Impacts of contaminants on the health of aquatic organisms

我申请NSERC继续我的长期研究目标，即调查暴露在污染物中对水生生物健康的影响。在这项研究中，我建议研究：i)影响污染物在鱼类和海洋哺乳动物中的生物积累和代谢的因素，以及ii)暴露在污染物中的鱼观察到的生物效应的机制。关于第一个研究目标，我们将研究相对水溶性的污染物在鱼类体内生物积累的可能性。我们将利用实验室和野外研究，评估水溶性污染物是否可以从水中进入血浆，并从那里进入其他组织。我们还将研究海洋哺乳动物对污染物的吸收和代谢。具体而言，我们将确定环海豹和北极熊血浆中羟基-多氯联苯化合物(即促甲状腺代谢物)的水平是否与脂肪中的多氯联苯浓度有关，或与动物的年龄、性别或健康状况有关。关于第二个研究目标，即研究污染物对鱼类的生物影响，我们将扩大与我们先前在五大湖下游几个地点收集的大量白花鱼“两性”睾丸相关的研究方案。利用实验室和野外研究，我们将研究寄生虫对鱼类睾丸的损害与性腺间性发育之间的可能关系。最后，作为我们之前对暴露于杀菌剂五氯硝基苯(PCNB)的日本青竹早期生命阶段发育异常的观察的继续，我们将调查这些异常是否由纤维连接蛋白的产生或结合特性改变引起，纤维连接蛋白是脊椎动物早期发育中对组织分化至关重要的糖蛋白。我们将利用我们之前开发的利用鲑鱼性腺细胞产生纤维连接蛋白的体外实验，以及一种使用二维异核核磁共振光谱来确定PCNB与纤维连接蛋白结合的新技术。

I am applying to NSERC to continue my long-term research goal of investigating the impacts of exposure to contaminants on the health of aquatic organisms.  In this study, I propose to examine: i) factors that influence the bioaccumulation and metabolism of contaminants in fish and marine mammals, and ii) the mechanisms for biological effects observed in fish exposed to contaminants. With respect to the first research goal, we will study the potential for relatively water-soluble contaminants to bioaccumulate in fish. Using both laboratory and field studies, we will evaluate whether water soluble contaminants can move from water into blood plasma, and from there into other tissues.  We will also study the uptake and metabolism of contaminants in marine mammals.  Specifically, we will determine whether the levels of hydroxy-PCB compounds (i.e. thyroidogenic metabolites) in the blood plasma of ringed seals and polar bears is related to concentrations of PCBs in the fat, or to the age, sex or condition of the animals. In relation to the second research goal to study the biological effects of contaminants in fish, we will extend the research programme related to our previous observations of large numbers of "inter-sex" testes in white perch collected at several locations in the lower Great Lakes. Using both laboratory and field studies, we will examine the possible relationship between parasite-induced damage to the testis of fish and the development of gonadal inter-sex.  Finally, as a continuation of our previous observations of developmental abnormalities in early life stages of Japanese medaka exposed to the fungicide, pentachloronitrobenzene (PCNB), we will investgate whether these abnormalities are caused by alterations to the production or binding properties of fibronectin, a glycoprotein important for the differentiation of tissues in the early development of vertebrates. We will utilize our previously developed in vitro assay for fibronectin production with trout gonadal cells, and a novel technique to determine binding of PCNB to fibronection using two-dimensional heteronuclear NMR spectroscopy.