Antifreeze Proteins in Antarctic Fishes: Ecological and Organismal Physiology, Protein Structure-Function and Mechanism, Genetics and Evolution

南极鱼类的抗冻蛋白：生态和生物生理学、蛋白质结构功能和机制、遗传学和进化

• 批准号: 9909841
• 负责人: Arthur DeVries
• 金额: $ 57.1万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9909841&HistoricalAwards=false
• 关键词: Antifreeze; Proteins; Antarctic; Fishes; Ecological

The Southern Ocean represents the world's coldest marine environment and its near-shore waters are perennially at the freezing point of seawater and replete with ice crystals. The group of marine teleost fishes are hypo-osmotic to seawater and therefore would readily freeze in these waters from nucleation by environmental ice. Cold-adapted fishes have more serum electrolytes, but these are insufficient to prevent freezing in Antarctic fishes. A number of polar and subpolar fish evolved special biological antifreeze proteins to avoid freezing and successfully colonized their frigid habitats. The impact of the evolution of the antifreeze function on organismal success is particularly clear in the Antarctic notothenioids. This research project involves ongoing and new research on the role of antifreeze glycopeptides, antifreeze peptides and a newly discovered antifreeze potentiator protein in freezing avoidance of Antarctic fishes. The specific areas of research include: the relationship between the severity of environment and exposure of fish to ice in the water column, the uptake of endogenous ice and its fate, structure of antifreeze proteins, the molecular mechanism of antifreeze adsorption to ice and inhibition of ice crystal growth, and comprehensive analyses of the antifreeze capacity at both the protein and gene levels across the suborder Notothenioidei. Research specific to antifreeze glycopeptides includes the chromosomal locus of the gene family and its protease progenitor gene, calibration of the rate of notothenioid nuclear protein coding sequences to arrive at a more precise time estimate of the gene evolution and the temporal aspects of antifreeze glycopeptides during embryogenesis and early larval stages. The multidisciplinary approach will lead to major advances in the molecular biology and evolution of the antifreeze systems and will be applicable to a wide range of disciplines.

南大洋是世界上最寒冷的海洋环境，其近岸沃茨常年处于海水冰点，并充满了冰晶。这类海洋硬骨鱼对海水渗透性低，因此在这些沃茨中很容易因环境冰的成核而冻结。适应寒冷的鱼类有更多的血清电解质，但这些都不足以防止南极鱼类冻结。许多极地和亚极地鱼类进化出特殊的生物防冻蛋白来避免结冰，并成功地在寒冷的栖息地定居。抗冻功能的进化对生物体成功的影响在南极南极的notothenioids中特别明显。该研究项目涉及对抗冻糖肽、抗冻肽和一种新发现的抗冻增效蛋白在南极鱼类防冻方面的作用进行的和新的研究。具体的研究领域包括：环境的严酷性与鱼类暴露于水体中的冰之间的关系，内源冰的摄取及其命运，抗冻蛋白的结构，抗冻剂吸附到冰和抑制冰晶生长的分子机制，以及在蛋白质和基因水平上对Notothenioidei亚目的抗冻能力进行综合分析。抗冻糖肽的具体研究包括基因家族的染色体位点及其蛋白酶祖基因，对拟南极鱼核蛋白编码序列的速率进行校准，以更精确地估计胚胎发生和早期幼虫阶段抗冻糖肽的基因进化和时间方面。多学科的方法将导致分子生物学和防冻系统的演变的重大进展，并将适用于广泛的学科。