RNA依存性エピジェネティック・サイレンシングは,イントロニック・リピート・エクスパンションによって引き起こされる転写下調を誘導する
Hannes Eimer1, Sridevi Sureshkumar1, Avilash Singh Yadav1
1School of Biological Sciences, Monash University, Clayton Campus, VIC 3800, Australia.
Cell
|July 31, 2018
まとめ
三重の繰り返し拡張は短い干渉RNA (siRNA) と表遺伝的変化を誘発し,遺伝子の静止を引き起こします. RNA依存性DNAメチル化 (RdDM) を含むこのメカニズムは,これらの拡張が病気の表型を引き起こす方法を説明します.
科学分野:
- 遺伝学
- エピジェネティクス
- 分子生物学
背景:
- 内臓の三重膨張は フレイドライヒの縮症のような病気と 関連しています
- 遺伝子発現の低下はこれらの拡大に伴いますが,そのメカニズムは不明です.
研究 の 目的:
- 内部三重複拡張によって引き起こされる転写のダウンレギュレーションの基礎にある分子機構を調査する.
- この過程における表遺伝的変異と小型のRNAの役割を明らかにする.
主な方法:
- アラビドプシス・タリアナのIIL1遺伝子の内定GAA/TTCトリプルエクスパンションの分析
- DICER LIKE-3 (DCL3) とRNA依存DNAメチル化 (RdDM) 経路のコンポーネントの役割を調査する.
主要な成果:
- IIL1におけるトリプレート・リピート・エクスパンションは,24ntのsiRNAの蓄積と抑制ヒストンの痕跡をもたらした.
- DCL3またはRdDM経路のコンポーネントのノックダウンにより,IIL1のダウンレギュレーションおよび関連するフェノタイプが抑制されました.
- siRNA生物生成とRdDMは,繰り返し拡張誘発遺伝子サイレンスに不可欠です.
結論:
- トリプレット・リピート・エクスパンションは局所的な小干渉RNA (siRNA) の生成を誘導する.
- この siRNA 生成は,RNA依存性DNAメチル化 (RdDM) による転写下調を媒介する.
- この発見は 遺伝子の増殖を 遺伝子の静止と 病気に結びつける 新種の表遺伝的メカニズムを明らかにしています
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