Identification and characterization of CYPs induced in the Drosophila antenna by exposure to a plant odorant

Abstract

Members of the cytochrome p450 (CYP) enzyme family are abundantly expressed in insect olfactory tissues, where they are thought to act as Odorant Degrading Enzymes (ODEs). However, their contribution to olfactory signaling in vivo is poorly understood. This is due in part to the challenge of identifying which of the dozens of antennal-expressed CYPs might inactivate a given odorant. Here, we tested a high-throughput deorphanization strategy in Drosophila to identify CYPs that are transcriptionally induced by exposure to odorants. We discovered three CYPs selectively upregulated by geranyl acetate using transcriptional profiling. Although these CYPs are broadly expressed in the antenna in non-neuronal cells, electrophysiological recordings from CYP mutants did not reveal any changes in olfactory neuron responses to this odorant. Neurons were desensitized by pre-exposing flies to the odorant, but this effect was similar in CYP mutants. Together, our data suggest that the induction of a CYP gene by an odorant does not necessarily indicate a role for that CYP in neuronal responses to that odorant. We go on to show that some CYPs have highly restricted expression patterns in the antenna, and suggest that such CYPs may be useful candidates for further studies on olfactory CYP function.

Antennae-abundant expression of candidate cytochrome P450 genes associated with odorant degradation in the asian citrus psyllid, Diaphorina citri

“…Examples include antennal CYP6DE1 catalyzes the conversion of α -pinene into trans-verbenol, an aggregation pheromone released by female D. ponderosae ; CYP6DJ1 oxidizes terpinolene and limonene to alcohols and an epoxide, CYP6BW1 and CYP6BW3 oxidize several diterpene resin acids to cope with host defenses ( Chiu et al, 2019a ; Chiu et al, 2019b ; Chiu et al, 2019c ). Recent years, with antennal transcriptome analysis, some antennal CYPs have been identified in Locusta migratoria ( Wu H et al, 2020 ) and Drosophila ( Younus et al, 2014 ; Baldwin et al, 2021 ).…”

Monarda didyma Hydrolate Affects the Survival and the Behaviour of Drosophila suzukii

“…The observed variations in the expression level of genes encoding P450 enzymes ( Cyp4e3 , Cyp6d5-2 , and Cyp4g15 ) and GST ( GstD10 ) would somehow strengthen this assumption so that different pathways and physiological aspects of the flies might be affected by the M. didyma HY. The Cyp4e3 enzyme is implicated in the D. melanogaster tolerance to permethrin toxicity feeding-mediated and the Cyp6d5 enzyme showed a higher expression in antennae of D. melanogaster exposed to geraniol acetate and in midgut after xenobiotic treatments [ 69 , 70 , 71 ]. The gene Cyp4g15 codifying for the relative enzyme has been observed as being overexpressed in imidacloprid-resistant Diaphorina citri populations [ 72 ].…”

Age matters: Life-stage, tissue, and sex-specific gene expression dynamics in Ips typographus (Coleoptera: Curculionidae: Scolytinae)

“…We observed tissue-specific regulation of many genes; for instance, CYP6K1-like and CYP410A1 had higher expression in the head and lower expression in the gut and fat body, respectively, implying a role in olfaction as odorant degrading enzymes (ODEs) (Baldwin et al, 2021). Similarly, juvenile hormone epoxide hydrolase 1-like (JHEH 1-like) gene transcripts were more abundant in the gut and fat body than in the head, as these two tissues are the site of production and metabolism of aggregation pheromone in ESBB (Ramakrishnan et al, 2022).…”