発達的に調節されたXistプロモータースイッチは,Xの不活性化の開始を媒介する
C M Johnston1, T B Nesterova, E J Formstone
1MRC Clinical Sciences Centre, Imperial College School of Medicine, Hammersmith Hospital, London, United Kingdom.
Cell
|September 30, 1998
まとめ
マウスのXist遺伝子は,
科学分野:
- エピジェネティクスと遺伝子調節
- 哺乳類の発達について
- ノンコーディングRNAs
背景:
- X染色体不活性化 (XCI) は,雌性哺乳類における1つのX染色体を静止させます.
- Xist遺伝子は,XCIの開始に重要な役割を果たしています.
- 適正なXCIには,XistRNAレベルの調節が不可欠である.
- 以前のXist規制の理解は,単一のプロモーターに焦点を当てていた.
研究 の 目的:
- Xist RNAの安定性を調節する際の代替プロモーター使用の役割を調査する.
- Xist遺伝子転写に関与する新しいプロモーターを特定する.
- X染色体不活性化中にXist RNAの蓄積のメカニズムを理解する.
主な方法:
- トランスクリプトミックの技術を用いたXistRNA同型体の分析.
- 新型Xist遺伝子プロモーターの識別と特徴付け.
- X不活性化を受けている細胞におけるプロモーター活性に対する実験的操作.
- RNAの安定性測定は,安定したXistと不安定なXistのトランスクリプトを区別するためのものです.
主要な成果:
- 代替プロモーターの使用は,安定したおよび不安定なXist RNAの異形を生成します.
- 新しいアップストリームプロモーターは,不安定なXistトランスクリプトを生成します.
- 以前に知られているプロモーターと新しいダウンストリームプロモーターは,安定したXistRNAを生成します.
- プロモーター間の発達的に調節されたスイッチは,Xist RNAの安定化と蓄積を制御する.
結論:
- 代替プロモーターの使用は,XCI中にXist RNAの安定性を調節する重要なメカニズムです.
- プロモータースイッチは,不活性X染色体上の安定したXistRNAの蓄積を保証する.
- この調節メカニズムは,哺乳類の発達中の遺伝子サイレンシングを正確に制御します.
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