性的に敵対的な遺伝子:実験的な証拠
1Biology Board of Studies, University of California, Santa Cruz 95064.
Science (New York, N.Y.)
|June 5, 1992
まとめ
性的に敵対的な変異は,ある性において有益だが,別の性において有害であり,適応的進化に干渉する可能性がある. この研究は,そのような遺伝子が,高害対有益比であっても,新しい性決定遺伝子の近くに蓄積することを示しています.
科学分野:
- 進化遺伝学の進化遺伝学について
- 集団遺伝学 人口遺伝学
- 性紛争は性的な紛争である.
背景:
- 性対抗性 (SA) 選択は,突然変異が男性と女性において相反するフィットネス効果を持つときに起こります.
- 性別間の共有された遺伝子プールが,敵対的なプレオトロピー (pleiotropy) に繋がり,ある性において有益な遺伝子が,他の性において有害である.
- 理論は,SA変異が新しい性決定部位との結合不均衡に蓄積すると予測しています.
研究 の 目的:
- 性的に敵対的な変異が新しい性決定遺伝子の近くに蓄積するという理論を実験的に検証する.
- 制御されたシステムで性的に敵対的な選択の下で遺伝子の進化のダイナミクスを調査する.
主な方法:
- *Drosophila melanogaster*のモデルシステムを利用しました.
- 遺伝子マーカーと人工選択を用いて,新型の性決定システムとして分離するオートソーム遺伝子のペアを作成した.
- 29世代を対象とした実験的進化研究を行った.
主要な成果:
- 理論的予測を支持する実験的証拠を提供した.
- 性的に敵対的な遺伝子の蓄積が,誘発性性性決定遺伝子と密接に結びついていることを実証した.
- 遺伝子変異の害益比が高くても,この蓄積が観察されました.
結論:
- 性的に敵対的な遺伝子は,自然集団で一般的かもしれない.
- 新しい性決定遺伝子の進化は,性的に敵対的な突然変異の蓄積を促す可能性があります.
- このプロセスは,両性の適応的進化に大きく影響を与えます.
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