Antifreeze proteins and cold adaptation in fish

我的研究项目重点是鱼类抗冻蛋白及其基因：多样性、生物进化、作用机制、生理调节和商业化。这些蛋白质存在于生活在极地和亚极地/温带海洋的各种鱼类中，在这种潜在致命环境的殖民过程中发挥着至关重要的作用。抗冻蛋白通过结合和防止体液中可能形成的冰晶的生长来保护鱼类免受冻结。这有效地将鱼的冰点降低到安全水平，并使它们能够在致命的冰冻环境中生存。抗冻蛋白还通过在低温下稳定细胞膜在冷适应中发挥作用：正在探索这种特性以保存哺乳动物细胞和组织用于治疗应用。对抗冻蛋白的研究还导致了基因的开发，这些基因可以帮助提高加拿大大西洋地区鱼类水产养殖的经济可行性。在接下来的五年里，我们将继续详细检查各种防冻蛋白质，这些蛋白质是大自然挑选出来的，以保护鱼类免受冻结。关于这些蛋白质以及它们在防冻中的作用，我们还有很多不知道的地方。例如，尽管对冬季比目鱼的防冻剂进行了30年的研究，但我们直到最近才发现另一种“超活性”防冻剂的存在，其效果是它的10-100倍。这种蛋白质本身就可以解释鱼对冰冻的抵抗力。未来的研究将确定是否可以在其他鱼类中发现这种高活性蛋白质。还将进行研究，以确定在这些比目鱼中大量存在的低活性防冻剂的功能作用。它们有不同于过度活跃的特殊功能吗？目前正在进行分离过度活跃的抗冻基因的研究。一旦完成，我们将能够将它们转移到大西洋鲑鱼中，并测试仅有高度活性的防冻剂就可以防止鱼类冻结的假设。

My research program focuses on fish antifreeze proteins and their genes: diversity,  evolution, mechanisms of action, physiological regulation, and commercialization. These proteins, present in a wide variety of fish species inhabiting polar and subpolar/temperate oceans, play an essential role in the colonization of such potentially lethal environments. The antifreeze proteins protect the fish from freezing by binding to and preventing the growth of ice crystals that may form within their body fluids. This effectively lowers the fish's freezing point to safe levels, and allows them to survive in lethal freezing environments. Antifreeze proteins also play a role in cold adaptation by stabilizing cell membranes at low temperatures: properties that are being explored for the preservation of mammalian cells and tissues for therapeutic applications. Research on antifreeze proteins has also led to the development of genes that could help improve the economic viability of finfish aquaculture in the Canadian Atlantic region. Over the next five years we will continue to examine in detail the various antifreeze proteins  that have been selected by nature to protect fish from freezing. There is a great deal that we do not know about these proteins and their role in freeze protection. For example despite 30 years of research on the well-described antifreeze from winter flounder we only recently discovered the presence of another "hyperactive" antifreeze protein that is 10-100 times more effective. This protein alone can explain the resistance of the fish to freezing. Future research will determine whether such highly active proteins can be found in other fish. Research will also be carried out to determine the functional role of the low activity antifreeze that is present in abundance in these flounder. Do they have a specialized function that differs from that of the hyperactive one?  Research is underway to isolate the hyperactive antifreeze genes. Once this has been accomplished we will be able to transfer them to Atlantic salmon and test the hypothesis that the hyperactive antifreeze alone can prevent fish from freezing.