In moth, pheromone biosynthesis activating neuropeptide (PBAN) regulates pheromone biosynthesis by binding to its receptor (PBANr). In this study, we cloned a PBANr gene (Mvi-PBANr) from sex pheromone gland in M. vitrata, which encodes 475 amino acid and includes 7 transmembrane domains. As a results of phylogenetic analysis, Mvi-PBANr is clustered with lepidopteran PBANrs. Mvi-PBANr was investigated for the effect of pheromone biosynthesis via RNA interference (RNAi), gas chromatography (GC) and bioassay. Consequently, expression level of Mvi-PBANr suppressed via RNAi, resulting in decrease pheromone component (E10E12-16:Ald). Mating rate was also reduced when performing the RNAi. These results revealed that Mvi-PBANr played important role in the pheromone biosynthesis in M. vitrata, and Mvi-PBANr can be used as new pest control targets.

A cDNA of PBAN receptor (Plx-PBANR) isolated from female pheromone gland of the diamondback moth encodes 338 amino acids and has 7 transmembranes, belonging to G-protein coupled receptor family. The fact that Plx-PBANR expression was only found in female pheromone gland revealed that pheromone gland is the only molecular target of Plx-PBAN. Plx-PBANR expressing cells increased level of Ca2+ influx when challenged with PBANs. When RNAi fragment for PBANR was injected into pupae, suppression of PBANR expression was maintained for at least 2 days at post-emergence. Injection of RNA fragment for inhibition of Plx-PBANR expression also inhibited mating behavior and suppressed sex pheromone production, suggesting that some molecular target was affected by reduced Plx-PBANR expression. We cloned partial Δ9 and Δ11 desaturase gene and investigated expression level in Plx-PBANR-RNAi moth. It is of interest that desaturases expression was reduced by RNA fragment injection. These results suggest of PBANR expression affects the molecular biological events of PBAN and eventually suppresses mating behavior.

Sex pheromone production in lepidopteran is stimulated and regulated by a pheromone biosynthesis activating neuropeptide (PBAN). A cDNA of PBAN receptor (Plx-PBANR) isolated from female pheromone gland of the diamondback moth (DBM, Plutella xylostella (L.) encodes 338 amino acids. Plx-PBANR has conserved biochemical motifs and 7 transmembranes, indicating it belongs to G-protein coupled receptor family. Plx-PBANR expression was only found in female pheromone gland, demonstrating that pheromone gland is the only molecular target of Plx-PBAN. Human uterus carcinoma (HeLa) was stably transfected with Plx-PBANR gene and its expression was confirmed by RT-PCR analysis. Plx-PBANR expressing cells increased level of Ca2+ influx when challenged with Plx-PBAN and Hez-PBAN from Heliothis zea. When RNAi fragment for PBANR was injected into pupae, suppression of PBANR expression was confirmed by RT-PCR and maintained for at least 2 days at post-emergence. Injection of RNA fragment into pupae for inhibition of Plx-PBANR expression also inhibited mating behavior, revealing that reproductive organ of the female has no spermatocyte and that there are no successful reproductive behaviors. These results suggest of PBANR expression affects the molecular biological events of PBAN and eventually suppresses mating behavior.

Many female moths produce and release sex pheromones to mate successfully with a conspecific male. Sex pheromone production in lepidopteran moth is known to be under the regulation of a pheromone biosynthesis activating neuropeptide (PBAN). A PBAN polypeptide is processed into five neuropeptides (NPs) after post-translational modification, resulting in diapause-like NP, PBAN, α-, β- and γ-NP. All of the peptides are amidated in their C-termini and shared a conserved motif, FXPR(or K)L structure. PBAN (Plx-PBAN) from Plutella xylostella consists of 30 amino acids, the shortest PBAN so far reported. When female adults were injected with synthetic Plx-PBAN, pheromone production showed a maximal increase 1 h post-injection. RT-PCR screening revealed that Plx-PBAN cDNA was expressed in both sexes, with the highest expression level in the head of female adults. Plx-PBAN binds to its receptor on pheromone gland cells. PBAN receptor has seven transmembranes, indicating G-protein coupled receptor family and transduces its signal via G-protein mediated signal transduction. Subsequently, calcium channels remain activated and stimulate biochemical reactions for sex pheromone production in the pheromone gland.