title: Genetic architecture of skeletal evolution in European lake and stream stickleback.
abstract: Advances in genomic techniques are greatly facilitating the study of molecular signatures of selection in diverging natural populations. Connecting these signatures to phenotypes under selection remains challenging, but benefits from dissections of the genetic architecture of adaptive divergence. We here perform quantitative trait locus (QTL) mapping using 488 F2 individuals and 2011 single nucleotide polymorphisms (SNPs) to explore the genetic architecture of skeletal divergence in a lake-stream stickleback system from Central Europe. We find QTLs for gill raker, snout, and head length, vertebral number, and the extent of lateral plating (plate number and height). Although two large-effect loci emerge, QTL effect sizes are generally small. Examining the neighborhood of the QTL-linked SNPs identifies several genes involved in bone formation, which emerge as strong candidate genes for skeletal evolution. Finally, we use SNP data from the natural source populations to demonstrate that some SNPs linked to QTLs in our cross also exhibit striking allele frequency differences in the wild, suggesting a causal role of these QTLs in adaptive population divergence. Our study paves the way for comparative analyses across other (lake-stream) stickleback populations, and for functional investigations of the candidate genes.
authors.affiliation: Zoological Institute, University of Basel, Vesalgasse, 1, CH-4051 Basel, Switzerland. daniel.berner@unibas.ch.
authors.forename: Daniel
authors.initials: D
authors.lastname: Berner
authors.forename: Dario
authors.initials: D
authors.lastname: Moser
authors.forename: Marius
authors.initials: M
authors.lastname: Roesti
authors.forename: Heinz
authors.initials: H
authors.lastname: Buescher
authors.forename: Walter
authors.initials: W
authors.lastname: Salzburger
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology*; D019143:Evolution, Molecular; D005260:Female; D029941:Fish Proteins / Q000235:genetics; D005787:Gene Frequency; D049810:Genetic Speciation; D060106:Lakes; D008297:Male; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D045483:Rivers; D023701:Smegmamorpha / Q000033:anatomy & histology / Q000235:genetics*
chemical_list: D029941:Fish Proteins
keywords: Effect size; Gasterosteus aculeatus; QTL mapping; RAD sequencing; lateral plate; vertebral number