Collaborative Research: Extending the potential for hydrogen isotope tracers in ecology: experiments, biochemistry and field studies

动物组织的氢同位素组成已成为研究动物运动和栖息地利用研究的宝贵工具。 然而，动物生态学家自信地将同位素分析应用于生态问题所需的生化基础尚未得到充分揭示。 该项目将通过增进我们对控制脊椎动物组织中同位素组成的基本过程的理解来解决这一知识差距。 新的方法将用于分析动物组织中单个氨基酸的化合物特异性同位素，并确定氢是否可以直接从膳食氨基酸进入组织。 将在一系列实验室实验中探索负责确定在大量组织中观察到的氢同位素模式的生物合成机制。 这项研究的结果将解决动物组织同位素辨别的变化幅度和程度，以及氢从食物和水中掺入动物组织的生化机制。 为了完成这项工作，罗非鱼将在水箱中饲养，水箱中的水和食物成分具有独特且受控的同位素组成。将测量单个氨基酸的同位素组成，特别是那些生长必需的氨基酸，以追踪从膳食蛋白质、碳水化合物、脂质和水进入鱼组织的情况。 该研究将扩展到以黑喉蓝莺为基础的种群研究，其中羽毛、骨骼和肝脏组织中单个氨基酸的氢同位素组成将从横跨北美大陆范围的三个地点进行测量。该项目的结果将推进一种新的方法，并为动物生态和行为研究的同位素方法提供基础知识。 该项目将开发和教授同位素生态学研究生课程，让本科生参与实验室研究，并对高中生物学课程进行推广，以促进对生化生态学的理解。 它还将支持旨在提高人们对稳定同位素在生物科学中的潜在用途的认识的研讨会，并为未来与几个拉丁美洲国家的研究人员的合作奠定基础。

The hydrogen isotopic composition of animal tissues has become as a valuable tool in the investigation of animal movements and the study of habitat use. However, the biochemical foundation needed for animal ecologists to apply isotopic analyses to ecological problems with confidence has yet to be adequately revealed. This project will address that knowledge gap by advancing our understanding of fundamental processes controlling isotopic composition in tissues of vertebrates. New methodologies will be applied to analyze compound-specific isotopes of individual amino acids in animal tissues and to determine whether hydrogen can be directly routed from dietary amino acids into tissues. Biosynthetic mechanisms responsible for determining hydrogen isotope patterns observed in bulk tissues will be explored in a series of laboratory experiments. Results from this research will address the magnitude and degree of variation in isotope discrimination for animal tissues, and the biochemical mechanism of hydrogen incorporation into an animal's tissue from its food and water. To accomplish this work, the fish species tilapia will be reared in tanks with water and food components having unique and controlled isotopic compositions. The isotopic composition of individual amino acids, particularly those that are indispensible for growth, will be measured to trace incorporation from dietary protein, carbohydrate, lipid, and water into fish tissues. The research will be extended to a population-based study of black-throated blue warblers, for which the hydrogen isotopic composition of individual amino acids from feather, bone, and liver tissues will be measured from three locations that span the continental range for this bird species in North America. Results from this project will advance a new methodology and provide foundational knowledge for isotopic approaches to the study of animal ecology and behavior. The project will develop and teach a graduate level course on isotopic ecology, involve undergraduate students in the laboratory research, and conduct outreach to high school biology classes to foster understanding of biochemical ecology. It will also support workshops designed to raise awareness of the potential uses of stable isotopes in the biological sciences and set the stage for future collaboration with researchers in several Latin American countries.