Korea Polar Research Institute, Yeonsu-gu, Incheon, South Korea.
PLoS One. 2012;7(8):e43762. doi: 10.1371/journal.pone.0043762. Epub 2012 Aug 16.
For the past 10 to 13 million years, Antarctic notothenioid fish have undergone extraordinary periods of evolution and have adapted to a cold and highly oxygenated Antarctic marine environment. While these species are considered an attractive model with which to study physiology and evolutionary adaptation, they are poorly characterized at the molecular level, and sequence information is lacking. The transcriptomes of the Antarctic fishes Notothenia coriiceps, Chaenocephalus aceratus, and Pleuragramma antarcticum were obtained by 454 FLX Titanium sequencing of a normalized cDNA library. More than 1,900,000 reads were assembled in a total of 71,539 contigs. Overall, 40% of the contigs were annotated based on similarity to known protein or nucleotide sequences, and more than 50% of the predicted transcripts were validated as full-length or putative full-length cDNAs. These three Antarctic fishes shared 663 genes expressed in the brain and 1,557 genes expressed in the liver. In addition, these cold-adapted fish expressed more Ub-conjugated proteins compared to temperate fish; Ub-conjugated proteins are involved in maintaining proteins in their native state in the cold and thermally stable Antarctic environments. Our transcriptome analysis of Antarctic notothenioid fish provides an archive for future studies in molecular mechanisms of fundamental genetic questions, and can be used in evolution studies comparing other fish.
在过去的 1000 万至 1300 万年里,南极鳕鱼已经经历了非凡的进化阶段,并适应了寒冷且富含氧气的南极海洋环境。虽然这些物种被认为是研究生理学和进化适应的有吸引力的模型,但它们在分子水平上的特征描述很差,缺乏序列信息。通过对归一化 cDNA 文库进行 454 FLX Titanium 测序,获得了南极鱼 Notothenia coriiceps、Chaenocephalus aceratus 和 Pleuragramma antarcticum 的转录组。总共组装了超过 190 万个读长,共分为 71539 个 contigs。总体而言,40%的 contigs基于与已知蛋白或核苷酸序列的相似性进行了注释,超过 50%的预测转录本被验证为全长或推定全长 cDNA。这三种南极鱼在大脑中有 663 个基因表达,在肝脏中有 1557 个基因表达。此外,与温带鱼类相比,这些耐寒鱼类表达了更多的 Ub 连接蛋白;Ub 连接蛋白参与在寒冷和热稳定的南极环境中维持蛋白质的天然状态。我们对南极鳕鱼的转录组分析为今后研究基础遗传问题的分子机制提供了一个档案,也可以用于与其他鱼类进行进化研究。