Role of Antifreeze Proteins in Freezing Avoidance in Antarctic Fishes: Ecological and Organismal Physiology, Structure-Function and Mechanism, Genetics and Evolution

9615023 DeVries该项目包括在五个特定领域就抗冻糖肽和抗冻肽在南极鱼类避免受冻中的作用进行的正在进行的和新的研究：(1)环境严重程度与鱼类中冰的联系；(2)内源冰的吸收及其去向；(3)抗冻蛋白的结构和功能，包括AP吸附和抑制冰生长的分子机制；(4)AP基因和基因家族的结构和组织及其与蛋白质特性和基因进化的关系；(5)AFGP表达的组织特异性。麦克默多地区的鱼类经历了南极地区最冷和最多冰的水域，外源和内源冰的范围将被确定。将通过从麦克默多海湾和麦克默多冰架下水域的CTD数据得出冻结等温线，并与冰存在的物理和生物测量相关联，来调查环境的严重性。类似的实验将在南极半岛较不严重的海洋环境中进行。这些研究将把极端冰冻与与这些环境相关的鱼类中AFGP的循环水平联系起来。内源性冰的吸收及其命运将通过将标记的冰引入鱼类的实验中来确定，以找出它从血液中消失的路线，并最终确定它的命运。实验将被设计用来测试巨噬细胞是否能增加溶质浓度并“融化”或溶解冰晶。AP的结构与功能的关系将被确定为一些鳗鱼嘴AFP。将从X射线结晶学和计算机辅助模拟中获得详细的结构信息，以确定表面极性残基与吸附平面上冰晶格中的水分子之间的晶格匹配的性质。一种新的独特的AP将在南极熔融Pleuragramma antarcticum中得到表征，并研究其冰晶大小依赖的抗冻活性。AFGP和APP基因和基因家族的分子特征及其在基因组中的排列将进一步加深我们对基因剂量与环境紧迫性、蛋白质丰度、复杂蛋白质异质性以及这些基因家族的进化的遗传参数的理解。AFGP在胰腺中表达的细胞和分子方面将被研究，胰腺是新发现的主要合成组织。

9615023 DeVries The project includes on-going and new studies on the role of antifreeze glycopeptides (AFGPs) and peptides (AFPs) in freezing avoidance of Antarctic fishes in five specific areas: (1) relationship of severity of environment and association of ice in fish; (2) the uptake of endogenous ice and its fate; (3) structure-function of antifreeze proteins including the molecular mechanism of AP adsorption and inhibition of ice growth; (4) structures and organizations of AP genes and gene families and their relationship to protein characteristics and gene evolution; (5) tissue specificity of AFGP expression. The extent of exogenous and endogenous ice will be determined for McMurdo area fishes, which experience the coldest and most ice-laden waters of the Antarctic region. The severity of the environment will be investigated by deriving freezing isotherms from CTD data in McMurdo Sound and waters beneath the McMurdo Ice Shelf and correlated with physical and biological measurements of the presence of the ice. Similar experiments will be conducted for the less severe marine environment of the Antarctic Peninsular. These studies will correlate freezing extremes with circulating levels of AFGPs in the fishes associated with these environments. The uptake of endogenous ice and its fate will be determined by experimentally introducing labeled ice into the fish to find out its route of disappearance from the blood and ultimately its fate. Experiments will be designed to test whether macrophages can increase solute concentration and "melt" or dissolve ice crystals. The relationship of AP structure to function will be determined for some of the eel pout AFPs. Detailed structural information will be obtained from X-ray crystallography and computer aided modeling to determine the nature of the lattice match between the surface polar residues and the water molecules in the ice lattice on the adsorption plane. A new unique AP will be characterized in the Antarctic smelt Pleuragramma antarcticum and its ice crystal size-dependent antifreeze activity investigated. Molecular characterizations of AFGP and APP genes and gene families, and their arrangement in the genome will be carried out to further our understanding of the genetic parameters governing gene dosage versus environmental exigency, protein abundance, complex protein heterogeneity, and the evolution of these gene families. Cellular and molecular aspects of the expression of AFGPs in pancreas, the newly discovered major synthetic tissue, will be investigated.