title: Phenotypic stochasticity protects lytic bacteriophage populations from extinction during the bacterial stationary phase.
abstract: It is generally thought that the adsorption rate of a bacteriophage correlates positively with fitness, but this view neglects that most phages rely only on exponentially growing bacteria for productive infections. Thus, phages must cope with the environmental stochasticity that is their hosts' physiological state. If lysogeny is one alternative, it is unclear how strictly lytic phages can survive the host stationary phase. Three scenarios may explain their maintenance: (1) pseudolysogeny, (2) diversified, or (3) conservative bet hedging. To better understand how a strictly lytic phage survives the stationary phase of its host, and how phage adsorption rate impacts this survival, we challenged two strictly lytic phage λ, differing in their adsorption rates, with stationary phase Escherichia coli cells. Our results showed that, pseudolysogeny was not responsible for phage survival and that, contrary to our expectation, high adsorption rate was not more detrimental during stationary phase than low adsorption rate. Interestingly, this last observation was due to the presence of the "residual fraction" (phages exhibiting extremely low adsorption rates), protecting phage populations from extinction. Whether this cryptic phenotypic variation is an adaptation (diversified bet hedging) or merely reflecting unavoidable defects during protein synthesis remains an open question.
authors.affiliation: Department of Biological Sciences, University at Albany, 1400 Washington Avenue, Albany, New York 12222, USA. rgallet@gmail.com
authors.forename: Romain
authors.initials: R
authors.lastname: Gallet
authors.forename: Thomas
authors.initials: T
authors.lastname: Lenormand
authors.forename: Ing-Nang
authors.initials: IN
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D010582:Bacteriophage lambda / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D004926:Escherichia coli / Q000254:growth & development* / Q000821:virology*; D056084:Genetic Fitness; D008242:Lysogeny; D008954:Models, Biological; D010641:Phenotype; D013269:Stochastic Processes; D013997:Time Factors; D010948:Viral Plaque Assay; D017376:Viral Tail Proteins / Q000235:genetics
chemical_list: D017376:Viral Tail Proteins