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Updated: May 26, 2026

Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics
09:23

Understanding the Impact of Temperate Bacteriophages on Their Lysogens Through Transcriptomics

Published on: January 5, 2024

Counting to two: how phages decide between lysis and lysogeny

Janni Harju1, Ghita Guessous1, Zemer Gitai2

  • 1Joseph Henry Laboratories of Physics, Princeton University, Princeton, NJ, USA.

Biorxiv : the Preprint Server for Biology
|May 25, 2026
PubMed

Insights

Temperate phages decide between lysis or lysogeny based on infection conditions. A minimal model reveals key molecular mechanisms, like host proteases, enable this crucial decision for phage survival.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Systems Biology

Background:

  • Temperate phages infecting bacteria face a critical choice: lysis (cell death for phage reproduction) or lysogeny (a symbiotic state).
  • This decision is influenced by bacterial host status and the multiplicity of infection (MOI), the number of phage particles infecting a single bacterium.
  • Phage gene copy number increases with MOI, necessitating a rapid regulatory asymmetry for MOI-dependent decision-making.

Purpose of the Study:

  • To develop a minimal model explaining the lysis-lysogeny decision mechanism in temperate phages.
  • To identify the essential coupling mechanisms that create pathway asymmetry based on MOI.
  • To generalize the understanding of phage regulatory logic across different species.

Main Methods:

  • Development of a minimal mathematical model for phage regulatory networks.
  • Analysis of coupling mechanisms (e.g., host protease, kinase, RNase) influencing lytic and lysogenic pathways.
  • Distillation of complex genetic circuits into core components.

Main Results:

  • The model demonstrates that only a few specific coupling mechanisms can generate the required asymmetry for MOI-dependent lysis-lysogeny decisions.
  • Identified host factors like proteases, kinases, or RNases as potential key regulators acting on one pathway.
  • The model provides a simplified framework for understanding diverse phage regulatory strategies.

Conclusions:

  • The lysis-lysogeny decision is governed by a limited set of molecular interactions that create rapid asymmetry.
  • Understanding these core mechanisms is crucial for deciphering phage-host dynamics and phage evolution.
  • This work offers a generalized logic applicable to various temperate phage systems.

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