Comparative dissection of the peripheral olfactory system of the Chagas disease vectors < i > Rhodnius prolixus < /i > and < i > Rhodnius brethesi < /i >

by Florencia Campetella, Rickard Ignell, Rolf Beutel, Bill S. Hansson, Silke Sachse American trypanosomiasis, or Chagas disease, is transmitted by both domestic and sylvatic species of Triatominae which use sensory cues to locate their vertebrate hosts. Among them, odorants have been shown to play a key role. Previous work revealed morphological differences in the sensory apparat us of different species of Triatomines, but to date a comparative functional study of the olfactory system is lacking. After examining the antennal sensilla with scanning electronic microscopy (SEM), we compared olfactory responses ofRhodnius prolixus and the sylvaticRhodnius brethesi using an electrophysiological approach. In electroantennogram (EAG) recordings, we first showed that the antenna ofR.prolixus is highly responsive to carboxylic acids, compounds found in their habitat and the headspace of their vertebrate hosts. We then compared responses from olfactory sensory neurons (OSNs) housed in the grooved peg sensilla of both species, as these are tuned to these compounds using single-sensillum recordings (SSRs). InR.prolixus, the SSR responses revealed a narrower tuning breath than its sylvatic sibling, with the latter showing responses to a broader range of chemical classes. Additionally, we observed significant differences between these two species in their response to particular volatiles, such as amyl acetate and butyryl chloride. In summary, the closely related, but ecologically differen...
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research