Bacterial predator-prey coevolution accelerates genome evolution and selects on virulence-associated prey defences

Area of Science:

• Microbial Ecology
• Evolutionary Biology
• Genomics

Background:

• Generalist bacterial predators are known to influence microbial community structure and function.
• However, their specific impact on the pace and patterns of molecular evolution within these communities remains under-investigated.

Purpose of the Study:

• To investigate how predator-prey interactions between Myxococcus xanthus (predator) and Escherichia coli (prey) affect the evolution of fitness, genomes, and phenotypic diversity.
• To compare these effects in coevolving communities versus single-species controls.

Main Methods:

• Co-cultivation of Myxococcus xanthus and Escherichia coli under controlled laboratory conditions.
• Genomic sequencing and analysis to identify evolutionary changes.
• Phenotypic assays to measure fitness and specific traits like mucoidy and OmpT expression.

Main Results:

• Evidence of reciprocal adaptation between predator and prey populations.
• Accelerated genomic evolution observed in coevolving communities, including the emergence of mutator genotypes.
• Predator-driven parallel evolution in prey, specifically enhancing mucoidy and outer-membrane protease OmpT, traits linked to bacterial virulence.

Conclusions:

• Generalist bacterial predators are key drivers of evolutionary dynamics in microbial communities.
• Predator-prey interactions can accelerate molecular evolution and shape community-level adaptations, influencing traits relevant to pathogenicity.