The Systematic Identification and Analysis of Replication Origins in Drosophila

果蝇复制起点的系统鉴定与分析

• 批准号: 7417603
• 负责人: David M MacAlpine
• 金额: $ 45.72万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-04 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7417603
• 关键词: Algorithms; All Sites; Architecture; Automobile Driving; Cations; Cell Cycle; Cell Line; Cell division; Cells; Chromatin; Chromosomes; Classification; Complex; Cues; DNA Replication Timing; DNA biosynthesis; Data; Development; Drosophila genome; Drosophila genus; Elements; Event; Failure; Genetic Transcription; Genome; Genome Stability; Genomics; Histocompatibility Testing; Individual; Lead; Location; Maps; Mediating; Messenger RNA; Modification; Nuclear; Pattern; Phase; Polyploidy; Positioning Attribute; Process; Proliferating; Proteins; Publishing; Regulation; Replication Initiation; Replication Origin; Research Personnel; Resolution; Sequence Alignment; Site; Techniques; Time; Tissues; Transcriptional Activation; Up-Regulation; base; cell type; comparative; comparative genomic hybridization; density; insight; programs; tumorigenesis

DESCRIPTION: DNA replication is an essential cell cycle process required to duplicate the chromosomes each and every cell division. Very little is known about how replication is coordinated with other nuclear processes such as transcription and chromatin modification. Although recent genomic studies have demonstrated a correlation between time of DNA replication and transcriptional activity, with actively transcribed regions of the genome being replicated early, the underlying mechanism driving this correlation remains unclear. Only by systematically characterizing the replication dynamics of a metazoan genome in multiple cell types will we be in a position to understand the mechanisms by which these processes are coordinated to maintain genomic stability. We will use high-density genomic tiling-path arrays to characterize fully the Drosophila replication program in multiple cell lines and tissues. Specifically, we will determine the time of replication for all unique sequences in Drosophila genome, identify and map all functional origins of replication, and identify all sites of prereplicative complex (preRC, an essential multi-protein complex required for replication initiation) assembly. The high-resolution mapping of sites of preRC assembly will enable us to apply computational approaches (including comparative genomics) to identify potential sequence motifs that direct and regulate preRC function. Finally, we will also characterize the differential replication of polytene chromosomes in fully differentiated Drosophila tissues to identify genomic regions that are amplified or underreplicated. The differential replication of polytene chromosomes provides a unique opportunity to understand how developmental cues and chromosomal domains influence the replication program. In proliferating cells, duplication of the genome is a critical cell-cycle event, not only must the genome be copied accurately; it must also be copied exactly once. The regulation of origin selection and activation is essential to maintain genomic stability. The failure to completely replicate the genome or the inappropriate over-replication of select sequences may lead to tumorigenesis.

描述：DNA复制是复制每个细胞分裂染色体所需的必不可少的细胞周期过程。关于如何与其他核过程（例如转录和染色质修饰）协调的复制知之甚少。尽管最近的基因组研究表明，DNA复制时间与转录活性之间存在相关性，并且具有积极转录的基因组的转录区域正在早期复制，但驱动这种相关性的基本机制尚不清楚。只有通过系统地表征多种细胞类型中后生基因组的复制动力学，我们才能理解这些过程协调以维持基因组稳定性的机制。 我们将使用高密度的基因组瓷砖路径阵列来充分表征多个细胞系和组织中的果蝇复制程序。具体而言，我们将确定果蝇基因组中所有唯一序列的复制时间，识别和绘制复制的所有功能起源，并识别预先复合复合物的所有位点（PRERC，复制起始必需的必需多蛋白质复合物）组装所需的基本多蛋白质复合物。 PRERC组装位点的高分辨率映射将使我们能够应用计算方法（包括比较基因组学）来识别指导和调节PRERC功能的潜在序列基序。最后，我们还将表征完全分化的果蝇组织中多型染色体的差异复制，以鉴定放大或复制不足的基因组区域。多烯染色体的差异复制提供了一个独特的机会，可以理解发育线索和染色体领域如何影响复制程序。 在增殖细胞中，基因组的重复是一个关键的细胞周期事件，不仅必须准确地复制基因组；还必须精确复制一次。原点选择和激活的调节对于维持基因组稳定性至关重要。未能完全复制基因组或选择序列的不当过度复制可能会导致肿瘤发生。