Biomaterial Database

Effects of epistasis and the evolution of genetic architecture: exact results for a 2-locus model. 2009

José M Alvarez-Castro, and Michael Kopp, and Joachim Hermisson

Swedish University of Agricultural Sciences, Department of Animal Breeding and Genetics, SE-75007 Uppsala, Sweden.

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.

UI	MeSH Term	Description	Entries
D008957	Models, Genetic	Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.	Genetic Models,Genetic Model,Model, Genetic
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D004843	Epistasis, Genetic	A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.	Deviation, Epistatic,Epistatic Deviation,Genes, Epistatic,Genes, Hypostatic,Epistases, Genetic,Gene-Gene Interaction, Epistatic,Gene-Gene Interactions, Epistatic,Genetic Epistases,Genetic Epistasis,Interaction Deviation,Non-Allelic Gene Interactions,Epistatic Gene,Epistatic Gene-Gene Interaction,Epistatic Gene-Gene Interactions,Epistatic Genes,Gene Gene Interaction, Epistatic,Gene Gene Interactions, Epistatic,Gene Interaction, Non-Allelic,Gene Interactions, Non-Allelic,Gene, Epistatic,Gene, Hypostatic,Hypostatic Gene,Hypostatic Genes,Interaction, Epistatic Gene-Gene,Interaction, Non-Allelic Gene,Interactions, Epistatic Gene-Gene,Interactions, Non-Allelic Gene,Non Allelic Gene Interactions,Non-Allelic Gene Interaction
D005075	Biological Evolution	The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.	Evolution, Biological
D000483	Alleles	Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.	Allelomorphs,Allele,Allelomorph
D013269	Stochastic Processes	Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.	Process, Stochastic,Stochastic Process,Processes, Stochastic