血红蛋白与脊椎动物高海拔适应进化

Hemoglobins and High-altitude Adaptive Evolution in Vertebrates

高海拔环境是研究脊椎动物对极端环境适应进化过程的典型范例之一.血红蛋白在脊椎动物呼吸和氧化能量代谢中的核心作用决定了其无论在进化生物学还是高原医学研究领域都有着极其重要的意义.然而,如果不清楚研究对象的系统进化地位和机体本身的适应进化特点,就无法对各个水平的适应进化机制作出全面诠释.因此,对脊椎动物的低氧适应进化研究首先从机体生理需求的差异出发.此外,血红蛋白的功能适应性还表现在物种或种群间的空间分布差异导致不同程度的低氧需求.因此,本文从个体和系统发育水平评述了血红蛋白的分子进化及功能适应研究,深入比较了长期定居和短期移居物种间的适应机制区别,系统分析了鸟类及其他脊椎动物适应高海拔低氧环境的趋同和趋异进化特征.最后通过评价不同研究方法的优缺点,结合功能蛋白和物种进化相似的分子遗传规律,为未来高海拔低氧适应进化及高原医学研究提出一些新的思考.总之,本文支持功能验证在适应性进化相关基因研究中的必要性,强调整合分子、细胞和系统水平确定研究方案的重要性,以及系统发育背景和种群进化历史在研究对象选择中的重要意义.

High-altitude environments provide a model system to investigate adaptive evolution of vertebrates that live in extreme conditions.In vertebrates,the key role of hemoglobin in respiration and oxidative metabolism received significance attention in both evolutionary biology and high-altitude medicine.It is difficult,however,to comprehensively understand different adaptive mechanisms of hemoglobins without a phylogenetic context.Additionally,functional adaptation in hemoglobins also results in the spatially varying patterns within and among species.Here,we review case studies of adaptative evolution of hemoglobins from both the ontogenetic and phylogenetic perspectives,further comparing distinct adaptation between highland residents and short-time migrants.We then systematically compare convergent and divergent adaptations to high-altitude hypoxia in birds and other vertebrates.In accordance with evaluations of relative merits of multiple molecular techniques and a common genetic basis of molecular evolution and speciation,we propose suggestions for future studies of adaptive evolution to high-altitude environment and high-altitude medicine.This review highlights the importance of functional evidences in adaptation studies and the significance of a phylogenetic and phylogeographic framework,emphasizing the integration of molecular,cellular and systematic studies.