Emergence of microbial host dormancy during a persistent virus epidemic

Area of Science:

• Microbial ecology
• Evolutionary biology
• Epidemiology

Background:

• Microbial populations face challenges from persistent viral epidemics.
• Stable coexistence between host and virus populations is a key ecological dynamic.
• Introduction of novel host traits can alter population dynamics.

Purpose of the Study:

• To investigate the invasion potential of a dormant microbial mutant into an established host-virus system.
• To determine the conditions and probability of successful mutant invasion.
• To analyze the long-term population fate after successful mutant emergence.

Main Methods:

• Development of a minimal stochastic individual-based model.
• Mathematical analysis of invasion probability in a large population limit.
• Characterization of parameter regimes for trait emergence.
• Heuristic arguments and simulations for population dynamics.

Main Results:

• A non-trivial parameter range exists for successful mutant invasion, despite a reduced reproduction rate.
• Invasion probability is bounded away from zero in the large population limit.
• The study identifies specific parameters enabling the emergence of a host dormancy trait.
• The time to reach macroscopic population size for successful invaders is determined.

Conclusions:

• Host dormancy can be a viable strategy for microbial invasion in virus-challenged populations.
• The emergence of dormancy is contingent on specific ecological and viral parameters.
• Post-invasion dynamics can result in either stable coexistence or competitive exclusion of resident hosts.