title: A population genomic scan in Chorthippus grasshoppers unveils previously unknown phenotypic divergence.
abstract: Understanding the genetics of speciation and the processes that drive it is a central goal of evolutionary biology. Grasshoppers of the Chorthippus species group differ strongly in calling song (and corresponding female preferences) but are exceedingly similar in other characteristics such as morphology. Here, we performed a population genomic scan on three Chorthippus species (Chorthippus biguttulus, C. mollis and C. brunneus) to gain insight into the genes and processes involved in divergence and speciation in this group. Using an RNA-seq approach, we examined functional variation between the species by calling SNPs for each of the three species pairs and using FST -based approaches to identify outliers. We found approximately 1% of SNPs in each comparison to be outliers. Between 37% and 40% of these outliers were nonsynonymous SNPs (as opposed to a global level of 17%) indicating that we recovered loci under selection. Among the outliers were several genes that may be involved in song production and hearing as well as genes involved in other traits such as food preferences and metabolism. Differences in food preferences between species were confirmed with a behavioural experiment. This indicates that multiple phenotypic differences implicating multiple evolutionary processes (sexual selection and natural selection) are present between the species.
authors.affiliation: Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany.
authors.forename: Emma L
authors.initials: EL
authors.lastname: Berdan
authors.affiliation: Berlin Center for Genomics in Biodiversity Research, Königin-Luise-Str 6-8, 14195, Berlin, Germany.|Leibniz-Institut für Zoo- und Wildtierforschung (IZW), Alfred-Kowalke-Straße 17, 10315, Berlin, Germany.
authors.forename: Camila J
authors.initials: CJ
authors.lastname: Mazzoni
authors.affiliation: Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Waurick
authors.affiliation: Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany.
authors.forename: Johannes T
authors.initials: JT
authors.lastname: Roehr
authors.affiliation: Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstraße 43, 10115, Berlin, Germany.|Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Altensteinstraße 6, 14195, Berlin, Germany.
authors.forename: Frieder
authors.initials: F
authors.lastname: Mayer
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D005260:Female; D005518:Food Preferences; D005828:Genetics, Population / Q000379:methods*; D049750:Genome, Insect; D023281:Genomics / Q000379:methods; D005838:Genotype; D006110:Grasshoppers / Q000145:classification* / Q000235:genetics; D008297:Male; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D060047:Reproductive Isolation; D017423:Sequence Analysis, RNA; D013045:Species Specificity; D059467:Transcriptome
keywords: F
  ST; RNA-seq; acoustic communication; chorthippus; outlier