Ecophysiological Correlates of Vertebrate Cold Hardiness

脊椎动物抗寒性的生态生理学相关性

• 批准号: 9817087
• 负责人: Jon Costanzo
• 金额: --
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2003-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9817087&HistoricalAwards=false
• 关键词: Ecophysiological; Correlates; Vertebrate; Cold; Hardiness

The PIs will investigate physiological, ecological, and evolutionary aspects of cold hardiness in certain amphibians and reptiles. This research will use the wood frog and hatchlings of the painted turtle as models to investigate two cold-hardiness strategies employed by lower vertebrates: supercooling and freeze tolerance. Supercooled animals are in a metastable state in which the body fluid remains liquid (uncrystallized) at temperatures well below its freezing point. Freeze-tolerant animals survive exposure to subzero temperatures by tolerating the freezing of their body tissues. Studies will identify environmental and physiological factors influencing the ability of hatchling painted turtles to remain supercooled during hibernation in their nests, which lie within the frost zone. Field and laboratory studies will explore the effects of moisture on cold hardiness. A comparative study will examine the relationship between desiccation resistance and supercooling capacity in hatchlings of several species of northern turtles from diverse habitats. This work will provide insight into the physiological and morphological adaptations permitting some species of northern turtles to hibernate on land. Research in ecological physiology often considers the benefits of a particular adaptation without regard to its deleterious consequences. This project will identify "trade-offs" incurred by freeze-tolerant animals by investigating the impact of freezing and thawing on selected aspects of organismal performance. Studies of the wood frog will expand recent findings of freezing-induced impairment of locomotor performance and reproductive potential, and provide a rigorous evaluation of freeze tolerance as an adaptive, winter-survival strategy. Physiological studies, including NMR imaging of intact frogs during freezing and thawing, are aimed at identifying the underlying cause of the impairment. By integrating field and laboratory studies, this research will provide novel insights concerning adaptations that not only promote survival at subzero temperatures, but also influence the geographic distributions of some amphibians and reptiles. In addition, this work has implications for applied disciplines, such as the development of methods for cryopreserving mammalian organs and the use of cryopreserved gametes from amphibians for ex situ propagation and reintroduction programs.

研究员将调查某些两栖动物和爬行动物耐寒性的生理、生态和进化方面。 本研究将以木蛙与彩龟幼体为模型，探讨低等脊椎动物的两种耐寒策略：过冷与抗冻。 过冷的动物处于亚稳态，其中体液在远低于其冰点的温度下保持液体（未结晶）。 耐寒动物通过忍受身体组织的冷冻而在零度以下的温度下生存。 研究将确定环境和生理因素影响的能力，孵化彩绘龟冬眠期间保持过冷在他们的巢，这是在霜冻区。 田间和实验室研究将探讨水分对抗寒性的影响。 比较研究将探讨不同生境的几种北方海龟孵化时抗干燥性和过冷能力之间的关系。 这项工作将提供深入了解的生理和形态的适应，使一些物种的北方龟冬眠的土地。 生态生理学的研究通常只考虑特定适应的益处，而不考虑其有害后果。 该项目将通过调查冷冻和解冻对生物体性能的选定方面的影响来确定耐冷冻动物所产生的“权衡”。 对林蛙的研究将扩大冷冻诱导的运动能力和生殖潜力受损的最新发现，并提供一个严格的评估冷冻耐受性作为一种适应性，冬季生存策略。 生理学研究，包括冷冻和解冻过程中完整青蛙的核磁共振成像，旨在确定损伤的根本原因。 通过整合实地和实验室研究，这项研究将提供有关适应的新见解，这些适应不仅促进了在零度以下温度下的生存，而且还影响了一些两栖动物和爬行动物的地理分布。 此外，这项工作的应用学科的影响，如哺乳动物器官的冷冻保存方法的发展和使用冷冻保存的配子从两栖动物的异地繁殖和再引入计划。