Travaux exploratoires du GT Immunomarquage
(01/06/2026)
Glyco-MEV, UNIROUEN, NU, HeRacLeS, UNIROUEN, NU, IRIB, UNIROUEN, NU, INSERM, CNRS, INSERM, INC-CNRS, CNRS, IBS - UMR 5075, CNRS, IRIG, DRF (CEA), CEA, UGA, IBGC, UB, CNRS, CMEAB, TRI-Genotoul, INSERM, CNRS, INRAE, EPE UT, Comue de Toulouse, BIC, UB, INSERM, CNRS, SBR, SU, CNRS, IBS, CHU Angers, IGDR, UR, CNRS, Biosit : Biologie - Santé - Innovation Technologique, PF I2BC, I2BC, CEA, CNRS, IBDM, AMU, CdF (institution), CNRS, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CICS, UdA
Adverse effects of sodium fluoride exposure on the development, thyroid morphology and disease resistance in rainbow trout (Oncorhynchus mykiss) embryos and larvae
Endocrine disruptors, ubiquitous in terrestrial and aquatic environments, have come under increased public and scientific scrutiny and are classified as substances of great concern for human health and the environment. The main objective of which is to determine the potential role of sodium fluoride (NaF) on rainbow trout health, with a particular interest in the thyroid hormone system, the immune system, and the development and behavior in early life stages. Rainbow trout ( Oncorhynchus mykiss ) embryos (265DD) were exposed for 15 days to NaF at 0, 0.5, 1, 5, 8 and 15 mg/L of F-. After the first 15 day-exposure, larvae were divided into three batches (1) exposed to NaF for further 8 days at the same concentrations, (2) infected with the Infectious Hematopoietic Necrosis virus, or (3) held in clean water. Fish were monitored daily to follow their development, morphology and behavior and sampled after 15 or 23 days of exposure, with and without viral infection, to evaluate effects on the THS (eye development, thyroid) and their capacity of resistance to IHNV. Results show impaired growth (decrease in size and an increase in the rate of abnormalities rate) and significative behavior impact at 15 mg/L of F- with a decrease of activity (speed, and light stress reaction). 5 mg/L of F- caused delayed hatching, a decrease in virus-related mortality, an increase of thyroid follicles number, and increased photoreceptor layer thickness. Further analyses will determine the immunotoxicity of this potential ED by analyzing gene activity and blood parameters in older fish.
(Aquatic Toxicology. vol. 295, n° 0166-445X, pp. 107815, 01/06/2026)
VIMEP, ANSES, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, VU, UB, ANSES
Copper coprecipitation with hydrous Mg carbonates via brucite carbonation: Application to remediation of ultramafic mine tailings
Ultramafic mine tailings, which contain high concentrations of Ni and Cr as well as economically valuable metals such as Co, Cu, Zn, and Fe, are highly reactive and likely to transform rapidly into hydrated magnesium carbonate (HMC) minerals (i.e. nesquehonite, dypingite, hydromagnesite) upon reaction with aqueous solutions. This process not only traps atmospheric CO2 but also concentrates critical metals limiting the dispersion of toxic elements in the environment. However, the mechanisms by which metals are incorporated into hydrated Mg carbonates, and the effects of these metals on the stability and growth/transformation kinetics of these phases have not yet been quantitatively assessed. This study investigates copper coprecipitation with HMC during brucite (Mg(OH)2) carbonation over one month at 25, 40, and 60°C, with Cu concentrations ranging from 0.02 to 157 mmol/L (1–10,000 mg/L). Microscopic and spectroscopic analyses of reaction products revealed Cu removal via co-precipitation, with 95% of aqueous Cu removed within one month, even at high concentrations. Temperature influenced HMC crystallization and Cu removal efficiency, while elevated Cu levels promoted the formation of Cu-rich phases such as hydrous carbonates (e.g., malachite and mcguinnessite) and oxy/hydroxides/chlorides. These findings provide insight into Cu immobilization mechanisms in hydrous Mg-carbonates, with implications for critical metal recovery and CO₂ sequestration as well as remediation of waste water. Future work should optimize reaction parameters and analytical techniques to enhance the scalability of these processes for environmental and industrial applications.
