Mitochondrial DNA sequence variation among triatomine vectors of Chagas disease

Lyman DF, Monteiro FA, Escalante AA, Cordón-Rosales C, Wesson DM, Dujardin JP, Beard CB

    Kissing bugs or triatomines (Reduviidae: Triatominae) are vectors of the Chagas´ disease agent Trypanosoma cruzi. There is a current need for more sensitive tools for use in discrimination of different bug populations and species, thus allowing a better understanding of these insects as it relates to disease transmission and control. In a preliminary analysis of the mitochondrial large subunit ribosomal RNA (mt1surRNA) and cytochrome B (mtCytB) genes, we used DNA sequencing to study species identification and phylogeny. In both examined gene regions, about 46% of nucleotide positions exhibited polymorphism. The examined region of mtCytB appears to have evolved more rapidly than the examined region of mt1surRNA. Phylogenetic analysis of both gene fragments in the examined species produced similar results that were generally consistent with the accepted taxonomy of the subfamily. The two major tribes, Rhodniini and Triatomini, were supported, along with additionally clades that corresponded to accepted species complexes with the Rhodnius and Triatoma genera. The one chief exception was the Psammalostes coreodes sorted into the Rhodnius prolixus-robustus-neglectus cade, with boots rap values of 99% and 81%, respectively, for the mtlsurRNA and mtCytB fragments. All of the individual species examined could be distinguished at both genetic loci.