Sexual isolation in bacteria

Bacteria exchange gents rarely but are promiscuous in the choice of their g enetic partners. Inter-specific recombination has the advantage of increasi ng genetic diversity and promoting dissemination of novel adaptations, but suffers from the negative effect of importing potentially harmful alleles f rom incompatible genomes. Bacterial species experience a degree of 'sexual isolation from genetically divergent organisms - recombination occurs more frequently within a species than between species. In this review, I outline the sources and mechanisms of sexual isolation within the context of selec tive pressures acting on different types of recombination events. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Sci ence B.V. All rights reserved.