Scope of the meeting

This is the third international Genome Maintenance Meeting (GMM3) to address microbial genome dynamics in a multidisciplinary setting. The stability of microbial genomes and gene pools will constantly be challenged by horizontal gene transfer and recombination, as well as DNA damage induced by endogenous as well as exogenous agents. Mechanisms for rapid genome variation, adaptation and maintenance are a necessity to ensure microbial fitness and survival in rapidly changing environments. Indeed, all the recently released genome sequences reveals that most if not all bacterial species have elaborate mechanisms for DNA repair and genome maintenance.

Understanding DNA repair and horizontal transfer mechanisms requires an interdisciplinary approach of molecular biology and bacterial physiology. Importantly, much can be learned by recognition of the structural and functional relations between systems for transformation/conjugation and DNA repair/recombination/replication. However, several new components specific for these processes are yet to be discovered and a more complete understanding of the entire DNA metabolism in bacterial organisms is required. The emergence of DNA sequence data for multiple microbial genomes has revealed marked evolutionary relatedness among genes involved in DNA repair and transformation but also interesting and important differences. In retrospect, such differences would be expected in view of the differences that exist in physiology, life cycles and environmental habitats between these various organisms. Characterisation of the components of the different systems and evaluation of the functional relationships is in rapid progress. 

The objective of the meeting is to highlight recent progress in understanding of actions and interactions between components of several DNA transfer pathways and genome maintenance systems. Biochemical, genetic, immunological and ultrastructural approaches are being used to probe the interactions between proteins of these pathways. These studies are expected to reveal a more integrated understanding of the architecture of the DNA transfer, recombination and maintenance machinery. The dynamics of genomic changes and genome maintenance/DNA repair affect the net outcome in terms of DNA sequence variability and conservation and can thereby influence microbial fitness for survival and virulence.

The first two GMM meetings were quite successful in generating new knowledge and networking in the field (Trends Microbiol. 9:356-358, 2001; Trends Microbiol. 12:1-4, 2004). We believe that an important field has emerged focused on genome repair mechanisms in virulent and symbiotic microbes and their relationships to genome variability, (in)stability and strain variation. Microbes experience serious counterattack from the human host and environment, for instance through the oxidative burst, which require appropriate survival responses on the part of the microbe. At the same time, changing environments and immune pressures require mechanisms for rapid genome adaptability and diversification. Systematic approaches have revealed major differences in DNA repair and recombination capacities, qualitatively as well as quantitatively in different microbes. It is clear that these mechanisms do not always function and interact as they do in E. coli.