Balancing selection in self-fertilizing populations.

Area of Science:

• Evolutionary biology
• Population genetics

Background:

• Self-fertilization is common in hermaphroditic species, influencing genetic processes like homozygosity and drift.
• Balancing selection maintains genetic diversity but is less understood in selfing species compared to outcrossing ones.

Purpose of the Study:

• To develop a unifying framework for analyzing balancing selection in partially selfing species.
• To quantify the impact of selfing on polymorphism maintenance and the efficacy of different balancing selection forms.

Main Methods:

• Developed a theoretical framework to analyze balancing selection under selfing.
• Classified balancing selection into categories based on their sensitivity to selfing.
• Derived analytical results for weak selection scenarios.

Main Results:

• Selfing significantly reduces the efficacy of overdominance-like selection (including true overdominance, spatially/temporally variable selection, and antagonistic selection).
• Negative frequency-dependent selection is largely unaffected by selfing, even across multiple loci.
• The study provides a general treatment for balancing selection in partially selfing populations.

Conclusions:

• The framework aids in analyzing the genomic signature of balancing selection in selfing species.
• Findings offer insights into the evolution of selfing syndromes, pathogen interactions, and the evolutionary trajectory of selfing lineages.