光合成の初期の進化の分子証拠
J Xiong1, W M Fischer, K Inoue
1Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Science (New York, N.Y.)
|September 8, 2000
まとめ
この研究は,さまざまな細菌の遺伝子配列を分析することによって,光合成の進化を調査しています. この発見は,紫色の細菌が最初に現れたことを示しており,初期の光栄養生物に関する以前の理論に異議を唱えている.
科学分野:
- 微生物学 微生物学とは
- 進化生物学の進化生物学について
- バイオケミストリー バイオケミストリー
背景:
- 光合成の進化史は,遺伝データが限られているため,ほとんど理解されていない.
- 光合成の鍵となる遺伝子は,さまざまな光合成生物で分析されています.
研究 の 目的:
- 光合成の初期の進化と光合成遺伝子の起源を調査する.
- 初期の光合成細菌の遺伝関係を再構築する.
主な方法:
- クロロビウム・テピドゥムとクロロフレクサス・オーランティアカス.のゲノム解析.
- 距離,最大節制,最大確率のメソッドを用いた系統遺伝分析.
- バクテリオクロロフィール/ポルフィリン生物合成,カロテノイド生物合成,電子移転に関与する遺伝子の分析.
主要な成果:
- 系統遺伝学的分析によると,ヘリオバクテリアは酸素光合成系統の最後の共通の祖先に最も近いものである.
- 緑の硫黄と緑の非硫黄のバクテリアは,互いに最も近い親類である.
- 紫色のバクテリアは,初期の新興光合成系統として特定され,以前の仮説に異議を唱えました.
結論:
- バクテリオクロロフィルの生物合成は,クロロフィルの生物合成より前に進化した可能性があり,グラニックの仮説と矛盾しています.
- この研究は,光合成の進化的経路に関する新しい洞察を提供します.
- 光合成遺伝子の系統遺伝的分析は,以前の方法よりもより堅固な進化的枠組みを提供している.
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