The chemosensory protein of Chinese honeybee, Apis cerana cerana: Molecular cloning of cDNA, immunocytochemical localization and expression

Abstract

Chemosensory proteins (CSPs) are ubiquitous soluble small proteins isolated from sensory organs thought to be involved in chemical communication. Here we report the first cDNA of CSPs, called Ac-ASP3, cloned and characterized from antennas of adult worker bees in Chinese honeybee, Apis cerana cerana. The Ac-ASP3 cDNA comprises 2 exons, with an ORF of 393-bp encoding 130 aa. Protein signature analyses show that the protein consists of four conserved cysteines and a signal peptide with 19 aa in the N-terminal sequence. The deduced protein sequence shares high homology with Am-ASP3 of Apis mellifera and low similarity with other species of insects. Immunocytochemical localization shows that Ac-ASP3 is only specifically expressed on the antenna contact chemosensilla such as sensilla trichodea B and sensilla basiconica, whereas Ac-ASP3 is scarcely expressed on olfactory chemosensilla such as sensilla placodea. Real-time PCR of Ac-ASP3 transcripts shows that Ac-ASP3 is highly expressed on wings and legs, but expression is lower on antenna. Temporal expression patterns suggest that Ac-ASP3 is expressed during the period of pupa and adults from 1-d to 6-d stages when bees act as house bees, cleaning the comb and taking care of the queen and larvae in comb. The above evidence suggests that Ac-ASP3 is unique in species and is generally not involved in olfaction during searching for honey and pollen. Rather, the protein seems to function in recognition of chemosensory substances on bees' cuticle and mechanical movement of antenna.

Comprehensive History of CSP Genes: Evolution, Phylogenetic Distribution and Functions

“…The bee protein AmelASP3c is highly expressed in the antennae (in sensilla trichodea B and sensilla basiconica), but it is absolutely not restricted to antennal sensilla. It is also found on wings and legs, suggesting a very much more general function than queen pheromone recognition for this CSP protein [81,82]. The tissue distribution of CSP-EST sequences in the honeybee A. mellifera confirms that ASP3c is not specifically expressed in a peripheral organ such as the antennae.…”

BIOTYPE EXPRESSION AND INSECTICIDE RESPONSE OF Bemisia tabaci CHEMOSENSORY PROTEIN‐1

“…However, Western blot experiments show that ASP3c is detected in different parts of the body from all castes (Calvello et al., ). qPCR of ASP3c transcripts showed that ASP3c is highly expressed in wings and legs (Li et al., ). We find that BtabCSP1 is more expressed in the head than in the rest of the body.…”

Spatio-temporal expression analysis of two kinds of chemical communication-related proteins in the worker bee Apis cerana cerana Fabricius (Hymenoptera: Apidae)

“…Another gene participating in chemical communication, Ac-ASP3, has transcript amounts that seem to be higher in the wings and legs, lower in the antennae, and lowest on the thorax, head and abdomen in different tissues of A. cerana cerana, as derived from the normalized relative quantification 2 -DDCt method (Li et al, 2007). In the present study, we found some variation in the results in that the original copy number per microgram for Ac-ASP3 was higher in the wings (4.14r10 6 t4.79r10 5 ) and abdomen (3.32r10 6 t3.59r10 5 ), lower in the thorax (1.19r10 6 t2.60r10 5 ) and legs (5.38r10 5 t8.53r10 4 ), and lowest in the antennae (3.36r10 5 t2.02r10 4 ) and head (1.56r10 5 t2.09 r10 4 ) ( Table 2 and Fig.…”

“…Recombinant plasmid containing Ac-ASP3 (Li et al, 2007) was cloned into pGEM-T vector (Promega) with Escherichia coli TG-1 from an earlier study. The single colony and Ac-ASP3 were inoculated in LB medium and incubated at 37 C overnight while being shaken (at 180 rpm).…”

“…The Asian honey bee, Apis cerana cerana Fabricius (Hymenoptera: Apidae), has economic importance as an indigenous species, with about two million colonies being kept in China (Chen, 2001), and has several unique characteristics different from A. mellifera. Its one putative OBP gene, Ac-ASP2 (Li et al, 2008), and one CSP gene, Ac-ASP3 (Li et al, 2007), have been identified through molecular cloning and immunocytochemical localization; however, both genes required further identification of their spatio-temporal expression profiles in chemosensory tissues to establish their hypothesized roles in chemical communication.…”