蝶の色覚を拡大する三方向ストカスティック選択の背後にある分子論理
Michael Perry1, Michiyo Kinoshita2, Giuseppe Saldi3
1Department of Biology, New York University, New York, New York 10003, USA.
Nature
|July 8, 2016
まとめ
蝶は新しい遺伝的メカニズムを使って 2つの光感受細胞を使って 3種類のオマチディアを作り 色覚を拡張します これはより複雑な色比較と 多様な環境への適応を可能にします
科学分野:
- * 発達生物学
- * 神経科学
- * 進化生物学
背景:
- * 蝶は複雑な色覚を持ち,異なる単位の目 (オマチディア) にある複数のロドプシンタンパク質に依存しています.
- * ドロソフィラ・メラノガスターは,転写因子で制御される2つのオマチディアルのタイプを使用し,蝶は3つのタイプを使用します.
- * 蝶 の 3 種類 の オマチディアル の 遺伝 的 な 基礎 を 理解 する こと は,蝶 の 色彩 感知 能力 の 向上 を 説明 する 鍵 と なり ます.
研究 の 目的:
- * 蝶の3つのストキャスティックオマティディアル型を生成する発達メカニズムを解明する.
- * 蝶の網膜の発達における転写因子の作用を調査する.
- * このメカニズムが 色彩認識の拡大と 進化的適応にどのように貢献するのかを理解する.
主な方法:
- * 日本黄色いスワローテール (Papilio xuthus) とペインテッド・レディ (Vanessa cardui) の蝶のオマティディアルの発達を比較した分析
- CRISPR/Cas9遺伝子編集を用いて,光受容体細胞の脊椎のない遺伝子をノックアウトした.
- * 野生型と変異型蝶のロドプシン発現パターンとオマチディアル型分布を調べた.
主要な成果:
- * 蝶はオマティジウムごとに2つのR7のような光受容体を持ち,ストキャスティックな無脊椎表現が青色や紫外線に対する感受性を決定する.
- * この二元決定は,調整されたロドプシン発現と組み合わせて,3つの異なるオムマチディアルタイプを生成します.
- * 脊髄のないノックアウトは,均一なUV/UVオムマチディアをもたらし,オムマチディアの多様性を生み出す上で重要な役割を果たしました.
結論:
- * 2つのバイナリストカスティック決定の単純な遺伝的メカニズムが蝶の3つのオムマチディアルタイプを生成します.
- * この戦略により,追加的なロドプシン (例えば赤に敏感な) が配備され,色覚が向上します.
- * 発見は,発達的多様性や進化的新奇性を生み出すために,潜在的に一般化可能なメカニズムを示唆しています.
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