(Journal of Hazardous Materials. vol. 510, n° 0304-3894, pp. 142089, 01/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, GET, IRD, INSU - CNRS, CNES, CNRS, EPE UT, Comue de Toulouse, UNIPG, UniGe, CNRS
Molecular detection reveals infection phenology of a host – Trematode system (Cerastoderma edule – Bucephalus minimus) in southwestern France
Accurate detection of parasites in their hosts is essential for pathogen control and ecosystem studies. The trematode Bucephalus minimus (Digenea: Bucephalidae) infects the edible cockle Cerastoderma edule, a commercially fished and ecologically important bivalve that serves as its first intermediate host, in which it can be difficult to detect. We investigated detection accuracy and infection phenology of this host-parasite system in Arcachon Bay, France. Cockles were collected monthly over one year to compare detection methods: stereomicroscopy of tissues versus molecular detection by quantitative PCR (qPCR) and digital PCR (dPCR). Visual detection reported 30% prevalence, qPCR 36%, and dPCR 50%, the most sensitive method. Seasonal cockle sampling and cohort analysis enabled tracking of the 2021 cohort over two years (Sep 2022 – Jun 2024) using both visual and molecular detection. With both approaches, first infection appeared when the cohort reached 14 mm shell length in fall 2022, most likely coinciding with sexual maturity. Molecular detection consistently revealed higher prevalence and greater temporal variation than visual detection, allowing for the first description of an infection phenology in this system. Prevalence sharply rose in spring 2023, was highest in summer, declined in fall, and increased again in spring 2024 to a lesser extent. These fluctuations appear linked to cockle size and maturity, as well as to the migration pattern of the definitive host (Dicentrarchus labrax), both influencing parasite transmission. Our results highlight the importance of using sensitive molecular methods to accurately assess parasite prevalence and understand transmission dynamics, essential for monitoring parasite and host populations.
(Journal of Invertebrate Pathology. vol. 216, n° 0022-2011, pp. 108570, 01/06/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMS POREA, INSU - CNRS, CNRS, INRAE, ECOMAP, AD2M, SU, CNRS, SBR, SU, CNRS, SBR, SU, CNRS
Physiologically based kinetics and toxicodynamic (PBK-TD) modelling in zebrafish embryos: A novel approach to assess endocrine disrupting chemicals acting on brain aromatase
Endocrine-disrupting chemicals (EDCs) can interfere with neurodevelopment through modulation of estrogen signaling pathways, including brain aromatase (cyp19a1b) expression. However, linking external exposure to internal dose and biological effects remains a key challenge for risk assessment. In this study, we developed a physiologically based kinetic-toxicodynamic (PBK-TD) model to describe the time-and concentration-dependent induction of brain aromatase in zebrafish embryos. Using EASZY assay protocol, transgenic tg(cyp19a1b:GFP) embryos were exposed to three model estrogenic compounds, 17α-ethinylestradiol (EE2), bisphenol A (BPA), and bisphenol F (BPF), from 0 to 96 h post-fertilization. GFP fluorescence and RT-qPCR measurements were used to characterize temporal dynamics of brain aromatase expression. A previously established PBK model was adapted to predict internal concentrations, particularly in the brain, and coupled to an indirect response TD model describing aromatase induction. The PBK model adequately predicted internal concentrations for all compounds (majority within 3-fold error). The PBK-TD model successfully captured the onset of inducibility (~44 hpf) and reproduced the full time-course of GFP responses. Internal dose-response analysis revealed substantial differences in potency between compounds, with EE2 showing markedly higher potency than bisphenols. Importantly, relative potency rankings differed when based on internal versus external concentrations, including an inversion between BPA and BPF. Overall, this work demonstrates that combining EASZY assay and PBK-TD modelling provides a more mechanistically relevant assessment of endocrine activity, improved interpretation of zebrafish embryo assays and is first step toward for quantitative in vitro-in vivo extrapolation and qAOP development.
