title: Multiple-Line Inference of Selection on Quantitative Traits.
abstract: Trait differences between species may be attributable to natural selection. However, quantifying the strength of evidence for selection acting on a particular trait is a difficult task. Here we develop a population genetics test for selection acting on a quantitative trait that is based on multiple-line crosses. We show that using multiple lines increases both the power and the scope of selection inferences. First, a test based on three or more lines detects selection with strongly increased statistical significance, and we show explicitly how the sensitivity of the test depends on the number of lines. Second, a multiple-line test can distinguish between different lineage-specific selection scenarios. Our analytical results are complemented by extensive numerical simulations. We then apply the multiple-line test to QTL data on floral character traits in plant species of the Mimulus genus and on photoperiodic traits in different maize strains, where we find a signature of lineage-specific selection not seen in two-line tests.
authors.affiliation: Institut für Theoretische Physik, University of Cologne, 50937 Köln, Germany nriedel@thp.uni-koeln.de.
authors.forename: Nico
authors.initials: N
authors.lastname: Riedel
authors.affiliation: Institut für Theoretische Physik, University of Cologne, 50937 Köln, Germany.
authors.forename: Bhavin S
authors.initials: BS
authors.lastname: Khatri
authors.affiliation: Institut für Theoretische Physik, University of Cologne, 50937 Köln, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lässig
authors.affiliation: Institut für Theoretische Physik, University of Cologne, 50937 Köln, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Berg
mesh_terms: D002874:Chromosome Mapping; D003433:Crosses, Genetic; D035264:Flowers / Q000235:genetics; D017343:Genes, Plant; D005828:Genetics, Population; D032241:Mimulus / Q000235:genetics*; D008957:Models, Genetic; D040641:Quantitative Trait Loci; D012641:Selection, Genetic
keywords: hypothesis testing; natural selection; quantitative traits