The evolution of genetic regulatory systems in bacteria

The genomes of bacterial species show enormous plasticity in the function of individual genes, in genome organization and in regulatory organization. Over millions of years, both bacterial genes and their genomes have been extensively reorganized and adapted so that bacteria occupy virtually every environmental niche on the earth. In addition, changes have occurred in the regulatory circuitry that controls cell operations, cell-cycle progression and responses to environmental signals. The mechanisms that underlie the adaptation of the bacterial regulatory circuitry are crucial for understanding the bacterial biosphere and have important roles in the emergence of antibiotic resistance.