Publications by authors named "Maria Tercilia Vilela de 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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Chagas disease affects about eight million people. In view of the issues related to the influence of anthropogenic changes in the dynamics of the distribution and reproductive interaction of triatomines, we performed experimental crosses between species of the Rhodniini tribe in order to evaluate interspecific reproductive interactions and hybrid production capacity. Reciprocal crossing experiments were conducted among , , , , ; × and × .

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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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  • The study demonstrated that despite morphological similarities, distinct genetic and reproductive barriers exist between the species, confirming their separate identities.
  • Experimental crossbreeding between these species showed no hybridization, indicating prezygotic reproductive isolation.
  • The findings suggest that one species is the most evolved member of the complex, rather than just a chromatic variant of another.
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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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Triatomines are hematophagous insects of great epidemiological importance, since they are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma brasiliensis complex is a monophyletic group formed by two subspecies and six species: T. b.

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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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  • 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 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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  • Triatoma sordida is a prevalent species in Brazil's peridomestic environments, known for its adaptability to various habitats and food sources.
  • This species has a tendency to invade homes and create multiple colonies, making it a priority for pest control efforts in Brazil.
  • Genetic analysis shows that all Brazilian populations have low genetic variability but high haplotypic diversity, which is crucial for understanding their biology and guiding effective vector control strategies.
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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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Chagas disease is a public health problem caused by the , and the I (TcI) and II (TcII) groups are considered important genotypes from the clinical point of view. Currently, the groups need to be molecularly analyzed for their identification; thus, we cytogenetically analyzed these groups with the objective of developing more accessible techniques for the characterization of these parasites. TcI and TcII groups were differentiated by nucleus characterization with lacto-acetic orcein (TcI-nucleus with positive heteropycnosis and TcII-nucleus with negative heteropycnosis), emphasizing the importance of the application of this technique for epidemiological and clinical studies of Chagas disease.

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The subfamily Triatominae currently consists of 154 species, most of them being of great importance for public health because they are considered potential vectors of the protozoan , the etiologic agent of Chagas disease. In addition to their epidemiological importance, these insects are considered important biological models for cell studies because they have peculiar characteristics in their cells, for example, persistence of the nucleolus during spermatogenesis. This phenomenon is characterized by the presence of the nucleolus or nucleolar corpuscles during all phases of meiosis.

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Chagas disease is caused by the protozoan . This disease is distributed in 21 Latin American countries, where it is mostly vector-borne. In Brazil, there are 68 triatomine species.

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  • The study focuses on a key Brazilian species known to transmit Chagas disease, highlighting its low genetic diversity and strong population structuring across regions.
  • Genetic analyses were conducted using cytogenetic markers on specimens from seven Brazilian states, revealing uniform chromosomal characteristics.
  • The findings indicate that the Brazilian populations likely descended from a small ancestral group and suggest that these vectors do not exhibit cryptic speciation, confirming their classification as a specific type.
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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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The genus within the subfamily Triatominae and tribe Rhodniini comprises the species , , and , all potential vectors of Chagas disease. A feature of is their close association with birds, which makes them an interesting model for evolutionary studies. We analyzed cytogenetically spp.

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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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