系統遺伝学的な分析は,細菌から脊椎動物への水平遺伝子転送を裏付けていない
M J Stanhope1, A Lupas, M J Italia
1Bioinformatics, GlaxoSmithKline, Collegeville, PA 19426, USA. Michael_J_Stanhope@sbphrd.com
Nature
|June 22, 2001
まとめ
水平遺伝子転送 (HGT) は,ゲノム進化の鍵である. ある研究では,ヒトにおける最も提案されたHGT遺伝子は,実際に共通の祖先から受け継がれ,直接的な細菌伝染ではないことが判明しました.
科学分野:
- ゲノミクスゲノミクスとは
- 進化生物学の進化生物学について
- 分子生物学は分子生物学である.
背景:
- 水平遺伝子転送 (HGT) は,プロカリオットのゲノム進化の重要な原動力である.
- 最近のヒトゲノム解析では,細菌と脊椎動物の間で多数の直接的なHGTイベントが示唆されています.
- 多細胞生物におけるこのような現象は,細菌系においてのみ発生することが予想されます.
研究 の 目的:
- ヒトゲノムにおけるバクテリアと脊椎動物の間の提案された直接的なHGTイベントの妥当性を調査する.
- HGT.を被ったと疑われる遺伝子の進化的起源を決定する.
主な方法:
- ポリメラーゼ連鎖反応 (PCR) によりヒトゲノムで確認された28の遺伝子の系統遺伝分析.
- 非脊椎動物の発現配列タグ (ESTs) を含むデータベースに対する遺伝子配列の比較.
主要な成果:
- 系統遺伝学的分析は,最も推定されるHGT遺伝子が,より古くから派生したエウカリオットに存在することを示しました.
- 遺伝子の存在は,バクテリアから脊椎動物への直接的なHGTよりも,共通の祖先によってよりよく説明されます.
- 中間ユカリオットのない脊椎動物への直接的な細菌HGTの証拠は支持されなかった.
結論:
- 人間のゲノムにおける提案された細菌HGTイベントのほとんどは,共通の祖先の人工物である可能性が高い.
- 系統遺伝分析は,HGTイベントを正確に特定するために不可欠です.
- バクテリアから脊椎動物への直接的なHGTは,これまで考えられていたよりも少ない.
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