S段階の初期と後半のS段階における転写能力の確立
Jianmin Zhang1, Feng Xu, Tamar Hashimshony
1Department of Cellular Biochemistry and Human Genetics, Hebrew University, Ein Kerem, Jerusalem, Israel.
Nature
|November 15, 2002
まとめ
初期のS相核に導入された場合,外因的な遺伝子発現はより高い. このDNA複製のタイミングは,染色体構造に影響を与え,潜在的に表遺伝子状態を維持することによって,遺伝子発現に影響を与えます.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- エピジェネティクス エピジェネティクス
背景:
- DNA複製のタイミングは動物細胞でプログラムされており,遺伝子領域は固定されたS相スロットで複製されます.
- ハウスキーピング遺伝子は早期に複製され,組織特異遺伝子は,発現の組織を除いて,遅れて複製されます.
研究 の 目的:
- Sフェーズ中の転写能力の違いが変数遺伝子複製のタイミングを説明するかどうかを調査する.
- DNA複製のタイミングが遺伝子発現状態の確立と維持に影響を与えるかどうかを判断する.
主な方法:
- 異なるS相段階の細胞に核DNAを注入する.
- 外生的な遺伝子発現レベルの分析.
- クロマチン構造の評価,特にヒストンのアセチル化.
主要な成果:
- S相初期核に注入された外来遺伝子は,S相後半核に注入された遺伝子と比較して,著しく高い転写活性を示した.
- 注入されたDNAの確立された発現状態は,細胞分裂を通じて維持された.
- S期末に注入されたDNAは抑制され,クロマチンが含有するデセチル化ヒストンと関連し,後期複製の染色体DNAに似ています.
結論:
- 複製のタイミングは,転写能力の確立の能力に影響を与え,初期のS段階はより許容的である.
- クロマチンの構造,特にヒストンのアセチル化が,S相後半の遺伝子発現を抑制する役割を果たします.
- DNA複製のタイミングと遺伝子発現の間に機械的なリンクが存在し,潜在的に表遺伝子状態の維持を説明します.
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