Abstract: 【Aim】 Chemosensory proteins (CSPs) play important roles in reception and recognition of chemical signal, and regulation of insect development. This study aims to explore the function of CSP16 in the silkworm, Bombyx mori. 【Methods】 Real-time quantitative PCR (RT-qPCR) was used to investigate the expression patterns of csp16 gene in different developmental stages and different tissues of the 5th instar larvae of B. mori. Prokaryotic expression system was used to express and purify CSP16. The binding properties of CSP16 were analyzed by fluorescence binding assay. 【Results】 The RT-qPCR results showed that csp16 was regularly expressed in the 1st-5th instar larvae, and highly expressed in molting larvae of each instar. In day-3 5th instar larvae, csp16 was mainly expressed in head, epidermis, testis and ovary. The expression level of csp16 was up-regulated in larvae of different instars and different tissues of the 5th instar larvae after treatment with 20-hydroxyecdysone. Purified CSP16 showed weak affinity to different compounds including alcohols, esters, aldehydes, phenols and benzene. 【Conclusion】 Csp16 is highly expressed in molting larvae of each instar of B. mori, and the expression level is up-regulated by 20-hydroxyecdysone in larvae during feeding, suggesting that CSP16 may be involved in molting process of silkworm larvae.

Key words: Bombyx mori, chemosensory protein, RT-qPCR analysis, 20-hydroxyecdysone, binding property