Abstract: Olfactory receptors in insects were found to be extremely diverse, but there is a kind of olfactory receptor, Or83b, which shares a high identity among different insects and plays an important role in the regulation of insect behavior. In order to research the function of Or83b, the gene encoding Or83b receptor from Bactrocera cucurbitae (Coquillett) was cloned and named as BcucOr83b-like (GenBank accession no. HM745934). The sequencing results showed that the open reading frame of BcucOr83b-like was 1 422 bp in length, encoding 473 amino acid residues. Homology analysis showed that the deduced amino acid sequence of BcucOr83b-like had the characteristics of Or83b, with seven putative transmembrane domains and conserved C domains. BcucOr83b-like had very high similarity of amino acid sequence with those from other insects and shared 99.6% identity with the Or83b sequence from Bactrocera dorsalis. Tissue expression pattern revealed that BcucOr83b-like transcript was observed clearly in the antenna of B. cucurbitae, and highly expressed in the head (with antennae removed), female foreleg and wings. The temporal expression pattern further indicated that BcucOr83b-like was also expressed in different developmental stages at different expression levels, with the highest level in female adult newly emerged. This study provides a basis for further researching the function of Or83b from B. cucurbitae.

Key words: Bactrocera cucurbitae, odorant receptor, Or83b, gene cloning, expression pattern analysis, real-time PCR