Exploring the functional diversity and activity of microbial communities related to mercury cycling in Lake Geneva with new omics approaches
Mercury (chemical symbol Hg) is considered as a priority pollutant, including in Europe, mainly because of the toxicity of its organic form, methylmercury (MeHg), and its propensity to biomagnify, i.e. to increase its concentration in the tissues of organisms as it travels up the food chain. It is known that the Hg methylation, the transformation of divalent Hg (HgII) to MeHg, occurs under oxygen-free conditions and depends essentially on the activity of microorganisms characterized by specific genes – the hgcAB gene cluster. In addition, HgII methylation depends on the HgII bioavailability, the abundance of electron acceptors, the abundance and nature of organic matter as well as the activity and structure of the microbial community. It is therefore instrumental to understand the compendium of metabolic processes that can affect directly or indirectly HgII methylation. This project aims to determine and compare HgII-methylation, microbial biodiversity and activity involved in HgII methylation in contrasted physico-chemical contexts in Lake Geneva. We aim to overcome some of the current limits for predicting MeHg concentrations in the environment.
This project will be a proof of concept of the interest of coupling cutting-edge high-throughput biological analysis (metagenomics and metaproteomics, i.e. global analysis of genes and proteins, respectively) with a physico-chemical characterization. An increased knowledge of the relationship between microbial community activity, physico-chemical conditions, MeHg production and demethylation is necessary to predict the variability in MeHg concentrations across environments and consequently mitigate the Hg methylation to protect environment and human health .
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High-Throughput Multi-Cell Platform for the Analysis of Endocrine Disruptive Stress in Fish
The POMELO project focused on the "stress-on-stress" effects of exposure to tebuconazole (TBZ) and infectious hematopoietic necrosis virus (IHNV) in rainbow trout (Oncorhynchus mykiss). The study involved three exposure conditions to TBZ: a control (no pollutant), an environmentally relevant concentration (230 ng/L), and an acute/accidental concentration (10 µg/L). Blood and tissue samples (liver, gills, gonads) were collected at multiple time points post-contamination (1, 7, and 28 days; T1–T3). Following 28 days of chemical exposure, surviving trout from each condition were subjected to a viral challenge using the IHNV strain N61 via immersion, or maintained as non-infected controls. Additional sampling was conducted at 48 and 96 hours post-infection (T4–T5).A comprehensive set of analyses was performed, including transcriptomic, epigenetic, immunological, histopathological, and metagenomic assessments. Special attention was given to evaluating impacts on energy metabolism, antioxidant and detoxification pathways, immune parameters, reproductive function, microbiome composition (circulating and mucosal), and DNA methylation patterns. Complementary in vitro assays on human cell lines were also conducted to investigate the impact of TBZ on epigenetic regulators. Finally, biobanking strategies (e.g., FTA cards, tissue microarrays) were implemented to enable future targeted analyses. This integrative, high-throughput multi-omics approach provided a robust framework to investigate endocrine-disrupting stress in fish and supports the development of mechanistically informed environmental risk assessments. ...
Réduction de la pollution des perturbateurs endocriniens à la source : mise à disposition d'outils innovants
Le projet RedPol se concentre sur la question des perturbateurs endocriniens. Les perturbateurs endocriniens sont des substances chimiques qui peuvent interférer avec les systèmes endocriniens (ou hormonaux) à certaines doses et peuvent provoquer des tumeurs cancéreuses, des anomalies congénitales et d'autres troubles du développement chez les êtres humains. Cela a également un impact sur l'environnement au sens large, entraînant des problèmes de reproduction et d'infertilité chez la population d'animaux sauvages, ce qui peut générer un déséquilibre dans la répartition de la population entre les hommes et les femmes à la base de la chaîne alimentaire.
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Surveillance des norovirus humains et des indicateurs de la contamination virale dans un contexte de santé publique : développement d’une approche d’encagement d’invertébrés couplée à de la modélisation
Le projet ANSES 2020-038 SENTINEL propose une approche originale basée sur la biosurveillance active recourant à l’utilisation d’invertébrés accumulateurs de la contamination : Dreissena polymorpha et Gammarus fossarum, couplée à la définition de modèles cinétiques de bioaccumulation. Ce projet a pour ambition de proposer un outil de diagnostic de la contamination virale des masses d’eau via la conversion en termes de charges du milieu aquatique des teneurs en NoV et/ou de ses indicateurs potentiels (FRNAPH) mesurés dans les organismes encagés. Pour atteindre les objectifs, le consortium a associé des compétences et expertises diverses dans le domaine des sciences environnementales (écotoxicologie, UMR-I 02 SEBIO, INRAE ; modélisation : UMR 5558 LBBE et virologie : UMR 7564 LCPME). ...
Monitoring of human noroviruses and indicators of viral contamination in a public health context: development of an invertebrate caging approach coupled with modelling.
The ANSES 2020-038 SENTINEL project proposes an original approach based on active biomonitoring using contamination-accumulating invertebrates: Dreissena polymorpha and Gammarus fossarum, coupled with the definition of kinetic bioaccumulation models. The aim of this project is to propose a tool for diagnosing viral contamination of water bodies by converting NoV levels and/or its potential indicators (FRNAPH) measured in encaged organisms into terms of loads in the aquatic environment. To achieve its objectives, the consortium has brought together a wide range of skills and expertise in the environmental sciences (ecotoxicology, UMR-I 02 SEBIO, INRAE; modelling: UMR 5558 LBBE and virology: UMR 7564 LCPME). ...
Proposition d’un pilote basé sur l’utilisation de biomarqueurs pour un appui à la surveillance de la qualité des masses d’eau du district Seine-Normandie
L’objectif principal du projet est de proposer un pilote, basé sur la méthodologie développée dans le projet SASHIMI (Surveillance active de l’impact de la pression chimique par des biomarqueurs- financement AFB), afin d’appuyer la surveillance des masses d’eau continentales, de transition et côtières sur le district Seine Normandie. De façon plus précise, le projet BIOSURVEILLANCE visera à i) valider l’utilisation des biomarqueurs comme appui à la surveillance par un déploiement à l’échelle des masses d’eau du district Seine Normandie, ii) construire une démarche visant à être pérennisée et transférable aux gestionnaires.
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Surveillance des norovirus humains et des indicateurs de la contamination virale dans un contexte de santé publique : développement d’une approche d’encagement d’invertébrés couplée à de la modélisation
This work proposes a comparative study of the immune responses of two bivalves, one from the littoral environment: Mytilus edulis, and the other from the freshwater environment: Dreissena polymorpha. The main objective is to improve the reading of immune responses in the two bivalves with the operational output being a better interpretation of biomonitoring based on immunomarkers along an aquatic continuum. ...
Développement de biomarqueurs subcellaires liés au Métabolisme énergétique chez la Moule zébrée : cryofixation et paramètres structuraux des mitochondries
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Use of the three-spined stickleback to study the effects of a cocktail of pesticides from rice cultivation in the Camargue, under conditions of variable salinity: influence of rapid selection mechanisms on the ecotoxicological response
Using the three-spined stickleback to study the effects of a cocktail of pesticides from rice cultivation in the Camargue, under conditions of variable salinity: influence of rapid selection mechanisms on the ecotoxicological response ...
