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| Registros recuperados: 12 | |
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| Behrens, Daphne; Rouxel, Julien; Burgeot, Thierry; Akcha, Farida. |
| Herbicides are one of the major classes of pollutants contaminating coastal waters over the world. Among them, diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) is a phenylurea herbicide frequently detected in oyster-producing area, known to be toxic for this important exploited non-target species. With the aim to investigate the mechanisms by which diuron displays its toxicity in oyster, the implication of both biotransformation and oxygen reactive species (ROS) production was studied considering embryotoxicity and genotoxicity as endpoints. Comparative embryotoxicity and genotoxicity of diuron and its main metabolites (DCPMU, DCPU and 3,4-DCA) were thus studied on oyster larvae by the embryo-larval bioassay on D larvae and the comet assay on trochophore... |
| Tipo: Text |
Palavras-chave: Oyster; Herbicide; Embryotoxicity; Genotoxicity; Oxidative stress; Biotransformation. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00324/43521/43053.pdf |
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| Sussarellu, Rossana; Lebreton, Morgane; Rouxel, Julien; Akcha, Farida; Riviere, Guillaume. |
| Copper contamination is widespread along coastal areas and exerts adverse effects on marine organisms such as mollusks. In the Pacific oyster, copper induces severe developmental abnormalities during early life stages; however, the underlying molecular mechanisms are largely unknown. This study aims to better understand whether the embryotoxic effects of copper in Crassostrea gigas could be mediated by alterations in gene expression, and the putative role of DNA methylation, which is known to contribute to gene regulation in early embryo development. For that purpose, oyster embryos were exposed to 4 nominal copper concentrations (0.1, 1, 10 and 20 μg L−1 Cu2+) during early development assays. Embryotoxicity was monitored through the oyster embryo-larval... |
| Tipo: Text |
Palavras-chave: Oyster; Embryotoxicity; Copper; Gene expression; DNA methylation. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00417/52856/53756.pdf |
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| Perez Garcia, Maria Concepcion; Rouxel, Julien; Akcha, Farida. |
| In this work, the DNA-damaging effect of hydrogen peroxide on the structural integrity of nucleolar organizer regions (NORs) was studied for the first time by comet-FISH in the Pacific oyster Crassostrea gigas. Global DNA damage was assessed in hemocytes using an alkaline version of the comet assay. Next, NOR sensitivity was analysed by mapping major rDNA repeat unit by fluorescence in situ hybridisation (FISH) on the same comet slides. Exposure of hemocytes to 100 μM of hydrogen peroxide induced a significant increase in both DNA damage and number of FISH-signals of major ribosomal genes versus the control. Moreover, a significant positive correlation was shown between DNA damage as measured by the comet assay (percentage of DNA in comet tail) and the... |
| Tipo: Text |
Palavras-chave: Crassostrea gigas; Hydrogen peroxide; Comet assay; Comet-FISH; Genotoxicity. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00250/36157/34712.pdf |
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| Akcha, Farida; Barranger, Audrey; Bachere, Evelyne; Berthelin, C. Heude; Piquemal, D.; Alonso, P.; Sallan, R. Rondon; Dimastrogiovanni, G.; Porte, C.; Menard, Dominique; Szczybelski, A.; Benabdelmouna, Abdellah; Auffret, M.; Rouxel, Julien; Burgeot, Thierry. |
| Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation... |
| Tipo: Text |
Palavras-chave: Oyster; Pesticide; Reproduction; Histology; Gene expression; RT-qPCR; Steroid; Immunity. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00309/41983/83232.pdf |
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| Akcha, Farida; Spagnol, Charlene; Rouxel, Julien. |
| We investigated the effects of genotoxicant exposure in gametes and embryos to find a possible link between genotoxicity and reproduction/developmental impairment, and explore the impact of chemical genotoxicity on population dynamics. Our study focused on the genotoxic effects of two herbicides on oyster gametes and embryos: glyphosate (both as an active substance and in the Roundup formulation) and diuron. France is Europe's leading consumer of agrochemical substances and as such, contamination of France's coastal waters by pesticides is a major concern. Glyphosate and diuron are among the most frequently detected herbicides in oyster production areas; as oyster is a specie with external reproduction, its gametes and embryos are in direct contact with... |
| Tipo: Text |
Palavras-chave: Genotoxicity; Embryotoxicity; Oyster; Gametes; Pesticides; Diuron; Glyphosate. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00070/18128/15783.pdf |
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| Stachowski-haberkorn, Sabine; Jerome, Marc; Rouxel, Julien; Khelifi, Celia; Rince, Maeva; Burgeot, Thierry. |
| To investigate the ability of microalgae to develop stable, long-term resistance to herbicides, the marine microalga Tetraselmis suecica was exposed to the herbicide diuron (5 µg/L) for a 43-generation exposure period followed by a 12-generation depuration phase. During the first 25 generations, diuron-exposed cultures showed doubling times ranging from 1.95 to 2.6 days, which was 2 to 2.5-fold longer than control cultures. Between generations 25 and 38, during diuron exposure, two out of the three exposed cultures exhibited a spontaneous drop in doubling time. These results provided evidence of culture adaptation to diuron. To assess persistence of the diuron adaptation observed on growth performance, one of the adapted cultures (D3) was maintained for 12... |
