Project 4: Biotransformation Gene-Environment Interactions in Coho Salmon

美国西部的太平洋鲑鱼数量明显减少。尤其令人担忧的是，暴露于某些杀虫剂和痕量金属中的鲑鱼会造成亚致命性神经损伤。这些行为影响包括失去对捕食者的检测和猎物的选择，改变繁殖时机和失去归宿。在个体中观察到的上述神经行为影响现在与群体影响有关。鲑鱼嗅觉系统是环境化学品神经毒性的敏感目标，包括超级基金网站常见的金属和杀虫剂。然而，对鱼类化学嗅觉神经毒性的机制知之甚少。我们第一个供资周期的研究产生了重要的发现，我们将在竞争更新中详细探讨这些发现。具体地说，我们知道：1)鲑鱼的嗅觉组织是化学生物转化的重要部位，尤其是细胞色素P4503A和黄素单加氧酶(FMO)似乎介导了有机磷生物转化中组织和化合物的特异性差异，并可能对神经毒性产生影响。2)模型超级基金有机磷化学物质(毒死磷)和金属(铜)的嗅觉损伤涉及嗅觉信号转导通路的中断。然而，铜主要影响G蛋白偶联的嗅觉受体信号，可能是通过氧化应激，而毒死蜱激活参与抑制嗅觉信号转导的基因，3)转录特征可以帮助我们识别与混合物相关的独特基因靶点，以及区分金属和有机磷驱动的影响。根据我们的发现，此次竞争性更新的目标是：1)使用cDNA克隆、重组蛋白表达、微阵列分析和酶学方法确定嗅觉细胞色素P3A和黄素单加氧酶在从淡水到咸水的鲑鱼移动过程中对有机磷的神经毒性所起的作用；2)使用原位杂交和免疫组织化学分析结合行为研究来了解氧化应激在铜和镉介导的嗅觉损伤中的作用；3)使用蛋白质组学方法来确定和区分铜和毒死磷的重要嗅觉蛋白质靶标；4)使用上述研究产生的一套嗅觉生物标记物来评估通过Superfund站点迁徙的鲑鱼的亚致死嗅神经毒性。

Pacific salmon populations have declined markedly in the Western United States. Of particular concern has been sublethal neurological injury occurring in salmon exposed to certain pesticides and trace metals. These behavioral impacts include loss of predator detection and prey selection, altered reproductive timing and loss of homing. These aforementioned neurobehavioral effects observed in individuals are now linked to population impacts. The salmon olfactory system is a sensitive target for the neurotoxicity of environmental chemicals, including metals and pesticides commonly found in Superfund sites. However, little is known about the mechanisms of chemical olfactory neurotoxicity in fish. Studies from our first funding cycle have produced important findings that will be explored in detail in our competitive renewal. Specifically, we know that: 1) the olfactory tissues of salmon are important site of chemical biotransformation, and in particular, cytochrome P4503A and flavin monooxygenases (FMO) appear to mediate tissue- and compound-specific differences in organophosphate biotransformation with potential impacts on neurotoxicity, 2) the olfactory injury by a model superfund organophosphate chemical (chlorpyrifos) and metal (copper) involves disruption of olfactory signal transduction pathways. However, copper primarily impacts G-protein coupled olfactory receptor signaling, likely through oxidative stress, whereas chlorpyrifos activates genes involved in the inhibition of olfactory signal transduction, and 3) transcriptional signatures can help us identify unique gene targets relevant to mixtures, as well differentiating metal- and organophosphate-driven affects. Based upon our findings, the objectives of the competing renewal are to: 1) use cDNA cloning, recombinant protein expression, microarray analysis and enzymatic approaches to determine the role of olfactory CYP3A and flavin monooxygenases in organophosphate neurotoxicity in salmon during movement from freshwater to saltwater, 2) use in situ hybridization and immunohistochemistry analyses coupled with behavioral studies to understand the role of oxidative stress in copper and cadmium-mediated olfactory injury, 3) use proteomics approaches to identify and discriminate important olfactory protein targets of copper and chlorpyrifos, 4) use a suite of olfactory biomarkers generated from the aforementioned studies to assess sublethal olfactory neurotoxicity in salmon migrating through Superfund sites.