Metabolic and Ultrastructural Adaptations to Chronically Cold Body Temperature in Antarctic Fishes

南极鱼类物种进化所处的热条件在全球水域中是独一无二的。南极的海水温度非常低（接近零下1度）。0摄氏度)，季节性变化很小)。本项目将描述南极鱼类在代谢和肌肉组织亚细胞组织方面对长期低温的适应。主要目标是：(1)评估组织分解大量中性脂质燃料的分解代谢能力；(2)确定线粒体和过氧化物-氧化的相对作用以及各自的底物偏好；(3)评估南极鱼类体内高脂含量对氧气通过肌肉组织运动的可能适应性意义；(4)确定南极鱼类组织亚细胞组织的独特方面。实验将集中在南极半岛水域丰富的两种红血鱼（Notothenia gibberifrons, Trematomus newnesi）和一种无血红蛋白鱼（Chaenocephalus aceratus）。研究结果将更好地定义高体脂含量南极鱼类的意义，而体脂含量是南极生态系统中重要的热量来源。研究结果也可能适用于表现出相似特征的、不太容易研究的肌肉系统的生理学和生物化学，例如，包括人类在内的哺乳动物物种的耐力训练。

Thermal conditions under which the evolution of Antarctic fish species occurred are unique among the the waters of the globe. Sea temperatures in the Antarctic are severely cold (near -l.0 degrees C) and vary little seasonally). This project will characterize adaptations to chronically cold body temperature in metabolism and subcellular organization of muscle tissues from Antarctic fishes. Major objectives are: (1) to assess the catabolic capacity of tissues for breakdown of abundant neutral lipid fuels; (2) to determine the relative roles of mitochondrial and peroxismal beta-oxidation and the substrate preferenda of each; (3) to evaluate the possible adaptive significance of high corporeal lipid content of Antarctic fishes in the movement of oxygen through muscle tissues, and; (4) to identify unique aspects of subcellular organization of tissues in Antarctic fishes. Experiments will focus upon two red-blooded (Notothenia gibberifrons, Trematomus newnesi) and one hemoglobinless (Chaenocephalus aceratus) fish species that are abundant in waters of the Antarctic Peninsula. Results will better define the significance in Antarctic fishes of high corporeal fat content which represents an important caloric resource in the Antarctic ecosystem. Findings may also apply to the physiology and biochemistry of less easily studied muscle systems which show similar characteristics, for example, endurance training in mammalian species, including man.