Abstract: Chemosensory proteins (CSPs) are a class of the most important proteins involved in chemical communications and perception in insects. In this study, one CSP gene from the Chinese honeybee, Apis cerana cerana, was cloned and characterized, which was named Acer-CSP1 (GenBank accession no.: FJ157352). The Acer-CSP1 cDNA was 351 bp in length, encoding 116 amino acid residues with the predicated molecular mass of approximately 13.85 kD and pI of 4.89, of which four conservative cysteines are included. With the general characteristics of the CSP gene family in insects, AcerCSP1 showed high similarity (99.1%) with the CSP1 gene of A. mellifera and moderate similarity (45.3%-68.0%) with the CSP genes of other ten insects analyzed with the deduced amino acid sequences. The expression of the Acer-CSP1 in different sensory organs of A. cerana cerana was compared using both relative (2^-ΔΔCt) and absolute quantitative analyses of real-time PCR. The results indicated that the Acer-CSP1 was primarily expressed in the antennae, followed by the head, but least expressed in other organs (wings, legs, thorax, and abdomen). Since the antennae are the major olfactory organs and the head is the major sensory and gustatory organ of the honeybee, the results suggest that the Acer-CSP1 gene is most likely involved in the olfaction, gestation and other chemosensory functions of the insect.

Key words: Apis cerana cerana, chemosensory proteins, molecular cloning, DNA sequence analysis, expression profile