|GEMOVE: Genes in motion: Mobile genes in microbial communities, how to catch them?|
Cláudia Sofia Soares de Oliveira
Programme - EXPL/BIA-MIC/1567/2012
Execution dates - 2013-06-03 - 2014-06-02 (12 Months)
Funding for CESAM - 40.133 €
Total Funding - 40.133 €
Proponent Institution - Universidade de Aveiro
Bacterial communities are able to adapt to almost every environment on the planet. Adaptation is a consequence of the diversity of strains and the plasticity of genomes. Massive sequencing projects have revealed that bacterial genomes are not rigid and finite structures, where as such as 20% of their gene content is considered to have origins in other microbial organisms. The evidences for gene flow across bacterial species support the important role of gene exchanges and shuffling among microbial communities and making bacterial species barriers thinner and weaker. Major agents involved are known to be mobile genetic elements (MGE) that have shown to foster the mobilization and rearrangements of genes. Selective pressures have driven the success of useful genes for bacteria in the environment. Examples are antibiotic resistance and virulence genes and genes encoding enzymes for degradation of toxic compounds. This ensemble of "mobile" genes in a bacterial community is of great research interest because of their biotechnological potential (for example exploring genes encoding for degradation of pollutants), risk assessment (when coselection of virulence and antibiotic resistance genes is observed) and also because they may provide a snapshot of the microbial communities response to environmental drift or pressures. Horizontal gene transfer (HGT) and associated MGE has been the focus of intense research efforts in the last years and have shown that plasmid mediated gene transfer is main responsible for gene mobilization within microbial communities. They are typically modular structures made up of essential and accessory genes. The later comprise all the sequence information that has the potential to be transferred to other bacterial hosts and are the central subject of this research proposal. Plasmids as main agents of gene mobilization across microbial communities respond to environmental pressures by triggering gene rearrangements and transfer rates increasing the chances of mobilization of useful genes for the bacterial species/bacterial community. Enclosed in the accessory plasmid DNA region are genes that reflect a response to environmental conditions. Currently there are no clear-cut approaches to directly assess to plasmid encoded genes. The (apparent) high diversity in plasmid accessory genes, together with the high diversity of plasmid types, featuring different backbone structure and possibly different insertion sites for accessory gene sequences are some of the difficulties that can be anticipated when envisaging molecular methodologies to probe for mobile genes. However, the development of molecular tools could provide for tremendous innovation on risk assessment studies and a powerful tool to explore biotechnological potential from plasmid encoded functions. So it is the main aim of this research proposal to create innovative strategies for high-throughput screening of plasmid encoded mobile genes.