Abstract: 【Aim】 The aim of this study is to clone the full-length cDNA of mab-21 gene in the head of the Chinese honeybee, Apis cerana cerana, and then to analyze its expression characteristics in different developmental stages of the workers and after infection of mites, in attempt to provide a theoretical support for revealing the resistance mechanism of A. cerana cerana to Varroa mites. 【Methods】 The cDNA sequence of mab-21 in A. cerana cerana was cloned by RT-PCR, and a quantitative analysis of its expression level in the head of workers at different developmental stages (newly emerged bee, nurse, guarder and forager) and after infection of Varroa destructor mites was conducted using real-time PCR. 【Results】 The cDNA sequence of mab-21 was cloned from A. cerana cerana, and named as Accmab21 GenBank accession no. KR000001). Its open reading frame (ORF) is 1 098 bp in length, encoding 395 amino acids with the predicted molecular weight of 41.63 kD and the theoretical isoelectric point of 8.53. Phylogenetic analysis indicated that mab-21 of A. cerana cerana, A. mellifera, A. florea and Bombus impatiens gather in the same clade. The mab-21 transcript was clearly detected in different developmental stages of the workers of A. cerana cerana, and was significantly higher in nurses than in other stages (P<0.05). After being inoculated with V. destructor, the expression of mab-21 in the nursesand guarders significantly decreased as compared to the control (P<0.05), but the expression level of mab-21 showed no obvious regularity in newly emerged bees and foragers. 【Conclusion】 These results suggest that mab-21 may be involved in the resistance to mites in A. cerana cerana.

Key words: Apis cerana cerana, mab-21, gene cloning, sequence analysis, differential expression, mite resistance