Antifreeze Proteins in Antarctic Fishes: Integrated Studies of Freezing Environments and Organismal Freezing Avoidance, Protein Structure-Function and Mechanism, Genes & Evolut

该项目包括抗冻糖蛋白（AFGPs）和一种新的抗冻增强蛋白（AFPP）在南极鱼类及其卵和幼虫在寒冷的南极环境中的防冻作用的正在进行的和新的研究。具体研究领域包括：(1)无冰标本对内源冰的吸收速率；(2) AFPP的结构及其增强大型AFPP而非小型AFPP抗冻活性的机制；(3)利用定向进化方法阐明鳗鱼嘴AFP的结构-功能；(4)胚胎和幼鱼的避冻机制，以及AFGP和AFPP在胚胎发生过程中的表达时间；(5)在蛋白质和基因水平上综合分析了南极鱼亚目的抗冻能力；(6) AFGP基因家族和基因位点的进化；(7) AFPP的演化；(8)的起源Patagonotothen血统,最大的进化枝non-Antarctic nototheniids是近亲的南极notothenioid特有物种。麦克默多湾海洋环境的极端寒冷和冰冷的条件源于它与巨大的罗斯冰架的联系以及冰架冷水的影响。为了阐明麦克默多环境与当地鱼类冰暴露之间的关系，将对海湾各种微环境中冰形成的深度和程度进行平行物理测量，并完成生物实验，通过测量鱼类脾脏中冰晶的数量以及冰进入鱼类体内的速度来确定这些地点鱼类的冰负荷。这些研究将确定极端环境的程度和鱼类的冰负荷之间的关系。该项目有广泛的国际合作，研究结果可能对农业、食品科学和低温医学有广泛的影响。公众宣传和培训研究生和本科生是计划工作的组成部分。

This project includes on-going and new studies on the role of antifreeze glycoproteins (AFGPs) and a new antifreeze potentiating protein (AFPP) in the freezing avoidance of Antarctic fishes, their eggs and larvae in the freezing Antarctic environment. The specific areas of research to be investigated are: (1) the rate of uptake of endogenous ice by ice-free specimens; (2) structure of AFPP and the mechanism whereby it potentiates the antifreeze activity of the large AFGPs, but not the small ones; (3) structure-function elucidation of eel pout AFP through directed-evolution methodologies; (4) mechanism of freezing avoidance in embryos and young larval fish, and the temporal aspects of AFGP and AFPP expression during embryogenesis; (5) comprehensive analyses of the antifreeze capacity at both the protein and gene levels across the suborder Notothenioidei; (6) evolution of the AFGP gene family and gene locus; (7) evolution of AFPP; and (8) origin of the Patagonotothen lineage, the largest clade of non-Antarctic nototheniids who are close relatives to the endemic Antarctic notothenioid species. Extreme cold and icy conditions of the McMurdo Sound marine environment arise from its association with the massive Ross Ice Shelf and the influence of cold shelf water. To elucidate the relationship between the McMurdo environment and ice exposure in the local fish population, parallel physical measurements of the depth and extent of ice formation in various microenvironments in the Sound will be conducted and biological experiments will be completed to determine ice load in fish at these locations by measuring the number of ice crystals in their spleens, as well as the rate of ice entry into fish. These studies will ascertain the relationship between the degree of environmental extremes and the ice load in fish.This project has extensive international collaborations and findings may have broad implications for agriculture, food science, and cryomedicine. Public outreach and training of graduate and undergraduate students are integral components of the planned work.