title: Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron.
abstract: The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes occurring in oyster spats (non exposed) originating from genitors exposed to an environmentally relevant concentration of diuron during gametogenesis using the RNAseq methodology. We identified a transcriptomic remodeling revealing an effect of the herbicide. Different molecular pathways involved in energy production, translation and cell proliferation are particularly disturbed. This analysis revealed modulated candidate genes putatively involved in response to oxidative stress and mitochondrial damage in offspring of genitors exposed to diuron. Complementary measures of the activity of enzymes involved in these latter processes corroborate the results obtained at the transcriptomic level. In addition, our results suggested an increase in energy production and mitotic activity in 5-month-spats from diuron-exposed genitors. These results could correspond to a "catch-up growth" phenomenon allowing the spats from diuron-exposed genitors, which displayed a growth delay at 3 months, to gain a normal size when they reach the age of 6 months. These results indicate that exposure to a concentration of diuron that is frequently encountered in the field during the oyster's gametogenesis stage can impact the next generation and may result in fitness disturbance.
authors.affiliation: Ifremer, IHPE UMR 5244, Univ. Perpignan Via Domitia, CNRS, Univ. Montpellier, F-34095 Montpellier, France; Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France.
authors.forename: R
authors.initials: R
authors.lastname: Rondon
authors.affiliation: Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l'ile d'Yeu, BP 21105, 44311 Nantes Cedex 03, France.
authors.forename: F
authors.initials: F
authors.lastname: Akcha
authors.affiliation: CNRS, IHPE UMR 5244, Univ. Perpignan Via Domitia, IFREMER, Univ. Montpellier, F-34095 Montpellier, France.
authors.forename: P
authors.initials: P
authors.lastname: Alonso
authors.affiliation: Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l'ile d'Yeu, BP 21105, 44311 Nantes Cedex 03, France.
authors.forename: D
authors.initials: D
authors.lastname: Menard
authors.affiliation: Ifremer, Department of Biogeochemistry and Ecotoxicology, Laboratory of Ecotoxicology, Rue de l'ile d'Yeu, BP 21105, 44311 Nantes Cedex 03, France.
authors.forename: J
authors.initials: J
authors.lastname: Rouxel
authors.affiliation: Ifremer, IHPE UMR 5244, Univ. Perpignan Via Domitia, CNRS, Univ. Montpellier, F-34095 Montpellier, France. Electronic address: cmontagn@ifremer.fr.
authors.forename: C
authors.initials: C
authors.lastname: Montagnani
authors.affiliation: Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France.
authors.forename: G
authors.initials: G
authors.lastname: Mitta
authors.affiliation: Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France.
authors.forename: C
authors.initials: C
authors.lastname: Cosseau
authors.affiliation: Univ. Perpignan Via Domitia, IHPE UMR 5244, CNRS, IFREMER, Univ. Montpellier, F-66860 Perpignan, France.
authors.forename: C
authors.initials: C
authors.lastname: Grunau
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000187:drug effects* / Q000235:genetics; D004249:DNA Damage / Q000187:drug effects; D004237:Diuron / Q000633:toxicity*; D005602:France; D005718:Gametogenesis / Q000187:drug effects; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000187:drug effects*; D006540:Herbicides / Q000633:toxicity*; D016133:Polymerase Chain Reaction / Q000379:methods; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D006540:Herbicides; D014874:Water Pollutants, Chemical; D004237:Diuron
keywords: Diuron; Ecotoxicology; Mollusk; Oyster; Transcriptomic