cDNA cloning, characterization, and developmental expression of the 20S proteasome alpha5 subunit in the Mediterranean fruit fly Ceratitis capitata

RNAi-based silencing of proteasome 20S subunit alpha 2 affected the survival and development of Henosepilachna vigintioctopunctata

Henosepilachna vigintioctopunctata is a notorious pest of solanaceous plants in Asia, which is mainly managed by chemical pesticides. RNA interference (RNAi) technique is considered to be a promising and effective alternative for pest control. In this study, we selected the proteasome 20S subunit alpha 2 (Prosα2) gene, a cellular protein involved in many proteins regulatory processes, to explore the RNAi efficiency in H. vigintioctopunctata. The obtained results confirmed the significant lethal effects of HvProsα2 silencing on the H. vigintioctopunctata 1st instar larvae at concentrations of 100, 50, and 5 ng/μL. Ingestion of the bacterially expressed dsHvProsα2 caused high mortality in both larvae and adults. Moreover, silencing of HvProsα2 resulted in feeding disorders, growth delay, and abnormal intestinal development of the larvae. Overall, HvProsα2 acts as an important regulator for the growth and development of H. vigintioctopunctata, and can serve as a candidate target gene for the RNAi-based control of H. vigintioctopunctata.

Cloning, sequence identification and expression profile analysis of α-L-fucosidase gene from the Mediterranean fruit fly Ceratitis capitata

The Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) is one of the most destructive agricultural pests, a polyphagus insect of relevant economic importance and is widespread in many regions around the world. It is the best-studied fruit fly pest at genetic and molecular level and much has been learned on its ecology and behaviour. An α-L-fucosidase has been recently hypothesized to be involved in sperm-egg interactions in Drosophila melanogaster and in other Drosophila species. Here, a complete cDNA encoding a putative α-L-fucosidase of the medfly was amplified using the reverse polymerase chain reaction (RT-PCR) with degenerate based on the conserved coding sequence information of several insect α-L-fucosidases, cloned and sequenced (GenBank accession no. FJ177429). The coding region consisted of 1482 bp which encoded a 485-residues protein (named CcFUCA) with a predicted molecular mass of 56.1 kDa. The deduced protein sequence showed 75% amino acid identity to D. melanogaster α-L-fucosidase, and in fact the phylogenetic tree analysis revealed that CcFUCA had closer relationships with the α-L-fucosidases of drosophilid species. The tissue expression analysis indicated that CcFuca was expressed in a single transcript in all tissues, suggesting a ubiquitous localization pattern of the encoded protein. Our findings provide novel insights on a gene encoding a protein potentially involved in primary gamete interactions in C. capitata.