Genotypic variation for a quantitative character maintained under stabilizing selection without mutations: epistasis

Area of Science:

• Population Genetics
• Quantitative Genetics
• Genetics

Background:

• Understanding the genetic basis of quantitative traits is crucial in evolutionary biology.
• Traditional models often focus on additive gene action, potentially overlooking complex interactions.

Purpose of the Study:

• To propose a novel model for gene action on quantitative traits that incorporates epistasis.
• To investigate the maintenance and release of genetic variation under different selection regimes.

Main Methods:

• Development of a gene action model combining multiplicative and additive approximations for loci.
• Theoretical analysis of genetic variation dynamics under stabilizing selection.

Main Results:

• The model demonstrates that epistasis can maintain substantial genotypic variation for quantitative traits, even without mutations.
• Significant additive variation and high heritability can remain undetected under stabilizing selection.
• Relaxing stabilizing selection can lead to the release of this hidden genetic variation.

Conclusions:

• Epistatic gene interactions play a critical role in the maintenance of genetic diversity for quantitative traits.
• The proposed model offers new insights into the dynamics of hidden heritability and its potential for evolutionary response.