藻類は,細菌との共生関係を介してビタミンB12を取得します
Martin T Croft1, Andrew D Lawrence, Evelyne Raux-Deery
1Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
Nature
|November 4, 2005
まとめ
多くの藻類は,成長のために,主にメチオニン合成酵素のために,ビタミンB12 (コバラミン) を必要とします. このビタミンB12オクストロフィーは,細菌が源として機能した可能性が高いため,何度か進化し,重要な藻類-細菌共生を示しています.
科学分野:
- バイオケミストリー バイオケミストリー
- マリン・バイオロジー マリン・バイオロジー
- 微生物学 微生物学とは
背景:
- ビタミンB12 (コバラミン) は人間の健康に不可欠ですが,植物には依存性酵素が不足しているため欠落しています.
- 藻類は植物とは異なり,ビタミンB12が豊富である可能性がありますが,これらの生物におけるその役割と源は不明です.
- 調査された藻類の半分以上 (326種中171種) はコバラミンオクストロフであり,成長には外部からビタミンB12を必要とします.
研究 の 目的:
- 藻類におけるビタミンB12の代謝作用を解明する.
- 藻類王国におけるコバラミンオクストロフィーの進化的起源を調査する.
- 藻類のビタミンB12の源を特定するために.
主な方法:
- 成長のためのコバラミン要件を決定するために,326種類の藻類を調査しました.
- 藻類の代謝におけるビタミンB12の機能を分析した.
- コバラミンオクストロフィーの進化パターンを調査した.
主要な成果:
- ビタミンB12は,主に藻類のメチオニン合成酵素のコファクターとして機能します.
- コバラミンオクスオトロフィーは藻類で独立して何度も進化しており,おそらくビタミンB12独立メチオニン合成酵素の喪失によるものである.
- バクテリアの共生生物は,オクスオトロフ藻類のビタミンB12の潜在的な源として特定されています.
結論:
- 藻類におけるビタミンB12の主な役割は,メチオニン合成酵素のコファクターである.
- 藻類における広範囲に広がるコバラミンオクストロフィは,酵素損失によって引き起こされるコンバージェント進化を強調しています.
- ビタミンB12の獲得のために藻類と細菌の間に重要な共生関係が存在する.
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