Research press release


Nature Ecology & Evolution

Antarctic blackfin icefish genome reveals cool adaptions



Hyun Park、Manfred Schartlたちは今回、南極のスイショウウオ(Chaenocephalus aceratus)のゲノム塩基配列を解読した。その結果、スイショウウオは、トゲウオ類など他の硬骨魚類と比較して、不凍性糖タンパク質および卵外被タンパク質の遺伝子が多いことが分かった。卵外被タンパク質は、氷の融点を低下させて胚を包み、南極の冷水中での生存に役立つ。スイショウウオは、酸素を含む化学反応性分子が引き起こす細胞損傷の影響を受けやすく、ゲノム中に、活性酸素種の恒常性に関係する遺伝子ファミリーの増大も認められた。


A high-quality genome of the Antarctic blackfin icefish is reported in a paper published online this week in Nature Ecology & Evolution. This genome reveals genetic adaptations that enable the icefish to survive in the Southern Ocean, which is cooled to subzero temperatures.

Antarctic icefish developed unique physiological adaptations to the extreme polar marine environment in which they live. They are the only vertebrates that are ‘white-blooded’, meaning that they lack functional red blood cells and haemoglobin genes. To compensate for this, icefish evolved enormous hearts and enhanced vascular systems.

Hyun Park, Manfred Schartl and colleagues sequenced the genome of an Antarctic blackfin icefish, Chaenocephalusaceratus. The authors found that in Antarctic blackfin icefish, as compared with other bony fish, such as sticklebacks, there is an expansion of antifreeze glycoprotein genes and egg coat proteins, which lower the melting point of ice and surround embryos to help them survive in the cold Antarctic waters. C. aceratusis is sensitive to cell damage caused by chemically reactive molecules containing oxygen. The authors also identified an expansion of gene families associated with reactive oxygen species homeostasis in the genome.

The authors conclude that the availability of this icefish genome may advance our understanding of adaptation to extreme Antarctic environments.

doi: 10.1038/s41559-019-0812-7

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