An environmentally realistic pesticide and copper mixture impacts embryonic development and DNA integrity of the Pacific oyster, Crassostrea gigas

• Published in: Environmental Science and Pollution Research
• Main Authors: Mai, Huong, Cachot, Jérôme, Clérandeau, Christelle, Caroline, Martin, Mazzella, Nicolas, Gonzalez, Patrice, Morin, Bénédicte
• Other Authors: UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Ecosystèmes aquatiques et changements globaux (UR EABX), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Genotoxicity; Gene expression; Copper; Pesticide mixture; Embryotoxicity; Pacific oyster; [SDE]Environmental Sciences; Pacific; Crassostrea gigas
• Online Access: https://hal.inrae.fr/hal-03066007; https://hal.inrae.fr/hal-03066007/document; https://hal.inrae.fr/hal-03066007/file/Mai%20et%20al,%20ESPR%20version%20finale%20%281%29.pdf; https://doi.org/10.1007/s11356-018-3586-6

International audience Frequent occurrences of pesticides in the environment have raised concerns that combined exposure to these chemicals may result in enhanced toxicity through additive or synergistic interaction between compounds. Spermatozoa and embryos of the Pacific oyster, Crassostrea gigas, were exposed to different concentrations of a pesticide mixture with and without copper, mimicking the cocktail of pollutants occurring in the oyster culture area of Arcachon Bay. For the 1× exposure condition, measured concentration corresponds to a total concentration of 1.083 μg L−1 for the mixture of 14 pesticides and to 6.330 μg L−1 for copper (Cu). Several endpoints including larval abnormalities, DNA damage to spermatozoa and embryo and gene expression in D-larvae were investigated. Results demonstrated that pesticide mixtures in combination with or without copper induced a dose-dependent increase in embryotoxic and genotoxic effects on D-larvae from the lowest tested dose of 0.1×. Transcription of genes involved in anti-oxidative stress (cat), respiratory chain (coxI), metal detoxification (mt1 and mt2), and cell cycle arrest and apoptosis (p53) was found to be significantly downregulated while the xenobiotic biotransformation gene gst was significantly upregulated in embryos exposed to pesticide mixture with and without Cu. These findings raise the question of the possible impacts of mixtures of pesticides and metals on wild or farmed oyster populations from polluted coastal marine areas.