Functional Transcriptomics of Native Canadian Fish Species

这些研究将侧重于描述调节加拿大淡水生态系统中本地鱼类繁殖的生物路径的特征，其变化可用作潜在健康风险的指标。这项拟议研究的目的是比较鱼类对与加拿大水体相关的模拟环境应激源的敏感性差异，并阐明这些差异的分子基础。目标鱼种是北方梭子鱼(Esox Lucius)和愚头鱼(Pimephales proelas，FHM)。被调查的应激源是暴露在雌激素化学物质中。雌激素在加拿大生态系统中被认为是令人关注的生殖毒物，雌激素潜力与许多人类活动有关，包括污水处理厂废水，最近与油砂工艺水有关。这项工作将研究转录组范围的基因表达模式和相关的进一步上游生理功能(卵黄蛋白原；性类固醇；类固醇合成/代谢；性腺和肝脏组织学和躯体指数；条件；大体形态；生育能力；繁殖力)，在野外和实验室条件下，以及在暴露于模型雌激素(乙烯雌二醇)后，使用基于互信息的生物网络分析。这将能够比较物种间生殖的分子调控和雌激素化学物质对生殖的干扰，并将能够评估特定物种的敏感性和确定生物靶标，以应对雌激素的暴露。这将代表着朝着更好地了解加拿大本土鱼类的基本生物学以及它们的环境变化如何影响它的方向迈出了重要的一步。这些数据将作为评估环境雌激素对加拿大淡水鱼物种影响的基础。最后，这项工作将开发特定的生物标记，以阐明雌激素干扰与鱼类长期适应相关的过程的机制。虽然只侧重于两种物种和一种模式化学品，但将制定的办法将适用于其他物种和应激源，因此，将对该领域具有普遍意义。

The studies will focus on the characterization of biological pathways that regulate reproduction in fish native to Canadian freshwater ecosystems, and alterations of which can be used as indicators of potential health risks. The aim of the proposed research is to compare differences in sensitivity of fishes to a model environmental stressor of relevance to Canadian water bodies, and to elucidate the molecular basis for these differences. Target fish species are the northern pike (Esox lucius) and the fathead minnow (Pimephales promelas, FHM). The stressor to be investigated is exposure to estrogenic chemicals. Estrogens are considered reproductive toxicants of concern in Canadian ecosystems, and estrogenic potentials are associated with numerous anthropogenic activities including sewage treatment plant effluents, and more recently with oil sands process water. This work will study transcriptome-wide gene expression patterns and associated further upstream physiological functions (vitellogenin; sex steroids; steroid synthesis/metabolism; gonad and liver histology and somatic indices; condition; gross morphology; fertility; fecundity) in both test species under field and laboratory conditions, and after exposure to a model estrogen (ethinylestradiol) using mutual information based biological network analyses. This will allow for comparison of molecular regulation of reproduction between species and its disruption by estrogenic chemicals, and will enable assessment of species-specific sensitivity and identification of biological targets in response to exposure to estrogens. This will represent an important step towards better understanding of the basic biology of fishes native to Canada, and how it can be influenced by changes in their environment. The data will serve as a foundation for the assessment of the impacts of environmental estrogens to Canadian freshwater fish species. Finally, this work will develop specific biological markers to elucidate the mechanism by which estrogens interfere with processes relevant to the long-term fitness of fish. While focusing on only two species and one model chemical, the approaches to be developed will be applicable to other species and stressors, and thus, will be of general relevance to the field.