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初期のプロカリオットエンドシンバイオシスの証拠
1Department of Molecular, Cellular and Developmental Biology, University of California, Los Angeles, California 90095, USA. lake@mbi.ucla.edu
Nature
|August 21, 2009
まとめ
この研究では,グラム陰性細菌は,古代のアクチノバクテリアとクラストリディアの共生から生まれたことを示唆しています. このプロカリオット現象は生命に深い影響を及ぼし,真核生物の出現と地球の酸素大気を可能にしました.
科学分野:
- 進化生物学の進化生物学について
- 微生物ゲノミクス
- プロカリオットの進化
背景:
- エンドシンビオティックイベントは,真核生物の生命を著しく形作っていることが知られている.
- エンドシンビオシスのプロカリオット進化への影響は,一般的に最小限と考えられています.
- グラム陰性細菌は,独特の二重膜構造を持っています.
研究 の 目的:
- グラム陰性プロカリオットの進化的起源を調査する.
- プロカリオットの進化におけるエンドシンビオシスの潜在的な役割を調査する.
- シンビオティックイベントの証拠としてタンパク質ファミリーフローを分析する.
主な方法:
- 古代バクテリアの系統間のタンパク質ファミリーの遺伝子フローの分析.
- 比較ゲノミクスは,先祖の関係と遺伝子転送を推論する.
- 進化の歴史を再構築するための系統遺伝分析.
主要な成果:
- 証拠によると,グラム陰性細菌は,古代のアクチノバクテリアと古代クラストリジウムとの間の共生イベントから生じたことを示唆しています.
- このエンドシンビオティックな出来事は,二重膜のプロカリオット分類に成功した結果となった.
- タンパク質ファミリーフローは,この新しい系統に寄与する重要な遺伝子交換を示しています.
結論:
- エンドシンビオシスによるグラム陰性細菌の起源は,生命の歴史における重要な出来事です.
- このプロカリオット共生は,ユーカリオットの後の進化に決定的であった.
- これらのバクテリアによって促進された酸素 fotosynthesisの出現は,地球の大気を変えました.
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