単細胞で観察された変異動態と適性効果
Lydia Robert1,2, Jean Ollion3, Jerome Robert3
1Laboratoire Jean Perrin, UMR 8237 Sorbonne Universités, UPMC Université Paris 06, Paris, France. lydia.robert@polytechnique.org marina.elez3@gmail.com.
Science (New York, N.Y.)
|March 29, 2018
まとめ
研究者は,E. coliの単細胞変異を高度なイメージングを使用して視覚化し,ほとんどの変異が準中性であり,変異率とフィットネスコストの個々の違いを明らかにしました.
科学分野:
- 微生物学 と 遺伝学
- 細胞生物学
- 進化生物学
背景:
- 単一の細胞の変異を観察することは困難で,その動態とフィットネス効果の理解を制限します.
- 以前の研究では,個々の細胞レベルでの突然変異の発生と影響を追跡するための解像度が欠けていました.
研究 の 目的:
- 単細胞における突然変異のダイナミクスを視覚化および定量化するための新しい方法を開発し,適用する.
- 変異のフィットネス効果と集団内の分布を特徴付ける.
- 変異率と相互作用の単細胞変異を調査する.
主な方法:
- 単一のEscherichia coli細胞を高解像度で観察するために,微流体とタイムラップ画像を用いた.
- ミューテーションイベントを視覚化するために,不一致修復システムに光タグを使用した.
- 細胞の成長と寿命と ゲノム全体の変異を 何百世代にもわたって追跡した
主要な成果:
- 単細胞での突然変異の出現を視覚化し,ポイソンのダイナミクスを示した.
- 数千世代に渡って 約2万のゲノムに及ぶ変異を記録しています
- 1%の変異が致死性であったが,非致死性変異は重尾性フィットネス効果分布を示し,準中性変異が支配していた (平均コストは0. 3%).
結論:
- 開発されたアプローチは,単細胞レベルで突然変異の動態と適性効果の直接観察を可能にします.
- 変異適性効果は主に準中性であり,個々の細胞の有意な変動性がある.
- この研究は,変異率の個性,フィットネスコスト,相互作用に関する新しい洞察を提供します.
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