Control of Heterocyst Differentiation in Free-Living and Symbiotic Cyanobacteria

自由生活和共生蓝藻异囊分化的控制

• 批准号: 9206130
• 负责人: John Meeks
• 金额: $ 33.8万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-01 至 1996-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9206130&HistoricalAwards=false
• 关键词: Control; Heterocyst; Differentiation; Free; Living

The PI hypothesizes that the mechanisms regulating the differentiation of heterocysts (sites of aerobic N2 fixation by Nostoc sp. differ when Nostoc is in symbiotic association relative to growth in the free-living state. He plans to use physiological and molecular genetics to test the hypothesis with analyses in both free-living and symbiotic growth states. Existing mutants will be complemented by electroporation of genomic DNA after in vitro ligation into a plasmid. Insertional mutagenesis will be used to isolate additional mutants. Interrupted genes will be isolated by rescue of the insertion elements; genomic DNA adjacent to the insertions will be cloned form cosmid libraries and characterized. Transcriptional regulation of glucose-6-phosphate dehydrogenase (zwf) will be analyzed in response to nitrogen deprivation and symbiotic interaction using the recently cloned gene. Insertional mutants of zwf will be used to analyze its role in heterocyst function. Recently identified potential nitrogen and anaerobic regulatory genes will be isolated from cosmid libraries by heterologous hybridization and used to construct insertional mutants in Nostoc for analysis of heterocyst differentiation. The results will lead to an understanding of the environmental signals and mechanisms of regulation of cell differentiation in filamentous cyanobacteria in two different growth states.

PI假设，调节 异形胞的分化（通过 当念珠藻处于共生关系中时，念珠藻的种类不同 在自由生活状态下的增长。 他计划用生理学方法 和分子遗传学来验证这一假设， 自由生活和共生生长状态。 现有的变种人将 通过体外后的基因组DNA的电穿孔补充 连接到质粒中。 插入诱变将用于 分离其他突变体。 中断的基因将被分离， 插入元件的拯救;与插入元件相邻的基因组DNA 将从粘粒文库中克隆插入片段并进行表征。 葡萄糖-6-磷酸脱氢酶的转录调控 (zwf)将分析对氮剥夺的反应， 共生互动使用最近克隆的基因。 插入性 ZWF的突变体将用于分析其在异形胞中的作用。 功能 最近确定的潜在氮和厌氧 调节基因将从粘粒文库中分离， 异源杂交，并用于构建插入 突变体进行异形胞分化分析。 的 结果将导致对环境信号的理解 和调控细胞分化的机制 蓝藻在两种不同的生长状态。