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characterized by divergent alleles in the European and American genomes, and we hypothesize that they may have been replaced by some of the duplicated ORs in corresponding neurons, a hypothesis reciprocally confirmed by electrophysiological recordings.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.

Ramasamy, S.; Ometto, L.; Crava, M.C.; Revadi, S.; Senza Cognome, R.K.; Horner, D.S.; Pisani, D.; Dekker, T.; Anfora, G.; Rota Stabelli, O. (2016). The evolution of olfactory gene families in Drosophila and the genomic basis of chemical-ecological adaptation in Drosophila suzukii. GENOME BIOLOGY AND EVOLUTION, 8 (8): 2297-2311. doi: 10.1093/gbe/evw160 handle: http://hdl.handle.net/10449/35428

The evolution of olfactory gene families in Drosophila and the genomic basis of chemical-ecological adaptation in Drosophila suzukii

Ramasamy, Sukanya;Ometto, Lino;Crava, Maria Cristina;Revadi, Santosh;Senza Cognome, Rupinder Kaur;Anfora, Gianfranco;Rota Stabelli, Omar
2016-01-01

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.
Odorant receptors
Adaptation
Drosophila suzukii
Comparative genomics
Settore AGR/11 - ENTOMOLOGIA GENERALE E APPLICATA
2016
Ramasamy, S.; Ometto, L.; Crava, M.C.; Revadi, S.; Senza Cognome, R.K.; Horner, D.S.; Pisani, D.; Dekker, T.; Anfora, G.; Rota Stabelli, O. (2016). The evolution of olfactory gene families in Drosophila and the genomic basis of chemical-ecological adaptation in Drosophila suzukii. GENOME BIOLOGY AND EVOLUTION, 8 (8): 2297-2311. doi: 10.1093/gbe/evw160 handle: http://hdl.handle.net/10449/35428
File in questo prodotto:
File Dimensione Formato  
2016 GBE_Ramasamy.pdf

accesso aperto

Licenza: Creative commons
Dimensione 3.74 MB
Formato Adobe PDF
3.74 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/35428
Citazioni
  • ???jsp.display-item.citation.pmc??? 26
  • Scopus 54
  • ???jsp.display-item.citation.isi??? 54
social impact