HAL ENVT (Ecole Nationale Vétérinaire de Toulouse)
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Développement et mise en œuvre d’une approche innovante de criblage à grande échelle pour une caractérisation étendue de l’exposition humaine aux pesticides [Poster 26 – S5-P26]
No full textInternational audienceL’exposition chimique aux pesticides est un sujet de préoccupation majeure en santé.Actuellement, l’analyse de cette exposition chimique est effectuée de manière plus ou moins directe,par exemple via des questionnaires ou en quantifiant un nombre restreint de substances dans desmatrices biologiques, sang ou urine (méthodes ciblées de biosurveillance). Ces approches sontinsuffisantes pour prendre en compte la complexité et la totalité des expositions auxquelles lesindividus sont exposés. L’objectif de ce projet est de développer un nouveau workflow analytiquemultiplexe en associant trois techniques analytiques complémentaires (HILIC-LC-HRMS ; LC-ESI-HRMS; GC-HRMS) et des outils bio-informatiques innovants permettant de caractériser à large échelle,l’exposition interne de l’homme aux pesticides. L’approche utilisée est celle du « profilage desuspects » en utilisant des données acquises en spectrométrie de masse haute résolution afin decribler plusieurs milliers de marqueurs provenant de produits phytosanitaires, leurs métabolites(phase I et II) ou produits de dégradation. Une librairie de marqueurs de plus de 200 pesticides et deleurs métabolites (i.e., via Biotransformer) a été élaborée pour couvrir une large gamme de propriétésphysicochimiques (logKow : (-4.71;8.38) ; MM/g.mol (72;720). Les données LC-ESI-HRMS présentéesont été pré-traitées par Galaxy (XCMS) et le profilage de suspect grâce à l’outil Scannotation et MS-DIAL4. Cette approche multiple permettra de caractériser et de complémenter les donnéesd’exposition liées à l’usage de pesticides et de tester leurs relations avec des paramètres de santé afind’identifier des substances délétères pour la santé humaine
An innovative ex vivo model to assess the efficacy of an ectoparasiticide repellent against Phlebotomus perniciosus sandflies in dogs
No full textInternational audienc
Genetic variation of HPA axis activity in farm animals and beyond
No full textInternational audienceBackground: Many experimental data in several species clearly demonstrate the important genetic contribution to variations in HPA axis activity. The influence of corticosteroid hormones on adaptive processes and on production traits such as growth rate, feed efficiency, carcass composition and meat quality is a strong impetus to the search for the molecular bases of these differences for efficient genetic selection. Summary: Three main sources of genetic variability have been documented so far in farm animal species, the adrenal cortex sensitivity to ACTH regulating corticosteroid hormone production, the bioavailability of corticosteroid hormones and especially corticosteroid-binding globulin capacity, and glucocorticoid receptor function. The effect of single mutations may be dependent on the genetic background and genetic variation of cortisol levels may have different functional consequences depending on the molecular mechanisms responsible for this change. Key Messages: Understanding the genetic basis of HPA axis activity allows the development of genomic tools and breeding technologies aimed at improving adaptive capacity and stress tolerance in farm animals and their use as valuable models for the genetic study of the HPA axis and the correlation with adaptation, metabolism and other functions regulated by adrenal hormones, and associated pathologies (obesity, cardiovascular, etc.). The next step will be to explore HPA axis variability from a system genetics perspective including the multiple sources of variation and their interactions. This multifactorial approach is a prerequisite to the use of the HPA axis phenotypes in the genetic selection for more productive and robust animals, with a high level of production of quality products
Étude de la résistance des strongles gastro-intestinaux aux anthelminthiques usuels dans trois élevages ovins laitiers de corse
No full textIn recent years, dairy farming has increasingly faced environmental issues and the associated challenges. As a result, various sectors of French farming have had to learn to overcome obstacles in order to develop strategies for resource optimization, disease control, and optimal production. Thus, our work focuses on a study of the efficacy of three market molecules intended to combat digestive strongyles in small ruminants in South Corsica (2A), where little information on the subject has been available until now. We selected three farms to conduct coproscopies before and after treatment with three commonly used anthelmintic molecules (Fenbendazole, Moxidectin, Eprinomectin), in order to numerically estimate their effectiveness and conclude whether there is resistance of local digestive strongyles to these molecules. Coproscopies, followed by coprocultures and finally identification of the larvae from the latter, allow us to draw conclusions regarding the expected presence of resistance at the island level. Fenbendazole shows only a very slight reduction in excretion in the majority of the farms, while macrocyclic lactones present irregular results. Cydectin was moderately effective and below the FECR threshold of 95% in terms of reduction in excretion, but few larvae were identified in farms A and C, and there was a clear resistance observed in farm B. Eprinomectin, the only molecule with a marketing authorization for lactating animals and no waiting period, remains the most effective of the three tested molecules, with satisfactory reduction in excretion and significant larval identification of a molecule that is still relevant. The only exception was in farm A, where eprinomectin showed an unsatisfactory result, despite uncertainty regarding the qualitative and quantitative composition of the lot concerned at day 0.L’élevage laitier des dernières années est de plus en plus confronté aux problématiques environnementales et aux enjeux qui y sont associés. De ce fait, les différentes filières de l’élevage français ont dû apprendre à franchir les obstacles afin de développer des stratégies d’optimisation de la ressource, de lutte contre les maladies, et de production optimale. Ainsi, notre travail, portant sur une étude d’efficacité de trois molécules du marché et destinées à lutter contre les strongles digestifs du petit ruminant en Corse-du-Sud (2A), où jusque-là peu d’informations concernant le sujet sont disponibles. De ce fait, nous avons sélectionné trois élevages afin de réaliser des coproscopies avant et après traitement anthelminthique avec trois molécules couramment utilisées (Fenbendazole, Moxidectine, Eprinomectine), afin d’estimer numériquement leur efficacité, et de conclure de la présence ou non de résistance des strongles digestifs locaux vis-à-vis de ces molécules. Des coproscopies puis des coprocultures et enfin une identification des larves issues de ces dernières nous permettent ainsi de conclure quant à la présence attendue de resistances au niveau insulaire. Le fenbendazole ne présente qu’une très faible de réduction d’excrétion dans la majorité des élevages, tandis que les lactones macrocycliques présentent des résultats irréguliers. La cydectine a été moyennement efficace et en-dessous du seuil de FECR de 95% en termes de réduction d’excrétion, mais peu de larves ont été identifées dans les élevages A et C. Et une résistance très nette dans l’élevage B. L’eprinomectine, seule molécule possédant une AMM en lactation avec un temps d’attente nul, reste la plus efficace des trois molécules testées avec une réduction d’excrétion satisfaisante et une identification larvaire significative d’une molécule toujours d’actualité. Seule exception dans l’élevage A où l’éprinomectine présente un résultat insatisfaisant, malgré une incertitude quant à la composition qualitative et quantitative du lot concerné à J0
Endoparasitic Diseases in Breeding Kennels: A Frequent and Complex Problem Requiring a Holistic Approach
No full textInternational audienceAll over the world, kennels are held by different kinds of breeders: occasional, regular hobby, and professional breeders. Even if these dog breeders have various breeding practices, manage canine populations of very different sizes, and have various final purposes (i.e., companion dogs or working dogs), all conscientious breeders of dogs have the same priority: the health and wellbeing of their animals. Although parasites are extremely common pathogens in all dogs, they are particularly problematic in breeding kennels as they can interfere with breeding performance and the health of dogs. This review aims to explain why breeding kennels are predisposed to parasitic infestations, how the most common parasites can influence dog breeding performance and health, and how to prevent parasite infestations in this specific environment
Root-associated Streptomyces produce galbonolides to modulate plant immunity and promote rhizosphere colonization
No full textInternational audienceThe rhizosphere, which serves as the primary interface between plant roots and the soil, constitutes an ecological niche for a huge diversity of microbial communities. Currently, there is little knowledge on the nature and the function of the different metabolites released by rhizospheric microbes to facilitate colonization of this highly competitive environment. Here, we demonstrate how the production of galbonolides, a group of polyene macrolides that inhibit plant and fungal inositol phosphorylceramide synthase (IPCS), empowers the rhizospheric Streptomyces strain AgN23, to thrive in the rhizosphere by triggering the plant’s defence mechanisms. Metabolomic analysis of AgN23-inoculated Arabidopsis roots revealed a strong induction in the production of an indole alkaloid, camalexin, which is a major phytoalexin in Arabidopsis. By using a plant mutant compromized in camalexin synthesis, we show that camalexin production is necessary for the successful colonization of the rhizosphere by AgN23. Conversely, hindering galbonolides biosynthesis in AgN23 knock-out mutant resulted in loss of inhibition of IPCS, a deficiency in plant defence activation, notably the production of camalexin, and a strongly reduced development of the mutant bacteria in the rhizosphere. Together, our results identified galbonolides as important metabolites mediating rhizosphere colonization by Streptomyces
SMARTER-database: a tool to integrate SNP array datasets for sheep and goat breeds
No full textUnderutilized sheep and goat breeds have the ability to adapt to challenging environments due to their genetic composition. Integrating publicly available genomic datasets with new data will facilitate genetic diversity analyses; however, this process is complicated by important data discrepancies, such as outdated assembly versions or different data formats. Here we present the SMARTER-database, a collection of tools and scripts to standardize genomic data and metadata mainly from SNP chips arrays on global small ruminant populations with a focus on reproducibility. SMARTER-database harmonizes genotypes for about 12,000 sheep and 6,000 goats to a uniform coding and assembly version. Users can access the genotype data via FTP and interact with the metadata through a web interface or programmatically using their custom scripts, enabling efficient filtering and selection of samples. These tools will empower researchers to focus on the crucial aspects of adaptation and contribute to livestock sustainability, leveraging the rich dataset provided by the SMARTER-database
Towards an edit distance between pangenome graphs
No full textInternational audienceA pangenome graph is a sequence graph that aims to represent variations among a collection of genomes in a single data structure. Each genome is segmented and embedded as a path in the graph with its successive nodes corresponding to contiguous segments on the associated genome. Building such graphs relies on alignment heuristics, and thus gives different graphs from the same input data depending on the chosen method, or the set of parameters. In this work, we would like to question to what extent the construction method influences the resulting graph and therefore to what extent the resulting graph reflects genuine genomic variations. We present here an algorithm that analyzes the differences in segmentation across two pangenome graphs, the segmentation being the way the genomes are split into nodes inside the graph structure. We define elementary operations, fusion and fission, that enables to transform one graph into another. Our algorithm provides a dissimilarity measure between each pair of variation graphs: the minimal number of elementary operations. It enables both to quantify the impact of the graph construction method and its parameters and to pinpoint specific areas of the graph and genomes that are impacted by the changes in segmentation. We applied our method on graphs from 21 yeast telomere-to-telomere phased genomes assemblies with the two current state-of-the-art pangenome graph builders, minigraph-cactus and pggb. We show that, with a fixed set of genomes, changing the reference in minigraphcactus mattered much more than shuffling the order of insertion of the other genomes, and that comparing two minigraph-cactus graphs with different references can result in a higher dissimilarity than comparing a minigraph-cactus graph and the pggb graph.</div