Abstract: 【Aim】 To clone bursicon genes from the fruit fly Zeugodacus tau and to analyze their molecular characteristics and spatiotemporal expression patterns, so as to develop a basis for further study of their physiological functions. 【Methods】 The complete cDNAs of bursicon-α and bursicon-β genes were cloned from the newly emerged adults of Z. tau by using homology-based cloning and RACE technology, and the phylogenetic trees were constructed with the homologous sequences of other insect species by using neighbor-joining method. The expression patterns of the two genes in different developmental stages (egg, 1st-3rd instar larva, prepupa, pupa and newly emerged adult) of Z. tau were detected by qPCR. 【Results】 The full-length cDNAs of two bursicon genes bursicon-α (GenBank accession no.: MH421861) and bursicon-β (GenBank accession no.: MH421862) were cloned from Z. tau. bursicon-α contains a 551 bp open reading frame (ORF) encoding 183 amino acid residues, and bursicon-β has a 467 bp ORF encoding 156 amino acid residues. Phylogenetic tree analysis based on the amino acid sequences of the two bursicon genes showed that Bursicon-α and Bursicon-β of Z. tau had a closest genetic relationship with the homologous proteins of Zeugodacus cucurbitae, and clustered into one independent group with the homologous proteins of other dipterous insects. The qPCR results indicated that both bursicon-α and bursicon-β were expressed in all developmental stages of Z. tau, and highly expressed in 5 d-old pupae and in the wing expansion stage of the newly emerged adults. 【Conclusion】 The expression levels of bursicon-α and bursicon -β are different in different developmental stages of Z. tau, suggesting a crucial role of bursicon genes in cuticular tanning and wing formation. This study provides a foundation for further exploring the functional mechanisms of bursicon in cuticle sclerotization and wing reconstruction of Z. tau.

Key words: Zeugodacus tau, bursicon, cuticle sclerotization, gene expression, wing expansion, phylogeny