Estudo citogenético de quatro espécies de Triatominae (Hemiptera:Reduviidade)

• Autor(a) principal: Santos, Silvia Menezes dos
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/886
• topic: Citogenética; Heteroptera; Triatoma vitticeps; Rhodnius pictipes; Rhodnius neglectus; Panstrongylus lutzi; Cytogenetics; Heteroptera; Triatoma vitticeps; Rhodnius pictipes; Rhodnius neglectus; Panstrongylus lutzi; CNPQ::CIENCIAS BIOLOGICAS::MORFOLOGIA::CITOLOGIA E BIOLOGIA CELULAR

The subfamily Triatominae possesses 141 reported species (Juberg et al., 2009; Schofield & Galvão, 2009), where all are capable of transmitting the parasite Trypanosoma cruzi, an etiological agent of Chagas disease. Although not all species present epidemiological importance as transmitters of this pathogen, many are considered secondary or occasional vectors, as occurs in Triatoma vitticeps, Panstrongylus lutzi, Rhodnius pictipes and Rhodnius neglectus. In general the Heteroptera are cytogenetically characterized by possessing holocentric chromosomes where the centromere do not show morphological differences, and are found distributed along the chromosome. As verified in the present study, R. pictipes presented a diploid number of 22 chromosomes, with 20 autosomes and two sex chromosomes denominated XY, which maintain the pattern typical for the tribe Rhodninii. In T. vitticeps the encountered results corroborate with those of literature, where this species presented a diploid number of 24 chromosomes and the observed sex system was X1X2X3Y. Results encountered in this study for C banding agreed with the hypothesis that in the order Heteroptera the chromosomes present small quantities of heterochromatin, and these bands are preferentially encountered at the extremities of these chromosomes. From this study it can be inferred that the greatest level of variation in the meiotic characteristics occurred in Triatoma followed by Panstrongylus, and the smallest variation occurred in Rhodnius which is a quite homogeneous genus in morphological terms and meiotic behavior. These results may corroborate with the theory that Panstrongylus and Triatoma belonging to the tribe Triatomiini, are the closest genera, and on the other hand, divergent of Rhodnius, tribe Rhodniini, according to the performed molecular, enzymatic, morphologic and taxonomic studies, as well as ecological studies within the subfamily Triatominae.