CTCFとコヘシン媒介のクロマチンループのダイナミクスは,生細胞イメージングによって明らかになった
Michele Gabriele1,2,3, Hugo B Brandão1,2,3, Simon Grosse-Holz4,5
1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Science (New York, N.Y.)
|April 14, 2022
まとめ
動物のゲノムにおけるクロマチンのループは希少でダイナミックで ゲノム折り畳みに関する以前のモデルに 挑戦しています この研究は,完全にループされたDNAではない単一のCTCF境界が,主に機能的相互作用を調節することを明らかにしています.
科学分野:
- ゲノミクス
- 分子生物学
- 細胞生物学
背景:
- 動物のゲノムは,CTCFとコヘシンタンパク質によってループとトポロジカルアソシエイトドメイン (TAD) に編成されている.
- TADs内のクロマチンのループ形成と安定性のダイナミックな性質は,ほとんど特徴づけられていない.
研究 の 目的:
- マウスの胚性幹細胞におけるFbn2 TADにおけるクロマチンのループのダイナミクスを直接視覚化および定量化する.
- クロマチンループの形成,安定性,機能的影響を調査する.
主な方法:
- クロマチンのループダイナミクスを観察するために超高解像度生細胞画像を用いた.
- ループ運動を定量的に分析するためにベイジアン推論を用いた.
- マウスの胚性幹細胞におけるFbn2 TADに焦点を当てた.
主要な成果:
- Fbn2ループは希少で,ループの割合は3~6.5%であることが判明した.
- ループの平均寿命は10〜30分と推定されています.
- Cohesin-extrudedループは,TAD内に存在し,CTCFの両方の境界を約92%で橋渡ししなかった.
結論:
- Fbn2 TADは高度にダイナミックで,ループは安定した構造ではなく,一時的なものである.
- 単一のCTCF境界線は,完全に形成されたCTCF-CTCFループよりも,機能的な相互作用の重要な規制者であるように見える.
- これらの発見は,CTCFとコヘシンによるゲノム組織と規制の既存のモデルに挑戦しています.
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