MOLECULAR CHARACTERIZATION OF TWO NICOTINIC ACETYLCHOLINE RECEPTOR SUBUNITS FROM Liposcelis bostrychophila BADONNEL (PSOCOPTERA: LIPOSCELIDIDAE)

Two nicotinic acetylcholine receptor (nAChR) subunit genes, Lb alpha 1 and Lb alpha 8, were isolated and characterized from psocid, Liposcelis bostrychophila Badonnel, using the rapid amplification of cDNA ends (RACE) technique. They are the first two nACHR family members isolated from the insect order of Psocoptera. The full-length cDNAs of Lb alpha 1 (GenBank accession number: EU871527) and (EU871526) consist of 2,2025 and 1,763 nucleotides, respectively, and an open reading frame of 1,644 and 1,608 bp encoding 547 and 535 amino acid proteins, respectively. Both genes have typical features of nAChR family members, though they share only 56% identity in amino acid sequence. The dendrogram generated by the MEGA 3.1 program shows that the protein deduced by Lb alpha 1 had the closest phylogenetic relationship to Agama alpha 1 from Anopheles gambiae and Amel alpha 1 from Apis mellifera, and Lb alpha 8 shares the highest identity with Agam alpha 8 from An. gambiae and Amel alpha 8 from A. mellifera. Quantitative real-time PCR analysis showed that Lb alpha 1 was expressed 2.03-6.54-fold higher than Lb alpha 8 at the different developmental stages of L. bostrychophila. The highest expression levels of Lb alpha 1 and Lb alpha 8 were both detected at adult stage and the lowest were at the third and fourth nymphal stages, respectively. There was a stable and relatively low expression, level for Lb alpha 1, whereas there was a descending expression Pattern for Lb alpha 8 in the 1st through the 4th nymphal stadia. (C) 2009 Wiley Periodicals Inc.