Research

•    The role of  specific genes and mutations in insecticide resistance

We employ CRISPR/Cas9 genome modification in Drosophila to validate candidate mutations through a reverse genetics approach (reviewed in Douris et al., 2020 Pestic Biochem Physiol). We also perform functional expression of candidate resistance genes (P450s) to investigate their ability to metabolize insecticides in vivo (Tsakireli et al., 2019 Pestic Biochem Physiol; Riga et al., 2020 Insects). We have previously investigated resistance against several chemistries, and currently focus on mechanisms of target-site and metabolic resistance to avermectins.

•    Synergistic interactions among different resistance mechanisms

While epistatic effects among genes involved in co-existing resistance mechanisms are postulated from field data, we were able to show a clear synergistic interaction between target-site mutations and metabolic resistance alleles in an engineered Drosophila system devoid of confounding genetic effects, regarding resistance to pyrethroids (Samantsidis, Panteleri et al., 2020 Proc Roy Soc B). Furthermore, we were able to assess potential fitness disadvantage conferred by the coexistence of multiple alleles. We now investigate a similar framework with different molecular targets and insecticide chemistries, involving resistance to avermectins.

•    Novel resistance mechanisms and new potential compounds

Having contributed to the establishment of a novel class of proteins (chemosensory proteins, CSPs) as potential players in pyrethroid resistance in mosquitoes (Ingham et al., 2020 Nature) we seek to investigate the role of CSPs as insecticide binding proteins with potential contribution in metabolic resistance or sequestration in vivo. Currently, we are functionally expressing candidate lepidopteran CSPs in insect cell (baculovirus) systems and assess their potential within the framework of iNEXT / INSTRUCT-ERIC in collaboration with the NKI protein facility (The Netherlands). We seek to identify optimal binding modules that could inform rational design of new potential compounds and/or synergists for insecticide formulations.