A global analysis of ploidy maintenance in S. cerevisiae

酿酒酵母倍性维持的全球分析。倍性是指生物体中一整套染色体的数量，在真核细胞中受到严格调控，对细胞功能和生存至关重要。细胞必须协调多条途径，以确保复制的DNA被准确和及时地分离，以防止染色体数量的变化。我们正在采取双管齐下的方法来发展对真核生物酿酒酵母模型中维持倍性的途径的机械性理解。首先，我们发现了SWI/SNF家族染色质重构体RSC在倍性维持中的一个意想不到的作用。其次，我们进行了基因组规模的筛选，以确定萌芽酵母中倍性维持基因的互补。这一筛选确定了蛋白质翻译和倍性维持之间的一种新的关系，我们发现这一途径中的基因丢失导致基因组大小翻了四番。我们现在准备深入研究RSC调节倍性的分子机制，探索细胞形态和倍性之间的关系，并定义蛋白质翻译和倍性维持之间的关系。*在理解RSC调节倍性的机制和倍性维持途径的基因组规模分析方面取得了很好的进展，我们建议在下一个资金阶段建立我们独特的发现。我们目前的分析已经确定核孔复合体是RSC维持倍性的关键目标。展望未来，我们将结合分子和高分辨率显微分析来了解RSC如何调节核孔复合体的功能。我们还发现了倍性和细胞形态的许多方面之间的独特联系。与东京大学的Yoshi Ohya合作，我们将使用多参数图像分析来根据形态特征识别新的倍性维持基因，最终目的是了解倍性增加如何改变真核细胞的形状和结构。最后，我们目前的基因组规模分析已经达到了令人兴奋的阶段，我们可以开始了解SESA翻译调控网络(包括mRNA和核糖体结合蛋白)调节倍性的机制。我们在倍性维持筛选中确定了SESA网络的多个组成部分，这表明在未来的机制研究中有很强的功能关系。*综上所述，我们将在一个模式真核生物中定义RSC和SESA维持倍性的机制，并将使用形态分析来确定额外的倍性维持途径，并了解倍性如何影响细胞的结构。我们期望对细胞如何维持倍性并准确地将基因组从一代传到下一代获得相当大的机械性洞察力。

A Global Analysis of Ploidy Maintenance in S. cerevisiae******Ploidy, the number of complete sets of chromosomes in an organism, is tightly regulated in eukaryotic cells, and is critical for cell function and survival. Cells must coordinate multiple pathways to ensure that replicated DNA is segregated accurately and in a timely fashion to prevent changes in chromosome number. We are taking a two-pronged approach to develop a mechanistic understanding of the pathways that maintain ploidy in the model eukaryote Saccharomyces cerevisiae. First, we discovered an unanticipated role for the SWI/SNF family chromatin remodeler RSC in ploidy maintenance. Second, we conducted a genome-scale screen to identify the complement of ploidy maintenance genes in budding yeast. This screen identified a novel relationship between protein translation and ploidy maintenance and we discovered that the loss of genes in this pathway caused a quadrupling in genome size. We are now poised to delve into the molecular mechanism by which RSC regulates ploidy, to explore the relationship between cell morphology and ploidy, and to define the relationships between protein translation and ploidy maintenance.******Having made excellent progress in our goals of understanding the mechanism by which RSC regulates ploidy and in genome-scale analysis of ploidy maintenance pathways, we propose to build on our unique findings during the next funding period. Our current analysis has identified the nuclear pore complex as the key target of RSC in maintaining ploidy. Going forward, we will combine molecular and high-resolution microscopic analyses to understand how RSC modulates the function of the nuclear pore complex. We have also discovered a unique connection between ploidy and many aspects of cellular morphology. In collaboration with Yoshi Ohya at the University of Tokyo we will use a multi-parameter image analysis to identify new ploidy maintenance genes on the basis of morphology profile, with the ultimate goal of understanding the ways in which ploidy increase alters the shape and structure of the eukaryotic cell. Finally, our current genome-scale analysis has reached the exciting stage where we can begin to understand the mechanisms by which the SESA network of translational regulators, which comprises mRNA and ribosome binding proteins, regulates ploidy. We identified multiple components of the SESA network in our ploidy maintenance screen, indicating a strong functional relationship to follow up in future mechanistic studies.******To summarize, we will define the mechanisms by which RSC and SESA maintain ploidy in a model eukaryote, and will use morphological analysis to identify additional ploidy maintenance pathways and understand how ploidy influences the structure of the cell. We expect to derive considerable mechanistic insight into how cells maintain ploidy and accurately transmit the genome from one generation to the next.