Abstract: 【Aim】 The objective of this study is to clone the coding sequence of the developmental gene optomotor-blind (omb) in Locus migratoria and to analyze its structure properties and expression profiles, so as to further understand the role of omb in the wing development of L. migratoria and to provide a new fundamental evidence for the pest management and control. 【Methods】 The cDNA sequence of omb was amplified from L. migratoria with RT-PCR, and the nucleotide and deduced amino acid sequences of the gene were analyzed using different bioinformatics software. The phylogenetic tree was constructed using neighbor-joining method of MEGA 6.0. The recombinant expression vector pET-30a/LmOmb was constructed and transformed into Escherichia coli BL21 (DE3). The recombinant protein was identified by SDS-PAGE and Western blotting. The expression profiles of omb in different developmental stages and adult tissues of L. migratoria was detected by qPCR. 【Results】 We cloned the partial cDNA sequence of omb from L. migratoria, which is named LmOmb (GenBank accession no.: MG867658) and 792 bp in length encoding 264 amino acids, with a conserved T-box superfamily domain between 37-219 amino acids. Homologous sequence alignment analyses showed that LmOmb has 93% amino acid sequence identity with NlOmb of Nilaparvata lugens. The recombinant expression vector pET-30a/LmOmb was constructed and the target protein was stably expressed in host bacteria in the form of 6×His tag fusion protein after IPTG induction. The qPCR result revealed that LmOmb was expressed in L. migratoria at different developmental stages, and the expression level was the highest in the embryonic stage. The expression level of LmOmb decreased in the nymphal stage, and was relatively stable among nymphs of different instars. LmOmb was expressed in the thorax, leg, abdomen and wing of adults, and showed obviously different expression level between male and female. 【Conclusion】 LmOmb may be involved in the embryonic development of L. migratoria. The results provide a basis for further studying the function of LmOmb in L. migratoria.

Key words:  Locusta migratoria, Omb; gene cloning, prokaryotic expression, expression profile