Abstract:

【Objective】Odorant binding proteins (OBPs) are olfactory-related proteins that are involved in the recognition process of most odor molecules and combine with odor molecules. However, the research on the OBPs has not been reported at home and abroad in Micromelalopha troglodyta (Graeser) . Therefore, this study would like to obtain the OBP and clarify its characteristics in M. troglodyta. 【Method】The MtroOBP1 gene was obtained from the cDNA template of antenna using reverse transcription polymerase chain reaction (RT-PCR), and the gene sequence and protein structure were analyzed by bioinformatics analysis software, and the tissue expression pattern of MtroOBP1 was studied by real-time fluorescence quantitative PCR (qPCR) in M. troglodyta.【Result】MtroOBP1 was amplified by RT-PCR using total RNA from the antennae of M. troglodyta (GenBank accession no. MN056510). The gene harbors a 777-bp-long open reading frame and a protein-coding region with 258 amino acids. Its translated amino acid sequence contained only four conserverd cysteines, suggesting that it belonged to the Minus-C OBP . Prediction of physicochemical properties of the protein showed that the molecular weight of MtroOBP1 protein is 29 664.57 u and isoelectric point (PI) is 6.23. The protein contains 18 potential phosphorylation sites but no transmembrane region, and it is a secretory protein with an hydrophobic index of -2.011 to 3.078.There was a signal peptide consisting of 19 amino acids, indicating that it is a secreted protein. The tissue expression pattern showed that MtroOBP1 was expressed in all tissues of the M. troglodyta. but the highest expression was in the antennae.【Conclusion】In a word, the MtroOBP1 gene firstly cloned is highly expressed in the antennae. Presumably this protein has the function of transporting odor molecules, and plays an important role in olfactory recognition in M. troglodyta.

Key words: Micromelalopha troglodyta, MtroOBP1 gene, gene cloning, olfactory system, expression profiling