Identification of Yeast Chromosome Condensation Factors

描述(由申请人提供)解除精确染色体分离所需的因素可能导致非整倍体，这是癌症病因学的重要贡献。复制基因组的平等分裂要求姐妹染色单体在分裂后期迁移到有丝分裂纺锤体的相反两极：分离的保真度依赖于精细的机制，依赖于适当的染色体组织。参与染色体凝聚和基因组组织化的因素也是维持基因组稳定性的关键。总之，基因组不稳定和非整倍体是恶性进展的关键因素。已知的与染色体结构有关的蛋白质在人类和萌芽酵母(酿酒酵母)之间高度保守。然而，这些过程中涉及的许多因素仍有待隔离。由于酵母菌在基因上是易驯化的，它们提供了理想的系统，在其中可以快速识别细胞过程所需的新因素。我们的目标是识别和了解新的发芽酵母蛋白，这些蛋白在细胞周期中控制染色体组织和结构的动态。我们的假设是，人类需要这些蛋白质的同源物来维持染色体分离的保真度和基因组的完整性。因此，这些因素将与癌症的病因相关。 酵母遗传筛选将被用来分离染色体凝集缺陷的新突变体。在酵母细胞中，两个绿色荧光蛋白(GFP)标记的染色体位点被-10-50kb的DNA分隔为单一的离散荧光信号。然而，影响染色体凝聚状态的突变体将允许通过荧光显微镜相互区分标记的基因座。其他表型，如信号强度降低，也可能出现在许多缩合突变体中。基于这些表型，影响染色体组织的突变将通过肉眼检查和自动显微镜和计算机辅助诊断的组合来识别。

DESCRIPTION (provided by applicant) Deregulation of factors needed for accurate chromosome segregation can result in aneuploidy, a significant contributor to cancer etiology. Equal division of a replicated genome requires that sister chromatids migrate to opposite poles of the mitotic spindle in anaphase: segregation fidelity relies on elaborate mechanics and is dependent on proper chromosome organization. Factors involved in chromosome condensation and genome orgatization are also critical for maintaining genome stability. Together, genome instability and aneuploidy are key factors in malignant progression. Known proteins involved in chromosome architecture are highly conserved between humans and budding yeast (S. cerevisiae). However, many factors involved in these processes remain to be isolated. Since yeasts are genetically tractable, they provide ideal systems in which novel factors required for cellular process can be rapidly identified. Our goal is to identify and understand new budding yeast proteins that control the dynamics of chromosome organization and structure through the cell cycle. Our hypothesis is that human homologs of these proteins will be required to maintain the fidelity of chromosome segregation and the integrity of the genome. These factors will therefore be relevant to the etiology of cancer. Yeast genetic screens will be used to isolate novel mutants defective in chromosome condensation. Two green fluorescent protein (GFP)-tagged chromosome loci, separated by -10-50 kilobases of DNA are visualized as a single discrete fluorescence signal in yeast cells. However, mutants that affect chromosome condensation states will allow the tagged loci to be discerned from one another by fluorescence microscopy. Other phenotypes, such as reduced signal intensity, are also expected in many condensation mutants. Based on these phenotypes, mutants affecting chromosome organization will be identified, both by visual inspection and a combination of automated microscopy and computer-aided diagnosis.