Genes encoding defensins of important Chagas disease vectors used for phylogenetic studies.
Insects possess both cellular and humoral immune responses. The latter makes them capable to recognize and control invading pathogens after synthesis of a variety of small proteins, also known as antimicrobial peptides. Defensins, cysteine-rich cationic peptides with major activity against Gram-positive bacteria, are one ubiquitous class of antimicrobial peptides, widely distributed in different animal and plant taxa. Regarding triatomines in each of the so far analyzed species, various defensin gene isoforms have been identified. In the present study, these genes were sequenced and used as a molecular marker for phylogenetic analysis. Considering the vectors of Chagas disease the authors are reporting for the first time the presence of these genes in Triatoma sordida (Stål, 1859), Rhodnius nasutus (Stål, 1859), and Panstrongylus megistus (Burmeister, 1835). Members of the Triatoma brasiliensis species complex were included into the study to verify the genetic variability within these taxa. Mainly in their mature peptide, the deduced defensin amino acid sequences were highly conserved. In the dendrogram based on defensin encoding nucleotide, sequences the Triatoma Def3/4 genes were separated from the rest. In the dendrogram based on deduced amino acid sequences the Triatoma Def2/3/4 together with Rhodnius DefA/B pre-propeptides were separated from the rest. In the sub-branches of both the DNA and amino acid dendrograms, the genus Triatoma was separated from the genus Rhodnius as well as from P. megistus.
Laboratório de Biodiversidade Entomológica, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, Brazil.|Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz - FIOCRUZ, Av. Brasil 4365, 21045-900, Rio de Janeiro, Brazil.
Catarina Andréa Chaves
CA
de Araújo
Laboratório de Biodiversidade Entomológica, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, Brazil.
Ana Carolina Bastos
AC
Lima
Laboratório de Biologia de Tripanosomatídeos, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, Brazil.
Ana Maria
AM
Jansen
Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz - FIOCRUZ, Av. Brasil 4365, 21045-900, Rio de Janeiro, Brazil.
Cleber
C
Galvão
Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz - FIOCRUZ, Av. Brasil 4365, 21045-900, Rio de Janeiro, Brazil.
José
J
Jurberg
Laboratório de Biodiversidade Entomológica, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, Brazil.
Jane
J
Costa
Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, Brazil.
Patricia
P
Azambuja
Laboratório de Bioquímica e Fisiologia de Insetos, Instituto Oswaldo Cruz - FIOCRUZ, Rio de Janeiro, Brazil. peter.waniek@cityweb.de.
Peter Josef
PJ
Waniek
D000595:Amino Acid Sequence; D000818:Animals; D014355:Chagas Disease / Q000635:transmission*; D023082:Defensins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007303:Insect Vectors / Q000145:classification / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D010203:Panstrongylus / Q000145:classification / Q000235:genetics* / Q000502:physiology; D010802:Phylogeny; D012239:Rhodnius / Q000145:classification / Q000235:genetics* / Q000502:physiology; D016415:Sequence Alignment; D014224:Triatoma / Q000145:classification / Q000235:genetics* / Q000502:physiology
D023082:Defensins; D019476:Insect Proteins
Antimicrobial peptides; Chagas disease; Defensin; Phylogenetic analysis; Triatominae