Parity between kinetoplast DNA and mini-exon gene sequences supports either clonal evolution or speciation in Trypanosoma rangeli strains isolated from Rhodnius colombiensis, R-pallescens and R-prolixus in Colombia

Trypanosoma rangeli are kinetoplastid protozoa which have been largely recognized and defined in several Latin American countries in relation to T. cruzi, because the two trypanosome species are frequently found in mixed infections in triatominae vectors, humans and a variety of wild and domestic mammals. We report the molecular characterization of 18 T. rangeli strains isolated from the salivary glands of naturally infected Rhodnius colombiensis, R. pallescens and R. prolixus by using two independent set of molecular markers. kDNA and mini-exon amplification indicated dimorphism within both DNA sequences: KP1, KP2 and KP3 or KP2 and KP3 products for kDNA mini-circles and 380 or 340 bp products for the mini-exon. One of two associations was observed within individual strains: KP1, KP2 and KP3 kDNA products with the 340 bp mini-exon product and the KP2 and KP3 kDNA products with the 380 bp mini-exon product. Independent mitochondrial and nuclear molecular markers showed a clear division of T. rangeli into two major phylogenetic groups associated with specific vectors in Colombia and in other Latin America countries. These results support either clonal evolution or speciation in T. rangeli populations, probably derived as a secondary adaptation to their parasitic condition in triatomine vectors. (C) 2002 Elsevier Science B. V. All rights reserved.