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植物性細胞におけるゲメトジェニック遺伝子の不適切な発現は,ユニパレンタルディソミーを引き起こします
H Diego Folco1, Venkata R Chalamcharla1, Tomoyasu Sugiyama1
1Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
Nature
|February 16, 2017
まとめ
RNA干渉 (RNAi) またはMmi1の欠陥は,ゲメトゲン遺伝子の早期発現を可能にすることで,ユニパレンタルディソミー (UPD) を引き起こします. これはヒトの病気に関連した現象である染色体分離ミスとUPDにつながります.
科学分野:
- 遺伝学
- 分子生物学
- 細胞生物学
背景:
- シングル・ペアレント・ディソミー (Single-parent disomy,UPD) は,同性染色体の両方を1つの親から受け継ぐことであり,しばしば先天性疾患や癌につながる.
- 主に染色体分離に起因する UPD の根本的な原因はほとんど不明です.
研究 の 目的:
- UPDを駆動する分子メカニズムをモデルシステムとして分裂酵母 Schizosaccharomyces pombe を用いて調査する.
- 植物性二倍体細胞におけるUPDの頻度に影響を与える要因を特定する.
主な方法:
- モデル生物として Schizosaccharomyces pombe を利用した.
- RNA干渉 (RNAi) 機構とMmi1因子のUPDへの影響を調査した.
- 遺伝子発現を分析し,特にゲメトゲン遺伝子を変異細胞で分析した.
- UPDを抑制するメオティックコヘシンRec8とサイクリンCrs1の役割を調べた.
- Rec8とコヘシンサブユニット Psc3の局所化と機能を評価した.
主要な成果:
- RNAiまたはMmi1の欠陥は,ベジタティブ二重体細胞のUPDレベルを著しく増加させる.
- これらの変異体におけるUPDは,中心性ヘテロクロマチン欠陥ではなく,ゲメトゲン遺伝子の早期発現に関連しています.
- Rec8またはCrs1の削除は,RNAiおよびmmi1変異体におけるUPDを抑制する.
- Rec8の過剰発現は,ワイルド型細胞でUPDを誘発する可能性があります.
- セントロメアにおけるRec8およびPsc3の局所化は,染色体の分離によってUPDを促進し,還元分離を引き起こします.
結論:
- UPDの直接的な原因は ギャメトジェニック遺伝子の早発性発現です
- これらの発見は,UPDとその人間疾患との関連性についてのメカニズム的理解を提供します.
- UPDの調節に関与する特定の遺伝子とタンパク質を特定し,将来の研究のための潜在的なターゲットを提供した.
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