Dominance reversals and the maintenance of genetic variation

Beneficial reversals of dominance reduce the costs of genetic trade-offs and can enable selection to maintain genetic variation for fitness. Beneficial dominance reversals are characterized by the beneficial allele for a given context (e.g. habitat, developmental stage, trait, or sex) being dominant in that context but recessive where deleterious. This context-dependence at least partially mitigates the fitness consequence of heterozygotes carrying one non-beneficial allele for their context and can result in balancing selection that maintains alternative alleles. Dominance reversals are theoretically plausible and are supported by mounting empirical evidence. Here we highlight the importance of beneficial dominance reversals as a mechanism for the mitigation of genetic conflict and review the theory and empirical evidence for them. We identify some areas in need of further research and development and outline three methods (dominance ordination, allele-specific expression, and allele-s..., This is the python code and supporting files for a custom forward-time population genetic simulation of a biophysically explicit gene network subject to sexually antagonistic selection., , # simDominanceModifier

Our simulation model builds off of Porter et al. (2017) and is based on the premise that transcription factors (TF) and binding sites behave according to the thermodynamic and kinetic properties of molecular interactions.

Our diploid model consists of two unlinked interacting genes, A and B. The alternative alleles of Gene A codes for TFs that have opposite effects on the expression of Gene B, and Gene B’s expression is under additive sexually antagonistic selection. Gene A’s experession is determined by cis-regulatory binding site that can mutate/evolve toward being a better binder of either the male- or female-limited regulatory stimuli, approximating sex-limited hormones. Gene B's expression is determined by cis-regulatory binding site that can mutate/evolve toward being a better binder to either of the TFs expressed by Gene A. Finally, fitness is determined by the expression of Gene B, where females and males benefit from increased and decreased expression, ...