The Molecular Organization of Yeast Chromosome I

酵母 I 号染色体的分子结构

• 批准号: 9018923
• 负责人: David Kaback
• 金额: $ 11.28万
• 依托单位: New Jersey Medical School
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-02-15 至 1992-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9018923&HistoricalAwards=false
• 关键词: Molecular; Organization; Yeast; Chromosome

There is much to be learned about how chromosomes are faithfully transmitted during mitosis and meiosis. Determining the detailed structure of an entire eucaryotic chromosome should yield much information about its functions. As a first step towards this goal, we have been examining the structure of the 250 kb DNA molecule from chromosome I, the smallest Saccharomyces cerevisiae chromosome. We have cloned almost all of it and have determined the physical location of all but two of its classically identified genes on a restriction map of the entire chromosomal DNA molecule. In collaborative efforts, we have determined the transcription map on 160 kb of chromosome I and are in the process of locating all the cloned ARS elements. We propose to continue elucidating the transcription map of the entire chromosome. These studies will provide the foundation for further analyses on many aspects of chromosome function and behavior. Classical genetic studies have succeeded in identifying less than 20% of all yeast genes. In this respect, chromosome I is typical. Hybridization studies suggested that chromosome I encodes 90-100 genes. However, despite intense efforts, only 15 of these genes were identified by classically obtained mutations. These proportions also apply to essential genes. The number of essential genes identified by classical genetic studies throughout the entire yeast genome and on chromosome I in particular was far lower than predicted. If we are to understand the molecular biology of a simple organism, it would be advantageous to have a more complete set of mutations in genes essential for its life cycle. It is clear that molecular approaches are needed to obtain this large number of mutants. We have already produced deletion mutations in 28 genes that were defined only by the presence of an unidentified transcribed region. Five of these genes were essential for vegetative growth on rich medium. Counting the previously identified genes, we now have mutants for 41 of the 90-100 genes on this chromosome. Based on these results, we suggest that 18-24% (1100-1500) of the genes in yeast are essential for growth on rich medium. We propose to continue these studies in order to eventually obtain a catalogue of mutants for every gene on chromosome I. Deletion mutations in approximately 5 additional transcribed regions will be produced using one-step gene replacement and their phenotypes will be partially characterized. These studies will enhance our knowledge about a large number of genes that have not been investigated previously.

关于在有丝分裂和减数分裂过程中忠实传播染色体的方式有很多值得了解的知识。 确定整个桉树染色体的详细结构应产生有关其功能的大量信息。 作为朝着这一目标的第一步，我们一直在检查最小的酿酒酵母染色体I染色体I的250 kb DNA分子的结构。 我们几乎将其克隆了所有这些，并在整个染色体DNA分子的限制图上确定了除两个经典鉴定的基因以外的所有物理位置。 在协作工作中，我们确定了160 kb染色体I的转录图，并正在定位所有克隆的ARS元素。 我们建议继续阐明整个染色体的转录图。 这些研究将为进一步分析染色体功能和行为的许多方面提供基础。 经典遗传研究成功地鉴定了所有酵母基因的20％。 在这方面，染色体I是典型的。 杂交研究表明，染色体I编码90-100基因。 然而，尽管做出了巨大的努力，但仅通过经典获得的突变鉴定了其中15个基因。 这些比例也适用于必需基因。 在整个酵母基因组和染色体I的经典遗传研究中鉴定出的必需基因的数量尤其低于预测。 如果我们要了解一种简单生物体的分子生物学，那么在其生命周期必不可少的基因中具有更完整的突变集将是有利的。 显然，需要分子方法来获得大量的突变体。 我们已经在28个基因中产生了缺失突变，这些突变仅由未识别的转录区域的存在来定义。 这些基因中的五个对于在富培养基上的营养生长至关重要。 考虑到先前鉴定的基因，我们现在在该染色体上有41个基因中的41个突变体。 基于这些结果，我们建议酵母中18-24％（1100-1500）对富培养基的生长至关重要。 我们建议继续这些研究，以最终获得染色体I上的每个基因的突变体目录。将使用一步基因置换量产生大约5个其他转录区域中的缺失突变，其表型将得到部分表征。 这些研究将增强我们对以前尚未研究的大量基因的了解。