分子レベルでの選択の集団遺伝的テストである
M F Taylor1, Y Shen, M E Kreitman
1Department of Entomology, Center for Insect Science, University of Arizona, Tucson 85721, USA.
まとめ
自然淘汰は分子進化の原動力である. 研究者は,ピレトロイド殺虫剤に曝されたたばこ芽虫の集団の電圧ゲートされたナトリウムチャネルを検査することで,これをテストし,選択を確認しました.
科学分野:
- 集団遺伝学 人口遺伝学
- 分子進化は分子進化である.
- 昆虫剤に対する耐性が高い.
背景:
- 分子進化における自然選択の役割は,選択の特定の予測を裏付けるのではなく,中立理論を反証することによってしばしば推論される.
- 選択の役割を理解するには,DNA多形化に関する予測の直接的なテストが必要です.
研究 の 目的:
- DNAポリモルフィズムに作用する自然選択の特定の予測の集団遺伝子テストを実施する.
- 煙草の芽虫の集団における電圧誘導ナトリウムチャネルの分子進化にピレトロイド殺虫剤の使用の影響を調査する.
主な方法:
- 選択を研究するための制御された実験条件として,ピレトロイド殺虫剤の適用を活用した.
- ピレトロイドの既知の分子標的として,電圧ゲートされたナトリウムチャネルに焦点を当てた.
- ナトリウムチャネルマーカーのアレル周波数と,異なる集団における任意の遺伝的場所のアレル周波数を比較した.
主要な成果:
- ナトリウムチャネルマーカーのアレル周波数において,地理的に有意な異質性が観察されました.
- この異質性は,ピレトロイドの選択圧力の差異と直接関連していた.
- 任意の場所でのアレル周波数は,比較可能な地理的変動を示せず,選択の役割を支持しました.
結論:
- この研究は,特定の分子標的におけるDNA多形性を形作る自然選択の直接的な証拠を提供します.
- ピレトロイド殺虫剤の使用は強力な選択力として作用し,標的遺伝子の検出可能な遺伝的差異につながります.
- この研究は,現実世界の実験条件を用いて,分子進化における選択の役割をテストするための方法を検証しています.
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