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バシルス・トゥリンギエンシス の 毒素 の 継続 的 な 進化 は,昆虫 の 抵抗 力 を 克服 する
Ahmed H Badran1,2, Victor M Guzov3, Qing Huai3
1Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
Nature
|April 28, 2016
まとめ
科学者はバチルス・チューリンギエンシス (Bt) の毒素を進化させ 昆虫の抵抗力を克服しました 新しいBt毒素は 昆虫の受容体に結合し 耐性のある害虫を殺し 農作物を保護します
科学分野:
- 生物化学
- 分子生物学
- 昆虫学
背景:
- バチルス・チューリンギエンシス (Bt) の δ-エンドトキシンは,人工栽培作物にとって重要な殺虫剤タンパク質である.
- Bt毒素に対する昆虫の耐性は この害虫対策の持続可能性を脅かしています
研究 の 目的:
- 昆虫の受容体への結合を強める新しいBt毒素の変種を進化させる
- Bt毒素に対する 既存の昆虫の抵抗を克服するためです
主な方法:
- 高アフィニティのタンパク質相互作用を迅速に進化させるため,ファージ支援連続進化 (PACE) を採用した.
- Cry1Ac Bt毒素の変種は,Trichoplusia niからカデリンのような受容体 (TnCAD) に結合するために進化しました.
主要な成果:
- 進化したCry1Ac変種はTnCAD (解離常数Kd=11−41nM) に高親和結合を示した.
- これらの変種は,野生型のCry1Acに耐性のあるTnCADを発現する昆虫の細胞を効果的に殺しました.
- 進化した毒素は,野生型Cry1Acと比較して,Cry1Ac耐性T. ni昆虫に対して最大335倍強力であった.
結論:
- 遺伝子組み換えBt毒素は 抗生物質を克服できます
- このアプローチは,耐性昆虫集団に対するBt毒素の有効性を回復し,野生型の効力に接近します.
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