title: How long can bacteriophage λ change its mind?
abstract: A key event in the lifecycle of a temperate bacteriophage is the choice between lysis and lysogeny upon infection of a susceptible host cell. In a recent paper, we showed that a prolonged period exists after the decision to lysogenize, during which bacteriophage λ can abandon the initial decision, and instead develop lytically, as a response to the accumulation of the late lytic regulatory protein Q. Here, we present evidence that expression of Q does not induce replication of λ DNA, suggesting that the DNA to be packaged into the resulting phage progeny was already present at the time of the initial decision to lysogenize. We summarize our findings in a working model of the key determinants of the duration of the post-decision period during which it is possible for the infected cell to switch from the lysogeny decision to successful lytic development.
authors.affiliation: Center for Models of Life; Niels Bohr Institute ; University of Copenhagen ; Copenhagen, Denmark.
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Semsey
authors.affiliation: Department of Biology; University of Copenhagen ; Copenhagen, Denmark.
authors.forename: Christopher
authors.initials: C
authors.lastname: Campion
authors.affiliation: Department of Biology; University of Copenhagen ; Copenhagen, Denmark.
authors.forename: Abdu
authors.initials: A
authors.lastname: Mohamed
authors.affiliation: Department of Biology; University of Copenhagen ; Copenhagen, Denmark.
authors.forename: Sine Lo
authors.initials: SL
authors.lastname: Svenningsen
keywords: Bacteriophage λ; DNA replication; cell fate commitment; gene regulatory circuit; lysis-lysogeny decision