DNA REPLICATION IN ANIMAL CELLS

动物细胞中的 DNA 复制

• 批准号: 6498860
• 负责人: HOWARD CEDAR
• 金额: $ 14万
• 依托单位: HEBREW UNIVERSITY OF JERUSALEM
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6498860
• 关键词: DNA replication; Prader Willi syndrome; cell cycle; fluorescent in situ hybridization; gene expression; genetic mapping; genetic regulatory element; genetically modified animals; globin; happy puppet syndrome; laboratory mouse; tissue /cell culture

DESCRIPTION (Verbatim from the applicant's abstract): The entire genome is divided into individual units (chromosomal bands) whose replication timing in the cell cycle is under developmental control. This process plays a wide spread role in the regional regulation of expression, both for tissue specific genes and as a differential marker of monoallelic transcription as seen in genomic imprinting and allelic exclusion. Although little is known about this process, a new approach which takes advantage of Fluorescence In Situ Hybridization (FISH) to interphase nuclei should now allow us to decipher the basic elements which direct replication timing in vivo. Preliminary data indicates that sequences located within the Locus Control Region (LCR) of the human globin domain are involved in regulating replication timing during development. The investigator has developed a new tissue culture assay which can be employed for deciphering the exact cis acting elements which mediate this effect, and this will pave the way towards cloning the trans acting factors that direct this process. This represents an entire new class of molecular effectors which are intimately involved in differentiation. Asynchronous replication is characteristic of monoallelically expressed genes. In order to understand how each allele controls replication timing separately, they have developed a transgenic mouse model system and have already identified the DNA regions which regulate imprinted replication timing patterns. This will be used to map the molecular interactions which bring about imprinting. We have also shown that the lgk domain is subject to primary allelic exclusion in a process which employs replication timing differences to mark each allele. This may represent a new biological strategy for controlling monoallelic gene expression in a clonal manner. Ultimately they would like to understand the relationship between late replication and gene repression. New studies using injection of genes into individual nuclei of cells in culture clearly show that the ability to set up basal transcription complexes is cell cycle dependent and is most active in early S as opposed to late S. These experiments will allow them to decipher the mechanism of S phase transcriptional control and explain the relationship between replication timing and expression.

描述（逐字摘自申请人的摘要）：整个基因组是 分为单独的单位（染色体带），其复制时间 细胞周期受发育控制。这个过程发挥着广泛的作用 在组织特异性基因表达的区域调节中的作用 并作为基因组中单等位基因转录的差异标记 印记和等位基因排除。尽管人们对这个过程知之甚少， 一种利用荧光原位杂交的新方法 （FISH）到间期核现在应该可以让我们破译基本元素 指导体内复制时间。初步数据表明 位于人珠蛋白基因座控制区 (LCR) 内的序列 域参与调节发育过程中的复制时间。这 研究人员开发了一种新的组织培养测定法，可用于 破译介导这种效应的确切顺式作用元件，并且这 将为克隆指导这一过程的反式作用因子铺平道路 过程。这代表了一类全新的分子效应器，它们是 密切参与分化。异步复制是 单等位基因表达基因的特征。为了了解如何 每个等位基因分别控制复制时间，他们开发了一个 转基因小鼠模型系统并已经鉴定了DNA区域 调节印记复制计时模式。这将用于映射 分子相互作用，从而产生印记。我们还表明 lgk 结构域在一个过程中受到初级等位基因排除的影响 利用复制时间差异来标记每个等位基因。这可能代表 控制单等位基因表达的新生物学策略 克隆方式。最终他们想了解这种关系 晚期复制和基因抑制之间。新研究使用注射 将基因转移到培养物中的细胞的单个细胞核中清楚地表明了这种能力 建立基础转录复合物是细胞周期依赖性的，并且是最重要的 活跃于早期 S 而不是晚期 S。这些实验将使他们能够 破译S期转录控制机制并解释 复制时间和表达之间的关系。