TY - JOUR T1 - Exposure to toxic Alexandrium minutum activates the detoxifying and antioxidant systems in gills of the oyster Crassostrea gigas A1 - Fabioux,Caroline A1 - Sulistiyani,Yeni A1 - Haberkorn,Hansy A1 - Hegaret,Helene A1 - Amzil,Zouher A1 - Soudant,Philippe AD - Univ Bretagne Occidentale, Lab Sci Environm Marin LEMAR, Inst Univ European Mer, UMR 6539,CNRS UBO IRD IFREMER, F-29280 Plouzane, France. AD - IFREMER, Lab Phycotoxines, F-44311 Nantes, France. UR - https://doi.org/10.1016/j.hal.2015.07.003 DO - 10.1016/j.hal.2015.07.003 KW - Crassostrea gigas KW - Alexandrium minutum KW - Paralytic shellfish toxins KW - Antioxidant enzymes KW - Detoxification enzymes KW - mRNA N2 - Harmful algal blooms of Alexandrium spp. dinoflagellates regularly occur in French coastal waters contaminating shellfish. Studies have demonstrated that toxic Alexandrium spp. disrupt behavioural and physiological processes in marine filter-feeders, but molecular modifications triggered by phycotoxins are less well understood. This study analyzed the mRNA levels of 7 genes encoding antioxidant/detoxifying enzymes in gills of Pacific oysters (Crassostrea gigas) exposed to a cultured, toxic strain of A. minutum, a producer of paralytic shellfish toxins (PST) or fed Tisochrysis lutea (T. lutea, formerly Isochrysis sp., clone Tahitian (T. iso)), a non-toxic control diet, in four repeated experiments. Transcript levels of sigma-class glutathione S-transferase (GST), glutathione reductase (GR) and ferritin (Fer) were significantly higher in oysters exposed to A. minutum compared to oysters fed T. lutea. The detoxification pathway based upon glutathione (GSH)-conjugation of toxic compounds (phase II) is likely activated, and catalyzed by GST. This system appeared to be activated in gills probably for the detoxification of PST and/or extra-cellular compounds, produced by A. minutum. GST, GR and Fer can also contribute to antioxidant functions to prevent cellular damage from increased reactive oxygen species (ROS) originating either from A. minutum cells directly, from oyster hemocytes during immune response, or from other gill cells as by-products of detoxification. Y1 - 2015/09 PB - Elsevier Science Bv JF - Harmful Algae SN - 1568-9883 VL - 48 SP - 55 EP - 62 ID - 38601 ER -