Genetics of E. coli Development

奇异变形杆菌有两种生物现象值得详细的遗传分析：(1)菌群发育，涉及细菌生长、细胞分化和多细胞群的有规律的循环；(2)Dienes反应，来自不同菌株的两个群在共同的底物上相遇时产生特定的边界结构。变形杆菌生物学的这两个方面提出了关于多细胞生物模式是如何产生以及自我/非我识别如何发生的基本问题。这项拟议的研究需要使用体内插入突变和分子克隆的方法来鉴定不同奇异P.mirabilis菌株的基因组片段，这些片段编码控制形态发生和菌株鉴定的系统的组件。这项研究将测试关于可扩散物质在引导群体群体发展中的作用以及关于原噬菌体序列在菌株间边界形成中的作用的具体假设。这些数据将为组成奇异假单胞菌物种的许多(可能超过10亿)不同菌株的分子比较提供基础，这些结果将成为理解多细胞控制以及它们如何在自然环境中作为细菌发挥作用的基础。

Proteus mirabilis exhibits two biological phenomena that merit detailed genetic analysis: (1) Swarm colony development, involving regular cycles of bacterial growth, cellular differentiation and migration of multicellular groups; and (2) the Dienes reaction, whereby two swarms from different strains produce specific boundary structures when they encounter each other on a common substrate. These two aspects of Proteus biology raise fundamental questions about how multicellular biological patterns are generated and how self/non-self recognition occurs. The proposed research entails the use of in vivo methods for insertional mutagenesis and molecular cloning to identify segments of the genomes of different P.mirabilis strains which encode components of the systems that control morphogenesis and strain identity. The research will test specific hypotheses about the role of diffusible substances in guiding swarm colony development and about the role of prophage sequences in interstrain boundary formation. The data will provide a foundation for a molecular comparison of the many (possible over a billion) distinct strains which comprise the species P. mirabilis, and these results will serve as a basis for understanding multicellular controls and how they operate as bacteria function in natural environments.