Effect of chronic exposure to zinc in young spats of the Pacific oyster ( Crassostrea gigas )

• Published in: Environmental Toxicology and Chemistry
• Main Authors: Devos, Alexandre, Voiseux, Claire, Caplat, Christelle, Fievet, Bruno
• Other Authors: Laboratoire d'écotoxicologie des radionucléides (IRSN/PRP-ENV/SERIS/LECO), Service de Recherche et d'Expertise sur les Risques environnementaux (IRSN/PRP-ENV/SERIS), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: Zinc; Chronic exposure; Metallothionein; Gene expression; Oyster spat; [SDE]Environmental Sciences; Pacific; Crassostrea gigas; Pacific oyster
• Online Access: https://hal-normandie-univ.archives-ouvertes.fr/hal-02314079; https://doi.org/10.1002/etc.2012

International audience The marine coastal environment is exposed to a mixture of environmental pollutants of anthropogenic origin, resulting in chronic low concentrations of contaminants. As a consequence, most coastal marine species are exposed to low doses of such pollutants during their entire life. Many marine species live for years in their natural environment, whereas they do not under laboratory exposure conditions. Using early stages of development in laboratory work allows animals to be chronically exposed from an early age over a reasonable experiment period. In the present study, the authors investigated the effect of chronic exposure to zinc in spats of the Pacific oyster (Crassostrea gigas), from metamorphosis up to 10 weeks. The authors investigated integrated biological endpoints that would account for the apparent general health of the animals as well as molecular markers showing more subtle effects that could potentially go unnoticed at a biologically integrated level. The authors measured in parallel both growth and the transcriptional level of target stress genes. Growth was monitored by image analysis of large samples to avoid high variability and ensure statistical robustness. A dose–response relationship was derived from growth data, yielding a median effective concentration (EC50) of 7.55 µM. Stress genes selected on the basis of available RNA sequences in C. gigas included genes involved in chaperone proteins, oxidative stress, detoxification, and cell cycle regulation. Out of nine stress target genes, only metallothionein displayed overexpression in response to high levels of zinc. Environ. Toxicol. Chem. 2012; 31: 2841–2847. © 2012 SETAC