Chromosome analysis of different lineages of Triatoma sordida of Brazil, with emphasis on the phenomenon of cryptic speciation

Abstract

Triatoma sordida is an important vector species in Brazil, because it presents great geographic distribution, and has been captured in thirteen Brazilian states and has been found infected with Trypanosoma cruzi in regions peridomicile and intradomicile.Populations of T. sordida in Bolivia were analyzed by isozymes and the phenomenon of cryptic speciation was described because it was possible to divide two groups of T. sordida with genetic distance that supports distinct species. Specimens from Brazil and Argentina were analyzed cytogenetically and large differences could be observed, as the absence of heterochromatic blocks autosomes in insects from Argentina and presence of constitutive heterochromatin in eight to ten pairs of autosomes the copies of Brazil.Recently, the chromosomes of mutants of T. sordida were analyzed with morphological changes and chromosomal abnormalities during meiosis were also observed. These characteristics led the authors to propose that the phenomenon of cryptic speciation may also be occurring in Brazil. Thus, the present study aims to analyze the cytogenetic characteristics of T. sordida from four different Brazilian states (Bahia, São Paulo, Goiás and Minas Gerais), with emphasis on the phenomenon of cryptic speciation.