The sialotranscriptome of the blood-sucking bug Triatoma brasiliensis (Hemiptera, Triatominae)

Abstract

Triatoma brasiliensis is the most important autochthon vector of Trypanosoma cruzi in Brazil,where it is widely distributed in the semiarid areas of the Northeast. In order to advance the knowledge of the salivary biomolecules of Triatominae, a salivary gland cDNA library of T. brasiliensis was mass sequenced and analyzed. Polypeptides were sequenced by HPLC/Edman degradation experiments. 1,712 cDNA sequences were obtained and grouped in 786 clusters. The housekeeping category had 24.4% and 17.8% of the clusters and sequences, respectively. The putatively secreted category contained 47.1% of the clusters and 68.2% of the sequences. Finally, 28.5% of the clusters, containing 14% of all sequences, were classified as unknown. The sialoma of T. brasiliensis showed a high amount and great variety of different lipocalins (93.8% of secreted proteins). Remarkably, a great number of serine proteases that were not observed in previous blood-sucking sialotranscriptomes were found. Nine Kazal peptides were identified, among them one with high homology to the tabanid vasodilator vasotab, suggesting that the Triatoma vasodilator could be a Kazal protein.

An insight into the sialome of the blood-sucking bug Triatoma infestans, a vector of Chagas’ disease

“…The South American T. brasiliensis was also shown to contain salivary cDNA sequences similar to these three previously described Triatoma lipocalins (Sant'Anna et al, 2002). More recently, the sialotranscriptome of T. brasiliensis revealed a high content of lipocalins in its (SG)s, comprising 93.8% of the transcripts coding for putative secreted protein (Santos et al, 2007). Lipocalins have also been found in tick saliva and in Rhodnius performing similar functions, such as histamine and serotonin binding (Ribeiro et al, 2004a;Paesen et al, 2000;Sangamnatdej et al, 2002).…”

“…albopictus . And recently, the sialotranscriptome of the triatomine Triatoma brasiliensis demonstrated the presence of nine clusters coding for Kazal-type peptides (Santos, et al, 2007).…”

“…A great array of (SG) proteins belonging to the lipocalin family has generated a large number of different molecules having anti-hemostatic functions while maintaining the fundamental structure of the protein fold (Montfort et al, 2000). Lipocalins were found in the saliva of other blood-sucking insects such as Rhodnius prolixus (Ribeiro et al, 2004a) and Triatoma brasiliensis (Santos et al, 2007), and also in tick saliva (Paesen et al, 2000). In R. prolixus, three types of salivary lipocalins have been characterised: the nitrophorins consisting in a group of lipocalins working as NO carrier, and also as anti-clotting; the ADP-binding protein RPAI1, which inhibits platelet activation and aggregation (Francischetti et al, 2000); and a group of lipocalins related to T. pallidipenis thrombin inhibitor triabin (Fuentes-Prior et al, 1997).…”

An Insight into the Sialotranscriptome of Triatoma matogrossensis, a Kissing Bug Associated with Fogo Selvagem in South America

“…Like other triatomines that have been studied, [18][19][20][21][22] T. matogrossensis is most probably capable of counteracting host hemostatic responses triggered to prevent blood loss following tissue injury, such as vasoconstriction, blood coagulation, and platelet aggregation. 23 The molecular diversity of hematophagous insect saliva presents a rich field for the discovery of novel pharmacologically active compounds and for understanding evolutionary mechanisms leading to insect adaptation to this feeding habit.…”

Genomic resources for invertebrate vectors of human pathogens, and the role of VectorBase

“…Identifying any of these compounds is potentially of interest to the medical industry. Ribeiro and collaborators have already characterized some of these agents through studies of mosquito salivary gland gene expression (Ribeiro et al, 2006;Calvo et al, 2007;Santos et al, 2007).…”