title: Allelic diversity for neutral markers retains a higher adaptive potential for quantitative traits than expected heterozygosity.
abstract: The adaptive potential of a population depends on the amount of additive genetic variance for quantitative traits of evolutionary importance. This variance is a direct function of the expected frequency of heterozygotes for the loci which affect the trait (QTL). It has been argued, but not demonstrated experimentally, that long-term response to selection is more dependent on QTL allelic diversity than on QTL heterozygosity. Conservation programmes, aimed at preserving this variation, usually rely on neutral markers rather than on quantitative traits for making decisions on management. Here, we address, both through simulation analyses and experimental studies with Drosophila melanogaster, the question of whether allelic diversity for neutral markers is a better indicator of a high adaptive potential than expected heterozygosity. In both experimental and simulation studies, we established synthetic populations for which either heterozygosity or allelic diversity was maximized using information from QTL (simulations) or unlinked neutral markers (simulations and experiment). The synthetic populations were selected for the quantitative trait to evaluate the evolutionary potential provided by the two optimization methods. Our results show that maximizing the number of alleles of a low number of markers implies higher responses to selection than maximizing their heterozygosity.
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, 36310, Vigo, Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Vilas
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, 36310, Vigo, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Pérez-Figueroa
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, 36310, Vigo, Spain.
authors.forename: Humberto
authors.initials: H
authors.lastname: Quesada
authors.affiliation: Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, 36310, Vigo, Spain.
authors.forename: Armando
authors.initials: A
authors.lastname: Caballero
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics*; D000483:Alleles; D000818:Animals; D003198:Computer Simulation; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D006579:Heterozygote; D008297:Male; D018895:Microsatellite Repeats; D008957:Models, Genetic; D040641:Quantitative Trait Loci; D012641:Selection, Genetic
keywords: gene diversity; heterozygosity; number of alleles; response to selection; synthetic populations