Fine-scale Adaptation to Temperature: A Physiological, Biochemical and Molecular Analysis Using Congeneric Species

研究具有不同纬度或深度分布模式的海洋鱼类和无脊椎动物，即不同的绝对温度和温度范围，以确定：(1)对温度的精细适应在酶的动力学特性和结构稳定性中的重要性；(2)导致这些动态和稳定特性适应性差异的氨基酸序列变化；(3)多基因座和等位基因酶变异体在进化和季节性适应温度过程中的作用；(4)进化适应和季节性驯化对线粒体呼吸和膜流动性的影响；(5)蛋白质亚型和线粒体呼吸和流动性的驯化变化动力学。这些研究旨在填补我们在理解动物热生物学方面的重要空白，特别是对温度的细微适应在建立生物分布模式中所起的作用，蛋白质一级结构的精确变化建立酶(M4-乳酸脱氢酶和胞浆苹果酸脱氢酶)的适应性差异，有利于选择新的蛋白质变种或线粒体特性所需的最小温度变化，以及驯化发生的速度。对常温和狭温同系物的比较将揭示潜在的生化和分子差异，这些差异有助于确定物种的热耐受范围。对温度的精细适应研究将为预测全球变暖对经济动物的分布和功能的影响提供更坚实的基础。

Congeneric marine fishes and invertebrates with different latitudinal or depth distribution patterns, i.e., different absolute temperatures and thermal ranges, will be studied to determine: (1) the importance of fine-scale adaptations to temperature in kinetic properties and structural stabilities of enzymes; (2) the amino acid sequence changes that underlie these adaptive differences in kinetic and stability characteristics; (3) the roles played by multi-locus and allelic enzyme variants in adaptation to temperature over evolutionary and seasonal time course; (4) the effects of evolutionary adaptation and seasonal acclimatization on mitochondrial respiration and membrane fluidity; and (5) the kinetics of acclimatory change in protein isoforms and mitochondrial respiration and fluidity. These studies are designed to fill in important gaps in our understanding of the thermal biology of animals, specifically the role played by fine-scale adaptation to temperature in establishing organismal distribution patterns, the precise changes in protein primary structure that establish adaptive differences in enzymes(M4 - lactate dehydrogenase and cytosolic malate dehydrogenase), the minimal amounts of change in temperature required to favor selection for new protein variants or mitochondrial properties, and the rate with which acclimation occurs. Comparisons of eurythermal and stenothermal congeners will reveal underlying biochemical and molecular differences that help to establish species' thermal tolerance ranges. Study of fine-scale adaptations to temperature will provide a firmer basis for predicting the effects of global warming on the distributions and functions of economics animals.