Mechanisms linking replication stress to genome instability in fission yeast

基因组不稳定性是指染色体序列、结构或数量的变化， 正常的细胞功能。这种不稳定性是癌症的特征，以及某些发育和 神经缺陷和衰老来自多个生物体的数据表明，DNA复制应激是 基因组不稳定的关键因素。稳定复制叉的机制，防止异常 分裂和促进DNA修复是疾病的主要障碍;因此，了解它们的 其功能及其中断的后果直接关系到人类健康。 该方案采用已建立的模式细胞生物学系统--裂殖酵母S.粟酒， 来描述活细胞对复制压力的反应。S.粟酒是一种公认的遗传 染色体生物学模型，与人类细胞有许多共同特征。值得注意的是，几乎所有 正在研究的基因在人类中具有与疾病相关的直系同源物。 该方法的一个关键方面是使用活细胞成像来表征对 复制应力和表征其长期后果。首要目标是了解 复制压力的动力学及其在正常和突变细胞中的解决方案。这包括 确定细胞如何部署分子机制，以允许损伤解决并确保 染色体分离我们解决分裂的细胞和遗传后果， 压力;研究复制如何在G2或有丝分裂后期发生，以促进解决;并检查 修复结构的三维组织。我们以前已经证明， 是一个脆弱的网站，我们已经扩大了检查核糖体DNA和阶段的作用， 分离有助于基因完整性，以及其他脆弱区域的识别。一种新型 组成部分是分析减数分裂过程中的复制应力作为染色体的贡献者 与出生缺陷和不孕症相关的基因重排。 通过将这种细胞生物学方法与高超的酵母基因发现工具相结合， 确定导致异常分裂和进一步压力的分子事件，这个项目解决了一个 目前认识上的巨大差距。哪些途径导致了对 压力及其相关的病理学，以及它们如何影响活细胞的生物学？在一起， 这些研究提供了保守蛋白如何相互作用以维持基因组稳定性的整体图景 在真核细胞中，识别人类疾病的标志物和风险因素。

Genome instability refers to changes in chromosome sequence, structure, or number that affect normal cell function. Such instability is characteristic of cancer, as well as certain developmental and neurological defects, and aging. Data from multiple organisms suggests that DNA replication stress is a key contributor to genome instability. Mechanisms that stabilize replication forks, prevent abnormal divisions, and promote DNA repair are a primary barrier to disease; therefore, understanding their function and the consequences of their disruption has direct relevance to human health. This proposal employs an established model cell biology system, the fission yeast S. pombe, to characterize how living cells respond to replication stress. S. pombe is a well-established genetic model for chromosome biology that shares many features with human cells. Significantly, nearly all the genes under study have orthologues in humans that have been associated with disease.. A key aspect of the approach is to use live cell imaging to characterize the response to replication stress and characterize its long term consequences. The overarching goal is to understand the dynamics of replication stress and its resolution in normal and mutant cells. This includes determining how the cell deploys molecular mechanisms to allow damage resolution and ensure chromosome segregations. We address the cellular and genetic consequences of division under stress; investigate how replication occurs late in G2 or mitosis to facilitate resolution; and examine the three-dimensional organization of repair structures. We have previously shown that the pericentromere is a fragile site, and we have expanded that to examine the ribosomal DNA and the role of phase separation in contributing to gene integrity, as well as identification of other fragile regions. A novel component is the analysis of replication stress during meiosis as a contributor to chromosome rearrangements associated with birth defects and infertility. By combining this cell biological approach with superb yeast gene-discovery tools, and identifying the molecular events that lead to abnormal divisions and further stress, this project tackles a critical gap in current understanding. What are the pathways that contribute to different responses to stress and their associated pathologies and how do they affect the biology of living cells? Together, these studies provide a holistic picture of how conserved proteins interact to maintain genome stability in a eukaryotic cell, identifying markers and risk factors for human disease.