広範囲に広がる巨大ウイルスの内生化が 緑藻のゲノムを形作る
Mohammad Moniruzzaman1, Alaina R Weinheimer1, Carolina A Martinez-Gutierrez1
1Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
Nature
|November 19, 2020
まとめ
核細胞プラズマの大型DNAウイルス (NCLDV) の巨大な内生性ウイルス要素 (EVE) が緑藻のゲノムに統合されていることが判明しました. これらの巨大なウイルスの配列は ユカリオットの既知のウイルスの遺伝子スケールを大幅に拡張します
科学分野:
- ゲノミクス
- 進化生物学
- ウイルス学
背景:
- 内生性ウイルス要素 (EVE) は,真核生物に共通する統合ウイルスゲノムであり,ゲノム進化において重要な役割を果たす.
- 特定されたEVEのほとんどは小さいが,大きな二重鎖DNAウイルスも内生化することがあります.
- 核細胞プラズマの大型DNAウイルス (NCLDV) は,その大きなゲノムと複雑な起源のために興味を惹かれるが,EVEとしての役割は不明である.
研究 の 目的:
- ユカリオットのゲノムにおけるNCLDVの内生化の発生率と特性を調査する.
- ユカリオットゲノム内のウイルス遺伝子のスケールにNCLDVが有意に寄与するかどうかを判断する.
主な方法:
- 統合されたウイルス配列を特定するために緑藻のゲノム解析.
- 特定された内生性NCLDVのサイズ,遺伝子含有量,およびゲノム特性の特徴.
- 遺伝子の共有と宿主ゲノムとの同化を評価するための比較ゲノム分析.
主要な成果:
- 広範囲にわたるNCLDVの内生化は,様々な緑藻で発見されました.
- これらの巨大なEVEは100万塩基対を超え ホストの開いた読み取りフレームの10%までを含んでいます
- 遺伝子の共有,イントロンの複製など,内在化した元素は同化証拠を示している.
結論:
- NCLDVは,ユーカリ生物における大規模な内生性ウイルス要素の重要かつ以前は過小評価されていた源である.
- NCLDVの内生化は,真核生物のゲノムにおけるウイルス遺伝子の規模を大幅に増加させる.
- この過程は新種の遺伝物質の伝達管として機能し,真核生物のゲノム構成と進化に影響を与えます.
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