Genome diversity: sources and forces - Editorial overview

At present, the genome sequences of 55 bacterial species have been determin ed and compared. As might be expected, this has revealed a wide range of di versity. More surprisingly, perhaps, is the significant variability also de tected in the few examples in which several members of a given species have been compared (see Dobrindt and Hacker; pp 550-557). In view of the rapid accumulation of genome sequence data, it is timely to consider the sources of such variability and the forces involved in its generation. This Genomic s section of Current Opinion in Microbiology attempts to present an overvie w of our current understanding of the forces and sources of genome, diversi ty in bacteria. The section includes a selection of reviews that highlight various aspects from both whole-genome and mechanistic perspectives. This c ollection is not exhaustive. Several important actors in genome plasticity (e.g. transposition and homologous recombination during transduction, conju gation or transformation) have not been treated in detail, as they are disc ussed regularly and extensively elsewhere.