Adaptive value of sex in microbial pathogens

Area of Science:

• Evolutionary Biology
• Microbiology
• Genetics

Background:

• The adaptive value of sexual reproduction remains a significant challenge in biology due to the costs associated with it.
• Investigating sex in viruses, bacteria, and fungi, particularly pathogenic microorganisms, offers insights into general evolutionary theories.
• Understanding the benefits and costs of sex for both hosts and pathogens is crucial.

Purpose of the Study:

• To examine the adaptive value of sex in microbial pathogens.
• To evaluate key hypotheses for the evolution of sex, including DNA repair, nutrient acquisition, and variation generation.
• To determine the most supported hypothesis for the short-term benefits of sex in pathogens.

Main Methods:

• Review of existing literature on the evolution of sex in microbial pathogens.
• Analysis of hypotheses concerning the benefits of sex: DNA repair, DNA as food, and variation.
• Focus on evidence supporting each hypothesis within pathogenic microorganisms.

Main Results:

• The DNA repair hypothesis is the most supported for short-term benefits in microbial pathogens.
• Recombinational repair of DNA damage provides substantial benefits against host oxidative defenses.
• Long-term benefits include mutation removal, increased adaptation rates, and potential creation of new strains.

Conclusions:

• Sex in microbial pathogens provides significant short-term benefits, primarily through DNA repair.
• While sex has long-term evolutionary advantages, its initial evolution may not have been driven by these outcomes.
• Consequences like antibiotic resistance transfer are likely byproducts, not the primary evolutionary drivers of sex.