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CHROMOSOME SEGREGATION IN A FILAMENTOUS BACTERIUM

丝状细菌中的染色体分离

基本信息

批准号：
8036672
负责人：
JOSEPH R MC CORMICK
金额：
$ 26.94万
依托单位：
DUQUESNE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8036672
关键词：
ATP phosphohydrolase Actinobacteria class Address Animal Model Anthelmintics Antibiotic Therapy Antifungal Antibiotics Architecture Attention Bacteria Bacterial Proteins Binding Binding Sites Biotechnology Candidate Disease Gene Cell Wall Cell division Cell physiology Cells Cellular biology Chromosome Positioning Chromosome Segregation Chromosomes Complex DNA DNA analysis DNA biosynthesis Dependence Development Developmental Cell Biology Developmental Gene Diploidy Fermentation Fluorescent Dyes Fluorescent in Situ Hybridization Gene Expression Regulation Genes Genetic Genetic Transcription Genome Glean Growth Health Herbicides Hyphae Immunosuppressive Agents Industry Infection Knowledge Laboratories Laser Scanning Confocal Microscopy Lead Life Cycle Stages Lobe Location Malignant Neoplasms Measures Medical Medicine Microbiology Molds Mycobacterium tuberculosis Nature Organism Outcome Physical condensation Ploidies Process Production Prokaryotic Cells Proteins Quality of life Regulation Regulator Genes Relative (related person)Replication Origin Reproduction spores Research Research Personnel Research Project Grants Shapes Site Soil Solutions Streptomyces Streptomyces coelicolor Streptomyces coelicolor A3(2)System Testing United States Walkers antitumor drug cost daughter cell design enhanced green fluorescent protein interest microorganism mutant novel research study retinal rods segregation yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): In the few organisms where it has been studied in detail, the single circular chromosome of a rod-shaped bacterium is highly organized and regions of the chromosome have particular subcellular addresses; origins of replication are located at the old cell poles, replication termini are near the new poles derived from cell division. Other loci are arranged in the cell in the order that they appear on the chromosome, origin to terminus. In contrast, the filamentous soil-dwelling bacterium Streptomyces coelicolor has a large linear genome. Little is known about the architecture of the linear chromosome within the Streptomyces spore and the mechanisms which govern its segregation during synchronous division of specialized aerial hyphae are poorly understood. These mycelial organisms are of particular and vital importance to health and biotechnology industries because they produce many biologically active compounds such as antibiotics, antifungals, antihelminthics, herbicides and antitumor drugs. For years researchers have assumed that there is a single copy of the genome per spore compartment of S. coelicolor. Strong preliminary evidence suggests that conventional wisdom is incorrect. First, there is genetic evidence. Mutants of certain genes involved in DNA segregation and condensation appear to produce spores containing DNA that is decondensed showing two lobes of DNA. In addition, apparent genetic diploids can be isolated from the wild type strain. Second, there is cytological evidence. Confocal laser scanning microscopy was used to measure the intensity of fluorescent dye bound to the wild type nucleoid, and the analysis supports the hypothesis of two genome copies per spore. Similarly, preliminary analysis of fluorescent in situ hybridization (FISH) results point to two copies of the genome per wild type spore. Hybridizing a probe to the origin region shows two fluorescent foci located at opposite ends of the spore. Furthermore, a partition protein- EGFP fusion, with binding sites near the origin, localizes in two foci to the poles of maturing spores, as was observed for the origin region using FISH. A candidate gene, encoding a Walker-type ATPase, involved in the establishment of the chromosome position within the spore has been identified. This study proposes experiments to complete the preliminary genetic experiments and extend the cytological analysis of the genome architecture in the spore. Additional genes encoding proteins required for development-associated genome segregation will be identified by bacterial two hybrid analyses. Transcription of several known genes encoding segregation proteins will be tested for their dependence on developmental regulatory genes. PUBLIC HEALTH RELEVANCE: We wish to understand how DNA is segregated and packaged in the special filamentous organisms that produce the majority of biologically active compounds used to treat infection and cancer. These are major producers of the compounds we all rely on for our health and quality of life. Basic knowledge of fundamental cell functions of these organisms may lead to better production of known and novel compounds and lower the cost of buying medicines.

描述(申请人提供)：在少数对其进行了详细研究的生物中，杆状细菌的单个环形染色体高度组织化，染色体的某些区域具有特定的亚细胞地址；复制的起始点位于旧的细胞极点，复制终点位于细胞分裂产生的新极点附近。其他基因座在细胞中的排列顺序是它们在染色体上的出现顺序，从起点到终点。相比之下，丝状土壤细菌天蓝色链霉菌有一个很大的线性基因组。人们对链霉菌孢子线性染色体的结构知之甚少，对其在专化气生菌丝同步分裂过程中控制其分离的机制也知之甚少。这些菌丝体对健康和生物技术行业特别重要，因为它们产生许多生物活性化合物，如抗生素、抗真菌药物、抗蠕虫药物、除草剂和抗肿瘤药物。多年来，研究人员一直假设天蓝色链霉菌的每个孢子隔间只有一个基因组副本。强有力的初步证据表明，传统观点是不正确的。首先，有遗传证据。与DNA分离和凝聚有关的某些基因的突变似乎产生了含有DNA的孢子，这些孢子解聚后显示出两个DNA裂片。此外，还可以从野生型菌株中分离出明显的遗传二倍体。其次，有细胞学证据。共聚焦激光扫描显微镜被用来测量结合在野生型类核上的荧光染料的强度，分析支持每个孢子两个基因组拷贝的假说。同样，荧光原位杂交(FISH)结果的初步分析表明，每个野生型孢子都有两个基因组副本。将探针杂交到起始区，显示出位于孢子两端的两个荧光焦点。此外，与使用FISH观察到的起源区一样，具有靠近起始点的结合部位的分割蛋白-EGFP融合定位在成熟孢子极点的两个焦点上。一个编码Walker型ATPase的候选基因已经被鉴定出来，该基因参与了孢子内染色体位置的确定。这项研究提出了一些实验，以完成初步的遗传学实验，并扩展对孢子基因组结构的细胞学分析。其他编码与发育相关的基因组分离所需蛋白质的基因将通过细菌双杂交分析来识别。几个编码分离蛋白的已知基因的转录将被测试它们对发育调控基因的依赖性。与公共卫生相关：我们希望了解DNA是如何在特殊的丝状生物体中分离和包装的，这种丝状生物体产生了大多数用于治疗感染和癌症的生物活性化合物。这些都是我们健康和生活质量所依赖的化合物的主要生产者。对这些生物体的基本细胞功能的基础知识可能会导致更好地生产已知和新的化合物，并降低购买药物的成本。