Single Stranded DNA: The Genome's Achilles Heel

DNA复制是一个基本的过程，所有生物体都依赖于它来忠实地传递遗传信息。 从一代到下一代的材料。DNA复制过程通常会受到以下因素的"压力"： 突变或外源性试剂可导致DNA损伤或复制障碍 机械.复制应激可引起基因组不稳定性，并可能最终导致疾病 包括癌症我的主要研究兴趣是缺陷复制如何导致基因组不稳定性。的 控制这一提议的一般假设是，复制时单链DNA（ssDNA）的产生 在复制检查点缺陷突变体中，分叉停滞和不稳定是潜在的致命事件， 阻止基因组的完全合成，导致染色体断裂，最终导致基因组 不稳定 该项目的具体目标是： 1.研究复制应激过程中大量ssDNA形成与染色体之间的联系 使用全基因组ssDNA和染色体断裂作图技术， 申请人结合其他遗传方法。 2.通过检查，阐明HU中检查点突变体中复制叉不稳定性的机制/原因 在微型染色体复制应激时复制复合物中发生的结构/组成变化 纯化系统与质谱联用。 3.使用ssDNA和DNA片段的组合鉴定人类的复制起点和染色体脆性位点。 染色体断裂作图，已经适用于哺乳动物系统。

DNA replication is a fundamental process on which all organisms depend for faithful passage of genetic material from one generation to the next. The DNA replication process is often "stressed" either by mutations or by exogenous reagents that can cause DNA damage or impediments to the replication machinery. Replication stress can give rise to genomic instability and may ultimately lead to diseases including cancer. My main research interest is how defective replication cause genomic instability. The general hypothesis governing this proposal is that single-stranded DNA (ssDNA) production upon replication fork stalling and destablization in replication checkpoint-deficient mutants is a potentially lethal event that prevents complete synthesis of the genome, causes chromosomal breakage, and ultimately genomic instability. The specific aims of this project are: 1. Investigate the link between extensive ssDNA formation during replication stress and chromosome breakage using the genome-wide ssDNA and chromosome breakage mapping techniques developed by the applicant in combination with other genetic approaches. 2. Elucidate the mechanism/cause of replication fork instability in checkpoint mutants in HU by examining the structural/compositional changes that occur in the replication complex upon replication stress by a minichromosome purification system coupled with mass spectrometry. 3. Identify origins of replication and chromosome fragile sites in humans using a combination of ssDNA and chromosome breakage mapping that have been adapted for the mammalian systems.