高級霊長類における色覚遺伝子の適応的進化
S K Shyue1, D Hewett-Emmett, H G Sperling
1Human Genetics Center, School of Public Health, University of Texas, Houston 77225, USA.
Science (New York, N.Y.)
|September 1, 1995
まとめ
リス類のサルとサメは,非常に異なった色彩のフォトピグメント遺伝子を示しており,独立した進化または広範な遺伝子変換を示唆しています. これらの異なるアレルは,過剰に支配的な選択により,何百万年もの間存続した可能性が高い.
科学分野:
- 進化遺伝学の進化遺伝学について
- 霊長類の分子進化について
- 視覚染色体の遺伝子進化
背景:
- X-リンクされた色フォトピグメントの位置は,視力にとって極めて重要です.
- この場所のポリモルフィズムは,色覚の変動につながる可能性があります.
- これらの遺伝子の進化的動態を理解することは,霊長類の適応に関する洞察を提供します.
研究 の 目的:
- カラーフォトピグメントロカスにおけるポリモルフアレルのイントロン4配列を分析する. リス類の猿とモモサギ.
- 各種内のこれらのアレルの進化史と分岐パターンを調査する.
- アレルの多様性と持続性を駆動するメカニズムを推論する.
主な方法:
- X-リンクされた色フォトピグメント遺伝子のイントロン4領域の配列決定.
- 各霊長類種の複数のアレル間の比較配列分析.
- 系統遺伝分析と分子集団遺伝学のアプローチ.
主要な成果:
- 異なったポリモルフィックアレルは,リス類の猿とモモサギの両方において異なった異性多様性があることが判明した.
- トライアレル系は,それぞれの系統で独立して進化したようで,または広範な遺伝子変換を含んでいる.
- 証拠によると,少なくとも7つの削除/挿入 (合計14個) が,各種内のアレル間で均質化されたことを示している.
結論:
- 観察されたアレル相違は,おそらく500万年以上,長い進化の持続を示唆しています.
- 過剰支配的選択は,これらの高度に異なるアレルを維持する主要なメカニズムとして提案されています.
- この発見は,新世界猿の視覚染色体遺伝子のユニークな進化の経路を強調しています.
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