Phenetic analysis of Panstrongylus megistus Burmeister, 1835 (Hemiptera: Reduviidae: Triatominae) in the State of Paraná-Brazil

Abstract

Panstrongylus megistus is an important Chagas Disease vector and is said to be one of the species that might replace Triatoma infestans as the main vector of that disease in Brazil. The different degrees of P. megistus domiciliation in Brazil and its epidemiological relevance draw forth the need for the development of genetic studies that make it possible to analyze and understand the interchange of individual and gene fluxes among different populations. Thus, the present work aimed at studying the genetic variability of P. megistus in the State of Paraná - south of Brazil- and at comparing it with populations of the same species from five other states in Brazil (SP, MG, SC, RS, SE). In order to attain the proposed objective, 25 populations were studied using fifteen isoenzymatic systems (6PGD, G6PD, ME¹, ME², ICD, PGM, GPI, GOT¹, GOT², NP¹, NP², DIA, MPI, F, and MDH). The phenetic analysis allowed the individuation of 22 electromorphs and five zymodemes. The G6PD enzyme was the only polymorphic one presenting four electromorphs for the studied populations, all of them described for the State of Paraná-BR. The P. megistus populations from other states grouped with those from Paraná-BR, evidencing a low genetic variability in that species. Despite the existing geographic barriers, sub-samples - away from one another by at most 570km - were grouped in one and the same zymodeme. The epidemiological implications of such results are discussed in the present work.