title: Evolutionary Insights into Taste Perception of the Invasive Pest Drosophila suzukii.
abstract: Chemosensory perception allows insects to interact with the environment by perceiving odorant or tastant molecules; genes encoding chemoreceptors are the molecular interface between the environment and the insect, and play a central role in mediating its chemosensory behavior. Here, we explore how the evolution of these genes in the emerging pest Drosophila suzukii correlates with the peculiar ecology of this species. We annotated approximately 130 genes coding for gustatory receptors (GRs) and divergent ionotropic receptors (dIRs) in D. suzukii and in its close relative D. biarmipes We then analyzed the evolution, in terms of size, of each gene family as well of the molecular evolution of the genes in a 14 Drosophila species phylogenetic framework. We show that the overall evolution of GRs parallels that of dIRs not only in D. suzukii, but also in all other analyzed Drosophila Our results reveal an unprecedented burst of gene family size in the lineage leading to the suzukii subgroup, as well as genomic changes that characterize D. suzukii, particularly duplications and strong signs of positive selection in the putative bitter-taste receptor GR59d. Expression studies of duplicate genes in D. suzukii support a spatio-temporal subfunctionalization of the duplicate isoforms. Our results suggest that D. suzukii is not characterized by gene loss, as observed in other specialist Drosophila species, but rather by a dramatic acceleration of gene gains, compatible with a highly generalist feeding behavior. Overall, our analyses provide candidate taste receptors specific for D. suzukii that may correlate with its specific behavior, and which may be tested in functional studies to ultimately enhance its control in the field.
authors.affiliation: Unit of Agricultural Entomology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trentino, Italy maria.crava@fmach.it omar.rota@fmach.it.
authors.forename: Cristina M
authors.initials: CM
authors.lastname: Crava
authors.affiliation: Unit of Agricultural Entomology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trentino, Italy.
authors.forename: Sukanya
authors.initials: S
authors.lastname: Ramasamy
authors.affiliation: Unit of Agricultural Entomology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trentino, Italy.
authors.forename: Lino
authors.initials: L
authors.lastname: Ometto
authors.affiliation: Unit of Agricultural Entomology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trentino, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Anfora
authors.affiliation: Unit of Agricultural Entomology, Research and Innovation Centre, Fondazione Edmund Mach, 38010 San Michele all'Adige, Trentino, Italy maria.crava@fmach.it omar.rota@fmach.it.
authors.forename: Omar
authors.initials: O
authors.lastname: Rota-Stabelli
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019295:Computational Biology / Q000379:methods; D004330:Drosophila / Q000145:classification / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics; D020440:Gene Duplication; D005786:Gene Expression Regulation; D049750:Genome, Insect; D023281:Genomics / Q000379:methods; D058977:Molecular Sequence Annotation; D010802:Phylogeny; D012641:Selection, Genetic; D055697:Taste Perception / Q000235:genetics*
chemical_list: D029721:Drosophila Proteins
keywords: Drosophilidae; Spotted wing drosophila; gene birth-and-death; gene duplication; gene families; gustation