Fig 1.
Temperate phages can insert their genomes (in red) into the host bacterial chromosome (in blue) to become a prophage in the lysogenic life cycle. Following lysogenic induction, prophages excise and enter the lytic life cycle.
Fig 2.
Mechanisms of genetic transduction.
Generalized (top), specialized (middle), and lateral transduction (bottom). The viral genome (in red) first undergoes theta replication, followed by rolling circle replication. In lateral transduction, theta replication occurs prior to prophage excision. Phage terminase initiates DNA packaging from phage pac sites (black triangles) or pseudo-pac sites (gray triangles).
Fig 3.
Pathogenicity island–mediated gene transfer.
SaPI element transduction (top) and island-mediated generalized transduction (bottom). The strain has a viral genome (in red) and an SaPI genome (in green). Upon lysogenic induction, both phage and SaPI genomes undergo theta replication, followed by rolling circle replication. Phage terminase initiates DNA packaging from phage pac sites (black arrows) or phage pseudo-pac sites (gray arrows). SaPI terminase initiates DNA packaging from SaPI pac sites (green triangles) or SaPI pseudo-pac sites (light green triangles). SaPI, S. aureus pathogenicity island.