(Computational Toxicology. vol. 38, n° 2468-1113, pp. 100423, 28/05/2026)
INERIS, SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
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Les Peer Community In… sont un processus éditorial de science ouverte. Il s'agit de communautés spécialisées effectuant une évaluation scientifique par les pairs et à la demande des auteurs, de preprints déposés sur des serveurs appropriés. Dans chaque PCI, les recommandeurs, gèrent une évaluation détaillée de l’article. S’ensuit une décision éditoriale qui mène soit au rejet, soit à la demande de corrections, soit à la validation de l’article. Dans ce dernier cas, le recommandeur écrit un texte de recommandation dans lequel il explique pourquoi il a validé l’article. L’ensemble de la communauté scientifique a accès gratuitement au contenu validé du preprint et aux évaluations/recommandations sur le site du PCI. Les PCIs peuvent également publier les preprints recommandés dans PCI Journal, mais les auteurs peuvent éventuellement le soumettre pour publication dans une revue scientifique de leur choix, notamment dans les revues qui se sont déclarées PCI-friendly. Peer Community in Ecotoxicology and Environmental Chemistry fait partie des 21 PCI existant à ce jour. Les articles rentrant dans le champ de PCI Ecotox Env Chem concernent des travaux originaux (observations, expérimentations, modélisations, approches théoriques…) qui permettent des avancées significatives de la connaissance dans les champs de l'écotoxicologie terrestre et aquatique, ainsi que de la chimie de l'environnement. PCI Ecotox Env Chem considère la dynamique et le transport des composés chimiques dans l'environnement, leur transfert vers les organismes au sein des réseaux trophiques, et leurs effets à différents niveaux d'organisation biologique et géographique. Ainsi, PCI Ecotox Env Chem intègre différentes disciplines et approches qui répondent aux problématiques d'écotoxicologie et de toxicologie de l'environnement : chimie analytique, physiologie, microbiologie, génétique, génomique, ingénierie environnementale, modélisation, science des données, évaluation des risques… PCI Ecotox Env Chem dispose à ce jour d'un panel international de 25 recommandeurs, et développe son partenariat avec les réseaux scientifiques et sociétés savantes, ainsi qu'avec des journaux partenaires.
(27/05/2026)
ECOSYS, INRAE, LPTC, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, INRS, SEBIO, INERIS, URCA, ULH, NU, URCA, CNRS
The Role of DNA Methylation and ZBTB Transcription Factors in Sex Differentiation, Maintenance and Heat‐Induced Masculinization in Zebrafish
Sex differentiation, the process by which an organism develops as a male or female, can be influenced by the environment in many species. High temperature, or pollutant exposure, can lead to skewed sex‐ratios and genotype‐phenotype mismatches that can seriously threaten populations and biodiversity. Understanding the mechanisms involved in sex differentiation is thus of crucial importance. In the present study, we analyzed the DNA methylation and transcriptional changes that occur during sex differentiation in zebrafish. Our results support the fact that DNA methylation is not only involved in sex differentiation but also in sex maintenance. Initiation of sex differentiation was associated with a DNA demethylation event. Subsequently, a second DNA methylation remodeling event, which coincided with the loss of bi‐potentiality, was observed in males. Among the genes under study, the methylation level of the aromatase gene was found to be the most robust sex marker. However, genes encoding for transcription factors of the ZBTB family offered a more precocious marker since sex‐specific changes in their transcription levels preceded changes in DNA methylation. In addition, their transcription levels were found be sensitive to a known masculinizing factor, i.e. temperature. Our results thus support an unexpected role of ZBTB proteins in sex differentiation.
(Molecular Reproduction and Development. vol. 93, n° 1040-452X, 26/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Evaluation of two versions of the IPSL-EPOC decadal prediction systems
This study compares two generations of the IPSL-EPOC decadal climate prediction system based on the IPSL-CM6A-LR Earth System Model, focusing on differences in ocean data assimilation. The first configuration (DCP1), developed for CMIP6-DCPP, is carbon concentration-driven, while the second (DCP2), operational since 2023 under the World Meteorological Organization (WMO), incorporates updated observations and a fully interactive carbon cycle. Both systems assimilate sea surface temperature (SST) and salinity (SSS), but differ in data sources and spatial coverage: DCP1 uses the Atlantic-focused Reverdin dataset, whereas DCP2 relies on the global EN4 dataset with climatological filling in data-sparse regions. Over the common 1980–2014 period, DCP2 improves SST and SSS initialization and enhances predictive skill, particularly for ocean temperatures during the first five forecast years. Improvements are most evident in the North Atlantic, tropical Pacific, and Southern Ocean. However, skill declines beyond 5 years, especially for large-scale indices such as the Atlantic Multidecadal Variability (AMV). This loss of skill is partly linked to the use of climatological SSS in EN4 in gridpoints where observations are missing, which appears to damp ocean variability, reduce deep-water variability, and limit fluctuations of the Atlantic Meridional Overturning Circulation (AMOC). These results highlight the need for careful treatment of sparse observational data in decadal prediction systems to preserve the low-frequency variability of ocean circulation.
