REGULATION OF DEVELOPMENTAL GENE EXPRESSION

发育基因表达的调控

• 批准号: 2186649
• 负责人: DAPHNE D BLUMBERG
• 金额: $ 15.87万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE COUNTY
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-05-01 至 1997-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2186649
• 关键词: Dictyostelium; biological signal transduction; cell differentiation; cyclic AMP; developmental genetics; early embryonic stage; fluorescence microscopy; fungal genetics; fusion gene; gene expression; genetic promoter element; genetic regulatory element; genetic transcription; messenger RNA; molecular cloning; mutant; northern blottings; nucleic acid sequence; radionuclide double label; reporter genes; spores

The cellular slime mold Dictyostelium discoideum is one of the simplest organisms to undergo true multicellular differentiation. Its relative simplicity offers the opportunity to study the interplay between receptor occupancy, signal transduction and spatially localized patterns of gene expression during development. The particular group of genes being studied, the prespore genes, are regulated at the transcriptional level in a temporal and spatial manner by cAMP - cell surface receptor occupancy. Additionally, the ability to stabilize the mRNA transcripts from these genes depends upon aspects of the multicellular environment. When developing cells are removed from their multicellular environment by disaggregation the prespore mRNAs are rapidly and specifically degraded. In this proposal attention is being focused on defining two aspects of the cis-acting regulation which places two members of this gene family under the above controls. In the promoter region elements important for correct spatial, temporal and cAMP mediated regulation of gene transcription will be defined. In the mRNAs work will be directed towards identifying the sites that render these mRNAs targets for disaggregation induced destabilization. A major question in development has been whether cells differentiate as a function of their position or whether they differentiate in a cell autonomous manner and then sort to position. Using reporter gene constructs fused to prespore gene promoters it has become clear that randomly located cells initiate the expression of prespore genes and then sort to their position in the posterior of the developing slugs. Comparison of the sequences of several different prespore gene promoters reveals considerable variation in potential regulatory sites. This raises the question of whether these prespore genes which appear to be coordinately induced by cAMP are if fact coordinately regulated at the individual cell level. Immunofluorescence microscopy with double labeled antibody probes will be used to determine if there is coordinate activation of expression of different members of the prespore gene family in the randomly isolated single cells that have started to express prespore genes in the early mound stage of development.

细胞粘液模具dictyostelium discoideum是最简单的 有机体会经历真正的多细胞分化。 它的亲戚 简单性提供了研究受体之间相互作用的机会 占用，信号转导和基因的空间局部模式 发育过程中的表达。 特定的基因是 所研究的，前基因在转录水平上受到调节 以营地 - 细胞表面受体的时间和空间方式 占用。 另外，稳定mRNA转录本的能力 这些基因取决于多细胞环境的各个方面。 当开发细胞被从其多细胞环境中删除时 分解前的mRNA被迅速，特异性降解。 在此提案中，注意力集中在定义两个方面 顺式作用法规，该法规置于该基因家族的两个成员 在上述控件下。 在启动子区域元素中对于 正确的空间，时间和cAMP介导的基因调节 转录将被定义。 在mRNA中将指导 旨在确定呈现这些mRNA目标的站点 分解引起的不稳定。 发展中的一个主要问题是细胞是否区分 其位置的功能或它们是否在细胞中区分 自主方式，然后排序位置。 使用报告基因 融合到前基因启动子的结构很明显， 随机位置的细胞启动前孔基因的表达，然后 将它们在发育中的sl骨后部的位置排序。 比较几个不同前基因启动子的序列 揭示了潜在调节地点的差异。 这 提出一个问题，即这些似乎是似乎是 如果事实协调在 单个细胞水平。 带有双重标记的免疫荧光显微镜 抗体探针将用于确定是否有坐标 激活前基因家族不同成员的表达 在已经开始表达的随机隔离单细胞中 在发展的早期阶段，前基因。