Maryoung Lindley A, Blunt Brian, Tierney Keith B, Schlenk Daniel
Department of Environmental Sciences, University of California, Riverside, CA 92521, United States.
Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2R3, Canada.
Aquat Toxicol. 2015 Apr;161:94-101. doi: 10.1016/j.aquatox.2015.01.026. Epub 2015 Jan 29.
Salmonid habitats can be impacted by several environmental factors, such as salinization, which can also affect salmonid tolerance to anthropogenic stressors, such as pesticides. Previous studies have shown that hypersaline acclimation enhances the acute toxicity of certain organophosphate and carbamate pesticides to euryhaline fish; however, sublethal impacts have been far less studied. The current study aims to determine how hypersaline acclimation and exposure to the organophosphate chlorpyrifos (CPF) impact salmonid olfaction. Combined acclimation and exposure to CPF was shown to impact rainbow trout olfaction at the molecular, physiological, and behavioral levels. Concurrent exposure to hypersalinity and 0.5μg/L CPF upregulated four genes (chloride intracellular channel 4, G protein zgc:101761, calcium calmodulin dependent protein kinase II delta, and adrenergic alpha 2C receptor) that inhibit olfactory signal transduction. At the physiological level, hypersalinity and chlorpyrifos caused a decrease in sensory response to the amino acid l-serine and the bile salt taurocholic acid. Combined acclimation and exposure also negatively impacted behavior and reduced the avoidance of a predator cue (l-serine). Thus, acclimation to hypersaline conditions and exposure to environmentally relevant concentrations of chlorpyrifos caused an inhibition of olfactory signal transduction leading to a decreased response to odorants and impairment of olfactory mediated behaviors.
鲑科鱼类的栖息地会受到多种环境因素的影响，比如盐碱化，这也会影响鲑科鱼类对人为应激源（如农药）的耐受性。先前的研究表明，高盐度驯化会增强某些有机磷和氨基甲酸酯类农药对广盐性鱼类的急性毒性；然而，亚致死影响的研究要少得多。当前的研究旨在确定高盐度驯化以及接触有机磷毒死蜱（CPF）如何影响鲑科鱼类的嗅觉。研究表明，同时进行CPF驯化和接触会在分子、生理和行为水平上影响虹鳟鱼的嗅觉。同时暴露于高盐度和0.5μg/L CPF会上调四个抑制嗅觉信号转导的基因（氯离子细胞内通道4、G蛋白zgc:101761、钙调蛋白依赖性蛋白激酶IIδ和肾上腺素能α2C受体）。在生理水平上，高盐度和毒死蜱导致对氨基酸L-丝氨酸和胆汁盐牛磺胆酸的感官反应降低。同时进行驯化和接触还对行为产生负面影响，并减少了对捕食者信号（L-丝氨酸）的回避。因此，适应高盐度条件并接触环境相关浓度的毒死蜱会导致嗅觉信号转导受到抑制，从而导致对气味剂的反应降低以及嗅觉介导行为受损。
