关键词: 苜蓿盲蝽, 气味结合蛋白, 基因克隆, 表达谱分析, 发育阶段

Abstract: In insects，there is now increasing evidence that the odorant binding proteins ( OBPs) are
involved in olfaction perception and play a key role in transporting hydrophobic odorants across the sensillum
lymph to the olfactory receptors ( ORs) . In order to better understand the role of OBPs in the olfactory
system of the lucerne plant bug，Adelphocoris lineolatus ( Goeze) ，we cloned a cDNA encoding odorant
binding protein 1 of A. lineolatus in the laboratory，which was named Alin-OBP1 ( GenBank accession no.
GQ477022) . The results of sequencing and sequence analysis showed that the open reading frame ( ORF)
of Alin-OBP1 was 438 bp in length，encoding 145 amino acids，the predicted molecular weight ( MW) was
15. 69 kDa，and the isoelectric point ( pI ) was 5. 01. The predicted N-terminal hydrophobic region
containing 18 amino residues displayed the characteristic features of a signal peptide. Protein signature
analyses revealed that it shared typical structural features of odorant binding proteins with other insects，
including six conservative cysteine residues. By RT-PCR and Real-time PCR methods，we determined the
expression pattern of Alin-OBP1 in different adult tissues and developmental stages of A. lineolatus. It was
found that Alin-OBP1 was dominantly expressed in the antenna of A. lineolatus. In addition，Alin-OBP1
was expressed in various nymphal and adult stages at different expression levels and had higher expression
level in the 5th instar nymphal and adult stages. The results suggest that Alin-OBP1 may play a key role in
the perception of sex pheromones and other chemical odorants in A. lineolatus.

Key words: Adelphocoris lineolatus, odorant binding protein, gene cloning, expression pattern analysis, developmental stage