Systematic mutagenesis of the model organism Streptomyces coelicolor: completion of an essential resource for the research community

链霉菌是令人着迷的土壤细菌，具有重要的经济意义，因为它们生产人类已知的70%的抗生素。不同寻常的是，它们表现出复杂的分化生命周期，这对抗生素的生产有影响。由于它们的重要性，BBSRC和Wellcome Trust资助了模式物种S. coelicolor的全基因组测序。因此，我们知道这种细菌拥有大约8000个基因。然而，到目前为止，我们只了解这些基因的一小部分的生物学功能。了解基因功能很重要，因为它使我们能够更多地了解链霉菌的生物学，特别是抗生素产生和分化调控的复杂性。此外，S. coelicolor是一种遗传上易于处理的模型，可以理解它与重要的人类病原体（如结核分枝杆菌）共享的保守过程。了解基因功能的一个关键方面是产生突变体，其中特定基因不再活跃。通过比较突变体与非突变体的特征，就有可能了解有关基因的功能。拟议的研究旨在完成一个多功能资源的构建，目前世界各地的研究人员正在使用该资源来创建S. coelicolor的特定基因突变。这种资源是通过将一个“跳跃基因”或转座子插入到每个葡萄球菌基因的DNA序列中而获得的。这些插入是在cosmid文库中克隆的基因拷贝中进行的，该文库用于获得S. coelicolor基因组序列。因此，对于每个携带大约30个连续基因的原始cosmid，我们构建了一个由单个cosmid组成的亚库，每个cosmid在每个基因中携带一个插入。有了这些突变瓢虫，研究人员可以很容易地在感兴趣的基因上构建一个有缺陷的变色瓢虫突变体。任何研究人员都可以通过一个在线数据库获得有关系统宇宙突变计划的信息，允许他们选择和订购特定的突变宇宙以供自己使用。此外，我们将利用这些资源更详细地研究链霉菌如何适应自然环境中不同的水分含量。这本身就会影响生命周期和抗生素的生产。

Streptomyces are fascinating soil bacteria of major economic importance as they produce 70% of antibiotics known to man. Unusually for bacteria, they exhibit a complex differentiating life-cycle that has implications for antibiotic production. Due to their importance, the BBSRC and Wellcome Trust funded the complete genome sequencing of the model species S. coelicolor. As a consequence, we know this bacterium possesses about 8000 genes. However, as yet we only understand the biological function of a small proportion of these genes. Understanding gene function is important as it enables us to learn more about the biology of Streptomyces and, in particular, the complexities of the regulation of antibiotic production and differentiation. In addition, S. coelicolor is a genetically tractable model to understand conserved processes it shares with important human pathogens such as Mycobacterium tuberculosis. A critical aspect of understanding gene function is the creation of mutants in which a specific gene is no longer active. By comparing characteristics of the mutant with those of a non-mutant, it is possible to learn about the function of the gene in question. The proposed research intends to complete the construction of a versatile resource that is currently being used by researchers worldwide to create specific gene mutations in S. coelicolor. This resource is made by insertion of a 'jumping gene' or transposon into the DNA sequence of each S. coelicolor gene. These insertions are made in gene copies cloned in a cosmid library: this library was used to obtain the S. coelicolor genome sequence. So for each original cosmid carrying approximately 30 contiguous genes, we construct a sub-library consisting of individual cosmids each carrying an individual insertion in each gene. With access to these mutant cosmids, researchers can easily construct a S. coelicolor mutant defective in a gene of interest. Information on the systematic cosmid mutagenesis programme is accessible to any researcher via an online database, allowing them to select and order specific mutant cosmids for their own use. In addition, we will ourselves use the resource to investigate in more detail how Streptomyces adapt to the varying moisture content of their natural environment. This itself impacts on the life-cycle and antibiotic production.