Genetic variability and differentiation between populations of Rhodnius prolixus and R. pallescens, vectors of Chagas' Disease in Colombia

López, Germán; Moreno, Jaime

doi:10.1590/s0074-02761995000300009

Cited by 31 publications

(20 citation statements)

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“…3,4 The great morphologic similarities among Rhodnius and definition of their geographic distribution complicate their study, [14][15][16] although biochemical and morphometric techniques are being applied to clarify the distinctions. 17,18 However, it has proved difficult to distinguish the members of prolixus group by isoenzyme analysis. 15,19 Our results support the specific status of R. neglectus and R. nasutus, as well as R. prolixus and R. robustus, which had been cast into doubt by their morphologic and isoenzymatic similarities.…”

Section: Resultsmentioning

confidence: 99%

Identification of morphologically similar Rhodnius species (Hemiptera: Reduviidae: Triatominae) by electrophoresis of salivary heme proteins.

Soares¹,

Sant’Anna²,

Gontijo³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

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Abstract. We examined intraspecific variability in the genus Rhodnius using starch gel electrophoresis of salivary heme proteins. Salivary protein profiles of 8 Rhodnius species (R. prolixus, R. robustus, R. neglectus, R. nasutus, R. ecuadoriensis, R. pallescens, R. pictipes, and R. domesticus) were compared. All species could be distinguished by this technique. The greatest protein polymorphism was found in R. ecuadoriensis, R. nasutus, R. robustus, and R. pictipes, followed by R. prolixus, R. neglectus, R. pallescens, and R. domesticus. This approach was able to distinguish R. prolixus from R. robustus and R. neglectus from R. nasutus, species with extreme phenotypical similarity.The genus Rhodnius Stål currently includes 13 species widely distributed in South and Central America and distinguishable based on morphologic features. Although all species are vectors of Trypanosoma cruzi, the causative agent of Chagas disease (American trypanosomiasis), they differ in their epidemiologic significance. 1,2 Rhodnius prolixus is the most important domestic vector of T. cruzi in Venezuela, Colombia, and parts of Central America, while R. pallescens is an important vector in Panama. The other species are mainly sylvatic in habit. 3 In sylvatic environments, Rhodnius species are most frequently found colonizing palm tree crowns where they feed on a variety of animals. 4 Such adaptation to different hosts may reflect variations in saliva composition, which is related to the feeding process. All species of Rhodnius (and the closely related genus Psammolestes, also within the tribe Rhodniini) have a characteristic red coloration in their salivary glands, which is not found in the salivary glands of other Triatominae. This red coloration is probably due to heme proteins. 5 Some of them, known as nitrophorins, are responsible for many of the antihemostatic activities of Rhodnius saliva such as vasodilation due to the release of nitric oxide, anticoagulant, and antihistamine action. [6][7][8][9] In a previous study, we showed that the electrophoretic profiles of salivary hemeproteins could distinguish R. prolixus from R. robustus, a morphologically similar species. 10 As part of a wider study on the biosystematics of Rhodnius species, we present a study of intraspecific variation of salivary heme proteins in 8 Rhodnius species. MATERIALS AND METHODSInsects. Specimens of Rhodnius were obtained from different regions, as shown in Table 1. Only adults were used in the experiments. We used 15 insects from each species, except for R. prolixus (11 insects) and R. domesticus (10 insects). The insects were reared under the same laboratory conditions (24.0 Ϯ 2.0ЊC; 56.0 Ϯ 6.0% relative humidity) and fed on chickens weekly, except for R. domesticus, which was fed on mice. During gland extraction, all insects had similar nutritional status (7 days of fasting).Sample preparation and electrophoresis. Salivary glands from each insect were dissected out, washed in 0.9% NaCl, and transferred to 5 l of running buffer on a microscope slide in...

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Section: Resultsmentioning

confidence: 99%

Identification of morphologically similar Rhodnius species (Hemiptera: Reduviidae: Triatominae) by electrophoresis of salivary heme proteins.

Soares¹,

Sant’Anna²,

Gontijo³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

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“…prolixus'' populations from Tolima, Colombia. 28 Initially, this sylvatic R. prolixus (formerly referred to as the ''Tolima form'') was thought to represent R. robustus, but it has since been shown to be similar to R. ecuadoriensis and to R. pallescens by both morphometry and isoenzyme analyses. 12,29 The ''Tolima form'' has now been described as a new species, R. colombiensis, 30 distinct from the two aforementioned species.…”

Section: Discussionmentioning

confidence: 99%

Phylogeny and molecular taxonomy of the Rhodniini derived from mitochondrial and nuclear DNA sequences.

Monteiro

Wesson²,

Dotson³

et al. 2000

The American Journal of Tropical Medicine and Hygiene

104

100

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Abstract. Eleven species of Rhodnius and one of Psammolestes were compared by DNA sequence analysis of fragments of the mitochondrial large subunit ribosomal RNA (mtlsurRNA), the mitochondrial cytochrome b (mtCytb), and the D2 variable region of the 28S nuclear RNA (D2), totaling 1,429 base pairs. The inferred phylogeny, using Triatoma infestans as an outgroup, revealed two main clades within the Rhodniini-one, including the prolixus group of species (Rhodnius prolixus, Rhodnius robustus, Rhodnius neglectus, and Rhodnius nasutus) together with Rhodnius domesticus and Rhodnius neivai, and the other comprising two groups formed by Rhodnius pictipes plus Rhodnius brethesi, and Rhodnius ecuadoriensis plus Rhodnius pallescens. Psammolestes tertius appeared most closely related to the prolixus group. The analysis strongly supports the validity of R. robustus as a species distinct from others of the prolixus group, but suggests higher genetic structuring of R. robustus populations compared to the other species. Although R. robustus has been found naturally infected by Trypanosoma cruzi, the fact that it is apparently entirely sylvatic and unable to establish in homes suggests that it is of no great importance as a Chagas disease vector in humans.

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“…[5][6][7][8][9][10][11][12][13][14][15] However, more sensitive tools that are able to distinguish both different populations of bugs as well as morphologically similar species are needed for a better understanding of triatomine population structure and biology. Greater definition of phylogenetic relations, species status, and rates of gene flow could be obtained from DNA sequence analysis of appropriately selected genes.…”

mentioning

confidence: 99%

Mitochondrial DNA sequence variation among triatomine vectors of Chagas' disease.

Lyman

Monteiro²,

Escalante³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

142

109

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Abstract. 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 (mtlsurRNA) 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 mtlsurRNA. 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 additional clades that corresponded to accepted species complexes within the Rhodnius and Triatoma genera. The one chief exception was that Psammolestes coreodes sorted into the Rhodnius prolixus-robustus-neglectus clade, with bootsrap 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.

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Genetic variability and differentiation between populations of Rhodnius prolixus and R. pallescens, vectors of Chagas' Disease in Colombia

Cited by 31 publications

References 0 publications

Identification of morphologically similar Rhodnius species (Hemiptera: Reduviidae: Triatominae) by electrophoresis of salivary heme proteins.

Identification of morphologically similar Rhodnius species (Hemiptera: Reduviidae: Triatominae) by electrophoresis of salivary heme proteins.

Phylogeny and molecular taxonomy of the Rhodniini derived from mitochondrial and nuclear DNA sequences.

Mitochondrial DNA sequence variation among triatomine vectors of Chagas' disease.

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