Collaborative Research: Fat metabolism and oxidative stress in migratory birds

生物-环境相互作用的一个基本方面是了解不同的生理和生化过程是如何跨不同层次的生物组织(分子、细胞和整个有机体)整合起来的，以支持生物在其自然环境中的表现。候鸟是研究这种综合问题的极好的模型系统，因为候鸟是令人印象深刻的耐力运动员，主要使用脂肪来为它们的飞行提供燃料，而饮食强烈地影响储存脂肪的脂肪酸组成，进而在运动中影响整个动物的能量。依赖脂肪酸氧化来为鸟类的高强度耐力运动提供燃料是值得注意的，部分原因是它增加了必须由鸟类的抗氧化防御系统处理的氧化应激。事实上，人类健康需要随时供应的饮食抗氧化剂来对抗作为正常新陈代谢的一部分而产生的自由基，许多当代医学研究都集中在了解饮食抗氧化剂如何促进人类健康。这两个拟议的研究项目的主要目标是通过实验确定某些必需脂肪酸如何刺激锻炼中的鸟类的脂肪代谢，鸟类的抗氧化防御系统如何应对与锻炼相关的氧化应激增加，以及脂肪代谢和抗氧化防御之间的这种相互作用如何取决于秋季和春季迁徙期间季节性需求的变化。拟议的研究建立在一个主要是本科生(圣心大学)和R1研究(罗德岛大学)机构的成功的合作研究和教学计划的基础上。这项拟议的研究将允许URI研究生在SHU学习脂肪酸分析，SHU本科生将帮助URI研究人员进行野外工作、圈养鸟类研究和实验室分析，以测量作为野生鸟类健康指标的血浆代谢物。这两个私人投资机构将继续他们的传统，通过利用URI的增强多样性倡议和SHU与市中心布里奇波特(CT)公立学校系统的合作来培训本科生和研究生。拟议的研究还将加强与新英格兰南部为自然保护协会、奥杜邦和当地土地信托基金等非政府组织工作的生物学家的现有合作，以及与西安大略大学鸟类研究高级设施和德国马克斯·普兰克鸟类学研究所的同事的国际合作(由NSF国际科学与工程(ISE)部门联合支持)。目前，公众对饮食抗氧化剂及其如何促进人类健康非常感兴趣。候鸟为研究饮食抗氧化剂和脂肪在运动过程中对脂肪代谢的作用提供了一个有趣的模型系统，因为尽管鸟类的代谢率较高，最长寿命也比类似体型的哺乳动物高得多，但鸟类的自由基生成率相对较低。此外，鸟类迁徙的模式与疾病的传播(例如禽流感)有关，由于候鸟在迁徙过程中失去了合适的栖息地作为中途停留地点，候鸟数量正在下降。PIS在新英格兰南部的长期合作实地研究保证了研究结果将继续用于土地保护和管理工作。

A fundamental aspect of organism-environment interactions is understanding how different physiological and biochemical processes are integrated across different levels of biological organization (molecular, cellular and whole-organism) to support an organism's performance in its natural environment. Migratory birds are excellent model systems for investigating such integrative questions because migratory birds are impressive endurance athletes that use primarily fats to fuel their flights, and diet strongly influences fatty acid composition of stored fat that in turn affects whole-animal energetics during exercise. Reliance on fatty acid oxidation to fuel high-intensity endurance exercise in birds is remarkable in part because it increases oxidative stress which must be dealt with by the bird's antioxidant defense system. In fact, human health requires a ready supply of dietary antioxidants to combat the free radicals produced as part of normal metabolism, and much contemporary medical research is focused on understanding how dietary antioxidants promote human health. The primary goals of the two proposed research projects are to experimentally determine how certain essential fatty acids stimulate fat metabolism in exercising birds, how the antioxidant defense system of birds responds to the increased oxidative stress associated with exercise, and how this interaction between fat metabolism and antioxidant defenses depends on changes in seasonal demands during fall and spring migration. The proposed research builds on the successful collaborative research and teaching programs at a primarily undergraduate (Sacred Heart University) and R1 research (University of Rhode Island) institution. The proposed research will allow URI graduate students to learn fatty acid analysis at SHU, and SHU undergraduates will help URI researchers with field work, captive bird studies, and laboratory analyses for measuring plasma metabolites as indicators of health in wild birds. The two PIs will continue their tradition of training undergraduate and graduate students by utilizing URI's enhancing diversity initiatives and SHU's collaborative with the inner-city Bridgeport (CT) public school system. The proposed research will also strengthen established collaborations with biologists in southern New England working for NGOs such as The Nature Conservancy, Audubon, and local land trusts as well as international collaborations (jointly supported by NSF International Science and Engineering (ISE) Section) with colleagues at the Advance Facility for Avian Research, University of Western Ontario, and Max Plank Institute for Ornithology, Germany. Currently, there is much public interest in dietary antioxidants and how they promote human health. Migratory birds offer an interesting model system for studying the role of dietary antioxidants and fats on fat metabolism during exercise because birds have relatively low rates of free radical production in spite of higher metabolic rates and much higher maximum longevity than mammals of similar body size. In addition, patterns of bird migration have been implicated in the dispersal of disease (e.g. avian flu) and migratory bird populations are declining due to the loss of suitable habitat for stopover sites during their migration. The PIs longstanding collaborative field studies in southern New England guarantees the results will continue to be used for land conservation and management efforts.