S. cerevisiaeのテロメアにおける位置効果:Pol IIトランスクリプションの可逆抑制

D E Gottschling¹, O M Aparicio, B L Billington

¹Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637.

Cell

|November 16, 1990

まとめ

イーストのテロメアは,位置効果として知られる現象である近くの遺伝子の発現を抑制することができます. この表遺伝子制御メカニズムは,テロメアの近さに基づいた遺伝子転写に影響します.

科学分野:

遺伝学遺伝学とは
分子生物学は分子生物学である.
エピジェネティクスエピジェネティクス

背景:

*Saccharomyces cerevisiaeの染色体は,繰り返されるテロメア配列で終了する.
* 遺伝子発現の調節は,細胞機能にとって極めて重要です.

研究の目的:

* テロメアの近接が酵母における隣接する遺伝子の転写に与える影響を調査する.
* テロメアが遺伝子発現に位置効果を発揮するかどうかを判断する.

主な方法:

* RNAポリメラーゼII (Pol II) 遺伝子をS. cerevisiaeのテロメア繰り返しの隣接に配置する.
* 現象型観察 (コロニー色) とmRNAレベルを通して遺伝子発現を分析する.
*発現分析のためにADE2やURA3のような遺伝子マーカーを利用する.

主要な成果:

*テロメアのすぐ隣に配置された遺伝子は,可逆的な転写抑制を示した.
* テロメア結合ADE2遺伝子は,白色セクターを持つ赤いコロニーを生み出し,発現が変化したことを示した.
* 内部のテロメア重複管は,テロメアになったときにのみ遺伝子発現を抑制しました.

結論:

* イーストのテロメアは,近くの遺伝子の転写に位置依存的な効果を発揮する.
* このテロメア媒介の遺伝子抑制は,表遺伝学的に制御されます.
* テロメアの近くは,遺伝子発現レベルに影響を与える重要な要因です.

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