title: Multiplicative versus additive selection in relation to genome evolution: a simulation study.
abstract: The evolution of molecular quantitative traits, such as codon usage bias or base frequencies, can be explained as the result of mutational biases alone, or as the result of mutation and selection. Whereas mutation models can be investigated easily, realistic modelling of selection-directed genome evolution is analytically intractable, and numerical calculations require substantial computer resources. We investigated the evolution of optimal codon frequency under additive and multiplicative effects of selected linked codons. We show that additive selective effects of many linked sites cannot be effective in genomes when the number of selected sites is greater than the effective population size, a realistic assumption according to current molecular data. We then discuss the implications of these results for isochore evolution in vertebrates.
authors.affiliation: Centre National de la Recherche Scientifique, Unité Mixte de Recherche 5558, Biométrie et Biologie Evolutive, Université Claude Bernard Lyon 1, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne, France. piganeau@biomserv.univ-lyon1.fr
authors.forename: G
authors.initials: G
authors.lastname: Piganeau
authors.forename: R
authors.initials: R
authors.lastname: Westrelin
authors.forename: B
authors.initials: B
authors.lastname: Tourancheau
authors.forename: C
authors.initials: C
authors.lastname: Gautier
mesh_terms: D003062:Codon / Q000235:genetics*; D003198:Computer Simulation; D019143:Evolution, Molecular; D005787:Gene Frequency; D008040:Genetic Linkage; D016678:Genome; D008433:Mathematics; D009154:Mutation; D009679:Nuclear Family; D019655:Quantitative Trait, Heritable; D012641:Selection, Genetic
chemical_list: D003062:Codon