In search of Varroa chemosensory related proteins using transcriptomic and proteomic tools

The tight synchronization between the life cycle of the obligatory parasitic mite Varroa destructor (Varroa) and its host the honeybee, is mediated by honeybee chemical stimuli. These stimuli are mainly perceived by a pit organ located at the distal part of the mite’s foreleg. In the present study, we searched for Varroa chemosensory molecular components by comparing transcriptomic and proteomic profiles between forelegs from different physiological stages, and rear legs. In general, a comparative transcriptomic analysis showed a clear separation of the expression profiles between the rear legs and the three groups of forelegs (phoretic, reproductive and tray-collected mites). Most of the differentially expressed transcripts and proteins in the mite’s foreleg were previously uncharacterized. Using a conserved domain approach, we identified 54 transcripts with known chemosensory-related domains, of which 17 were significantly up regulated in the mite’s forelegs when compared to rear legs. We characterized the chemosensory transcripts using phylogenetic analysis.