ゲノム 進化 の 速度 と 様式 50,000 世代 の 実験 で
Nature
|August 2, 2016
まとめ
大抵の有益な変異は5万世代に渡ってエシェリキア・コレイ菌群の適応を促す. 適格性が向上するにつれて 有益な突然変異の比率は低下し 中性突然変異は着実に蓄積します
科学分野:
- 進化生物学
- ゲノミクス
- 微生物の進化
背景:
- 自然選択の適応プロセスは 変異率,効果,相互作用に依存しています
- 進化する系統における 有益な突然変異の定量化が難しいのです
研究 の 目的:
- エシェリキア・コリ菌群の遺伝子動態を5万世代以上分析する.
- 適応中の有益な突然変異の割合を決定する.
- ゲノムの進化を左右する力を理解するために
主な方法:
- 12の集団から264のEscherichia coliゲノムの全ゲノムシーケンス.
- バトルネック条件下での変異蓄積線との比較分析
- 変異の種類と頻度に関する統計的分析
主要な成果:
- 祖先の変異率を維持している集団は,ほとんどの固定変異が有益なモデルをサポートします.
- 人口の健康状態が向上するにつれて 有益な変異の割合は減少する.
- 非同義的な変異,遺伝子間の変異,挿入,削除は適応した集団で過剰に表現されています.
結論:
- 適応する集団で高い頻度に達するほとんどの変異は,選択によって好まれる.
- ゲノム進化は 選択的・中立的な力の ダイナミックなバランスによって支配されます
- この発見は 微生物の進化の軌道を 明らかにしています
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