新しい ゲノム と 化石 の データは,エナメル の 起源 を 明らか に し ます
Qingming Qu1, Tatjana Haitina1, Min Zhu2
1Subdepartment of Evolution and Development, Department of Organismal Biology, Uppsala University, Norbyvägen 18A, SE 75236 Uppsala, Sweden.
Nature
|September 30, 2015
まとめ
脊椎動物の最も硬い組織であるエナメルが 歯とに含まれています この研究は,光魚のエナメルマトリックスタンパク質遺伝子を明らかにし,エナメルホモログとしてガノインを支持し,エナメルがスケールに由来することを示唆しています.
科学分野:
- 進化生物学
- 古生物学
- 遺伝学
背景:
- エナメルは脊椎動物の最も硬い組織で 多くの脊椎動物の歯と皮膚の装甲に不可欠です
- エナメル形成は特定のエナメルマトリックスタンパク質 (EMP) に依存し,軟骨魚には存在しない.
- ガノインは,いくつかの線羽魚で発見され,エナメルの提案された同類物ですが,その遺伝的根拠は不明でした.
研究 の 目的:
- アクチノプテリジアン (線羽魚) のガノインの遺伝的基礎を調査する.
- エナメルとガノインの進化的起源と同質性を決定する.
- これらの組織の形成における エナメルマトリックスタンパク質の役割を調べる
主な方法:
- 化石の魚 (Psarolepis romeri,Andreolepis) の組織成分を分析する
- EMP遺伝子を特定するために,斑点ガール (Lepisosteus oculatus) の遺伝子発現分析.
- 比較ゲノミクスと進化生物学のアプローチ
主要な成果:
- Psarolepis romeriは,エナメルで覆われた皮膚のオドントードと裸の歯茎を展示し,化石の証拠を提供します.
- 斑点のガは皮膚で発現するエナムとAMBN遺伝子を有しており,ガノイン形成に関与している可能性が高い.
- 遺伝子データはガノインがエナメルと同型であるという仮説を強めている.
結論:
- 遺伝学的な証拠は ガノインがエナメルに 同性組織であることを支持している.
- 化石の証拠は 皮膚の骨格でエナメルが生まれたことを示唆している
- エナメルは,保存されたパターンの境界線を通して,スケールから他の皮膚要素に拡大した可能性があります.
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