Bacterial genome plasticity - intercellular transfer of genetic information

Mutations in the bacterial genomes are responsible for minor genetic changes. Most extensive restructuring of bacterial genomes arise from inter- and intragenetic gene transfer. Multiple types of transposition elements responsible for movement of DNA within cells have been described. All these transposable elements may outreach other cells of the same bacterial species or bacteria of another species via transduction, conjugation and transformation. These three mechanisms of horizontal gene transfer have a great impact on evolution of prokaryotic organisms by allowing molecular innovations to spread among bacteria and promote their adaptation to a new environments. On the other hand, horizontal gene transfer also enables-bacteria to adapt to the host both, by spreading virulence determinants and allowing pathogens to acquire genes of resistance to many antimicrobials. This review presents phenomenons of transduction, conjugation and transformation, as three distinct mechanisms of intercellular DNA transfer that provide potential evolutionary advantage to prokaryotes.