酵母基因組分析表明，從有絲分裂向形成配子的減數(shù)分裂的轉(zhuǎn)化與基因表達譜所發(fā)生的一個驟變有關。只在減數(shù)分裂過程中表達的一種蛋白是細胞周期蛋白Rem1,，該蛋白增強減數(shù)分裂前的基因內(nèi)重組，保證減數(shù)分裂的順利進行,。
現(xiàn)在,，Moldon等人發(fā)現(xiàn)，Rem1在裂殖酵母Saccharomyces pombe中的表達不僅在轉(zhuǎn)錄層面上受控，而且也被接合控制,。在有絲分裂細胞中,，F(xiàn)kh2轉(zhuǎn)錄因子與Rem1啟動子的結合會產(chǎn)生一個能留住其內(nèi)含子（introns）的轉(zhuǎn)錄，從而只會有一個短蛋白產(chǎn)生,，該蛋白影響重組水平,。在減數(shù)分裂細胞中，一個減數(shù)分裂特定的轉(zhuǎn)錄因子Mei4與Rem1啟動子的結合會導致Rem1的接合,，并產(chǎn)生活性細胞周期蛋白,。所以，兩個轉(zhuǎn)錄因子可對同一基因的接合進行不同的修飾,。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 455, 997-1000 (16 October 2008) | doi:10.1038/nature07325; Received 28 May 2008; Accepted 6 August 2008; Published online 24 September 2008
Promoter-driven splicing regulation in fission yeast
Alberto Moldón1, Jordi Malapeira1, Natalia Gabrielli1, Madelaine Gogol2, Blanca Gómez-Escoda1, Tsvetomira Ivanova1, Chris Seidel2 & José Ayté1
1 Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, C/Doctor Aiguader 88, Barcelona 08003, Spain
2 Stowers Institute, Kansas City, Missouri 64110, USA
The meiotic cell cycle is modified from the mitotic cell cycle by having a pre-meiotic S phase that leads to high levels of recombination, two rounds of nuclear division with no intervening DNA synthesis and a reductional pattern of chromosome segregation. Rem1 is a cyclin that is only expressed during meiosis in the fission yeast Schizosaccharomyces pombe. Cells in which rem1 has been deleted show decreased intragenic meiotic recombination and a delay at the onset of meiosis I (ref. 1). When ectopically expressed in mitotically growing cells, Rem1 induces a G1 arrest followed by severe mitotic catastrophes. Here we show that rem1 expression is regulated at the level of both transcription and splicing, encoding two proteins with different functions depending on the intron retention. We have determined that the regulation of rem1 splicing is not dependent on any transcribed region of the gene. Furthermore, when the rem1 promoter is fused to other intron-containing genes, the chimaeras show a meiotic-specific regulation of splicing, exactly the same as endogenous rem1. This regulation is dependent on two transcription factors of the forkhead family, Mei4 (ref. 2) and Fkh2 (ref. 3). Whereas Mei4 induces both transcription and splicing of rem1, Fkh2 is responsible for the intron retention of the transcript during vegetative growth and the pre-meiotic S phase.
