サイクロストームにおける内耳の発達と脊椎動物の半円の進化
Shinnosuke Higuchi1,2, Fumiaki Sugahara3,4, Juan Pascual-Anaya4
1Department of Biology, Graduate School of Science, Kobe University, Kobe, Japan.
Nature
|December 7, 2018
まとめ
脊椎動物の内耳の進化は明示されている.ハグフィッシュの単一の半円形運河は派生する特徴であり,の脊椎動物の横の運河は二次的に進化した.
科学分野:
- 進化生物学
- 発達生物学
- 比較解剖学
背景:
- の脊椎動物 (gnathostomes) は内耳に3つの半円形の管があり,進化論の研究に不可欠です.
- のない脊椎動物 (オストラコダーム) には2つの運河があり,横の運河が欠けていた.
- 現代のサイクロストーム (ランプレイとハグフィッシュ) は様々な運河数を持ち,ハグフィッシュは1つ,ランプレイは通常2つで,進化論的な解釈を複雑にします.
研究 の 目的:
- サイクロストームの内耳の発達経路を研究し,特にラムプレイとハグフィッシュを研究する.
- 脊椎動物における半円数と横の進化的起源を明らかにする.
主な方法:
- 眼泡の微分化に関する詳細な観察 ランプレイ (Lethenteron camtschaticum) とハグフィッシュ (Eptatretus burgeri)
- サイクロストームの内耳発達中のOTX遺伝子を含む遺伝子発現パターンの分析.
主要な成果:
- ランプリー内耳の発達は,初期のグナトストームの発達に似た2つの沈み込みで始まります.
- ハグフィッシュの状態を反映した 単一の運河を形成します
- ハグフィッシュのシングルチャネルは 二次的に派生した特徴で 原始的なものではありません
- グナトストームの横管は下流の発達経路を通して二次的に進化した.
結論:
- シングル・セミサークル・チャネルは原始性の仮定に 異議を唱える特質です
- 脊椎動物の内耳の進化の経路,特に側耳の獲得は,発達に関する洞察によって明らかにされています.
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