Genome Evolution in Bacteria

细菌基因组进化

• 批准号: 8803506
• 负责人: Howard Ochman
• 金额: $ 13.96万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-15 至 1992-05-01
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8803506&HistoricalAwards=false
• 关键词: Genome; Evolution; Bacteria

The proposed research will investigate the factors promoting variation in the size and organization of the bacterial chromosome. By analysing isolates of Escherichia coli and other enteric bacteria of known genetic and genealogical relationships, he will examine many types of evolutionary events occurring above the level of individual gene loci. This research will address questions concerning: (1) the incidence of horizontal gene exchange, recombination and large-scale DNA rearrangements in natural populations, (2) variation in the physical maps of the E. coli chromosome, (3) the extent of insertion and deletion of chromosomal DNA causing variation in genome size among natural isolates, (4) the chromosomal location and stability of transposable elements, and (5) the rate and evolutionary history of genetic and chromosomal changes in enteric bacteria. To analyse these events among natural isolates, Dr. Ochman will: (1) Assess the nucleotide variation in a large number of genes positioned around the E. coli chromosome to search for regions that have been affected by recombination, as evident by inconsistencies in the phylogenetic relationships among strains based on a particular gene. (2) Produce physical maps of the chromosome for many strains of E. coli. Large DNA fragments generated by restriction enzymes with very infrequent recognition sequences are resolved by techniques such as pulsed-field gel electrophoresis and mapped by blot and hybridization procedures. (3) Compare homologous traits- nucleotide sequences and physical maps - among divergent taxa. In total, these methods provide a broad approach to studying the dynamics of the bacterial genome.//

拟议的研究将调查促进因素 细菌的大小和组织的变化 染色体 通过分析大肠杆菌和其他 已知遗传和谱系关系的肠道细菌， 他将研究上述发生的许多类型的进化事件， 单个基因位点的水平。 这项研究将解决 问题涉及：（1）水平基因的发生率 交换、重组和大规模DNA重排 自然种群;（2）E. coli染色体的插入和缺失程度; 染色体DNA导致自然界中基因组大小的变异 分离株的染色体定位和稳定性 转座因子;（5）转座因子的速率和进化历史 基因和染色体的变化。 为了分析自然分离物中的这些事件，Ochman博士 （1）在大量的基因组中评估核苷酸变异。 位于E.大肠杆菌染色体进行搜索 受重组影响的区域，如 菌株间系统发育关系的不一致性 基于特定的基因。 (2)制作地球物理地图 染色体的许多菌株的E.杆菌 大DNA片段 由限制性内切酶产生， 序列通过脉冲场凝胶等技术来解析， 电泳并通过印迹和杂交程序作图。 (3)比较同源性状-核苷酸序列和物理 地图-在不同的类群之间。 总之，这些方法提供了一个 研究细菌基因组动态的广泛方法。