Mutation spectra in DNA repair-deficient backgrounds

这项研究将直接解决关于DNA修复系统在塑造动物基因组中自发突变过程的比率、模式和适合性结果中所扮演的角色的基本问题。6个秀丽线虫基因都是广泛存在于酵母和人类中的切除DNA修复基因的同源基因，它们将被紫外线-三甲基补骨脂素(UV-TMP)诱变删除，并将对每一株敲除菌株启动突变积累实验。核基因组和线粒体基因组中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章动积累(MA)系中的突变来评估。将直接评估线虫不同修复途径所防止的突变谱以及不同修复途径之间的重叠程度。在一组长期的野生型线虫MA系中自发突变的适合性结果将提供一个前所未有的标准，修复缺陷背景中的突变将通过生活史特征分析进行检查。关于一组长期野生型线虫MA株自发突变的比率、模式和适合性后果的背景信息将提供一个前所未有的标准，用于直接比较修复缺陷MA株的突变。这项研究的实施将使人们更好地理解切除DNA修复因子在塑造突变过程中的作用，突变过程是遗传变异、人类遗传疾病的最终来源，也是基因组进化的燃料。

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.