(Frontiers in Climate. vol. 8, n° 2624-9553, pp. 1803256 [12 p.], 25/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LOCEAN, MNHN, IRD, INSU - CNRS, SU, CNRS, IPSL (FR_636), ENS-PSL, PSL, UVSQ, CEA, INSU - CNRS, X, IP Paris, CNES, SU, CNRS, UPCité
A multi-proxy sediment record of atmospheric contaminant deposition in the Paris Basin since the nineteenth century
Small ponds represent valuable but still underexploited archives for reconstructing long-term environmental contamination, particularly those disconnected to fluvial networks. In this study, a sediment core from the Saint-Denis pond (Paris Basin, France) was used to reconstruct the historical evolution of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and per- and polyfluoroalkyl substances (PFAS) over the last 150 years. The 137Cs record, characterized to the well-defined atmospheric fallout peak in 1963, was retained as the most robust age model, particularly for the second half of 20th century, when investigated contaminant dynamics were strongly influenced by human activities. The resulting chronology indicates continuous sediment accumulation from the late 19th century to 2021.Temporal trends in PAHs, PCBs, and PFAS closely match known historical production, use, and regulatory phases, providing independent validation of the 137Cs-based age model. Although indirect contaminant transfers via surrounding forest soils cannot be entirely excluded, the sediment record predominantly reflects atmospheric-driven contamination. This multi-proxy approach demonstrates the relevance of pond sediments for environmental monitoring and retrospective assessment of long-term contamination trends at the regional scale.
(Environmental Monitoring and Assessment. vol. 198, n° 0167-6369, pp. 625, 21/05/2026)
METIS, EPHE, PSL, INSU - CNRS, SU, CNRS, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, iSTeP, INSU - CNRS, SU, CNRS, CY, GéHCO, UT, NEOLAiA
Testing a new approach to quantify intracellular trace metal contents in microphytoplankton using sequential selective extraction
Current methodologies used to quantify intracellular trace metal (TM) contents in microphytoplankton rely on the assumption that samples consist exclusively of phytoplankton cells, with no contribution from inorganic particles. Therefore, the present study aimed to propose a sequential selective extraction protocol for suspended particulate matter that preserve the cellular integrity of phytoplankton until the final Aqua Regia extraction. Seawater was collected in the Arcachon Bay and filtered through polycarbonate membranes (PC; Isopore™, 2 μm pore size). These membranes were put in contact with various extractants to isolate specific TM fractions. A subset of membranes was used for observation with scanning electron microscope (SEM) to assess the impact of the extractants on phytoplankton integrity. Among the tested solutions (i.e. ascorbate, 0.1 M NaOH, hydrogen peroxide, EDTA, 1 M HCl), only hydrogen peroxide was found to be destructive for the phytoplankton cells. Accordingly, a four-step sequential extraction was established: (1) ascorbate solution, (2) 0.1 M NaOH, (3) EDTA, (4) 1 M HCl, in order to selectively remove TM associated with inorganic phases or organic matter. Subsequently, PC membranes were digested by Aqua Regia to break down the phytoplankton cells and quantify the intracellular TM contents. The established protocol proves to be robust and effective to quantification the minimal TM content in diatoms and silicoflagellates cells. Results showed that Al, V, Mn, Fe, Cu, As, Pb, and Th were present in low proportion in the Aqua Regia solution (less than 20 % of the total content), suggesting limited internalization. In contrast, Cr (93 ± 3 %), Co (74 ± 23 %), and Ni (79 ± 17 %) fractions were dominantly present in the intracellular fraction suggesting they play major roles in TM biogeochemical cycles involving phytoplankton.
(Marine Environmental Research. vol. 219, n° 0141-1136, pp. 108113, 20/05/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS