Publications by authors named "Joao A da Rosa"

We assessed the diversity of triatomines, the rates of natural infection, and the discrete typing units (DTUs) of Trypanosoma cruzi isolated from them in two municipalities in the state of Sergipe, Brazil. Active searches for triatomines were conducted in the peridomicily and wild enviroments of 10 villages within the two municipalities. Triatomines were taxonomically identified and their feces were extracted using the abdominal compression method.

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Morphological studies applied to the taxonomy of the Triatominae cover various structures (head, wing, thorax, genitalia, and eggs). Exochorial structures of hybrid eggs were characterized and compared with the parents, demonstrating that hybrids presented characteristics identical to the exochorial pattern observed in the females of the crosses, which resulted in the hypothesis that the pattern of triatomine eggs is possibly a characteristic inherited from females. Thus, we characterized the exochorium of the eggs of several triatomine hybrids and compared them with the parents, to assess the pattern of segregation and test the hypothesis of maternal inheritance.

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Article Synopsis
  • Hybridization among Triatoma species can affect their evolution and may lead to hybrid sterility, which is caused by gonadal dysgenesis (GD) or unviable gametes, but previous studies had not documented GD in triatomine hybrids.
  • This study performed reciprocal crosses between Triatoma longipennis and Triatoma mopan, and while hybrids were created from one specific cross, further intercrosses and backcrosses yielded no offspring, confirming sterility.
  • The findings revealed that the hybrids exhibited bilateral gonadal dysgenesis, with their male gonads being completely atrophied and devoid of germ cells, leading to the conclusion that GD is responsible for the observed sterility in these hybrids.
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Triatominae are associated with various Brazilian habitats, including bird nests, animal burrows, and peridomestic structures. Despite extensive studies on triatomines in domiciliary environments in Ceará, Brazil, there has been limited research on their presence in the wild. This study focuses on the municipality of Morrinhos in Ceará, which is characterized by a Caatinga biome and riparian forests along the Acaraú River.

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  • * The female genitalia of the hybrids displayed traits from both parent species, and cytogenetic analyses showed normal chromosome structures.
  • * Molecular studies linked the hybrids to both parent species through specific genetic markers, revealing similar feeding and defecation patterns as their parents.
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  • The geniculatus clade includes several species of triatomine bugs, some of which have been studied for their role in transmitting Chagas disease, but no natural hybrids have been previously documented among these species.
  • Experimental crossings between species within the megistus and lignarius groups were performed to assess reproductive compatibility; results showed no egg hatching, indicating prezygotic barriers and confirming specific distinctions among the species.
  • The findings suggest that while hybridization is possible in other triatomine groups, the geniculatus clade displays prezygotic barriers that prevent hybrid formation, suggesting its significance for evolutionary studies in this area.
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  • The Triatoma rubrovaria subcomplex includes several species that can transmit Trypanosoma cruzi, which causes Chagas disease.
  • The study analyzed the morphology, morphometric details, and genetic data of five species to understand their taxonomy and evolutionary relationships.
  • Findings revealed distinct morphological traits among the species, confirmed their monophyletic grouping, and supported the classification of these as important vectors in Southern Brazil.
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Background: Triatoma tibiamaculata is a species distributed in ten Brazilian states which has epidemiological importance as it has already been found infecting household areas. The taxonomy of this triatomine has been quite unstable: it was initially described as Eutriatoma tibiamaculata. Later, the species was transferred from the genus Eutriatoma to Triatoma.

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Background: Among the 18 genera of the Triatominae subfamily, three stand out for their diversity and epidemiological importance: Triatoma, Panstrongylus, and Rhodnius. Rhodnius includes 21 species that can transmit Trypanosoma cruzi (the etiological agent of Chagas disease, also known as American trypanosomiasis) and Trypanosoma rangeli. The Rhodnius prolixus complex comprises seven species, including Rhodnius marabaensis, Rhodnius prolixus, and Rhodnius robustus, which occur in the northern region of Brazil.

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Background: The evolutionary history of biodiversity in South America has been poorly studied in the seasonal dry tropical forest (SDTF). Species diversification in this ecosystem may have a twofold explanation. First, intermittent connections in the middle and late Pleistocene promoted species dispersal and/or genetic connectivity between lineages isolated in disjunct patches of forest.

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The study of geometric morphometry has an impact on Triatominae studies. Currently, several taxonomic and systematic studies use this approach. The Triatominae subfamily comprises three fossil species and 154 extant species potentially capable of transmitting Trypanosoma cruzi, the causative agent of Chagas disease.

