Redundancy of proteins in the salivary glands of Panstrongylus megistus secures prolonged procurement for blood meals

Panstrongylus megistus, a vector for the Chagas disease parasite Trypanosoma cruzi, is a hematophagous bug widely distributed in South America. This ubiquitous triatomine is known to colonize different wild life habitats. Additionally, P. megistus synanthropy, preying upon mammals, birds, reptiles, and eventually being predators upon insect's hemolymph probably increases its ability to survive after prolonged fasting. It was suspected that the P. megistus mechanisms of adaptation to survival might include a salivary gland complex tool-box with a diversity of pharmacologically active proteins for obtaining blood meals. Herein we describe comprehensive proteome and transcriptome of the P. megistus salivary gland. The proteomic analysis led to the identification of 159 proteins, and the transcriptome revealed 47 complete cDNAs. A diversity of protein functions associated to blood feeding was identified. The most prevalent proteins were related to blood clotting, anti-platelet aggregation and anti-vasoconstriction activities, which correlate with the insect's ability to obtain meals from different sources. Moreover, a gene of resistance to insecticides was identified. These features augments the comprehension towards P. megistus enormous capacity to survive in adverse wild life-changing habitats. [Display omitted] ► A total of 45 proteins expressed in the P. megistus salivary glands have vasodilatation, anti-clotting, anti-platelet aggregation activities. The redundancy shown was considered important for the insect's remarkable adaptability to feeding upon different classes of vertebrates. ► Additionally, the P. megistus proteome revealed 159 proteins showing similarities with apyrase, lipocalins, thrombin inhibitor, trialysin, trypsin, and glutathione S-transferase. ► The main conclusion is that the P. megistus complex salivary gland bioamines have important functions associated with the insects’ blood-feeding and resistance to insecticide.