絶滅種からＲＮＡ抽出　世界で初めて成功

【ストックホルムＡＦＰ＝時事】スウェーデンのストックホルム大学の研究者がこのほど、絶滅したフクロオオカミ（別名：タスマニアタイガー）の試料から初めてＲＮＡの抽出に成功したと明らかにした。（写真はフクロオオカミ〈別名：タスマニアタイガー〉の標本を見るダニエラ・カルソフ氏〈哺乳類担当〉。ストックホルムにあるスウェーデンの自然史博物館で）
　研究を共同で率いたストックホルム大学のロべ・ダレン教授（進化ゲノム学）によると、絶滅種からのＲＮＡの抽出および配列の解析はこれまで成功していなかった。
　同教授は「絶滅種からのＲＮＡ抽出の成功は、将来的に絶滅種の復活を可能にさせるための小さな一歩となる」と語った。
　研究チームは、スウェーデンの自然史博物館に常温保存されていた、１３０年前のクロオオカミの試料からＲＮＡの配列を解析。皮膚と骨格筋ＲＮＡを再構築した。
　ＲＮＡはゲノムからの情報を用い、細胞にタンパク質の合成に関する指示を出す役割を持つ。
　ダレン氏は、「絶滅した動物を復活させるためには遺伝子の場所と役割、どの組織に関わりがあるのかを知る必要がある」とし、ＤＮＡとＲＮＡ双方についての知識が必要であると説明した。
　肉食の有袋類であるフクロオオカミの最後の個体は、オーストラリア南部タスマニア島のビューマリス動物園で１９３６年に死んだ飼育個体だった。
　フクロオオカミが生息していたタスマニア島では絶滅前の自然環境がほぼそのままの状態で残っているため、科学者らは絶滅種を復活させる研究において同種に注目した。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2023/09/27-15:52）

Scientists have for the first time recovered RNA from an extinct species, the Tasmanian tiger, raising hope for the resurrection of animals once thought lost forever, Stockholm University researchers told AFP.
RNA has never been extracted and sequenced from an extinct species before, said Love Dalen, a Stockholm University professor of evolutionary genomics who co-led the project.
The ability to recover RNA from extinct species constitutes a small step (toward) maybe being able to resurrect extinct species in the future, he said.
Dalen and his team were able to sequence RNA molecules from a 130-year-old Tasmanian tiger specimen preserved at room temperature in Sweden's Museum of Natural History.
With this they were able to reconstruct skin and skeletal muscle RNA.
RNA is a molecule that is used to convey information from the genome to the rest of the cell about what it should do.
If you're going to resurrect an extinct animal, then you need to know where the genes are and what they do, and in what tissues they are regulated, Dalen said, explaining the need for knowledge about both DNA and RNA.
The last known living Tasmanian tiger or thylacine, a carnivorous marsupial, died in captivity in 1936 at the Beaumaris Zoo in Tasmania.
After European colonisation of Australia, the animal was declared a pest and in 1888 a bounty was offered for each full-grown animal killed.
Scientists have focused their de-extinction efforts on the Tasmanian tiger as its natural habitat in Tasmania is largely preserved.
- 'Exciting idea' -
Daniela Kalthoff, in charge of the mammal collection at the Museum of Natural History, said the idea of possibly resurrecting the Tasmanian tiger was an exciting idea.
This is a fantastic animal and I would love to see it live again, she said, demonstrating the black-and-brown striped skin the researchers used in their study.
Their findings also have implications for studying pandemic RNA viruses.
Many of the pandemics that have happened in the past have been caused by RNA viruses, most recently the coronavirus but also ... the Spanish flu, Dalen explained.
We could actually go and look for these viruses in wild animal remains stored in dry museum collections. That might actually help us understand the nature of pandemics and where pandemics come from, he said.
The study opens the door to using museum collections in this new way.
There are millions and millions of dried skins and dried tissue from insects, mammals and birds and so on in museum collections around the world, and one could actually now go and recover RNA from all these specimens, Dalen said.