Cloning and Expression Analysis of Chemosensory Protein AzanCSP4 from Agrilus zanthoxylumi (Coleoptera: Buprestidae)1

Chemosensory proteins (CSPs) are widely distributed in insect tissues and are involved in olfactory and non-olfactory functions. In this study, based on the transcriptome data of Agrilus zanthoxylumi Hou (Coleoptera: Buprestidae), the AzanCSP4 of was cloned by RT-PCR and bioinformatically analyzed, and RT-qPCR was conducted to analyze their expression levels of AzanCSP4 in different genders and tissues (head, thorax, abdomen, leg and wing). Sequence analysis showed that AzanCSP4 had an open reading frame (ORF) length of 366 bp, encoding 121 amino acids with an estimated molecular weight 13.96 kD. The encoded protein had no transmembrane domain, and the signal peptide was located in the position 1-15 at the N-terminal of the amino acid sequence. Sequence alignment revealed that AzanCSP4 had four conserved cysteines. Phylogenetic analysis revealed that the AzanCSP4 and AmalCSP6 from Agrilus mali Matsumura (Coleoptera: Buprestidae) were closely clustered into the same clade. RT-qPCR results showed that AzanCSP4 of A. zanthoxylumi was expressed in different tissues of both male and female adults, and the expression in the same tissue was greater in female adults than in male adults. The expression of AzanCSP4 in the head of female adults was significantly higher than that in other tissues of male and female adults. This study provides a theoretical basis for further research on the function of AzanCSP4, especially on the chemical communication mechanism in A. zanthoxylumi.