Antarctic Notothenioid Fish Freeze Avoidance and Genome-wide Evolution for Life in the Cold

南极诺托鱼类鱼类的冷冻避免和寒冷环境下生命的全基因组进化

• 批准号: 1142158
• 负责人: Chi-Hing Cheng
• 金额: $ 64.62万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1142158&HistoricalAwards=false
• 关键词: Antarctic; Notothenioid; Fish; Freeze; Avoidance

Antarctic notothenioid fishes exhibit two adaptive traits to survive in frigid temperatures. The first of these is the production of anti-freeze proteins in their blood and tissues. The second is a system-wide ability to perform cellular and physiological functions at extremely cold temperatures.The proposal goals are to show how Antarctic fishes use these characteristics to avoid freezing, and which additional genes are turned on, or suppressed in order for these fishes to maintain normal physiological function in extreme cold temperatures. Progressively colder habitats are encountered in the high latitude McMurdo Sound and Ross Shelf region, along with somewhat milder near?shore water environments in the Western Antarctic Peninsula (WAP). By quantifying the extent of ice crystals invading and lodging in the spleen, the percentage of McMurdo Sound fish during austral summer (Oct-Feb) will be compared to the WAP intertidal fish during austral winter (Jul-Sep) to demonstrate their capability and extent of freeze avoidance. Resistance to ice entry in surface epithelia (e.g. skin, gill and intestinal lining) is another expression of the adaptation of these fish to otherwise lethally freezing conditions.The adaptive nature of a uniquely characteristic polar genome will be explored by the study of the transcriptome (the set of expressed RNA transcripts that constitutes the precursor to set of proteins expressed by an entire genome). Three notothenioid species (E.maclovinus, D. Mawsoni and C. aceratus) will be analysed to document evolutionary genetic changes (both gain and loss) shaped by life under extreme chronic cold. A differential gene expression (DGE) study will be carried out on these different species to evaluate evolutionary modification of tissue-wide response to heat challenges. The transcriptomes and other sequencing libraries will contribute to de novo ice-fish genome sequencing efforts.

南极南极南极鱼类在寒冷的温度下表现出两种适应特征。首先是在它们的血液和组织中产生抗冻蛋白。第二种是在极冷的温度下执行细胞和生理功能的全系统能力。提案的目标是展示南极鱼类如何利用这些特征来避免冻结，以及哪些额外的基因被打开或抑制，以使这些鱼类在极端寒冷的温度下保持正常的生理功能。在高纬度的麦克默多湾和罗斯陆架地区，气候逐渐变冷，而附近的气候则相对温和。南极半岛西部海岸水环境（WAP）通过量化冰晶侵入和倒伏在脾脏的程度，将南方夏季（10 - 2月）麦克默多湾鱼类的百分比与南方冬季（7 - 9月）WAP潮间带鱼类的百分比进行比较，以证明它们的能力和程度。表面上皮（如皮肤、鳃和肠壁）对冰进入的抵抗力是这些鱼适应致命冰冻条件的另一种表现。一个独特的极性基因组的适应性将通过转录组（一组表达的RNA转录物，构成了整个基因组表达的一组蛋白质的前体）的研究来探索。将分析三种南极鱼（e.m oclovinus, d.m awsoni和c.a ceratus），以记录在极端慢性寒冷条件下生活形成的进化遗传变化（包括增益和损失）。一项差异基因表达（DGE）研究将在这些不同的物种上进行，以评估对热挑战的全组织反应的进化修饰。转录组和其他测序文库将有助于新的冰鱼基因组测序工作。