Molecular cloning and characterization of sensory neuron membrane protein and expression pattern analysis in the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

Abstract

Olfactory proteins in insects are extremely diverse. The sensory neuron membrane protein (SNMP) olfactory receptor, which shares a high identity among different insects, has been shown to be essential for olfaction perception in insects. To research the function of SNMP, the gene encoding SNMP from Plutella xylostella Linnaeus (Lepidoptera: Plutellidae) was cloned and named PxyloSNMP1 (GenBank accession no. HM536984). The sequencing results showed that the open reading frame of PxyloSNMP1 had the characteristics of SNMP, with two putative transmembrane domains flanking a large extracellular loop and a 34-residue hydrophobic signal peptide sequence. The amino acid sequence of PxyloSNMP1 had a high degree of similarity with those from other insect species and shared 78.8% identity with the SNMP sequence from Amyelois transitella Walker (Lepidoptera: Pyralidae). RT-PCR analysis revealed that the gene was expressed during all life-history stages and in all adult tissues. Quantitative real-time PCR (qPCR) analysis also showed that the PxyloSNMP1 transcript could be observed in different developmental stages at different levels of expression. The tissue expression pattern further indicated that PxyloSNMP1 was expressed most in the antenna of P. xylostella, followed by the abdomen, head (without antenna), wing, leg and thorax. This study provides a basis for further studies of the function of SNMP from P. xylostella.