The genetic basis of selfing rate evolution

Area of Science:

• Population Genetics
• Evolutionary Biology
• Plant Sciences

Background:

• Selfing (self-fertilization) is a common reproductive strategy in plants.
• The genetic underpinnings of how selfing rates evolve are not fully understood.
• Selfing modifiers, which influence the rate of self-fertilization, have unique genetic properties compared to mating-unrelated alleles.

Purpose of the Study:

• To investigate the genetic basis of selfing rate evolution using population genetic models.
• To understand how genetic properties of selfing modifiers affect their fixation probability.
• To explore the conditions favoring the evolution of selfing through multiple modifier loci.

Main Methods:

• Development and analysis of population genetic models.
• Comparison of fixation probabilities for mating-unrelated alleles versus selfing modifiers.
• Modeling the impact of dominance and background selfing rate on modifier fixation.

Main Results:

• Selfing can promote the fixation of dominant selfing modifiers, unlike recessive mating-unrelated alleles.
• Fixation probability of selfing modifiers peaks at intermediate selfing rates and with recessive alleles.
• Evolution of selfing is more probable with few large-effect selfing modifiers than many small-effect ones.

Conclusions:

• The genetic characteristics of selfing modifiers differ significantly from mating-unrelated alleles.
• These differences have implications for understanding the transition from outcrossing to selfing in plants.
• The number and effect size of selfing modifiers play a crucial role in the evolution of selfing.