Revadi, Santosh
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences
- Edmund Mach Foundation
Research article2016Peer reviewedOpen access
The Evolution of Olfactory Gene Families in Drosophila and the Genomic Basis of chemical-Ecological Adaptation in Drosophila suzukii
Ramasamy, Sukanya; Ometto, Lino; Crava, Cristina M.; Revadi, Santosh; Kaur, Rupinder; Horner, David S.; Pisani, Davide; Dekker, Teun; Anfora, Gianfranco; Rota-Stabelli, Omar
Abstract
How the evolution of olfactory genes correlates with adaption to new ecological niches is still a debated topic. We explored this issue in Drosophila suzukii, an emerging model that reproduces on fresh fruit rather than in fermenting substrates like most other Drosophila. We first annotated the repertoire of odorant receptors (ORs), odorant binding proteins (OBPs), and antennal ionotropic receptors (aIRs) in the genomes of two strains of D. suzukii and of its close relative Drosophila biarmipes. We then analyzed these genes on the phylogeny of 14 Drosophila species: whereas ORs and OBPs are characterized by higher turnover rates in some lineages including D. suzukii, aIRs are conserved throughout the genus. Drosophila suzukii is further characterized by a non-random distribution of OR turnover on the gene phylogeny, consistent with a change in selective pressures. In D. suzukii, we found duplications and signs of positive selection in ORs with affinity for short-chain esters, and loss of function of ORs with affinity for volatiles produced during fermentation. These receptors-Or85a and Or22a-are characterized by divergent alleles in the European and American genomes, and we hypothesize that they may have been replaced by some of the duplicated ORs in corresponding neurons, a hypothesis reciprocally confirmed by electrophysiological recordings. Our study quantifies the evolution of olfactory genes in Drosophila and reveals an array of genomic events that can be associated with the ecological adaptations of D. suzukii.
Keywords
odorant receptors; adaptation; Drosophila suzukii; comparative genomics
Published in
Genome Biology and Evolution
2016, volume: 8, number: 8, pages: 2297-2311
Publisher: OXFORD UNIV PRESS
SLU Authors
Dekker, Teun
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences
UKÄ Subject classification
Evolutionary Biology
Publication identifier
- DOI: https://doi.org/10.1093/gbe/evw160
Permanent link to this page (URI)
https://res.slu.se/id/publ/83049