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总体上适应气候变化提供一个模式。今天寒冷的极地水域对大多数硬骨鱼来说是不适宜生存的，但一些可以生活在冰冻的水中，因为它们进化出了抗冻蛋白。北方/北极鳕鱼的抗冻糖蛋白(AFGP)与入侵的冰晶结合，防止鱼类冻结。新的蛋白质通常被认为是从先前存在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基因的进化可能会挑战这一长期持有的模式。到目前为止分析的鳕鱼基因表明，编码AFGP的重复DNA来自重复复制祖先的非蛋白质编码DNA片段。此外，AFGP的特征出现在两个冷水鳕鱼群体中，这两个群体是远亲，这表明AFGP基因在这个家谱的不同分支中进化了两次。为了检验这两个相互交织的进化假说，AFGP特征的分布将被映射到鳕鱼的系谱上。然后将AFGP基因组区域与具有完整AFGP功能的两个相距较远的物种进行比较，并与不具有AFGP功能的相关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，结果将表明进化的新颖性有比之前想象的更多的来源。首席研究员将对研究生和本科生进行尖端基因组技术和科学方面的培训。该项目的序列数据还将用于为一群高中生举办的“寻找基因”研讨会，以进行生物信息学和基因组数据管理方面的基础培训。

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.