Genetic and functional basis of the reduction effect in bacteriophage ΦX174

Clayton L Bailes; Karin R H Biggs; LuAnn Scott; Holly A Wichman; Elissa J Schwartz

doi:10.1016/j.virol.2023.109905

Genetic and functional basis of the reduction effect in bacteriophage ΦX174

Virology. 2023 Oct 27:588:109905. doi: 10.1016/j.virol.2023.109905. Online ahead of print.

Authors

Clayton L Bailes¹, Karin R H Biggs¹, LuAnn Scott², Holly A Wichman³, Elissa J Schwartz⁴

Affiliations

¹ School of Biological Sciences, Washington State University, Pullman, WA, USA.
² Department of Biological Sciences, University of Idaho, Moscow, ID, USA.
³ Department of Biological Sciences and Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, ID, USA.
⁴ School of Biological Sciences and Department of Mathematics & Statistics, Washington State University, Pullman, WA, USA. Electronic address: ejs@wsu.edu.

PMID: 39492403
DOI: 10.1016/j.virol.2023.109905

Abstract

The ΦX174 reduction effect describes a plasmid-based inhibitory phenomenon that mimics the superinfection inhibition found in wild phage populations. In this effect, when a portion of the ΦX174 genome - the 3' end of the pilot protein gene (H), the 5' end of the replication gene (A), and the H-A intergenic region - is present on a plasmid in the host cell, almost complete protection from phage infection occurs. Here we demonstrate that only the phage pilot protein H portion of the plasmid is sufficient for the observed inhibition, that protein synthesis is necessary for inhibition to occur, that inserting the entire H gene in the plasmid may also impart a blocking effect, and that partial to complete recovery from this inhibition is possible with minimal viral evolution.

Keywords: Bacteriophage; Competition; Inhibition; Superinfection inhibition; Virus escape; ΦX174.