Physiological and Ecological Significance of Multiple Ribosomal RNA Operons in Bacteria

细菌中多个核糖体RNA操纵子的生理和生态意义

• 批准号: 9875254
• 负责人: Thomas Schmidt
• 金额: $ 33万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9875254&HistoricalAwards=false
• 关键词: Physiological; Ecological; Significance; Multiple; Ribosomal

As the genomes of bacteria are explored in greater detail, it has becomeobvious that most genes are present at a single position on thechromosome. The most obvious exceptions to this observation are the genesthat encode for ribosomal RNAs, for which there are as many as 15 copies.This work will represent the first comprehensive effort to explain thepuzzling occurrence of multiple ribosomal RNA genes in bacteria.Preliminary results suggest that the number of rRNA genes reflects theecological strategies of diverse bacteria: those possessing multiplecopies may exhibit increasing competitive fitness when nutrient availabilityfluctuates, while those possessing few copies may be more efficient atgrowth under constant, low-nutrient conditions. The PIs will examine thepossibility that the number of ribosomal RNA genes in a bacterial genomerepresents one trait among a group of interdependent traits that influencethe distribution of bacterial populations in nature. The principlesderived from this research should be applicable to understanding thedistribution of bacteria that play crucial roles in the global cycling ofelements as well as bacteria used in bioremediation or those that havesymbiotic relationships with plants or animals.

随着对细菌基因组的更详细的探索，很明显，大多数基因都存在于染色体上的一个位置。这一观察结果最明显的例外是编码核糖体RNA的基因，其拷贝数多达15个。这项工作将是第一次全面地努力解释细菌中令人费解的多个核糖体RNA基因的出现。初步结果表明，rRNA基因的数量反映了不同细菌的生态策略：那些拥有多个拷贝的细菌可能在营养可利用性波动时表现出越来越强的竞争适合度，而那些拥有较少拷贝的细菌可能在恒定的低营养条件下更有效地生长。PI将检查细菌基因组中核糖体RNA基因的数量是否代表影响自然界细菌种群分布的一组相互依赖的特征中的一种特征。这项研究得出的原则应适用于理解在全球元素循环中发挥关键作用的细菌以及用于生物修复或与植物或动物有共生关系的细菌的分布。