TRANSPOSITION AND DNA REPAIR IN DROSOPHILA

果蝇的转座和 DNA 修复

• 批准号: 6329634
• 负责人: William R. ENGELS
• 金额: $ 40万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-07-01 至 2002-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6329634
• 关键词: DNA repair; Drosophilidae; endonuclease; gene deletion mutation; gene expression; gene mutation; gene rearrangement; gene targeting; genetic mapping; genetic recombination; genetic screening; heterochromatin; in situ hybridization; nucleic acid sequence; polymerase chain reaction; sex chromosomes; site directed mutagenesis; transposon /insertion element

Goals: The repair of double-stranded DNA breaks in Drosophila mitotic cells will be analyzed genetically. Such breaks can be repaired by two main classes of mechanisms: recombinational and end-joining. These classes differ significantly in the kinds of repair products that are produced. Within each class, multiple individual pathways are thought to exist. The goal is to perform a genetic dissection of these mechanisms. For each major pathway, the genetic consequences and the structure of the repair products will be determined. Examination of these parameters in a series of mutations at loci involved in the repair processes will reveal how the pathways differ and the type of repair that is affected. Approach: Excision of P transposable elements provides a useful way to produce double-strand breaks at specific, known, locations in the genome. These excisions can be regulated by P transposase. In addition, two site-specific endonucleases, HO and I-SceI, have been shown to function in Drosophila. These three methods will be used to generate specific double-strand breaks in vivo under well-defined genetic conditions. A series of tests using these site-specific breaks will be applied in different genetic backgrounds to provide a detailed description of the consequences of double-strand break repair. Different pathways for repair will be distinguished by mutating genes thought to be involved with one or more mechanism. Seven genetic loci involved with repair were selected to include a variety of such functions. Two recently-developed methods will be used to obtain mutations: the first generates P insertions in or near the targeted genes, and the second uses these insertions to obtain flanking deletions which knock out the genes. Medical significance: DNA repair is recognized as crucial to maintaining the stability of the genome, especially in species with complex genomes. Human mutations in many DNA repair genes, including the human homologs of several of the loci in the present study, cause predisposition to cancer. A better understanding of these repair processes can come from studies using Drosophila, which, like humans, has a relatively complex genome and multicellular organization, thus requiring a high level of genomic stability. At the same time, Drosophila gives researchers the genetic tools needed to analyze the multi-pathway repair system.

目标：果蝇有丝分裂的双链DNA断裂的修复 细胞将进行遗传分析。 这样的休息可以通过两个修复 主要机制类别：重组和最终加入。 这些 课程在种类的维修产品中有很大差异 生产。 在每个班级中，都会想到多个单独的途径 存在。 目的是对这些进行遗传解剖 机制。 对于每个主要途径，遗传后果和 将确定维修产品的结构。 检查 这些参数在一系列突变中涉及修复的基因座 过程将揭示路径的不同和维修的类型 这受到了影响。 方法：P tosposobable Elements的切除提供了一种有用的方法 在特定的已知位置产生双链断裂 基因组。 这些切割可以通过P转座酶调节。 在 另外，两个特定于现场的核孔，HO和I-SCEI已经是 显示在果蝇中起作用。 这三种方法将用于 在定义明确的情况下在体内产生特定的双链断裂 遗传条件。 一系列使用这些特定网站特定断裂的测试 将在不同的遗传背景中应用以提供详细的 描述双链断裂修复的后果。 维修的不同途径将通过突变基因来区分 被认为与一种或多种机制有关。 七个遗传基因座 选择了维修，以包括各种此类 功能。 将使用两种最近开发的方法来获得 突变：第一个生成靶标内或附近的P插入 基因，第二个使用这些插入来获得侧翼缺失 敲除基因。 医学意义：DNA修复对维持至关重要 基因组的稳定性，尤其是在具有复杂基因组的物种中。 许多DNA修复基因中的人类突变，包括人类同源物 在本研究中的几个基因座中，使易感性 癌症。 更好地了解这些维修过程可能来自 使用果蝇的研究，与人类一样 基因组和多细胞组织，因此需要高水平 基因组稳定性。 同时，果蝇为研究人员提供 分析多条纹维修系统所需的遗传工具。