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

9615023 DeVries该项目包括正在进行的和新的关于抗冻糖肽（AFGPs）和抗冻肽（AFPs）在南极鱼类防冻中的作用的研究，涉及五个具体领域：（1）环境的严重程度与鱼类冰的关系;（2）内源冰的吸收及其归宿;（3）鱼类对冰的吸收和冰的吸收。（3）抗冻蛋白的结构与功能，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与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。 将确定麦克默多地区鱼类的外源性和内源性冰的程度，这些鱼类经历了南极地区最冷和最多冰的沃茨。环境的严重性将通过从麦克默多声音和水域下的麦克默多冰架的CTD数据得出冻结等温线进行调查，并与冰的存在的物理和生物测量相关。将对南极半岛较不严重的海洋环境进行类似的实验。这些研究将把极端冰冻与这些环境中鱼类的AFGP循环水平联系起来。内源性冰的摄取及其命运将通过实验性地将标记冰引入鱼中来确定，以找出其从血液中消失的途径以及最终其命运。实验将被设计来测试巨噬细胞是否可以增加溶质浓度和“融化”或溶解冰晶。 将确定某些鳗鱼河豚AFP的AP结构与功能的关系。将从X射线晶体学和计算机辅助建模获得详细的结构信息，以确定吸附平面上冰晶格中表面极性残基和水分子之间晶格匹配的性质。一种新的独特的AP将在南极胡瓜Pleuragramma anacuticum和其冰晶大小依赖的抗冻活性进行了研究。 AFGP和APP基因和基因家族的分子特征，以及它们在基因组中的排列，将进一步我们了解基因剂量与环境紧急性，蛋白质丰度， 复杂的蛋白质异质性，以及这些基因家族的进化。将研究AFGPs在胰腺（新发现的主要合成组织）中表达的细胞和分子方面。

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.