Differential DNA Replication in Drosophila Development

果蝇发育中的差异DNA复制

• 批准号: 8466980
• 负责人: Terry L. ORR-WEAVER
• 金额: $ 38.58万
• 依托单位: WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8466980
• 关键词: Affect; Binding; Biochemistry; Biological; Cells; Chromatin; Chromatin Remodeling Factor; Chromatin Structure; Chromosomal Instability; Chromosome Fragile Sites; DNA biosynthesis; Defect; Development; Double Strand Break Repair; Drosophila genus; Elements; Failure; Fat Body; Gene Amplification; Gene Dosage; Genetic; Genetic Transcription; Genome; Genomics; Human; Individual; Lead; Mental Retardation; Modeling; Movement; Mutation; Pattern; Proteins; Regulation; Replication Initiation; Replication Origin; Replicon; Repression; Research; S Phase; Series; System; brahma; cancer cell; chromatin protein; interdisciplinary approach; mutant; origin recognition complex; prevent; response; tumor progression

DESCRIPTION (provided by applicant): DNA replication must be regulated precisely to maintain gene copy number. Cancer cells contain many regions in which gene copy number has been amplified and these are associated with tumor progression, but the primary mechanisms causing gene amplification are unknown. Failure of replication may contribute to chromosome fragile sites that lead to chromosomal instability. Mutations in proteins needed for replication initiation are associated with human developmental defects. It is crucial to determine how replication origins are activated or inactivated and how replication fork progression is controlled in metazoan cells. This necessitates the analysis of individual origins, the localization of replication initiation proteins, and ways to examine fork progression. This research will exploit developmental models of genomic regions that become amplified in copy number or under-replicated in response to differentiation in Drosophila. These models provide defined replication origins to which replication initiation proteins, essential for replication in human cells, can be localized and that can be analyzed in differentiated cells as they undergo initiation of DNA replication. They also define specific domains through which replication fork progression is permitted or impeded. These models provide a paradigm for delineating the mechanisms of replication initiation and elongation not present in another metazoan system. The Specific Aims of this proposal are to use these models to answer fundamental questions about replication initiation and fork progression, utilizing interdisciplinary approaches of genomics, genetics and biochemistry. The mechanisms leading to origin activation will be defined for two amplified domains, regions of the genome permissive or restrictive for initiation will be investigated to determine how the Origin Recognition Complex (ORC) is localized and whether there are ORC- independent mechanisms of initiation. In the second aim, genomic regions that block initiation will be used to delineate the effects of chromatin configuration on ORC binding and origin activation. The last aim is to determine how replication fork progression is controlled by chromatin by identifying proteins that promote or block fork movement. Candidate proteins identified by mutants and localization patterns will be investigated. This aim also will analyze th requirement for double-strand break repair at the forks.

说明（由申请人提供）：DNA复制必须精确调控以维持基因拷贝数。癌细胞包含许多基因拷贝数扩增的区域，这些区域与肿瘤进展有关，但导致基因扩增的主要机制尚不清楚。复制失败可能导致染色体脆性位点的产生，从而导致染色体不稳定。复制起始所需的蛋白质突变与人类发育缺陷有关。确定如何激活或灭活复制起始点以及如何控制复制分叉进程是至关重要的