MicroRNA and multiple stressors: A mechanistic approach to understanding environmental stressor impacts in fish.

世界范围内的河流、湖泊和海洋在短期和长期内都面临着广泛而复杂的水量和水质威胁。城市中心的发展和水资源利用的增加意味着栖息地的丧失和改变以及随之而来的物种构成的变化，以及废水和农业径流造成的水生污染物水平的增加。这些众多的威胁不是独立的，而是累积在一起改变我们的生态系统。我们的水环境和依赖它们的水供应必须保持健康，以确保生态系统的可持续性。然而，我们这样做的能力受到我们理解和预测这些威胁产生的各种压力如何相互作用以导致变化的能力的限制。虽然这些挑战中的每一个都对水生生态系统构成了有案可查的问题，并影响到使用这些水体的每个人，但令人担忧的是，这些影响的组合将对这些环境，更具体地说，对生活在其中的水生生物造成更重大的挑战。许多法规、政策、监测和补救方案仅基于对单一因素(例如，一种特定污染物)的了解，因此是不够的。基于此，我的研究计划专注于扩大我们对环境中发现的多种混合应激源对水生物种，特别是硬骨鱼表观遗传机制的影响的基本理解。通过采取从DNA到整个动物功能和健康的综合方法，我的研究计划专注于表观遗传调节器，如microRNA(MiRNA)，它驱动斑马鱼暴露在多种应激源(新出现的污染物/气候应激源)下呈现的适应或不适应表型。我的研究将集中于与气候变化(温度)相关的非生物因素以及一种新出现的有机污染物(文拉法辛，一种令人担忧的主要药物污染物)，这些污染物已被证明影响了许多鱼类物种。这一新的方法将揭示与线粒体破坏相关的miRNA机制，这是我们以前在混合应激源暴露下看到的。此外，采取性别特异性的方法，我们将确定miRNA的男性和女性贡献及其对后代的影响，这将提供一些初步证据，说明性别特异性(男性与女性)、成人生活史暴露于环境应激源如何影响后代。通过我的计划产生的结果将有助于识别能量和性别特定的miRNA生物标记物，这些生物标记物可以翻译成加拿大的关键哨兵和重要的经济物种，如鲑鱼，识别的生物标记物将被保护管理者用来评估和预测敏感流域混合应激源对加拿大淡水物种保护的影响。

Worldwide rivers, lakes, and oceans face extensive and complex threats to water quantity and quality both in the short and long term. The growth of urban centres and the increased use of our water resource means lost and changed habitats and accompanying changes in species composition, and increased levels of aquatic contaminants from wastewater and agricultural runoff. These numerous threats are not independent but work cumulatively to alter our ecosystems. Our aquatic environments and the water supplies that depend on them must remain healthy to ensure ecosystem sustainability. However, our ability to do so is limited by our capacity to understand and predict how the various stressors resulting from these threats interact to cause change. While each of these challenges poses documented problems for aquatic ecosystems and affects everyone using these bodies of water, the concern is that combinations of these effects will create even more significant challenges to these environments and, more specifically, aquatic organisms living in them. Many regulations, policies, monitoring and remediation programs are based on an understanding of only single factors (e.g., one specific pollutant) and are therefore inadequate. Based upon this, my research program is focused on expanding our fundamental understanding of the impact of multiple, mixed stressors, found within the environment upon epigenetic mechanisms in aquatic species, specifically teleost fishes. By taking an integrative approach spanning from DNA to whole animal function and fitness, my research program focuses on epigenetic modulators, like microRNA (miRNA), that drive the adaptive or maladaptive phenotypes presented by zebrafish that have been exposed to multiple stressors (emerging contaminants/climate stressors). My research will focus on abiotic factors associated with climate change (temperature) in combination with an emerging organic pollutant (venlafaxine, a major pharmaceutical pollutant of concern), which have been shown to impact numerous fish species. This novel approach will uncover the miRNA mechanisms associated with mitochondrial disruption that we have previously seen with mixed stressor exposures. Moreover, taking a sex-specific approach, we will identify the male and female contributions of miRNA and their influence on their progeny, which will provide some of the first evidence of how sex-specific (male vs female), adult life-history exposure to environmental stressors can influence offspring in future generations. The results generated through my program will aid in the identification of energetic and sex-specific miRNA biomarkers, which are translational to key sentinel and economically important species in Canada, such as salmonids, and identified biomarkers will be used by conservation managers to assess and predict the impact of mixed stressors in sensitive watersheds for the protection of Canada's freshwater species.