Mitochondrial PCR-RFLP Assay to DistinguishTriatoma brasiliensis macromelasomafromTriatoma brasiliensis brasiliensisSubspecies (Hemiptera: Reduviidae)

Abstract

Triatoma brasiliensis sensu lato (s.l.), the main vector of Chagas disease in northeastern Brazil, is a species complex comprising four species, one with two subspecies (T. brasiliensis brasiliensis, T. brasiliensis macromelasoma, T. juazeirensis, T. sherlocki, and T. melanica), and each taxon displaying distinct ecological requirements. In order to evaluate the genetic relationships among nine T. brasiliensis s.l. populations from northeastern Brazil, we analyzed their mitochondrial cytochrome c oxidase subunit 1 sequences and suggested a PCR-RFLP assay to distinguish between T. b. macromelasoma and T. b. brasiliensis subspecies. All the specimens were morphologically identified as T. b. brasiliensis. The resulting phylogenies identified two major clades that are congruent with the geographical populations studied. Based on collection sites and in accordance with type-location, one clade was identified as the subspecies T. b. macromelasoma. The second clade grouped T. b. brasiliensis populations. Restriction endonuclease sites were observed in the sequences and used in PCR-RFLP assays, producing distinct fingerprints for T. b. macromelasoma and T. b. brasiliensis populations. The results suggest that these are different species and that gene flow occurs only among T. b. brasiliensis populations, possibly associated with human activity in the area.

Does Triatoma brasiliensis occupy the same environmental niche space as Triatoma melanica?

“…The authors mention that to be considered appropriate to identify species, intraspecific distances must always be lower than interspecific ones. Unlike the findings of Justi et al , the results of this study show that the CO1 barcode region is a robust marker for differentiating this species complex, and it may constitute a valuable tool for both epidemiologic studies and for Chagas disease control, including subspecies differentiation, as observed by Vendrami et al [ 49 ]. Furthermore, this methodology can be especially useful for identifying immature stages, whose traditional taxonomic method is made impossible in smaller nymphs, especially considering the species complexes that exhibit wide morphological and chromatic variation.…”

Checklist and phenetics studies of nymphs of two species of triatomines: Triatoma lenti Sherlock & Serafim, 1967 and Triatoma sherlocki Papa, Jurberg, Carcavallo, Cerqueira, Barata, 2002 (Hemiptera: Reduviidae: Triatominae)

“…However, the literature on immature forms of certain groups is scarce, difficult to use, or nonexistent 79 . Epidemiological studies and control measures require precise taxonomic determination of T. brasiliensis subcomplex 80 , 86 , 89 . Therefore, this study provides morphological and morphometric data on the nymphal instars of T. lenti and T. sherlocki , corroborating the specific taxonomy of these species.…”

Review of Kissing Bugs (Hemiptera: Reduviidae: Triatominae) from China with Descriptions of Two New Species

“…To calculate the genetic distances of this region between species, the Kimura two-parameter (K2P) model is frequently employed as a nucleotide substitution model [ 14 , 15 , 16 ]. Such methods have already been applied to distinguish Triatominae and may contribute significantly to our understanding of their biodiversity [ 17 , 18 ].…”