DNA複製の指向は,S. pombeの交配型切り替えパターンを確立する

J Z Dalgaard¹, A J Klar

¹Gene Regulation and Chromosome Biology Laboratory, ABL-Basic Research Program, NCI Frederick Cancer Research and Development Center, Maryland 21702-1201, USA.

Nature

|July 17, 1999

まとめ

分裂酵母細胞は,mat1.1.でDNAの改変を経由して交配型の切り替えを経験します. 複製のタイミングが,このインプリントを決定し,子細胞の発達の可能性に影響を与えます.

科学分野:

細胞生物学細胞生物学
遺伝学遺伝学とは
分子生物学は分子生物学である.

背景:

ハプロイド分裂酵母,Schizosaccharomyces pombeは,2つの交配タイプ (mat1) を持っている.
交配型のスイッチングは,非対称的な分裂後の4分の1の孫子細胞で発生します.
このプロセスは,ドナーロシ (mat2-P/mat3-M) からmat1.に遺伝情報の転送を伴う.

研究の目的:

Schizosaccharomyces pombeの交配型変異の分子メカニズムを解明する.
mat1.1.の遺伝子インプリントの性質を特定する.
インプリントとスイッチングにおけるDNA複製の役割を調査する.

主な方法:

DNAの改変を特定するための生化学分析.
改変した複製起源を用いたDNA複製の研究.
複製のタイミングを分析するための二次元ゲル電泳.

主要な成果:

遺伝的インプリントは,mat1.1.の鎖特異的,アルカリ-ラビルDNA改変である.
二重鎖DNAの断裂は,DNA浄化の人工物であり,主要なイベントではありません.
mat1は,偏ってセンターメア-ディスタル起源によって複製され,遅滞糸合成中にインプリントにつながります.
複製の起源を変更すると,インプリントとスイッチングの効率に影響されます.

結論:

DNA複製機構は,姉妹細胞に異なる発達可能性を授与する上で重要な役割を果たします.
複製中のストランド固有のDNA改変は,交配型切り替えを決定する.
この発見は,複製のタイミングと表遺伝学的調節の間の新しいリンクを明らかにしています.

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