Genome hypermobility by lateral transduction.

Abstract

Genetic transduction is a major evolutionary force that underlies bacterial adaptation. Here we report that the temperate bacteriophages of <i>Staphylococcus aureus</i> engage in a distinct form of transduction we term lateral transduction. Staphylococcal prophages do not follow the previously described excision-replication-packaging pathway but instead excise late in their lytic program. Here, DNA packaging initiates in situ from integrated prophages, and large metameric spans including several hundred kilobases of the <i>S. aureus</i> genome are packaged in phage heads at very high frequency. In situ replication before DNA packaging creates multiple prophage genomes so that lateral-transducing particles form during normal phage maturation, transforming parts of the <i>S. aureus</i> chromosome into hypermobile regions of gene transfer.