Abstract: 【Aim】 cDNA cloning and prokaryotic expression of Plutella xylostella odorant receptor Or83b were conducted in order to provide the basis for studying the molecular mechanism of selection behaviour between P. xylostella and host plants, and developing insect behavior regulators. 【Methods】 cDNA encoding Or83b of P. xylostella was amplified by RT-PCR and cloned into pMD18-T vector for sequence analysis, the target gene was subcloned into pET-32a (+) for prokaryotic expression and then expressed under the induction of IPTG. The expressed product was identified by SDS-PAGE and Western blot. 【Results】 A gene encoding odorant receptor 83b from P. xylostella was cloned and named PlxyOr83b (GenBank accession number: GQ923610). The ORF of PlxyOr83b was 1 413 bp in length, encoding 471 amino acid residues, with the predicted pI of 7.19. Prokaryotic expression recombinant vector, pET-PlxyOr83b, was successfully constructed. SDS-PAGE assay showed that the target gene was highly expressed in BL21(DE3) and the molecular weight of fusion protein was about 32.0 kD. Western blot indicated that PlxyOr83b was expressed correctly in DE3. 【Conclusion】 PlxyOr83b was successfully cloned and expressed, and its sequence and protein structure are consistent with those of Or83b genes in Drosophila and other insects.

Key words:  Plutella xyostella, odorant receptor, gene cloning, sequence analysis, prokaryotic expression