02410nas a2200169   4500008004100000245011000041210006900151300001500220490000700235520184100242100001602083700001402099700001902113700001402132700001702146856007702163       2010                        eng d00aComparative genome scan detects host-related divergent selection in the grasshopper Hesperotettix viridis0 aComparative genome scan detects hostrelated divergent selection   a4012 -40280 v193 a<p>In this study, we used a comparative genome scan to examine patterns of population differentiation with respect to host plant use in Hesperotettix viridis, a Nearctic oligophagous grasshopper locally specialized on various Asteraceae including Solidago, Gutierrezia, and Ericameria. We identified amplified fragment length polymorphism (AFLP) loci with significantly elevated FST (outlier loci) in multiple different-host and same-host comparisons of populations while controlling for geographic distance. By comparing the number and identities of outlier loci in different-host vs. same-host comparisons, we found evidence of host plant-related divergent selection for some population comparisons (Solidago- vs. Gutierrezia-feeders), while other comparisons (Ericameria- vs. Gutierrezia-feeders) failed to demonstrate a strong role for host association in population differentiation. In comparisons of Solidago- vs. Gutierrezia-feeding populations, a relatively high number of outlier loci observed repeatedly in different-host comparisons (35% of all outliers and 2.7% of all 625 AFLP loci) indicated a significant role for host-related selection in contributing to overall genomic differentiation in this grasshopper. Mitochondrial DNA sequence data revealed a star-shaped phylogeny with no host- or geography-related structure, low nucleotide diversity, and high haplotype diversity, suggesting a recent population expansion. mtDNA data do not suggest a long period of isolation in separate glacial refugia but are instead more compatible with a single glacial refugium and more recent divergence in host use. Our study adds to research documenting heterogeneity in differentiation across the genome as a consequence of divergent natural selection, a phenomenon that may occur as part of the process of ecological speciation.</p>1 aApple, J.L.1 aGrace, T.1 aJoern, Anthony1 aAmand, P.1 aWisely, S.M.  uhttps://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-294X.2010.04792.x