Evolutionary Origin and History of Antifreeze Glycoprotein Gene in the Northern Cod Fishes (Gadidae): Creating Sense from Non-Sense DNA?

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。对极地气候的进化适应可以为一般气候变化的适应提供一个模型。今天寒冷的极地水域不适合大多数硬骨鱼类生存，但有些鱼类可以在寒冷的水域生存，因为它们进化出了抗冻蛋白质。北方/北极鳕鱼的抗冻糖蛋白（AFGP）与入侵的冰晶结合，防止鱼被冷冻。新的蛋白质通常被认为是从已有的蛋白质基因进化而来，而不是从其他种类的DNA进化而来。鳕鱼AFGP基因的进化可能会违背这种长期存在的范式。迄今为止，对鳕鱼基因的分析表明，编码AFGP的重复DNA来自于对祖先的非蛋白质编码DNA片段的重复复制。此外，AFGP特征出现在两个远亲冷水鳕鱼群中，这表明AFGP基因在这个家族树的不同分支中进化了两次。为了验证这两种相互交织的进化假设，AFGP特征的分布将被映射到鳕鱼的家谱上。然后将两个具有完整AFGP功能的远缘物种的AFGP基因组区域与一个没有AFGP功能的亲缘物种的相应区域进行比较。如果抗冻基因不是从编码DNA进化而来的，那么结果将表明，进化的新颖性有比以前认为的更多的来源。首席研究员将在尖端基因组技术和科学方面培训研究生和本科生。该项目的序列数据还将用于为一组高中生举办的“寻找基因”研讨会，以进行生物信息学和基因组数据管理的基础培训。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The evolutionary adaptation to polar climates can provide a model for adaptations to climate changes in general. Today's frigid polar waters are inhospitable for most bony fishes, but some can live in freezing waters because they have evolved antifreeze proteins. The antifreeze glycoproteins (AFGP) of northern/Arctic cod fishes bind to invading ice crystals, preventing the fish from freezing. Novel proteins are commonly thought to evolve from a pre-existing protein gene rather than from other kinds of DNA. The evolution of the cod AFGP gene may defy this long-held paradigm. The codfish genes analyzed thus far suggest that the repetitive DNA encoding the AFGP arose from repeatedly copying a snippet of ancestral, non-protein coding DNA. Furthermore the AFGP trait appears in two cold-water codfish groups that are distant cousins, suggesting the AFGP gene evolved twice, in separate branches of this family tree. To test these two intertwined evolutionary hypotheses, the distribution of the AFGP trait will be mapped onto the codfish family tree. Then the AFGP genomic regions will be compared for two distant species bearing complete AFGP function, and with the corresponding region in a related species without AFGP function. If the antifreeze gene did not evolve from coding DNA, the result would indicate that evolutionary novelty has more sources than previously thought. The principal investigator will train graduate and undergraduate students in cutting edge genomics technology and science. The sequence data from the project will also be utilized in a "Find a Gene" workshop for a group of high school students for basic training in bioinformatics and genome data management.