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Due to its public health importance, as vectors of Chagas disease, the subfamily Triatominae, has received the attention of taxonomists. Knowing how to correctly identify these insects is of paramount importance for the surveillance and control of these vectors. Over many years, more than 40 triatomine subspecies were proposed.

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Background: Triatoma sordida is one of the main Chagas disease vectors in Brazil. In addition to Brazil, this species has already been reported in Bolivia, Argentina, Paraguay, and Uruguay. It is hypothesized that the insects currently identified as T.

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Triatoma sordida is an endemic Chagas disease vector in South America, distributed in Brazil, Bolivia, Paraguay, and Uruguay. Chromosomal, molecular, isoenzymatic, and cuticular hydrocarbon pattern studies indicate cryptic speciation in T. sordida.

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In Latin America, Chagas disease has been mostly transmitted to humans by contact with the feces or urine of triatomine species infected with the protozoan Trypanosoma cruzi. There are currently 156 species in the subfamily Triatominae, distributed in 18 genera and five tribes. The prolixus group of the genus Rhodnius is composed of 11 species.

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Article Synopsis
  • The taxonomy of the Meccus genus has changed multiple times since its first description in 1835, with recent studies supporting its synonymy with the Triatoma genus based on genetic evidence.
  • Natural hybridization among related species within the T. phyllosoma subcomplex has been confirmed, showing the potential for viable offspring across different species.
  • Experimental crosses between T. longipennis and T. mopan produced viable hybrids, indicating reproductive compatibility and supporting the reevaluation of species classification within the Triatominae subfamily.
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  • There are 156 species in the subfamily Triatominae, all potential vectors for Chagas disease, classified into 18 genera and five tribes, with Triatoma being a paraphyletic group.
  • The Triatoma brasiliensis complex, a monophyletic group, includes eight species, and experimental crosses among these species have been conducted to explore systematic and evolutionary questions.
  • The study found that hybrids displayed varying segregation patterns of phenotypic traits, emphasizing the need for integrative taxonomy to accurately identify Chagas disease vectors amid potential natural hybridization.
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Sodium valproate (VPA) is a classic anticonvulsive, a histone deacetylase inhibitor, and a chromatin remodeling inducer. When injected into specimens of Triatoma infestans, a vector of Chagas disease, VPA affects the chromatin supraorganization of chromocenter heterochromatin in only a few cells of the Malpighian tubules. To test whether this result was explained by the inaccessibility of all of the organ's cells to the drug, we investigated the nuclear phenotypes and global acetylation of lysine 9 in histone H3 (H3K9ac) in Malpighian tubules cultivated in vitro for 1-24 h in the presence of 0.

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Article Synopsis
  • All triatomine species are potential vectors for Chagas disease, but the genera Triatoma, Panstrongylus, and Rhodnius are particularly significant in understanding its epidemiology.
  • Cytogenetic analysis reveals that the species within the Rhodnius genus exhibit minimal chromosomal variation, prompting an examination of their chromatin and chromosome DNA composition.
  • Findings indicate that most Rhodnius species possess euchromatic autosomes without AT- and CG-rich blocks, and intriguing patterns of CG-rich heterochromatin suggest a unique evolutionary trajectory for specific groups within the genus.
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Chagas disease is a potentially life-threatening illness caused by the protozoan Trypanosoma cruzi and transmitted, mainly, by hematophagous insects of the Triatominae subfamily. In Brazil, there are currently about 66 triatomine species distributed throughout the country's 27 states. Triatoma infestans is considered as a species of great vectorial importance, mainly because of its biological characteristics, such as the high degree of anthropophilia, adaptation to the home environment, ability to withstand long periods of fasting, and present a wide geographical distribution.

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The parasite-vector interaction of Chagas disease is still poorly understood and the understanding of this relationship can help in the development of new strategies to control Trypanosoma cruzi transmission, which is the etiological agent of this disease. Considering the need to know if T. cruzi can cause some pathology in the reproductive system of the Chagas disease vectors, we investigated the spermatogenesis of Triatoma infestans infected by T.

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In semi-arid areas of northeastern Brazil, Chagas disease vectors of Triatoma brasiliensis species complex comprise a monophyletic group of kissing bugs that inhabit rock outcrops. Most of them exhibit allopatric or parapatric distribution; the exception is T. petrocchiae, which is found in cohabitation with T.

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