Conférence de l’Institut Jacques Monod – Richard Benton

Le mardi 11 février, Richard Benton (Center for Integrative Genomics, University of Lausanne) présentera une Conférence de l’Institut Jacques Monod sur le thème :

Fatal chemosensation, and how insects fight back

Résumé :

Insecticide resistance is a widespread challenge for the management of vectors transmitting pathogens and agricultural pests, requiring a better understanding of the genetic mechanisms underlying the evolution of resistance. Drosophila sechellia is a compelling model for such studies as it naturally evolved resistance to octanoic acid, an abundant chemical of its noni fruit host that is toxic for other insects, including close relatives D. simulans and D. melanogaster. We have used a multi-pronged strategy to identify genes contributing to octanoic acid resistance. We began by experimentally-evolving D. simulans strains with higher tolerance to octanoic acid and determined the resulting genetic architecture. To identify specific candidate genes, we integrated this analysis with a genome-wide association study of octanoic acid resistance in D. simulans and a genome-wide CRISPR selection screen upon octanoic acid exposure in D. melanogaster S2R+ cultured cells. We identified four candidates, with diverse predicted molecular and expression properties, and validated their relevance using genetic analyses in D. melanogaster. Two of these genes displayed an increased expression in the experimentally-evolved strains, paralleling their higher levels of expression in D. sechellia. Our results suggest an adaptive role of these genes in shaping toxin resistance both under laboratory conditions and during D. sechellia’s evolutionary history.