ミツバチにおける新しい性決定経路の進化的起源の証拠
Martin Hasselmann1, Tanja Gempe, Morten Schiøtt
1Department of Genetics, Heinrich Heine University Duesseldorf, Universitaetsstrasse 1, 40225 Duesseldorf, Germany.
Nature
|July 3, 2008
まとめ
ミツバチは,補完性決定体 (csd) 遺伝子でヘテロジゴシティーを介して性別を決定する. 新たに確認されたフェミニザー (fem) という遺伝子は,CSDの上流に作用し,ミツバチの雌性発育に不可欠である.
科学分野:
- 遺伝学 遺伝学とは
- 発達生物学 発達生物学とは
- 進化生物学の進化生物学について
背景:
- ミツバチの性別決定は,補完性性決定因子 (CSD) の位置におけるヘテロジゴシティに依存しています.
- CSDのアレル相互作用と性発達を結びつける正確な分子メカニズムは不明である.
研究 の 目的:
- ミツバチの性決定経路に関与する新しい遺伝子を特定する.
- フェミニザー (女性) とCSD遺伝子の進化的関係を明らかにする.
主な方法:
- RNA干渉 (RNAi) は,特定の遺伝子スペライス変種を倒す.
- 複数のミツバチ種のフェムとCSD遺伝子の比較配列分析.
主要な成果:
- 新しい遺伝子,フェミニザー (fem) は,csd. upstreamの12キロベースで特定されました.
- FemはSR型タンパク質をコードし,代替的にスプライスされ,女性特有の変種が機能的である.
- 雌性特異性の"fem splice"変種をノックダウンした結果,雄性ミツバチとなった.
- 女性のCSDトランスクリプトのノックダウンは,男性特異的な女性スペライス変種につながりました.
- 進化論的分析によると,CSDは,遺伝子の複製を経由して雌の祖先から発生したことを示唆している.
結論:
- フェム遺伝子は,ミツバチの性別決定経路の重要な構成要素であり,メスの発達に必要なものです.
- Femは,CSDの下流に作用し,CSDの異性交性に基づいた性発達のスイッチを実行します.
- 蜂の性別決定の新たな経路の起源は,遺伝子複製とCSDでのポジティブセレクションを含んでいた.
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