18SリボソームRNAの配列から得られた証拠は,ランプリとハグフィッシュが自然集団を形成していることを示している
1Department of Ecology, Ethology, and Evolution, University of Illinois, Urbana 61801.
まとめ
リボソームのRNA配列の系統遺伝学的分析は,サイクロストームの単一属性を支持する. この発見は,ランプレイがを持つ脊椎動物とより密接に関連していることを示唆する最近の見解に異議を唱える.
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
- 脊椎動物の古生物学について
背景:
- 伝統的に,ランプリとハグフィッシュ (サイクロストーム) は単一のモノフィレティック群と考えられていた.
- 最近の形態学的な分析によると,ランプレイはハグフィッシュよりも,のある脊椎動物 (gnathostomes) により密接に関連していることを示唆しています.
研究 の 目的:
- ランプレイ,ハグフィッシュ,その他の脊椎動物間の遺伝関係を調査する.
- 初期の脊椎動物の進化史を分子データに基づいて再評価する.
主な方法:
- 18SリボソームRNA (rRNA) 遺伝子配列を用いた系統遺伝分析.
- 2匹のハグフィッシュ,2匹のランプレイ,2匹のチュニカート,1匹のランチェレット,および様々なグナトストームの配列データの比較.
主要な成果:
- 分子データは,サイクロストームのモノフィリーを強く支持し,ランプレイとハグフィッシュを一緒にグループ化しています.
- 18S rRNA配列のデータは,ランプレイがハグフィッシュよりもグナトストームと密接に関連しているという仮説に矛盾しています.
結論:
- サイクロストームのモノフィリーは18S rRNA配列データによって支持されています.
- これらの発見は,初期の脊椎動物の進化と形態学的特徴の解釈に関する確立された仮説の再評価を必要とします.
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