CLONING AND EXPRESSION ANALYSIS OF G-PROTEIN Gαq SUBUNIT AND Gβ1 SUBUNIT FROM Bemisia tabaci GENNADIUS (HOMOPTERA: ALEYRODIDAE)

The heterotrimeric G proteins play an essential role in a wide variety of signal transduction pathways, mediating the process of chemical signals from the environment in all higher eukaryotic organisms. In this article, two G-protein subunit genes encoding Gq and G1 were cloned from Bemisia tabaci Gennadius. The full-length cDNA sequence of BtGq consisted of 2,336 bp with an ORF of 1,062 bp encoding 353 amino acids and BtG1 had a full length of 1,942 bp with an ORF of 1,023 nucleotides encoding 340 amino acids. The amino acid sequences of BtGq and BtG1 from B. tabaci B biotype were identical to those from the Q biotype. Phylogenetic analysis identified G protein and subunit families from insects based on their amino acid sequences. The expression patterns of BtGq and BtG1 at different development stages and in different body regions were analyzed by real-time quantitative PCR and Western blot. The results show that BtGq and BtG1 are neither developmental stage-specific nor tissue-specific. The transcript levels of BtGq in the B biotype are similar to that in the Q biotype, the transcript levels of BtG1 at egg, first instar and pupae in B biotype were significantly higher than that in Q biotype. The transcript levels of BtGq and BtG1 in the head were significantly higher than those in thorax and abdomen indicating that they are involved in nervous system and sensory functions.