title: Cellular and biochemical responses of the oyster Crassostrea gigas to controlled exposures to metals and Alexandrium minutum.
abstract: Effects of simultaneous exposure of Pacific oyster, Crassostrea gigas, to both a harmful dinoflagellate that produces Paralytic Shellfish Toxins (PST), Alexandrium minutum, and cadmium (Cd) and copper (Cu), were assessed. Oysters were exposed to a mix of Cd-Cu with two different diets (i.e. A. minutum or Tisochrysis lutea) and compared to control oysters fed A. minutum or T. lutea, respectively, without metal addition. Metals and PST accumulations, digestive gland lipid composition, and cellular and biochemical hemolymph variables were measured after 4 days of exposure. Oysters exposed to Cd-Cu accumulated about thirty-six times less PSTs than oysters exposed to A. minutum alone. Exposure to Cd-Cu induced significant changes in neutral lipids (increase in diacylglycerol - DAG - and decrease in sterols) and phospholipids (decreases in phosphatidylcholine, phosphatidylethanolamine, cardiolipin and ceramide aminoethylphosphonate) of digestive gland suggesting that lipid metabolism disruptions and/or lipid peroxidation have occurred. Simultaneously, concentrations, percentages of dead cells and phenoloxidase activity of hemocytes increased in oysters exposed to metals while reactive oxygen species production of hemocytes decreased. Feeding on the harmful dinoflagellate A. minutum resulted in significant decreases in monoacylglycerol (MAG) and DAG and ether glycerides (EG), as well as significant increases in hemocyte concentration and phagocytic activity as compared to oysters fed T. lutea. Finally, the present study revealed that short-term, simultaneous exposure to Cd-Cu and A. minutum may induce antagonistic (i.e. hemocyte concentration and phagocytosis) or synergic (i.e. DAG content in digestive gland) effects upon cellular and tissular functions in oysters.
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Hansy
authors.initials: H
authors.lastname: Haberkorn
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Lambert
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Le Goïc
authors.affiliation: IFREMER Centre de Brest, Laboratoire de Physiologie des Invertébrés, Unité Physiologie Fonctionnelle des Organismes Marins, BP 70, 29280 Plouzané, France.
authors.forename: Claudie
authors.initials: C
authors.lastname: Quéré
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Bruneau
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Riso
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Auffret
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France. Electronic address: Philippe.Soudant@univ-brest.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Soudant
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D003300:Copper / Q000633:toxicity*; D049896:Crassostrea / Q000187:drug effects* / Q000378:metabolism; D004141:Dinoflagellida / Q000502:physiology*; D006434:Hemocytes / Q000187:drug effects; D008387:Marine Toxins / Q000378:metabolism / Q000633:toxicity*; D010587:Phagocytosis / Q000187:drug effects; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D008387:Marine Toxins; D014874:Water Pollutants, Chemical; D002104:Cadmium; D003300:Copper
keywords: Harmful algae; Metals; Oysters; Physiological effects; Toxin accumulation