Eco-evolutionary dynamics of temperate phages in periodic environments

Area of Science:

• Microbiology
• Evolutionary Biology
• Ecology

Background:

• Bacteriophages (viruses infecting bacteria) utilize diverse strategies like lysis and lysogeny.
• Lysogeny shows short-term benefits in low-host conditions, but long-term advantages, especially in variable environments, are less understood.

Purpose of the Study:

• To investigate the eco-evolutionary dynamics of temperate viruses in periodically fluctuating environments.
• To determine the generalized drivers of viral infection strategies (lytic vs. lysogenic) over short and long terms.

Main Methods:

• Utilized a nonlinear system of ordinary differential equations to model periodically forced viral dynamics.
• Simulated distinct 'within-growth' and 'between-growth' phases with varying survival rates for viruses and lysogens.
• Employed invasion analysis to compare the fitness of different viral strategies.

Main Results:

• Identified conditions where short-term lysis-favoring strategies conflict with long-term lysogeny-favoring strategies.
• Quantified scenarios where temperate strategies outperform obligately lytic or lysogenic strategies.
• Demonstrated that temperate strategies enhance viral survival in fluctuating environments, reducing extinction risk.

Conclusions:

• Temperate strategies provide significant eco-evolutionary benefits, particularly in variable environments.
• Adaptability through temperate strategies is crucial for long-term viral persistence.
• This study highlights the advantages of viral behavioral plasticity in dynamic ecosystems.