LmCYP4G102: An oenocyte-specific cytochrome P450 gene required for cuticular waterproofing in the migratory locust, Locusta migratoria

Abstract

Cytochrome P450 superfamily proteins play important roles in detoxification of xenobiotics and during physiological and developmental processes. To contribute to our understanding of this large gene family in insects, we have investigated the function of the cytochrome P450 gene LmCYP4G102 in the migratory locust Locusta migratoria. Suppression of LmCYP4G102 expression by RNA interference (RNAi) does not interfere with moulting but causes rapid loss of body weight - probably due to massive loss of water, and death soon after moulting. Accordingly, maintaining these animals at 90% relative humidity prevented lethality. Consistently, RNAi against LmCYP4G102 provoked a decrease in the content of cuticular alkanes, which as an important fraction of cuticular hydrocarbons have been shown to confer desiccation resistance. In addition, the cuticle of LmCYP4G102-knockdown locusts was fragile and easier deformable than in control animals. Presumably, this phenotype is due to decreased amounts of cuticular water that is reported to modulate cuticle mechanics. Interestingly, LmCYP4G102 was not expressed in the epidermis that produces the cuticle but in the sub-epdiermal hepatocyte-like oenocytes. Together, our results suggest that the oenocyte-specific LmCYP4G102 plays a critical role in the synthesis of cuticular hydrocarbons, which are important for cuticle waterproofing and mechanical stability in L. migratoria

Hydrocarbons catalysed by TmCYP4G122 and TmCYP4G123 in Tenebrio molitor modulate the olfactory response of the parasitoid Scleroderma guani

“…High expression of CYP4G1 in D. melanogaster and CYP4G25 in Bombyx mori in the prothoracic glands plays an important role in regulating prothoracic gland function and ecdysteroid metabolism (Niwa et al, 2011;Qiu et al, 2012). Although regulating water loss by modulating HC biosynthesis was found to be its primary role in this research and some previous studies (Qiu et al, 2012;Chen et al, 2016;Yu et al, 2016), the potential secondary functions of CYP4G family members in the prothoracic gland and other T. molitor tissues remain to be elucidated.…”

Involvement of integument‐rich CYP4G19 in hydrocarbon biosynthesis and cuticular penetration resistance in Blattella germanica (L.)

“…The only CYP4G member in B. germanica , CYP4G19 , was reported to be overexpressed in a pyrethroid‐resistant strain, but no role in insecticide resistance has been attributed to CYP4G19 . Several CYP4G genes have been functionally characterized to be involved in the final decarbonylation step of hydrocarbon biosynthesis by baculovirus expression system or RNAi‐based functional studies . The insect‐specific CYP4G genes are among the rare P450 members with orthologs distributed throughout the Insecta .…”

“…Several CYP4G genes have been functionally characterized to be involved in the final decarbonylation step of hydrocarbon biosynthesis by baculovirus expression system 9,[35][36][37] or RNAi-based functional studies. 38,39 The insect-specific CYP4G genes are among the rare P450 members with orthologs distributed throughout the Insecta. 35 We therefore hypothesized that overexpressed CYP4G19 in the resistant strain facilitates the production of CHCs to facilitate the development of cuticular penetration resistance in B. germanica.…”

Functional characterization of CYP4G11—a highly conserved enzyme in the western honey bee Apis mellifera

“…Transcripts of variants of these genes in other Dendroctonus species, including D. rhizophagus , D. armandi , and D. valens, were found in antennae or hindguts, in some cases showing altered expression levels in response to exposure to plant host volatile terpenes (Cano‐Ramírez et al, ; López et al, ; Dai et al, ). In Locusta migratoria , CYP4G102 is also expressed in oenocytes and required for cuticular waterproofing (Yu et al, ); similarly, in the pea aphid Acyrthosiphon pisum , CYP4G51 contributes to cuticular hydrocarbon production (Chen et al, ).…”