On my research as a PhD candidate I am interested in study experimentally how altered bacterial strains with reduced fitness re-alter their genomes to regain fitness. Using this approach I intend to gain insight into the underlying problems and the mechanisms that can lead to its solution.
Project I: Amelioration of plasmid cost
In one of my projects, I study the mechanisms by which Escherichia coli can reduce the cost of plasmid carriage. The horizontal transfer of plasmids and other pieces of foreign DNA into naïve bacteria may impose a fitness cost that must be reduced by genetic changes. This type of evolutionary change is very relevant in medical microbiology where the acquisition of plasmid is associated with antibiotic resistance, and in biotechnology, where the introduction of expression vectors may disturb the physiological balance of the engineered strain.
Project II: Significance of location and orientation of highly expressed genes
In other project, I investigate the organization of the bacterial chromosome, which is often highly skewed. The current hypothesis is that genomic-scale organization reflects selection pressure for maximum growth rate, by increasing the relative copy number of highly transcribed genes and minimizing the frequency of clashes between DNA and RNA polymerases. For each case, I experimentally test the basis of the fitness cost and ask whether, how, and how rapidly, an altered strain could genetically adapt to the acquire changes in genome content and/or structure.
Project III: Fitness consequences of ancestral and homologous EF-Tu variants