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如何在不同水平的生物组织（分子、细胞和整个生物体）中整合，以支持生物体在自然环境中的表现。候鸟是研究这些综合问题的优秀模型系统，因为候鸟是令人印象深刻的耐力运动员，它们主要使用脂肪来为飞行提供燃料，饮食强烈影响储存脂肪的脂肪酸组成，进而影响运动期间整个动物的能量。鸟类依靠脂肪酸氧化来进行高强度耐力运动是值得注意的，部分原因是它增加了氧化应激，而氧化应激必须由鸟类的抗氧化防御系统来处理。事实上，人体健康需要膳食抗氧化剂来对抗正常代谢过程中产生的自由基，许多当代医学研究都集中在了解膳食抗氧化剂如何促进人体健康上。这两个拟议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运动鸟类的脂肪代谢，鸟类的抗氧化防御系统如何响应与运动相关的氧化应激增加，以及脂肪代谢和抗氧化防御之间的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的本科生（圣心大学）和R1研究（罗德岛大学）机构成功的合作研究和教学项目的基础上。拟议的研究将允许URI的研究生在SHU学习脂肪酸分析，SHU的本科生将帮助URI的研究人员进行实地工作，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。这两所学院将继续其培养本科生和研究生的传统，利用URI的加强多样性倡议和SHU与市中心布里奇波特（CT）公立学校系统的合作。拟议的研究还将加强与新英格兰南部为非政府组织（如大自然保护协会、奥杜邦和当地土地信托）工作的生物学家的既定合作，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研究所的同事的国际合作（由美国国家科学基金会国际科学与工程（ISE）部门联合支持）。目前，人们对膳食抗氧化剂及其如何促进人体健康非常感兴趣。候鸟为研究饮食抗氧化剂和脂肪在运动过程中脂肪代谢中的作用提供了一个有趣的模型系统，因为鸟类的自由基生成率相对较低，尽管它们的代谢率较高，并且比体型相似的哺乳动物的最长寿命要长得多。此外，鸟类迁徙的模式与疾病（例如禽流感）的传播有关，候鸟的数量正在减少，因为它们在迁徙期间失去了适合中途停留的栖息地。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.