米の遺伝子発現に対する自然選択の強さとパターン

Simon C Groen¹, Irina Ćalić², Zoé Joly-Lopez¹

¹Center for Genomics and Systems Biology, Department of Biology, New York University, New York, NY, USA.

Nature

|February 14, 2020

まとめ

米の遺伝子発現レベルは,湿った条件では弱い選択を示しますが,干ばつの条件ではより強い選択を示します. 表現の低さ,より高い可塑性,より低いネットワーク接続性は,より強い選択と相関しています.

科学分野:

進化生物学
分子遺伝学
植物学

背景:

遺伝子発現レベルは生物のフェノタイプにとって根本的なものです.
適応的進化における遺伝子発現に対する選択の役割はほとんど不明である.
遺伝子の発現に関する選択の理解は進化過程の解読に不可欠です

研究の目的:

米 (Oryza sativa) の遺伝子発現レベルに作用する選択の種類と強さを定量化する.
環境条件 (湿気と干ばつ) がトランスクリプトの選択にどのように影響するか調査する.
強い選択と関連した分子特性を特定し,その適応的意義を探求する.

主な方法:

遺伝子発現を15000以上の塩基配列で測定した.
選択の差と強みを推定するために現象型選択分析を使用した.
遺伝子発現ネットワークと光合成遺伝子の選択を評価するために多変量分析を用いた.

主要な成果:

ほとんどのトランスクリプトは湿った状態では中性または弱い安定化選択を示し,乾燥状態では選択が強化された.
表現が低くストキャスティックノイズが高く柔軟性が高いトランスクリプトは強い選択の対象となった.
OsMADS18遺伝子の発現が増加し,それが干ばつ脱出遺伝子の1つであると特定しました.

結論:

選択は遺伝子発現のレベルを大きく左右し環境条件は遺伝子の強さや標的を調整します
表現レベル,ノイズ,可塑性などのトランスクリプト特性は,選択に対する感受性に影響します.
この研究は,分子特性の選択を推定するための枠組みを提供し,適応的進化の洞察を提供します.

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