title: The effect of epistasis on sexually antagonistic genetic variation.
abstract: There is increasing evidence of segregating sexually antagonistic (SA) genetic variation for fitness in laboratory and wild populations, yet the conditions for the maintenance of such variation can be restrictive. Epistatic interactions between genes can contribute to the maintenance of genetic variance in fitness and we suggest that epistasis between SA genes should be pervasive. Here, we explore its effect on SA genetic variation in fitness using a two locus model with negative epistasis. Our results demonstrate that epistasis often increases the parameter space showing polymorphism for SA loci. This is because selection in one locus is affected by allele frequencies at the other, which can act to balance net selection in males and females. Increased linkage between SA loci had more marginal effects. We also show that under some conditions, large portions of the parameter space evolve to a state where male benefit alleles are fixed at one locus and female benefit alleles at the other. This novel effect of epistasis on SA loci, which we term the 'equity effect', may have important effects on population differentiation and may contribute to speciation. More generally, these results support the suggestion that epistasis contributes to population divergence.
authors.affiliation: Animal Ecology, Department of Ecology and Genetics, Uppsala University, SE-752 36 Uppsala, Sweden goran.arnqvist@ebc.uu.se.
authors.forename: Göran
authors.initials: G
authors.lastname: Arnqvist
authors.affiliation: Evolutionary Biology, Zoological Institute, University of Basel, CH-4051 Basel, Switzerland.
authors.forename: Nikolas
authors.initials: N
authors.lastname: Vellnow
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Canada, M5S 3B2.
authors.forename: Locke
authors.initials: L
authors.lastname: Rowe
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004843:Epistasis, Genetic; D005260:Female; D005787:Gene Frequency; D008297:Male; D008957:Models, Genetic; D011110:Polymorphism, Genetic; D012641:Selection, Genetic; D012727:Sex Characteristics
keywords: gene interaction; mutation-order speciation; recombination; sexual conflict; sexual dimorphism; simuPOP