バクテリアの有害な変異の間の相乗効果相互作用のテスト

S F Elena¹, R E Lenski

¹Center for Microbial Ecology, Michigan State University, East Lansing 48824, USA. selena@pilot.msu.edu

Nature

|December 6, 1997

まとめ

セックスの進化は謎である. この研究は,有害な突然変異がシナージで相互作用しないことを発見し,セックスがこれらの突然変異を浄化するという考えに異議を唱えた.

科学分野:

進化生物学の進化生物学について
遺伝学遺伝学とは
微生物学微生物学とは

背景:

性繁殖の起源と持続は,生物学における重要な未解決問題である.
変異決定論的仮説は,性によって有害な変異をシネージの相互作用によって除去することを示唆している.

研究の目的:

性別の進化に関する変異決定論的仮説を検証する.
複数の変異とそれらの相互作用のフィットネス効果を調査する.

主な方法:

一,二,または三つの変異を持つ225のEscherichia coli遺伝子型を生成しました.
無変異の競争相手に対する相対的適性を測定する.
双方向変異の相互作用を評価するために27の再結合遺伝子型を構築しました.

主要な成果:

変異数と平均フィットネスの関係は,ほぼログ・リニア的であった.
変異の間の相互作用が観察されましたが,それらはしばしば相乗効果と同じくらい敵対的でした.
この結果は,性進化のシナギスティック・エピスタシスの要求を裏付けていない.

結論:

この発見は,変異決定論仮説を支持しません.
交互効果のあるエピスタシスは,性の進化の必要条件ではないかもしれない.
セックスの維持を理解するためにさらなる研究が必要です.

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