Effects of epistasis and the evolution of genetic architecture: Exact results for a 2-locus model

Abstract

We study a two-locus model of a quantitative trait with a continuum-of alleles and multilinear epistasis that evolves under mutation, selection, and genetic drift. We derive analytical results based on the so-called House of Gauss approximation for the genetic variance, the mean phenotype, and the mutational variance in the balance of the evolutionary forces. The analytical work is complemented by extensive individual-based Computer simulations. We find that (1) analytical results are accurate in a large parameter space; (2) epistasis always reduces the equilibrium genetic variance, as predicted in earlier studies that exclude drift; (3) large-scale stochastic fluctuations and non-equilibrium phenomena like adaptive inertia can strongly influence the evolution of the genetic architecture of the trait. (C) 2009 Elsevier Inc. All rights reserved.

Keywords

Mutation-selection model; Epistasis; Genetic variance; Genetic architecture; Canalization

Published in

Theoretical Population Biology
2009, volume: 75, number: 2-3, pages: 109-122
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE

SLU Authors

• Alvarez-Castro, Jose

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Animal and Dairy Science
Veterinary Science

Publication identifier

• DOI: https://doi.org/10.1016/j.tpb.2008.12.003

Permanent link to this page (URI)

https://res.slu.se/id/publ/61241