Cloning and Expression Analysis of cDNA Encoding Or83b-Like Receptor from Helicoverpa assulta

An Or83b-like receptor gene was cloned from antennae of Helicoverpa assulta (Guenée) by using reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Sequence analysis revealed that the transcript of the Or83b-like receptor gene from H. assulta consists of 1 946 nucleotides and the open reading frame (ORF) encodes a peptide of 473 amino acids with 7 putative transmembrane domains. Alignment analysis suggested that amino acid sequence of Or83b-like receptor from H. assulta shares high identity with other Or83b family receptors and this gene was hence named as HassOr83b. Tissues expression analysis showed that the HassOr83b transcript is clearly observed in the antennae, labial palps and proboscises, but not in bodies, wings and legs. The further development expression analysis suggested HassOr83b is also expressed in several preadult stages, including early-stage larvae, late-stage larvae and pupae, but not in embryos. Locked nucleic acid (LNA)-based in situ hybridization of antennal section indicated that HassOr83b is expressed in a very large number of antennal cells, which suggests that HassOr83b may play a special role in olfaction in H. assulta.