抑制と3D再構成は,進化的に再編成されたゲノムにおける規制の衝突を解決する
Alessa R Ringel1, Quentin Szabo2, Andrea M Chiariello3
1Max Planck Institute for Molecular Genetics, Berlin, Germany; Institute for Medical and Human Genetics, Charité Universitätsmedizin Berlin, Berlin, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany.
Cell
|September 30, 2022
まとめ
新しい遺伝子は既存の規制領域に 統合されても 破壊されない. 特定の文脈でのDNAメチル化は干渉を防止し,独立した遺伝子発現と進化の柔軟性を可能にします.
科学分野:
- ゲノミクス
- 発達生物学
- 進化生物学
背景:
- 開発中の遺伝子発現には 規制環境が不可欠です
- 新しい遺伝子の組み込む過程で規制の整合性を維持することは,十分に理解されていません.
- トポロジカル・アソシエイトドメイン (TAD) はゲノムを組織し,遺伝子調節に影響を与えます.
研究 の 目的:
- 哺乳類特有の遺伝子 (Zfp42) が,既存の遺伝子 (Fat1) の発現に影響を与えることなく,古代のTADに統合された方法を調査する.
- 進化の過程で共有された TAD 内の独立した遺伝子調節を維持するメカニズムを解明する.
- TADs内の規制の複雑性が一般的な進化現象であるかどうかを判断する.
主な方法:
- 胚性幹細胞 (ESC) と胚性肢体におけるZfp42とFat1の遺伝子発現と調節メカニズムを調査した.
- 分析されたクロマチン活性,CTCF/コヘシン結合,増強剤活性,DNAメチル化パターン.
- TADの分割と核封筒の取り付けを検証した.
- TADs内の遺伝子分布の全ゲノム分析を行った.
主要な成果:
- Zfp42 と Fat1 は ESC で TAD 分割によって物理的に分離され,独立した発現を誘導する明確な強化剤があります.
- CTCF/コヘシンではなく,クロマチンの活動がESCの分離を促している.
- 胚の肢体では,Zfp42はFat1のTAD内で不活性であり,Fat1強化剤には反応しない.
- 文脈に依存するDNAメチル化で 強化剤の不適合性や核結合は Zfp42の反応不全を 説明している
- ほとんどのTADはゲノム全体で複数の独立した発現遺伝子を含んでいます.
結論:
- クロマチンの活性と文脈依存のDNAメチル化を含む様々なメカニズムは,既存のロシ内に独立して調節される遺伝子の統合を容易にする.
- TAD内の規制の複雑さは,脊椎動物の進化の共通の特徴です.
- この研究は,ゲノムが新しい遺伝子をどのように取り入れ,同時に規則的整合性を維持するかについての洞察を提供します.
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