数百万 年 前の DNA は マンモス の ゲノム 歴史 を 明らか に し て い ます
Tom van der Valk1,2,3, Patrícia Pečnerová4,5,6, David Díez-Del-Molino7,4,5
1Centre for Palaeogenetics, Stockholm, Sweden. tom.vandervalk@scilifelab.se.
Nature
|February 18, 2021
まとめ
100万年以上前の DNAは シベリアの2つの異なる マンモスの血統を示しています これらの血統がハイブリッド化し コロンビアのマモスを形成し マモスの進化の初期に 寒さに適応する遺伝子が存在した.
科学分野:
- パレオゲノミクス
- 進化生物学
- マンモスの遺伝子
背景:
- 定時的なゲノムデータは,種化と進化を理解するために不可欠です.
- これまでのゲノム研究は 入手可能なDNAサンプルの年齢によって制限されていました
- プレイストセンの初期には78万年以上前の古代DNA (aDNA) が必要である.
研究 の 目的:
- 早期・中期プレイストセンの マンモスの全ゲノムデータを 復元・分析する
- マンモスの進化史や 系統の分岐や 種の進化を調査する
- マンモスの遺伝子の変化のタイミングを 調べるためです
主な方法:
- マンモスの3つの標本から全ゲノムデータを回収した (その2つは100万年以上前のもの).
- 系統の分岐と混入を推論する 系統遺伝学と集団遺伝学的分析
- 適応のためのタンパク質コーディング領域の比較ゲノム解析
主要な成果:
- プレイストセンの初期東シベリアにおける2つの異なるマモスの系統の識別.
- 一方の系統は羊毛のマンモスに繋がり もう一方の系統は北米のマンモスの祖先でした
- コロンビアのマモスは,これらの系統の間の中期プレイストセンのハイブリッド化イベントから発生した.
- 寒さに適応した 重要な遺伝的変化は 100万年以上前に存在していました
結論:
- 進化の過程についての理解を 大きく広げることができます
- マンモスの種化には 異なる系統と 古代のハイブリッド化イベントが含まれていました
- 寒さへの適応を含む長期の適応進化は マンモスの歴史の初期に起きました
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