DIFFERENTIATION IN NITROGEN-FIXING BLUE-GREEN ALGAE

固氮蓝绿藻的分化

• 批准号: 3270717
• 负责人: ROBERT HASELKORN
• 金额: $ 20.83万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-05-01 至 1993-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3270717
• 关键词: Cyanophyta; DNA replication; Escherichia coli; cell differentiation; cell growth regulation; enzyme mechanism; gel electrophoresis; gene expression; genetic manipulation; genetic promoter element; genetic recombination; genetic transcription; membrane reconstitution /synthesis; messenger RNA; molecular cloning; mutant; nitrogen fixation; nucleic acid sequence; operon; peptidases; plant genetics; plant growth /development; plant proteins; protein biosynthesis; symbiosis

The goal of this project is an understanding, in molecular terms, of the processes governing the differentiation of heterocysts, cells specialized for nitrogen fixation, along filaments of the cyanobacterium Anabaena. Although Anabaena is a prokaryote, heterocyst differentiation is characterized by irreversible commitment. The process includes changes in mRNA abundance, vast changes in the synthesis of specific protein, and several cases of rearrangement of DNA. Transcriptional regulation of the differentiation will be studied in vivo and in vitro, using cloned genes as probes of transcription. Many promoter regions have been identified; some of these will be modified by in vitro mutagenesis, returned to Anabaena by conjugation from E. coli, and analyzed on the basis of the activity of reporter genes fused to the modified promoter. Regulation of the process by which DNA around the genes encoding nitrogen fixation functions (nif) is rearranged will be studied by purification of the enzyme(s) responsible for site-specific recombination during heterocyst differentiation in the determination of factors that govern that enzyme's synthesis and activity.

该项目的目的是从分子角度来理解 关于杂环分化的过程 专门用于氮固定的细胞，沿着细丝 蓝细菌Anabaena。 虽然阿纳巴纳是探针，但 杂环分化的特征是不可逆 承诺。 该过程包括mRNA丰度的变化， 特定蛋白质合成的巨大变化，有几种情况 DNA的重排。 转录调节 将使用克隆的体内和体外研究分化 基因作为转录探针。 许多发起人地区有 被确定；其中一些将通过体外修改 诱变，通过大肠杆菌的结合回到阿纳巴纳（Anabaena） 并根据融合的报告基因的活性进行分析 到修改后的启动子。 调节该过程 编码氮固定功能（NIF）的基因周围的DNA为 重新排列将通过纯化酶（S）进行研究 负责杂囊中特定地点重组 确定控制因素的分化 酶的合成和活性。