南极鱼类适应低温的分子进化研究进展

南大洋是地球上最冷的水域,水温常年在0℃以下,许多生物在南大洋降温过程中走向灭绝,而南极鱼亚目鱼类在南大洋逐渐变冷过程中快速进化,成为冰冻海域最繁盛的脊椎动物。随着越来越多的南极亚目鱼类基因组完成测序和分析,人们对这些鱼类在冰冻环境下生存和繁衍机制的认识也越来越深入和全面。本文从抗冻蛋白的起源、血液发生、抗过氧化机制、铁离子稳态调控、中性浮力的进化和基因组特征等方面综述了南极鱼类适应极端低温的分子进化及发育生物学机制,以期为鱼类抗冻与耐寒机制及适应性进化研究提供新的视角。

Current progress on understanding of molecular evolution enabling cold adaptation in Antarctic fishes:a review

During the period of more than 30 million years of temperature decline,many of the benthic fauna become extinct,only one group of teleosts,members in suborder Notothenioidei survive the climatic change and undergo an adaptive radiation and is the dominant fish fauna in the Southern Ocean as the coldest ocean in the world,with the water temperature of nearshore habitats perennially under 0℃.With genomes of many species being sequenced,the molecules and underpinning mechanisms that enable the survival and thriving of these fishes in the subzero waters are gradually unraveled.We briefly review the mechanisms of physiological adaption and genomic evolution in the constant cold fishes including origin of antifreeze proteins,adaptations in erythropoiesis,coping with oxidative stress,iron metabolism,and achievement of neutral buoyancy and drivers of genome expansion,helping the attempts for breeding of enhanced cold tolerant aquaculture varieties.