| Tipo: Text |
Palavras-chave: Microalgae; Diuron; Multigenerational; Adaptation; Flow cytometry. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00146/25718/23796.pdf |
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| Revel, Messika; Châtel, Amélie; Perrein-ettajani, Hanane; Bruneau, Mélanie; Akcha, Farida; Sussarellu, Rossana; Rouxel, Julien; Costil, Katherine; Decottignies, Priscilla; Cognie, Bruno; Lagarde, Fabienne; Mouneyrac, Catherine. |
| The aim of the present study was to evaluate the presence and potential toxic effects of plastic fragments (<400 μm) of polyethylene and polypropylene on the Pacific oyster Crassostrea gigas. Oysters were exposed to environmentally relevant concentrations (0, 0.008, 10, 100 μg of particles/L) during 10 days, followed by a depuration period of 10 days in clean seawater. Effects of microplastics were evaluated on the clearance rate of organisms, tissue alteration, antioxidant defense, immune alteration and DNA damage. Detection and quantification of microplastics in oyster's tissues (digestive gland, gills and other tissues) and biodeposits using infrared microscopy were also conducted. Microplastics were detected in oyster's biodeposits following... |
| Tipo: Text |
Palavras-chave: Microplastics; Crassostrea gigas; Biodeposits; Biomarkers; Bivalves. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00588/70055/68018.pdf |
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| Barranger, Audrey; Akcha, Farida; Rouxel, Julien; Brizard, Raphael; Maurouard, Elise; Pallud, Marie; Menard, Dominique; Tapie, N.; Budzinski, Helene; Burgeot, Thierry; Benabdelmouna, Abdellah. |
| Pesticides represent a major proportion of the chemical pollutants detected in French coastal waters and hence a significant environmental risk with regards to marine organisms. Commercially-raised bivalves are particularly exposed to pollutants, among them pesticides, as shellfish farming zones are subject to considerable pressure from agricultural activities on the mainland. The aims of this study were to determine (1) the genotoxic effects of diuron exposure on oyster genitors and (2) the possible transmission of damaged DNA to offspring and its repercussions on oyster fitness. To investigate these points, oysters were exposed to concentrations of diuron close to those detected in the Marennes-Oleron Basin (two 7-day exposure pulses at 0.4 and 0.6 μg... |
| Tipo: Text |
Palavras-chave: Herbicide; Diuron; Oyster; Genotoxicity; Comet assay; Cytogenetics. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00162/27311/25541.pdf |
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| Coquille, Nathalie; Menard, Dominique; Rouxel, Julien; Dupraz, Valentin; Eon, Melissa; Pardon, Patrick; Budzinski, Helene; Morin, Soizic; Parlanti, Edith; Stachowski-haberkorn, Sabine. |
| Microalgae, which are the foundation of aquatic food webs, may be the indirect target of herbicides used for agricultural and urban applications. Microalgae also interact with other compounds from their environment, such as natural dissolved organic matter (DOM), which can itself interact with herbicides. This study aimed to evaluate the influence of natural DOM on the toxicity of three herbicides (diuron, irgarol and S-metolachlor), singly and in ternary mixtures, to two marine microalgae, Chaetoceros calcitrans and Tetraselmis suecica, in monospecific, non-axenic cultures. Effects on growth, photosynthetic efficiency (Ф’M) and relative lipid content were evaluated. The chemical environment (herbicide and nutrient concentrations, dissolved organic carbon... |
| Tipo: Text |
Palavras-chave: Microalgae; Herbicides; Natural dissolved organic matter; DOM; Toxicity; Interactions. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00428/53964/55113.pdf |
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| Revel, Messika; Lagarde, Fabienne; Perrein-ettajani, Hanane; Bruneau, Mélanie; Akcha, Farida; Sussarellu, Rossana; Rouxel, Julien; Costil, Katherine; Decottignies, Priscilla; Cognie, Bruno; Châtel, Amélie; Mouneyrac, Catherine. |
| The impact of a microplastic (MP) mixture composed of polyethylene (PE) and polypropylene (PP) plastic particles, prepared from commercially available products, was evaluated in blue mussels Mytilus spp. exposed to three environmentally relevant concentrations: 0.008 μg L−1 (low), 10 μg L−1 (medium), and 100 μg L−1 (high). Organisms were exposed for 10 days followed by 10 days of depuration in clean seawater under controlled laboratory conditions. The evaluation of MP effects on mussel clearance rate, tissue structure, antioxidant defenses, immune and digestive parameters, and DNA integrity were investigated while the identification of plastic particles in mussel tissues (gills, digestive gland, and remaining tissues), and biodeposits (feces and... |
| Tipo: Text |
Palavras-chave: Microplastics; Polyethylene; Polypropylene; Mytilus; Oxidative stress; Biomarkers. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60089/63427.pdf |
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| Rondon, R.; Akcha, Farida; Alonso, P.; Menard, Dominique; Rouxel, Julien; Montagnani, Caroline; Mitta, Guillaume; Cosseau, C.; Grunau, C.. |
| 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... |
| Tipo: Text |
Palavras-chave: Mollusk; Oyster; Diuron; Transcriptomic; Ecotoxicology. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00318/42938/42438.pdf |
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| Registros recuperados: 12 | |
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