Genetic variability ofTriatoma rubrovaria(Reduviidae: Triatominae) from Brazil, Argentina and Uruguay as revealed by two different molecular markers

Abstract

Summary :Randomly amplified polymorphic DNA (RAPD) and nuclear ribosomal DNA sequence analyses were used to assess the genetic population structure of the South American triatomine species Triatoma rubrovaria throughout its geographical distribution. To investigate the genetic variability at both intraspecific and intrapopulational levels the RAPD profiles and the nucleotide sequences of the rDNA intergenic spacers, ITS-1 and ITS-2, were analysed and compared. The phenetic analysis based on RAPD profiles show three distinct clusters diverging by similarity coefficients ranging from 0.62 to 0.96. The ITS-1 and ITS-2 sequence variability detected may be considered very high, suggesting reproductive isolation between populations. A total of seven composite haplotypes (CH) were found, among which three are specific for Brazil, other three for Uruguay, and the last one common for the three countries studied. The population studied in Argentina does not represent an independent CH. Sequence analyses proved that the five populations studied are easily differentiable and that there is heterogeneity within each one. True mutations and indels are the responsible of sequence differences between haplotypes and populations, suggesting that divergence processes may presently go on within this species. The large intraspecific variability detected may underlie the known plasticity of T. rubrovaria, making it a potential intradomiciliary invader and consequently an appropriate vector for Chagas disease transmission. Therefore, this triatomine species must be continuously monitored throughout. Résumé

Rural Triatoma rubrovaria from Southern Brazil Harbors Trypanosoma cruzi of Lineage IIc

“…24 Recently, the potential adaptation of this bug to new environments was suggested by its genomic plasticity shown by the high intraspecific genetic variability detected in populations of T. rubrovaria from Brazil, Uruguay, and Argentina through molecular markers. 58 In our previous study, precipitin assays performed on the collected bugs showed one specimen of T. rubrovaria positive to human antiserum in Branquillos, a settlement closer to the urban perimeter of Quaraí. 29 This study on the genetic and biological characterization of T. cruzi isolates obtained from T. rubrovaria showed its pathogenicity and virulence in experimental animals.…”

Phylogeography and Genetic Variation of Triatoma dimidiata, the Main Chagas Disease Vector in Central America, and Its Position within the Genus Triatoma

“…The very scarce ITS-2 sequence differences between T. arthurneivai and T. rubrovaria , a species known in southern Brazil, Uruguay and northern Argentina [75], pose doubts on whether to keep the validity of T. arthurneivai as independent species. Recent genetic and morphometric studies have already raised several questions about T. arthurneivai , indicating that topotypes from Minas Geraes may represent a species different from populations of São Paulo State formerly also referred to T. arthurneivai and suggesting that these São Paulo populations might probably belong to T. wygodzinskyi [76].…”

Vetores da doença de Chagas no Brasil

“…Os espaçadores ribossomais internos ITS-1 e ITS-2, localizados entre as regiões 18S e 28S, também são bons marcadores para esses tipos de estudo, tendo sido utilizado para filogenia de espécies do gênero Panstrongylus (Marcilla et al 2002), taxonomia alfa e filogenia dos complexos T. phyllosoma (Martínez et al 2006) e T. dimidiata s.l. presentes no México (Tamay-Segovia et al 2008, Herrera-Aguilar et al 2009) e genética de populações de T. rubrovaria na Argentina, Brasil e Uruguai (Pacheco et al 2007).…”