Proteomic analysis of chemosensory organs in the honey bee parasite Varroa destructor: a comprehensive examination of the potential carriers for semiochemicals
The mite Varroa destructor is the major parasite of the honey bee and is responsible for great economical losses. The biochemical tools used by Varroa to detect semiochemicals produced by the host are still largely unknown. We have performed proteomic analysis on chemosensory organs of this species in order to identify putative soluble carriers for pheromones and other olfactory cues emitted by the host. In particular, we have analysed forelegs, mouthparts (palps, chelicera and hypostome) and the second pair of legs (as control tissue) in reproductive and phoretic stages of the Varroa life cycle. We identified 958 Varroa proteins, most of them common to organs and stages. Sequence analysis shows that four proteins can be assigned to the odorant-binding protein (OBP)-like class, which bear some similarity to insect OBPs, but so far are only reported in some Chelicerata. In addition, we have detected the presence of two proteins belonging to the Niemann-Pick family, type C2 (NPC2), which have been suggested to act as semiochemical carriers. This work contributes to elucidating the chemical communication systems in Varroa with the aim of understanding how detection of semiochemicals has evolved in terrestrial non-hexapod Arthropoda. Data are available via ProteomeXchange with identifier PXD008679.