International Research Fellowship Program: Mechanisms for Increased Intake of Toxic Plants by Marsupial Herbivores

0301898索伦斯国际研究奖学金计划使美国科学家和工程师能够在国外进行3至24个月的研究。该项目的奖项提供了联合研究的机会，并提供了使用国外独特或互补的设施、专业知识和实验条件的机会。该奖项将资助珍妮弗·S·索伦森博士与澳大利亚国立大学的威廉·J·福利博士和塔斯马尼亚大学的斯图尔特·麦克莱恩博士合作的为期24个月的研究奖学金。哺乳动物食草动物(10种)很少食用单一植物物种，这归因于这种饮食中存在高浓度的植物毒素。很少有经验性的工作研究哺乳动物草食动物用来应对植物毒素的机制。这个项目将包括研究毒素吸收在哺乳动物草食动物摄取有毒植物中所起的作用。饮食专家每单位摄入的毒素将比普通专家吸收的毒素少的假设将得到检验，方法是测量喂养有毒植物桉树的专家(考拉)和多面手(棕尾负鼠和山毛尾负鼠)的毒素摄入量、血液毒素浓度和粪便毒素排泄量。据预测，专家对毒素的吸收减少将导致更多的毒素摄入，但血液中的毒素浓度会更低。PI在新单胞菌属中发现了专家比多面手吸收更少的植物毒素的证据，拟议的研究将通过比较来自不同家族的专家和多面手的哺乳动物草食动物之间的毒素吸收和调节毒素吸收的机制来进一步扩大这些结果。

0301898SorensenThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-four month research fellowship by Dr. Jennifer S. Sorensen to work with Dr. William J. Foley at the Australian National University and Dr. Stuart McLean at the University of Tasmania.The paucity of mammalian herbivores (10 species) that consume a single plant species has been attributed to the high concentrations of plant toxins present in such a diet. Little empirical work has been conducted examining the mechanisms mammalian herbivores employ to cope with plant toxins. This project will involve the examination of the role toxin absorption plays in intake of toxic plants by mammalian herbivores. The hypothesis that dietary specialists will absorb fewer toxins per unit ingested than generalists will be tested by measuring toxin intake, blood concentration of toxins, and fecal excretion of toxins by specialists (koalas) and generalists (brushtail and mountain brushtail possums) fed the toxic plant, Eucalyptus. It is predicted that lower absorption of toxins by specialists will result in greater toxin intake yet lower concentrations of toxin in the blood. The PI has found evidence within the genus Neotoma that specialists absorb fewer plant toxins than generalists and proposed research will further expand these results by comparing toxin absorption and the mechanisms that mediate toxin absorption between specialist and generalist mammalian herbivores from different families.