INSTABILITY OF SIMPLE REPETITIVE DNA SEQUENCES IN YEAST

酵母中简单重复 DNA 序列的不稳定性

• 批准号: 6180614
• 负责人: THOMAS PETES
• 金额: $ 27.23万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-05-01 至 2002-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6180614
• 关键词: DNA repair; DNA replication; Saccharomyces cerevisiae; chemical stability; fungal genetics; gene mutation; genetically modified animals; laboratory mouse; mitochondrial DNA; neoplasm /cancer genetics; nucleic acid repetitive sequence; tissue /cell culture

DESCRIPTION: Microsatellites are regions of DNA in which a single base or a small number of bases is repeated multiple times. All eukaryotes examined thus far contain microsatellites. These sequences are inherently unstable, undergoing alterations in length at a much higher rate than that observed for "normal" DNA sequences. Genome-wide microsatellite instability is associated with certain types of human cancer. In yeast, mutations in DNA mismatch repair genes result in microsatellite instability and some human tumors with unstable microsatellites have mutations in human homologues of the yeast DNA mismatch repair genes. Some microsatellite unstable tumors, however, lack such mutations. In the current proposal, mutant screens designed to identify new genes affecting microsatellite instability in yeast are proposed. If new genes are identified, human homologues of these genes will be isolated. DNA isolated from tumors with unstable microsatellites that do not have mutations in known DNA mismatch repair genes will be examined to determine whether these tumors have mutations in human homologues of the newly-discovered yeast genes. Three other types of experiments concerning microsatellite instability are proposed. Since mistakes made during DNA replication are likely to contribute to microsatellite instability, a search for mutations in yeast DNA polymerase delta that result in unstable microsatellites will be performed. Second, the genetic regulation of microsatellite in mitochondrial DNA in yeast will be studied. Third, a transgenic mouse line will be constructed to allow the measurement of microsatellite instability in vivo.

描述：微卫星是 DNA 区域，其中单个碱基或 少量碱基重复多次。 检查所有真核生物 迄今为止包含微卫星。 这些序列本质上是不稳定的， 长度变化的速度比观察到的要高得多 对于“正常”DNA 序列。 全基因组微卫星不稳定性是 与某些类型的人类癌症有关。 在酵母中，DNA 突变 错配修复基因导致微卫星不稳定和一些人类 具有不稳定微卫星的肿瘤在人类同源物中存在突变 酵母DNA错配修复基因。 一些微卫星不稳定肿瘤， 然而，缺乏这样的突变。 在当前的提案中，突变体筛选 旨在识别影响酵母微卫星不稳定性的新基因 被提议。 如果发现新基因，这些基因的人类同源物 将会被孤立。 从具有不稳定微卫星的肿瘤中分离出 DNA 已知 DNA 错配修复基因中没有突变的 检查以确定这些肿瘤是否在人类中存在突变 新发现的酵母基因的同源物。 关于微卫星不稳定性的其他三种类型的实验是 建议的。 由于 DNA 复制过程中出现的错误很可能 导致微卫星不稳定，寻找酵母突变 导致不稳定微卫星的 DNA 聚合酶 delta 将被 执行。 二、微卫星的遗传调控 将研究酵母中的线粒体DNA。 三、转基因小鼠品系 将被建造用于测量微卫星的不稳定性 体内。