Host-parasite interactions and the evolution of gene expression

Area of Science:

• Evolutionary biology
• Genetics
• Mathematical modeling

Background:

• Host-parasite interactions drive reciprocal evolutionary changes in interacting species.
• Gene expression patterns are crucial for mediating these interactions, influencing resistance and infection dynamics.

Purpose of the Study:

• To investigate the evolutionary trajectories of gene expression at loci governing host resistance and parasite infection.
• To understand how selection shapes allele expression strategies in coevolving host-parasite systems.

Main Methods:

• Development of a genetically explicit mathematical model.
• Simulation of gene expression evolution under host-parasite selection pressures.

Main Results:

• Host resistance loci tend to evolve towards co-expression of multiple alleles.
• Parasite infection loci predominantly evolve to express a single allele.
• Co-expression in hosts enhances recognition and clearance of diverse parasite genotypes.
• Single-allele expression in parasites minimizes host detection and clearance.

Conclusions:

• Gene expression evolution follows divergent paths in hosts and parasites during coevolution.
• Co-expression is favored in host resistance for broader defense, while single-allele expression is favored in parasite infection for immune evasion.
• The model offers testable predictions for empirical studies on host-parasite gene expression.