Single Stranded DNA: The Genome's Achilles Heel

DNA复制是所有生物体依赖的一个基本过程，以确保基因的忠实通过 材料从一代传到下一代。DNA复制过程通常会受到以下两种因素的“压力” 突变或可能导致DNA损伤或复制障碍的外源试剂 机械设备。复制应激可引起基因组不稳定，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。这个 这一提议的一般假设是单链DNA(SsDNA)在复制时产生 复制检查点缺陷突变体中的分叉停滞和不稳定是一个潜在的致命事件， 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广泛的单链DNA形成与染色体的关系 使用基因组范围的单链DNA和染色体断裂图谱技术进行断裂 申请者与其他遗传方法相结合。 2.通过研究HU中检查点突变体的复制叉不稳定性的机制/原因 微染色体在复制压力下复制复合体中发生的结构/组成变化 纯化系统与质谱学联用。 3.结合使用单链DNA和染色体脆性部位鉴定人类复制和染色体脆性部位的起源 已经适应哺乳动物系统的染色体断裂图谱。

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.