トウモロコシの花粉ミトーシスIでゲノム活性化が発生する

Brad Nelms¹, Virginia Walbot²

¹Department of Plant Biology, University of Georgia, Athens, GA 30606, USA.

Science (New York, N.Y.)

|January 27, 2022

まとめ

トウモロコシの花粉は,最初,二倍体トランスクリプトを11日間保存する. ハプロイド遺伝子発現への急速なシフトは花粉ミトーシスIで起こり,ハプロイド選択を可能にします.

科学分野:

植物生殖生物学
分子遺伝学
進化生物学

背景:

咲く植物はハプロイド (ゲメトファイト) と二倍体 (スポロファイト) の世代を交互に交代するライフサイクルを示します.
花粉はハプロイドゲノムを活発に転写し,単一の植物の子孫内の表型多様性に貢献します.

研究の目的:

トウモロコシの花粉における二倍体から二倍体への遺伝子発現を調査する.
ハプロイド遺伝子発現のタイミングと,その選択における潜在的役割を決定する.

主な方法:

トウモロコシの単一の花粉前駆体におけるアレル特異的なRNA配列を活用した.
遺伝子発現パターンを二倍体からハプロイドの花粉発達の段階まで追跡した.

主要な成果:

微分化後11日間のスポロフィットからの持続的なバイアレル遺伝子発現が観察されました.
新型ハプロイドゲノムトランスクリプションにより,花粉ミトーシスIで,急激に,グローバルに単元エクスプレッションに切り替えることが記録されています.
ポリンのミトーシスI後に発現する遺伝子の浄化選択が増加した.

結論:

開発中のトウモロコシ花粉の遺伝子発現に作用するハプロイド選択の時間窓を確立した.
活性ハプロイド転写に取って代わられる前に,二倍体由来トランスクリプトがハプロイド段階に顕著に持続することを実証した.

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