Date

Friday 20 Feb 2026

Time

15:00 - 15:30

Location

BW007

Supervisor

Rene Olsthoorn

Jury

Rolf Boot

Phage satellites are a class of viral mobile genetic elements found in bacteria that lack genes encoding proteins for certain essential mechanisms in the lifecycle of standard viruses, such as the production of viral capsids or replication of DNA. Instead, they integrate themselves into the DNA of their host, and await infection of this host with a specific bacterial virus. If this helper phage infects, phage satellites hijack its viral machinery and use them to create viral particles containing the DNA of these phage satellites. While phage satellites normally hijack their helper phages in a comparable manner, the discovered families of satellites differ significantly in their choice of host bacterium, the phages they target and the exact mechanisms they use to take over these targets. Besides these hijacking mechanisms, some phage satellites have been found to express antiviral defense mechanisms, which are not effective only against their helper phages, but which also target other phages to protect the satellite’s host and itself. This defense causes a mutualistic relationship between the host and its parasite, where the parasite attempts to lengthen the life of its host until it is able to produce offspring. The varying mechanisms underlying the phage satellite’s abilities to hijack and defend against phages have potential to be used in a variety of applications, including in genome engineering and the defense of industrial bacterial cultures. Within this literature review, a few of these phage satellites and the mechanisms they use to hijack their helper phages or defend against hostile parasites will be described, as well as some of the potential applications of these mechanisms.