Abstract: Pheromone binding proteins (PBPs) play an important role in communication between male and female insects. The open reading frame and 3′ end full-length cDNA of a novel pheromone binding protein 2 gene was cloned from Helicoverpa assulta (Guenée) by using RT-PCR and RACE methods, which was named HassPBP2 (GenBank accession no. EU316186). The cloning and sequencing results showed that the full-length of open reading frame in HassPBP2 was 450 bp, encoding 149 amino acid residues with the predicted molecular weight and isoelectric point of 16.9 kD and 5.56, respectively. Gene structure analysis revealed that HassPBP2 consists of 3 exons and 2 introns with length of 90 and 261 bp, respectively. Amino acid sequence analysis showed that the deduced amino acid sequence of HassPBP2 had the characteristics of odorant binding proteins. HassPBP2 had 34%-91% identity with PBPs of other Lepidoptera moths, and shared 91% identity with the PBP2 sequences from H. armigera and Heliothis virescens. Temporal expression revealed that HassPBP2 transcript was observed clearly from mid-stage pupa to mid-stage adult, but not in the egg, larva and early-stage pupa. The tissue analysis further indicated that HassPBP2 was only expressed in the antennae of both male and female adults.

Key words: Helicoverpa assulta, pheromone binding protein, gene cloning, sequence analysis, spatio-temporal expression