LiT: Interactive effects of multiple environmental stressors on mitochondrial metabolism and bioenergetics in a model marine ectotherm, Crassostrea virginica

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。虽然河口和沿海地区是海洋最多产的地区之一，但由于盐度、温度、pH值、氧含量的自然变化以及污染物和营养物倾倒造成的人为压力，河口和沿海地区往往遭受高度的环境压力，这些压力可能对海洋生物造成毒性和/或导致缺氧的“死亡区”。海洋生物的生存取决于其压力耐受机制的灵活性，这种机制能够适应大多数自然变化，但人为变化发生得太快，无法进行进化适应。能量代谢在这些适应中起着关键作用。目前，由于大多数研究都集中在单一应激源的影响上，因此，在环境现实背景下，多种应激源对海洋生物能量代谢的相互作用尚未得到很好的理解。本研究将通过探索河口和海岸带常见的三种应激源（间歇性缺氧或缺氧、微量金属镉和温度应激）对模式海洋软体动物东方牡蛎（Crassostrea virginica）能量代谢的相互作用的基本生理和分子机制，帮助缩小这一重大知识空白。牡蛎是主要的生态系统建设者，在美国东部沿海各州的经济中发挥着重要作用，它们可以在极端环境中生存，这使它们成为本研究的优秀模式生物。该研究涉及有氧（线粒体）和无氧代谢的综合分析，并将通过提供环境现实应激暴露期间代谢变化的综合图景，从而显著推进代谢生理学领域，这些应激暴露可以在数量和质量上不同于单一应激源的影响。此外，由于能量代谢对所有生物的生存和耐受性至关重要，线粒体功能在进化过程中高度保守，因此该项目结果可以推断出牡蛎以外的生物，从而对海洋无脊椎动物线粒体应激反应的基本机制产生重要的新见解。该项目将对教育产生重要影响，涉及本科生、研究生、K-12学生和博士后，包括妇女和代表性不足的少数民族；加强北卡罗来纳大学夏洛特分校跨学科生物学博士项目对环境的关注；促进北卡罗来纳大学夏洛特分校与当地少数民族大学约翰逊·c·史密斯大学之间积极的合作项目和学生交流。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).While among the most productive areas of the ocean, estuaries and coastal zones often suffer a high degree of environmental stress from naturally-occurring changes in salinity, temperature, pH, oxygen content as well as manmade stresses caused by the dumping of pollutants and nutrients, which can cause toxicity in marine organisms and/or lead to oxygen-depleted 'dead zones'. The survival of marine organisms depends on the flexibility of their stress tolerance mechanisms, which adapt to handle most natural changes, but manmade changes happen too quickly for evolutionary adaptation to occur. Energy metabolism plays a key role in these adaptations. Currently, the interactive effects of multiple stressors on energy metabolism of marine organisms in an environmentally-realistic context are not well understood because most studies focus on the effects of a single stressor. This study will help close this significant gap in knowledge by exploring the basic physiological and molecular mechanisms of the interactive effects of three stressors commonly found in estuaries and coastal zones (intermittent anoxia, or lack of oxygen; a trace metal, cadmium; and temperature stress) on the energy metabolism of a model marine mollusk, the eastern oyster Crassostrea virginica. Oysters, which are major ecosystem builders and play an important role in the economies of the eastern US coastal states, can survive environmental extremes, making them excellent model organisms for this study. The study involves a comprehensive analysis of aerobic (mitochondrial) and anaerobic metabolism and will significantly advance the field of metabolic physiology by providing an integrative picture of metabolic change during environmentally-realistic stress exposures that can be quantitatively and qualitatively different than the effects of single stressors. Moreover, because energy metabolism is central to the survival and stress tolerance of all organisms and mitochondrial functions are highly conserved in evolution, the project results can be extrapolated beyond oysters to yield important new insights into the fundamental mechanisms of mitochondrial stress responses of marine invertebrates in general. This project will have important educational impacts by involving undergraduate, graduate, K-12 students and a post-doc, including women and underrepresented minorities, into research; strengthening an environmental focus in the interdisciplinary Ph.D. program in Biology at the University of North Carolina at Charlotte; and fostering active collaborative programs and student exchanges between UNC Charlotte and Johnson C. Smith University, a local minority undergraduate-level university.