Interspecies evolutionary dynamics mediated by public goods in bacterial quorum sensing

Area of Science:

• Microbiology and Evolutionary Biology
• Systems Biology and Network Modeling

Background:

• Bacterial quorum sensing (QS) is cell-cell communication regulating gene expression based on population density.
• QS involves secreting and responding to signaling molecules, impacting community behavior and evolution.
• Coexistence of multiple bacterial species (genotypes) raises questions about the evolution of public good production.

Purpose of the Study:

• To characterize the coevolution of bacterial genotypes in a multispecies setting with public good production.
• To model genotype interaction and evolution where fitness depends on public good production and uptake.
• To identify factors influencing the long-term survival of genotypes that produce public goods.

Main Methods:

• Introduced a network model combining a random graph for evolutionary pathways and differential equations for genotype abundance.
• Analyzed simple model variations analytically.
• Studied complex variations computationally.

Main Results:

• Identified a critical trade-off impacting the survival of public good-producing genotypes.
• Producer survival depends on the balance between the costs of producing and absorbing public goods.
• Non-producer survival is influenced by absorbing public goods and molecular compatibility with producers.

Conclusions:

• The model provides insights into the evolutionary dynamics of cooperation and competition in microbial communities.
• A delicate balance of costs and benefits determines whether public good producers can persist.
• Molecular compatibility plays a significant role in the coexistence dynamics of producer and non-producer genotypes.