Molecular cloning and sequencing of salivary gland-specific cDNAs of the blood-sucking bug Triatoma brasiliensis (Hemiptera: Reduviidae).
Haematophagous insects produce pharmacological substances in their saliva to counteract vertebrate host haemostasis events such as coagulation, vasoconstriction and platelet aggregation. To investigate the bioactive salivary molecules of the triatomine bug Triatoma brasiliensis, we produced subtraction-enriched cDNAs of salivary-gland specific genes using suppression subtractive hybridization. Six full-length differentially expressed cDNAs (Tb113, Tb125, Tb152, Tb169, Tb180 and Tb198) were selected, cloned and sequenced. Sequence similarity searches of the databases using the putative amino acid sequence of our clones gave the following results: Tb152 - Triabin, an antithrombin induced platelet aggregation factor found in salivary gland extracts of T. pallidipennis. Tb169 - Pallidipin, an anticollagen induced platelet aggregation factor also found in T. pallidipennis salivary homogenates. Tb180 - Procalin, the major allergen of T. protracta saliva. The other three salivary-gland specific cDNAs produced no obvious homologies. Comparison of these salivary gland-specific cDNAs of with those of other triatomines combined with functional studies using recombinant proteins will allow a better understanding of the co-evolutionary process occurring between these insects and their vertebrate hosts, and may also lead to the discovery of novel antihaemostatic agents.
Sant'Anna
M R V
MR
Departamento de Parasitologia/ICB, Universidade Federal de Minas Gerais-Caixa Postal 486, 31270-901, Belo Horizonte-MG-Brazil.
Araújo
J G V C
JG
Pereira
M H
MH
Pesquero
J L
JL
Diotaiuti
L
L
Lehane
S M
SM
Lehane
M J
MJ
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012469:Salivary Glands / Q000502:physiology; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014224:Triatoma / Q000235:genetics*
D018076:DNA, Complementary; D019476:Insect Proteins