Claveau Julie, Monperrus Mathilde, Jarry Marc, Baudrimont Magalie, Gonzalez Patrice, Cavalheiro Joana, Mesmer-Dudons Nathalie, Bolliet Valérie
INRA, UMR 1224 Ecobiop, Aquapôle, 64310 Saint Pée sur Nivelle, France; Université de Pau et des Pays de L'Adour, UMR 1224 Ecobiop, UFR Sciences et Techniques Côte Basque, Anglet, France.
Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l'Environnement et les Matériaux, UMR 5254 CNRS, Université de Pau et des Pays de l'Adour, Hélioparc Pau Pyrénées, 2 av. P. Angot, 64053 9 Pau cedex 9, France.
Comp Biochem Physiol C Toxicol Pharmacol. 2015 May;171:15-27. doi: 10.1016/j.cbpc.2015.03.003. Epub 2015 Mar 20.
The effect of methylmercury (MeHg) on glass eels' propensity to migrate, mitochondrial activity and antioxidative defence systems was investigated. Marine glass eels were first sorted in an experimental flume according to their response to dusk. Fish responding to the decrease in light intensity by ascending in the water column and moving with or against the flow were considered as having a high propensity to migrate (migrant). Glass eels still sheltering at the end of the 24 h catching period were considered as having a low propensity to migrate and were called non-migrant. Migrant and non-migrant glass eels were then individually tagged and exposed to isotopically enriched (201)MeHg (50 ng L(-1)) for 11 days. The effect of contamination was studied on muscle fibre structure, and the expression level of genes involved in mitochondrial activity and antioxidative defence systems. To investigate the effect of MeHg on glass eel behaviour, migrant and non-migrant glass eels were sorted again and the bioaccumulation of (201)MeHg and its demethylation product ((201)Hg(II)) were determined for each individual. MeHg exposure increased activity in non-migrant glass eels but not migratory behaviour. Contamination affected mitochondrial structure and metabolism and suggests a higher oxidative stress and activation of antioxidative defence systems in non-migrant glass eels. Overall, our results suggest that exposure to MeHg might induce an increase in energy expenditure and a higher vulnerability to predation in non-migrant glass eels in the wild.
研究了甲基汞（MeHg）对玻璃鳗迁移倾向、线粒体活性和抗氧化防御系统的影响。首先，在实验水槽中根据海洋玻璃鳗对黄昏的反应进行分类。那些通过在水柱中上升并随水流或逆水流移动来响应光强度降低的鱼被认为具有高迁移倾向（洄游者）。在24小时捕捞期结束时仍躲在隐蔽处的玻璃鳗被认为迁移倾向低，被称为非洄游者。然后对洄游和非洄游的玻璃鳗分别进行标记，并使其暴露于同位素富集的（201）MeHg（50 ng L(-1)）中11天。研究了污染对肌肉纤维结构以及参与线粒体活性和抗氧化防御系统的基因表达水平的影响。为了研究MeHg对玻璃鳗行为的影响，再次对洄游和非洄游的玻璃鳗进行分类，并测定每个个体中（201）MeHg及其去甲基化产物（（201）Hg(II)）的生物累积情况。MeHg暴露增加了非洄游玻璃鳗的活性，但没有影响洄游行为。污染影响了线粒体结构和代谢，并表明非洄游玻璃鳗中存在更高的氧化应激和抗氧化防御系统的激活。总体而言，我们的结果表明，在野外，暴露于MeHg可能会导致非洄游玻璃鳗的能量消耗增加以及被捕食的脆弱性更高。
