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 Staphylococcus aureus 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 S. aureus 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 S. aureus chromosome into hypermobile regions of gene transfer.

A novel uncultured marine cyanophage lineage with lysogenic potential linked to a putative marine Synechococcus ‘relic’ prophage

“…(McDaniel et al ., ). Among the benefits and consequences of lysogeny, reviewed elsewhere, for example (Howard‐Varona et al ., ), it has been proposed to play a role in the protection phages from decay (Breitbart, ), contribution to host survival under unfavourable environments by suppression of unneeded metabolic activities (Paul, ), and phage‐mediated horizontal gene transfer of bacterial DNA (Chen et al ., ). Although temperate phages infecting either freshwater cyanobacteria Anacystis nidulans (Lee et al ., ) or marine filamentous cyanobacteria (Ohki and Fujita, ) are known, to date, prophage induction in marine cyanobacteria has only been studied using natural populations or the cultured Synechococcus GM 9914 (McDaniel and Paul, ; McDaniel et al ., ).…”

Comparative genomics groups phages of Negativicutes and classical Firmicutes despite different Gram‐staining properties

“…The discrepancy with gut virome metagenome data demonstrating substantial amounts of ARG genes packaged in viral particles (Modi et al ., ) might be explained by the recently described phenomenon of ‘lateral transduction’ where pac ‐site prophages from Firmicutes are induced to replicate before the prophage genome is excised leading to a 1000‐fold or higher transduction of bacterial DNA including ARG located up to seven phage genome lengths away from the prophage integration site (Chen et al ., ). Instead of verifying by expression cloning whether the MBL‐annotated genes are truly candidate ARG within prophage context of Negativicutes, it might be more important to test whether the pac ‐site Sfi11‐like (Brussowvirus) prophages identified in Negativicutes of the present study replicate upon induction before genome excision as shown for Staphylococcus aureus phages (Chen et al ., ; Davidson, ). These experiments are, however, beyond the scope of our bioinformatic analysis of Negativicute prophages and necessitate an independent study.…”

Comparative genomics of globaloptrA-carryingEnterococcus faecalisuncovers common genetic features and a chromosomal hotspot foroptrAacquisition

“…optrA was not identified as integrated in a prophage in this work, but a diversity of prophages was found integrated in the chromosome of most strains including all the nine strains containing the Tn 6674 (Group 1 of Figure 3). Strikingly, phage-mediated lateral transduction was recently described as a putative new universal mechanism of transfer promoting the efficient exchange of large portions of bacterial genomes at high frequencies [64]. Considering the finding of optrA embedded in so many diverse genetic platforms amongst different Gram-positive genera (enterococci, staphylococci, streptococci), one can also speculate about the possible optrA mobilization through phage-mediated transduction.…”