game was developed for the 2024 academic year, centered around a collective foodborne illness caused by Staphylococcus aureus, an agent suspected in 31% of foodborne outbreaks in France in 2022. Students take on the role of health investigators managing a real crisis : epidemiological investigation, analyses, assessment of hygiene practices, and traceability. The scenario is based on a bibliography incorporating epidemiological, microbiological, and regulatory data. Tested with students, the game confirmed its educational relevance and was found to be immersive and engaging, while revealing areas for improvement: increased difficulty, more ergonomic materials, and better-paced gameplay, which were incorporated into the final version.Dans le cadre du module « Hygiène des aliments 2 » de l’École Vétérinaire de Toulouse, un nouvel escape game a été conçu pour la rentrée 2024, autour d’une toxi-infection alimentaire collective causée par Staphylococcus aureus, agent suspecté dans 31 % des TIAC en 2022 en France. Les étudiants y jouent le rôle d’enquêteurs sanitaires, menant une gestion de crise réelle : enquête épidémiologique, analyses, investigation des pratiques d’hygiène, traçabilité. Le scénario s’appuie sur une bibliographie intégrant données épidémiologiques, microbiologiques et réglementaires. Testé auprès d’étudiants, le jeu a confirmé sa pertinence pédagogique et a été jugé immersif et stimulant, tout en révélant des axes d’amélioration : hausse de la difficulté, supports plus ergonomiques, rythme de jeu mieux maîtrisé, qui ont été intégrés dans la version finale
Expression of bone morphogenetic protein signaling pathway players in the jejunum and colon of adult rats
No full textInternational audienceThe bone morphogenetic protein (BMP) pathway, which plays a crucial role in the control of intestinal epithelial cell homeostasis, has been studied in mice and humans, leading to an understanding of its involvement in several intestinal pathologies. However, the expression and localization of the various actors (ligands, antagonists, receptors) of this pathway remain unknown in the rat intestine, although this species is widely used in pathophysiology studies. Here, we aimed to determine the expression and localization of the various players in the BMP pathway in the jejunum and colon of the rat using RT-qPCR and immunohistochemistry. BMP2, mainly localized in epithelial cells, was the most expressed ligand in the jejunum and colon in comparison with BMP4, BMP6 and BMP7. We showed for the first time that BMP7 was highly expressed in epithelial cells in both tissues. BMP2, BMP6 and BMP7 ligands were also present in the enteric nervous plexuses, as the BMP receptors and antagonists Noggin and Chordin-like 1. The expression of BMP antagonists and ligands in enterocytes and mature colonocytes could suggest a paracrine or autocrine feedback modulation at the cellular level. Finally, all the studied BMP actors were present in colonic vessel walls including GREM1, a BMP antagonist described as pro-angiogenic and also being a ligand for VEGFR receptors. These data provided a good correlation between the observations in rats compared to those in humans and highlighted the importance of the BMP pathway not only in the intestinal epithelium, but also in both the enteric nervous system and vascular system. Our work lays the foundations for further studies on the involvement of the BMP pathway in rat models of intestinal pathophysiology
Thrombose et thromboembolie aortiques chez deux veaux: La thrombose et la thromboembolie aortiques sont des affections rares chez le veau qui nécessitent une prise en charge adaptée
No full textInternational audienceTwo calves were presented with super acute paraplegia or paraparesis. One of the calves also presented with respiratory and digestive comorbidities. The rest of the clinical examinations showed normal alertness and behaviour; signs of pain; peripheral motor neuron-type paraplegia or parapaersis with more or less complete loss of muscle tone, proprioception and posterior medullary reflexes; and coldness of the extremities. An ischaemic origin due to distal aortic thromboembolism was suspected in one case after additional ante mortem examinations. This diagnosis was confirmed in both cases post mortem.Deux veaux sont présentés pour une paraplégie ou une paraparésie d'apparition suraiguë. L'un présente des comorbidités respiratoires et digestives. L'examen clinique révèle une vigilance et un comportement normaux, mais des manifestations de douleur. Une paraplégie ou une paraparésie de type motoneurone périphérique est également notée, avec une perte plus ou moins complète du tonus musculaire, de la proprioception et des réflexes médullaires postérieurs, ainsi qu'une froideur des extrémités. Dans l'un des cas, des examens complémentaires ante mortem permettent de suspecter une origine ischémique liée à une thromboembolie aortique distale. Ce diagnostic est confirmé dans les deux cas après l'autopsie
Repeated in vitro exposure to PFOA impairs intestinal barrier integrity and leads to cytosolic accumulation as detected by subcellular chemical imaging
