ドロソフィラの非コーディングDNAの適応進化
1Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California San Diego, La Jolla, California 92093, USA. pandolfatto@ucsd.edu
Nature
|October 21, 2005
まとめ
ドロソフィラの非コーディングDNAの大部分は機能的に重要であり,制限と陽性選択の両方で進化しています. これは,非コーディングDNAの適応的変化が進化において一般的であることを示唆しています.
科学分野:
- 進化生物学の進化生物学について
- ゲノミクスゲノミクスとは
- 分子進化は分子進化である.
背景:
- ユカリオットのゲノムには,主に未知の機能を持つ非コーディングDNAが多く含まれています.
- 非コーディングDNAの進化のダイナミクスを理解することは,ゲノム進化の完全なイメージを得るために非常に重要です.
研究 の 目的:
- ドロソフィラの非コーディングDNAの様々なクラスに作用する進化の速度と選択的圧力を調査する.
- 非コーディングゲノム領域における機能的重要性と適応的進化の範囲を決定する.
主な方法:
- 異なるドロソフィラ種のDNA配列の比較分析.
- 浄化と陽性選択を区別するために拡張されたマクドナルド・クレイトマン試験の適用.
- 非コーディングDNAの進化を同名サイトと比較することによって,進化的制約の推定.
主要な成果:
- 非コーディングDNA領域 (インタージェニック,UTR,イントロン) は,同名サイトよりもゆっくりと進化し,選択的制約を示しています.
- ポリモルフィズムに対する差異の有意な過剰は,これらの地域における適応的進化を示唆する.
- 推定によると,非コーディング核酸の40~70%が制約を受け,その20~60%の差異はポジティブ・セレクションによるものである.
結論:
- 非コーディングDNAの大部分は,機能的に有意であり,浄化と適応進化の両方によって形作られています.
- 非コーディングDNAにおける適応的進化は,以前考えられていたよりも,ドロソフィラ・メラロノガスターの進化においてより一般的かもしれない.
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