Publications by authors named "Maria Tercilia Vilela Azeredo-Oliveira"

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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  • 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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Several cytogenetic studies have already been performed in Triatominae, such that different karyotypes could be characterized (ranging from 2n = 21 to 25 chromosomes), being the changes in the number of chromosomes related mainly to fusion and fission events. These changes have been associated with reproductive isolation and speciation events in other insect groups. Thus, we evaluated whether different karyotypes could act in the reproductive isolation of triatomines and we analyzed how the events of karyotypic evolution occurred along the diversification of these vectors.

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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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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: 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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  • 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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Chagas disease is the most prevalent neglected tropical disease in the Americas and makes an important contribution to morbidity and mortality rates in countries where it is endemic since 30 to 40% of patients develop cardiac diseases, gastrointestinal disorders, or both. In this paper, a new species of the genus is described based on specimens collected in the Department San Miguel, Province of Corrientes, Argentina. sp.

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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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Chagas disease is caused by the Trypanosoma cruzi and transmitted mainly by triatomines. Triatoma is a paraphyletic group and the species of this genus are grouped into complexes and subcomplexes. Morphological data and geographical distribution grouped initially T.

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The Triatoma genus is paraphyletic, and its species are grouped into complexes and subcomplexes. Given the fact that species that make up a given subcomplex generally share chromosomal traits, we analyzed the distribution of AT- and CG-rich DNA of the T. brasiliensis species subcomplex, in order to establish affinities among members of the T.

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Triatomines are vectors of , the etiologic agent of Chagas disease. Although the evolutionary process in triatomine is considered as disruptive, cryptic speciation and homoploid hybridization also are possible modes of speciation. Several analyses suggested as a product of hybridization between and .

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The use of subtle features as species diagnostic traits in taxa with high morphological similarity sometimes fails in discriminating intraspecific variation from interspecific differences, leading to an incorrect species delimitation. A clear assessment of species boundaries is particularly relevant in disease vector organisms in order to understand epidemiological and evolutionary processes that affect transmission capacity. Here, we assess the validity of the recently described Rhodnius taquarussuensis (da Rosa et al.

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Chagas disease is a public health problem caused by the protozoan that affects about 8 million people worldwide. The main form of transmission of is vectorial, through triatomines feces contaminated with the parasite. All species are considered as potential vectors of .

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is a Chagas disease vector that was found infected with in homes. As this species is endemic from Brazil (Bahia, Espírito Santo, Minas Gerais, and Rio de Janeiro) and no study comparing the specimens from different Brazilian states was conducted, we analyzed the genetic distance (16S rDNA, Cyt b, and COI mitochondrial genes) and the chromosomal characteristics for from Minas Gerais, Rio de Janeiro, and Espírito Santo. All specimens showed the same cytogenetic characteristics.

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As Chagas disease has no cure, vector control is the most effective method of preventing this neglected disease. Generally the anatomical teratologies are associated with hormonal dysfunction of the corpus allatum (juvenile hormone), presents genetic basis or unfavorable conditions, and are recessive and not sex linked. Thus, we characterize the male gonads and spermatogenesis of triatomines with anatomical teratologies to evaluate if the malformations interfere in the gametogenesis of these vectors.

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The Triatominae subfamily is composed of 153 hematophagous species that are potential vectors of , the etiological agent of Chagas disease. Karyotypic studies in triatomines were initiated in 1909. There are 92 karyotypes described, all grouped into the tribes Rhodniini and Triatomini.

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Background: Triatomines have been grouped into complexes and subcomplexes based largely on morphological and geographical distribution. Although these groupings are not formally recognised as taxonomic ranks, they are likely monophyletic. However, recent studies have demonstrated that some subcomplexes from South America did not form monophyletic groups, and reorganisations have been suggested.

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All species of triatomines are considered potential vectors of Chagas disease and the reproductive biology of these bugs has been studied by different approaches. In 1999, nucleolar persistence during meiosis was observed in the subfamily for the first time. Recently, it has been observed that all species within the genus Rhodnius exhibit the same phenomenon, suggesting that it may be a synapomorphy of the triatomines.

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The triatomines are vectors of the protozoan Trypanosoma cruzi, etiologic agent of Chagas disease. These insects are sexually active after the imaginal molt. Some aspects have been studied in Triatoma brasiliensis during the imaginal molt, such as autogeny in virgin females and the relationship between blood ingestion by fifth instar nymph and the realization of the imaginal molt.

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Since 1966 the triatomines were grouped in complexes and specific subcomplexes. Although the complex and subcomplexes not have taxonomic importance, should be monophyletic groups and cytogenetic tools have proved to be of great importance to characterize these species groupings. Based on this, this paper aims to describe the chromosomal characteristics and heterochromatic pattern of Matogrossensis and Rubrovaria subcomplexes, in order to contribute to the taxonomic and evolutionary relationships of these vectors.

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The reproductive capacity between Triatoma lenti and Triatoma sherlocki was observed in order to verify the fertility and viability of the offspring. Cytogenetic, morphological and morphometric approaches were used to analyze the differences that were inherited. Experimental crosses were performed in both directions.

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