Isolation and Characterization of P450 Gene from the Formosan Subterranean Termite, Coptotermes formosanus (Isoptera: Rhinotermitidae)

Abstract

A cytochrome P450 gene belonging to family9 was isolated from the midgut transcriptome of the termite Coptotermes formosanus Shiraki, for screening enzymes related to biomass degeneration. Some studies show that insect P450 enzymes have ligninase activities for catalyzing lignin degradation. We employed the RACE method to clone this cytochrome P450 gene, named CYP9AX1 (GenBank accession No.JN969113). To the best of our knowledge, CYP9AX1 is the first member of the CYP9 family cloned from this termite. The full-length CYP9AX1 cDNA was 2242 bp long and included a 1599bp open-reading-frame (ORF), a 61-bp 5’-untranslated region (UTR) and a 592-bp 3’-UTR (excluding the poly-A tail). The CYP9AX1 protein deduced from the ORF contains 532 amino acids with a predicted signal peptide composed of 20 amino acid at its N-terminal and the classic heme-binding domain FXXGXXXCXG (residues 468-477). At position 473, residue Arg (R) changes to Gln (Q), this suggests that CYP9AX1 is a new type of CYP subfamily 9A. The phylogenetic tree showed that C. formosanus has high genetic relationship with Blattella germanica and Diploptera punctata. Quantitative RT-PCR assays demonstrated that CYP9AX1 was expressed most abundantly in malpighian tubules, and slightly lower in the head, foregut, midgut and hindgut. The results suggested that CYP9AX1 may be involved in enzymatic detoxification systems of the delignification process in C. formosanus.

Keywords

• Characterization
• Coptotermes formosanus Shiraki
• Cytochrome P450
• Real-time PCR