No full textInternational audiencePerfluorooctanoic acid (PFOA) is a persistent organic pollutant recognised for its environmental presence and bioaccumulation, despite regulatory restrictions under the Stockholm Convention. While systemic effects of PFOA have been studied extensively, its interaction with the first biological barrier encountered after oral exposure, the gastrointestinal barrier, remains poorly characterised. In this study, we evaluated the fate, uptake and effects of PFOA in human intestinal cell culture models after acute (24 h) and repeated (11-day) exposures. Using radiolabelled PFOA profiling, we found that PFOA was not metabolised by Caco-2 cells nor by HT29-MTX mucus-producing cells, in monocultures or in co-culture. Mass balance studies revealed higher basolateral passage of PFOA in Caco-2 monocultures compared to Caco-2/HT29-MTX co-cultures, suggesting that the mucus in the co-culture may trap PFOA and limit its passage. These observations led us to conduct further toxicological evaluations in the Caco-2 monoculture model. Acute exposure, while having no effect on cell viability, increased cellular ATP at highest exposure concentration. Repeated exposure led to a progressive concentration-dependent decrease in trans-epithelial electrical resistance, indicating a compromised barrier function. This effect was not linked to changes in tight junction gene expression, but rather attributed to cell death. High-resolution chemical imaging revealed intracellular accumulation of PFOA in Caco-2 cell cytosol after repeated exposure. These findings highlight the potential of repeated exposure to PFOA, even at low concentrations, to impair intestinal barrier integrity, which may have implications for systemic absorption and toxicity
Updating the RZooRoH package for the analysis of inbreeding, identity-by-descent and relatedness from genomic data
No full textThe RZooRoH R package was implemented to characterize individual inbreeding levels. It identifies DNA segments inherited twice from a common ancestor through different paths, which are known as homozygous-by-descent (HBD) segments. The package accepts different data formats and provides multiple outputs: HBD segments, inbreeding rates and genome-wide and locus-specific HBD probabilities. In addition, it partitions HBD levels into multiple HBD classes. The length distribution varies between these classes, which therefore correspond to distinct groups of ancestors that can be traced back to different generations in the past. This provides information about mating structure and recent demographic history. The computational performance of the package has been substantially improved, enabling, for example, computing times to be reduced when working with whole-genome sequence data and more HBD classes to be fitted. It is now possible to fit one class per past generation, which facilitates interpretation of the results. New options allow models to be refined, for instance by defining HBD classes as intervals or constant inbreeding rates for neighboring classes. Finally, since we have previously demonstrated that the ZooRoH model can be used to characterize identity-by-descent (IBD) between haploid individuals or phased haplotypes, this option has been included in the new package version. Estimating kinship by characterizing IBD levels between the four possible pairs of haplotypes from two individuals is another feature we added to the package. Overall, the new version of the package offers improved computational efficiency and interpretability when characterizing inbreeding, IBD and relatedness levels
Does MBD2 repress gene transcription?: A meta-analysis of transcriptome studies after MBD2 perturbation.
No full textInternational audienceMethyl-DNA binding protein 2 (MBD2) binds methylated CpG in vitro or in vivo, and recruit the NuRD repressive complex. It has been previously assumed that MBD2 is playing a role in the transcriptional repression of genes with a methylated promoter in vertebrates. However in another study, a quadruple knock-out of MBD2 along with MeCP2, MBD1, and MBD4 lead to no widespread up-regulation of genes with a methylated promoters.A meta-analysis of transcriptome studies after MBD2 perturbation was carried out to investigate the contradictory results observed in the literature. Twenty-seven datasets were identified from 17 different studies in human or mouse, including 26 datasets with MBD2 removal and one dataset of MBD2 over-expression. The number of up-regulated or down-regulated genes was identified for each study using a differentially expressed gene reanalysis with {limma}, using four different null-hypothesis thresholds of fold-changes. Sixteen of the 26 datasets (61%) with MBD2 removal were showing more gene over-expressions than down-regulations, while the other datasets were showing more down-regulatins than over-expressions (4 datasets), balanced profiles (3 datasets), or no detectable differentially expressed genes (3 datasets). The number of up-regulated genes after MBD2 removal was globally estimated as 3.25 times (CI 95%: 1.45; 7.29) more than the number of down-regulated genes for a fold change threshold of 2. The only datasets with MBD2 over-expression had more down-regulated genes than upregulated genes. There was no obvious association between the role of MBD2 as a gene repressor and the species, the tissues / cell types, its oncogenic status, nor the perturbation method. This meta-analysis support a role for MBD2 in gene repression