Laboratoire des Sciences de l'Environnement Marin, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Place Copernic, Technopôle Brest-Iroise, 29280 Plouzané, France.
Aquat Toxicol. 2010 Apr 15;97(2):96-108. doi: 10.1016/j.aquatox.2009.12.006. Epub 2009 Dec 11.
The effects of an artificial bloom of the toxin-producing dinoflagellate, Alexandrium minutum, upon physiological parameters of the Pacific oyster, Crassostrea gigas, were assessed. Diploid and triploid oysters were exposed to cultured A. minutum and compared to control diploid and triploid oysters fed T. Isochrysis. Experiments were repeated twice, in April and mid-May 2007, to investigate effects of maturation stage on oyster responses to A. minutum exposure. Oyster maturation stage, Paralytic Shellfish Toxin (PST) accumulation, as well as several digestive gland and hematological variables, were assessed at the ends of the exposures. In both experiments, triploid oysters accumulated more PSTs (approximately twice) than diploid oysters. Significant differences, in terms of phenoloxidase activity (PO) and reactive oxygen species (ROS) production of hemocytes, were observed between A. minutum-exposed and non-exposed oysters. PO in hemocytes was lower in oysters exposed to A. minutum than in control oysters in an early maturation stage (diploids and triploids in April experiment and triploids in May experiment), but this contrast was reversed in ripe oysters (diploids in May experiment). In the April experiment, granulocytes of oysters exposed to A. minutum produced more ROS than those of control oysters; however, in the May experiment, ROS production of granulocytes was lower in A. minutum-exposed oysters. Moreover, significant decreases in free fatty acid, monoacylglycerol, and diacylglycerol contents in digestive glands of oysters exposed to A. minutum were observed. Concurrently, the ratio of reserve lipids (triacylglycerol, ether glycerides and sterol esters) to structural lipids (sterols) decreased upon A. minutum exposure in both experiments. Also, several physiological responses to A. minutum exposure appeared to be modulated by maturation stage as well as ploidy of the oysters.
研究了产毒素甲藻亚历山大藻（Alexandrium minutum）人工水华对太平洋牡蛎（Crassostrea gigas）生理参数的影响。将二倍体和三倍体牡蛎暴露于培养的亚历山大藻中，并与摄食 T. Isochrysis 的对照二倍体和三倍体牡蛎进行比较。2007 年 4 月和 5 月中旬重复进行了两次实验，以研究牡蛎成熟阶段对暴露于亚历山大藻的反应的影响。在实验结束时评估了牡蛎成熟阶段、麻痹性贝类毒素（PST）积累以及几个消化腺和血液学变量。在两次实验中，三倍体牡蛎积累的 PST 量（约两倍）都高于二倍体牡蛎。暴露于亚历山大藻的牡蛎与未暴露的牡蛎之间在酚氧化酶活性（PO）和血细胞中活性氧物质（ROS）的产生方面存在显著差异。在早期成熟阶段（4 月实验中的二倍体和三倍体以及 5 月实验中的三倍体），暴露于亚历山大藻的牡蛎的血细胞 PO 低于对照组牡蛎，但在成熟牡蛎中，这种差异则相反（5 月实验中的二倍体）。在 4 月实验中，暴露于亚历山大藻的牡蛎的粒细胞产生的 ROS 多于对照组；然而，在 5 月实验中，暴露于亚历山大藻的牡蛎的粒细胞中 ROS 的产生则较低。此外，还观察到暴露于亚历山大藻的牡蛎消化腺中的游离脂肪酸、单酰甘油和二酰甘油含量显著降低。同时，在两个实验中，暴露于亚历山大藻后，储备脂质（三酰甘油、醚甘油酯和固醇酯）与结构脂质（固醇）的比例降低。此外，暴露于亚历山大藻后的几种生理反应似乎受到牡蛎成熟阶段和倍性的调节。
