Abstract: Glutathione S-transferases are a ubiquitous superfamily of multifunctional enzymes, in which Omega-class GST is responsible for important physiological function in insects. In this study, the full-length cDNA of a GST Omega gene from Locusta migratoria was cloned by RT-PCR technique, and named as LmGSTo1 (GenBank accession no. JQ750592). The open reading frame (ORF) of LmGSTo1 is 738 bp in length coding 245 amino acids. LmGSTO1 consists of an N-terminal domain and a C-terminal domain. The N-terminal domain includes five β-sheets and three α-turns, while the C-terminal domain is composed of eight α-turns. Temporal expression pattern revealed that LmGSTo1 was constitutively expressed in all developmental stages of the locust. Tissue expression profiling further indicated that LmGSTo1 was slightly expressed in midgut and gastric caecum and had higher expression levels in foregut, Malpighian tubules, fat body and muscle. The expression level of LmGSTo1 was significantly decreased after deltamethrin treatment. The results provide a basis for further studying the function of LmGSTo1.

Key words: Locusta migratoria, glutathione S-transferase (GST), gene cloning, sequence analysis