Phylogenomic tracking of critically important molecular determinants of insecticide selectivity across the entire bee clade

Sunday, November 13, 2022

2:42 PM – 2:54 PM PT

Location: Vancouver Convention Centre, Meeting Room 213

Presenting Author(s)

Julian Haas

PostDoc Insecticide Resistance
Bayer AG
Monheim am Rhein, Nordrhein-Westfalen, Germany

Co-Author(s)

Ralf Nauen

Bayer Crop Science
Monheim, Nordrhein-Westfalen, Germany
CB

Chris Bass

University of Exeter
Penryn, England, United Kingdom
AH

Angela Hayward

University of Exeter
Penryn, England, United Kingdom

Pesticide risk assessment for bees is largely reliant on the honey bee Apis mellifera as a surrogate. However, the validity of this approach has been questioned due to uncertainties regarding potential differences related to exposure or toxicity within the bee clade Anthophila. Recent studies have demonstrated that cytochrome P450 enzymes belonging to the CYP9Q subfamily play an essential role in the detoxification of diverse insecticide chemotypes in honey bees leading to reduced bee toxicity of several insecticides. Closely related functional CYP9Q orthologs have been found in a handful of managed bee pollinators. To what extent similar P450s are distributed across the entire bee clade and if they share a similar metabolic capacity remained unknown. Here, we identified more than 100 putative CYP9Q functional orthologs across 75 bee species revealing an almost universal distribution of CYP9Q-related genes with the notable exception of the Megachilidae family where some species are lacking such genes. Furthermore, we functionally validated the conserved detoxification capacity of 26 of these P450s from 20 species towards the butenolide insecticide flupyradifurone and the neonicotinoid thiacloprid. Our results demonstrate an evolutionary conserved mechanism for insecticide detoxification in bees which may have been lost in a small subset of bees. This toxicogenomic investigation illustrates how new approach methodologies can be utilized to address issues of ecotoxicological concern and assess complex problems in pesticide risk assessment, such as the appropriateness of surrogate species, and thus may inform and complement bee pollinator risk assessment in the future.