Mutation spectra in DNA repair-deficient backgrounds

这项研究将直接解决有关DNA修复系统在塑造动物基因组中自发突变过程的速率、模式和适应性结果中的作用的基本问题。通过uv -三甲基补骨脂素（UV-TMP）诱变，将6个秀丽隐杆线虫基因（均为在酵母和人类中广泛存在的切除DNA修复基因的同源基因）删除，并对6个敲除菌株分别进行突变积累实验。细胞核和线粒体基因组的突变率和模式将通过使用直接DNA测序方法检测每组修复缺陷突变（MA）系中的突变来评估。线虫不同修复途径所阻止的突变谱和不同修复途径之间的重叠程度将被直接评价。在一组长期的野生型秀丽隐杆线虫MA系中，自发突变的适应度结果将提供一个前所未有的标准，用于生活史特征分析来检查修复缺陷背景中的突变。在一组长期的野生型秀丽隐杆线虫MA系中自发突变的比率、模式和适应性后果的背景信息将提供一个前所未有的标准，与修复缺陷的MA系的突变进行直接比较。这项研究的实施将使人们对切除DNA修复因子在形成突变过程中的作用有更深入的了解，而突变过程是遗传变异、人类遗传疾病和基因组进化的最终来源。

This study will directly address fundamental questions about the roles of DNA repair systems in shaping the rates, patterns and fitness consequences of spontaneous mutation processes in an animal genome. Six Caenorhabditis elegans genes, all orthologues of excision DNA repair genes extensive characterized in yeast and humans, will e deleted by UV-trimethylpsoralen (UV-TMP) mutagenesis and mutation- accumulation experiments will be initiated for each of the six knockout strains. Mutation rates and patterns in both the nuclear and mitochondrial genomes will be evaluated by detection mutations in each set of repair- deficient nutation-accumulation (MA) lines using direct DNA sequencing approaches. The spectra of mutation prevented by and extent of overlap between different repair pathways in C. elegans will be directly evaluated. The fitness consequences of spontaneous mutation in a long-term set of wild-type C. elegans MA lines will provide an unprecedented standard against which mutations in repair-deficient backgrounds will be examined with life history character assays. Background information on the rates, patterns and fitness consequences of spontaneous mutation in a long-term set of wild-type C. elegans MA lines will provide an unprecedented standard against which mutations in repair-deficient MA lines will be directly compared. Execution of this study will culminate in a greater understanding of the roles of excision DNA repair factors in shaping mutation processes that are the ultimate source of genetic variation, human genetic disorders and fuel for genome evolution.