Shin Seung Chul, Ahn Do Hwan, Kim Su Jin, Pyo Chul Woo, Lee Hyoungseok, Kim Mi-Kyeong, Lee Jungeun, Lee Jong Eun, Detrich H William, Postlethwait John H, Edwards David, Lee Sung Gu, Lee Jun Hyuck, Park Hyun
Genome Biol. 2014 Sep 25;15(9):468. doi: 10.1186/s13059-014-0468-1.
Antarctic fish have adapted to the freezing waters of the Southern Ocean. Representative adaptations to this harsh environment include a constitutive heat shock response and the evolution of an antifreeze protein in the blood. Despite their adaptations to the cold, genome-wide studies have not yet been performed on these fish due to the lack of a sequenced genome. Notothenia coriiceps, the Antarctic bullhead notothen, is an endemic teleost fish with a circumpolar distribution and makes a good model to understand the genomic adaptations to constant sub-zero temperatures.
We provide the draft genome sequence and annotation for N. coriiceps. Comparative genome-wide analysis with other fish genomes shows that mitochondrial proteins and hemoglobin evolved rapidly. Transcriptome analysis of thermal stress responses find alternative response mechanisms for evolution strategies in a cold environment. Loss of the phosphorylation-dependent sumoylation motif in heat shock factor 1 suggests that the heat shock response evolved into a simple and rapid phosphorylation-independent regulatory mechanism. Rapidly evolved hemoglobin and the induction of a heat shock response in the blood may support the efficient supply of oxygen to cold-adapted mitochondria.
Our data and analysis suggest that evolutionary strategies in efficient aerobic cellular respiration are controlled by hemoglobin and mitochondrial proteins, which may be important for the adaptation of Antarctic fish to their environment. The use of genome data from the Antarctic endemic fish provides an invaluable resource providing evidence of evolutionary adaptation and can be applied to other studies of Antarctic fish.
南极鱼类已经适应了南大洋的冰冷海水。对这种恶劣环境的典型适应性包括组成型热休克反应以及血液中抗冻蛋白的进化。尽管它们适应了寒冷环境，但由于缺乏测序基因组，尚未对这些鱼类进行全基因组研究。南极杜父鱼（Notothenia coriiceps）是一种分布于环南极地区的特有硬骨鱼，是理解基因组对持续零下温度适应性的良好模型。
我们提供了南极杜父鱼的基因组草图序列和注释。与其他鱼类基因组进行全基因组比较分析表明，线粒体蛋白和血红蛋白进化迅速。热应激反应的转录组分析发现了寒冷环境中进化策略的替代反应机制。热休克因子1中磷酸化依赖性SUMO化基序的缺失表明热休克反应演变成了一种简单快速的非磷酸化依赖性调节机制。快速进化的血红蛋白以及血液中热休克反应的诱导可能支持向适应寒冷的线粒体有效供应氧气。
我们的数据和分析表明，高效有氧细胞呼吸中的进化策略受血红蛋白和线粒体蛋白控制，这可能对南极鱼类适应其环境很重要。利用南极特有鱼类的基因组数据提供了一个宝贵资源，为进化适应提供了证据，并可应用于其他南极鱼类研究。
