Genomic Analysis of Akinete Differentiation

Akinete 分化的基因组分析

• 批准号: 7131848
• 负责人: MICHAEL L SUMMERS
• 金额: $ 10.69万
• 依托单位: CALIFORNIA STATE UNIVERSITY NORTHRIDGE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7131848
• 关键词: Cyanophyta; biological models; cell differentiation; cell growth regulation; gene expression; genetic promoter element; microarray technology; microorganism culture; minority institution research support; mutant; polymerase chain reaction; spores

The project objective is to identify and characterize genes involved in bacterial cell differentiation. Vegetative cells of the filamentous cyanobacterium Nostoc punctiforme (strain ATCC 29133) are capable of cellular differentiation into spore-like akinetes that function in perennation. N. punctiforme is an excellent model system in which to study cellular differentiation with respect to its recently sequenced genome, well developed genetic system, and availability of a newly developed DNA microarray. The first specific aim of this proposal is to identify genes differentially expressed during akinete differentiation using microarray analysis. This study will utilize a glucose-6-phosphate dehydrogenase mutant strain of N. punctiforme, designated UCD 466, that differentiates a large proportion of vegetative cells into akinetes following dark incubation in the presence of fructose. The wild-type strain is capable of heterotrophic growth under similar conditions and does not differentiate into akinetes. The DNA microarray technique will be performed with samples from various time points during akinete formation to identify regulated genes. The second specific aim is to construct and physiologically characterize mutants in selected differentially expressed genes by targeted gene replacement. Transcriptional reporter constructs will also be generated for selected genes and introduced into the wild-type and UCD 466 strains to determine temporal and spatial (cell-type specific) expression patterns. Promoter sequences from differentially expressed genes will be determined and the consensus sequence for common promoter elements used for future characterization of associated regulatory proteins. Functional characterization of differentially expressed gene products in akinetes will lead to a better understanding of how this specialized cell type can withstand harsh conditions. Regulatory mutants generated in this work will be used to identify regulons and regulatory cascades involved in akinete differentiation and allow identification of those that overlap differentiation processes in other cell types.

该项目目标是识别和表征与细菌细胞分化有关的基因。 丝状蓝细菌Nostoc点状（菌株ATCC 29133）的营养细胞能够 细胞分化为孢子状的孢子，在丧命中起作用。 N. Punctiforme是一个极好的 模型系统在其中研究细胞分化有关其最近测序的基因组的模型系统， 开发的遗传系统以及新开发的DNA微阵列的可用性。第一个具体目的的 该建议是识别使用微阵列在Akinete分化过程中差异表达的基因 分析。这项研究将利用葡萄糖-6-磷酸脱氢酶突变型链球菌的脱氢酶突变株， 指定的UCD 466，将大部分的营养细胞区分为黑暗 在存在果糖的情况下孵育。野生型菌株能够在相似的 条件，不区分Akinetes。 DNA微阵列技术将使用 在阿基内特形成过程中，来自各个时间点的样本以鉴定受调节的基因。第二个特定 目的是通过通过生理来构建和生理表征突变体在选定的差异表达基因中 靶向基因置换。转录报告基因构建体还将为选定的基因生成 引入野生型和UCD 466菌株以确定时间和空间（细胞类型） 表达模式。将确定来自差异表达基因的启动子序列，并确定 用于未来表征相关表征的常见启动子元素的共识序列 调节蛋白。在Akinetes中差异表达的基因产物的功能表征将 可以更好地了解这种专业的细胞类型如何承受恶劣的条件。监管 这项工作中产生的突变体将用于识别Akinete中涉及的规范和调节级联 分化并允许识别其他细胞类型中分化过程的重叠过程。