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

本文将研究具有不同纬度或深度分布模式（即不同绝对温度和热范围）的同属海洋鱼类和无脊椎动物，以确定：(1)精细温度适应对酶的动力学性质和结构稳定性的重要性；(2)氨基酸序列的变化决定了这些适应性差异的动力学和稳定性特征；(3)在进化过程和季节过程中，多位点和等位基因酶变异在温度适应中的作用；(4)进化适应和季节适应对线粒体呼吸和膜流动性的影响；(5)蛋白质异构体和线粒体呼吸和流动性的同化变化动力学。这些研究旨在填补我们对动物热生物学理解的重要空白，特别是对温度的精细适应在建立生物体分布模式中所起的作用，蛋白质初级结构的精确变化建立了酶（M4 -乳酸脱氢酶和细胞质苹果酸脱氢酶）的适应性差异，有利于选择新的蛋白质变异或线粒体特性所需的最小温度变化，以及驯化发生的速度。低温和低温同系物的比较将揭示潜在的生化和分子差异，有助于建立物种的热耐受范围。精细尺度的温度适应研究将为预测全球变暖对经济动物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.