Chromatoid body: Remnants of nucleolar proteins during spermatogenesis in triatomine (Heteroptera, Triatominae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Study of the nucleolar cycle and ribosomal RNA distribution during meiosis in triatomines (Triatominae, Heteroptera)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of the external female genitalia of six species of Triatominae (Hemiptera: Reduviidade) by scanning electron microscopy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differential characterization of holocentric chromosomes in triatomines (Heteroptera, Triatominae) using different staining techniques and fluorescent in situ hybridization

A comparative study of holocentric chromosomes in the triatomine species Panstrongylus megistus, Rhodnius pallescens and Triatoma infestans was carried out in order to characterize heterochromatin, rDNA active sites and nucleolar proteins. Cytological preparations of seminiferous tubules were stained by silver impregnation, C banding, fluorochromes CMA 3/DA and DAPI/DA, and fluorescent in situ hybridization (FISH) with Drosophila melanogaster 28S rDNA probe. Our results showed interesting aspects of the organization of chromatin and chromosomes in the meiotic cells of these insects. In R. pallescens, sex chromosomes (X, Y) were distinct from autosomes, when submitted to silver impregnation, C banding, CMA 3 staining, and FISH, confirming that these chromosomes bear nucleolar organizer regions (NORs). In P. megistus, two of the three sex chromosomes were CMA 3/DAPI-; at early meiotic prophase and at diakinesis, silver impregnation corresponded with FISH signals, indicating that in this species, two chromosomes (probably a sex chromosome and an autosome) bear NORs. In T. infestans, silver nitrate and FISH also stained corresponding areas on meiotic chromosomes. Our data suggest that in triatomines, in general, the number and location of NORs are species-specific. These regions may be considered important chromosome markers for comparative studies to improve the understanding of evolutionary mechanisms in these hematophagous insects. ©FUNPEC-RP.

Chagas disease and triatomine biology (Heteroptera, Triatominae), with emphasis on aspects of spermatogenesis

A century after the discovery of Chagas disease, it is still one of the most important parasitic diseases affecting humans. The subfamily Triatominae is important in medical health, because these insects are vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease. These insects are also of important cytological relevance because they have particular cell characteristics, such as persistence of nucleolar material in spermatogenesis. The germ cells of the animal kingdom have chromatoid bodies (CBs) in their cytoplasm that can originate from nucleolar material that is fragmented in the early stages of spermatogenesis and plays an important role in cellular communication between the spermatids during spermiogenesis. Currently, there are few studies on the function and formation of the CB in nucleologenesis, especially with emphasis on the ultrastructure of the cells involved in spermatogenesis of insects. Considering the importance of knowledge about the triatomine fauna, we conducted a study of the biogeography and reports of these insects and a survey of patients with Chagas disease in the northwestern region of São Paulo State. Data collected from 1995 to 2009 indicated 700 individuals with Chagas disease, demonstrating a range of 0 to 40 years, which shows that the disease may be active in this region. Moreover, of the 1150 patients treated for cardiomyopathy, 44% were chagasic. Regarding the triatomines noted and captured in the period from 2004 to 2009, the species were Triatoma sordida and Rhodnius neglectus, with T. sordida being the most abundant. In addition, some triatomines were infected by T. cruzi in various developmental stages. We also analyzed the nucleolar cycle and fibrillarin nucleolar protein expression in CB of spermatogenic cells of T. infestans and T. sordida, using histological, ultrastructural and immunocytochemical techniques. The results revealed fibrillarin nucleolar protein expression in the nucleus and in some cytoplasmic spots of germ cells during spermatogenesis in triatomines. These data suggest that fibrillarin could be a constituent of CB, which was most likely derived from nucleolar fragmentation. This is the first time that fibrillarin protein expression has been shown in CB during spermatogenesis progression in triatomines. Knowledge about the biology of triatomines was deepened in this study and, in particular, the structural and ultrastructural aspects of spermatogenesis in triatomines. This study showed that the disease may be active in the northwestern region of São Paulo and expanded our knowledge of the biology of triatomines, the main vectors of Chagas disease. © FUNPEC-RP.

Análise citogenética molecular em túbulos seminíferos de triatomíneos (Triatominae, Heteroptera)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Doença de chagas e biologia de triatomíneos (Heteroptera, Triatominae), com ênfase aos aspectos da espermatogênese

Pós-graduação em Genética - IBILCE

Isolamento e caracterização de cepas de Trypanosoma cruzi Chagas,1909 (Kinetoplastida, Trypanosomatidae) a partir de triatomíneos silvestres do Estado do Rio Grande do Sul

Pós-graduação em Biociências e Biotecnologia Aplicadas à Farmácia - FCFAR

Genetic Variability and Geographical Diversity of the Main Chagas' Disease Vector Panstrongylus megistus (Hemiptera: Triatominae) in Brazil Based on Ribosomal DNA Intergenic Sequences

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comportamento e organização dos cromossomos holocêntricos de heterópteros da região Sul do Brasil baseados em sequências repetitivas DNA, meiose e análise ultraestrutural

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A study of the scutellum in eight Chagas disease vector species from genus Triatoma (Hemiptera, Reduviidae) using optical and scanning electron microscopy

The aim of this study was to analyze the external morphology of the scutellum through optical microscopy and scanning electron microscopy (SEM) in male specimens of Triatoma costalimai, T. delpontei, T. eratyrusiformis, T. matogrossensis, T. infestans melanosoma, T. sherlocki, T. tibiamaculata, and T. vandae. A total of 30 photographs of the scutellum were made. Magnification varied from 50X to 750X. Regarding depth and forms of the central depression, the heart-shaped form was predominant, with some exceptions, so that this shape appears to be a common characteristic for species of genus Triatoma Laporte, 1832. In T. eratyrusiformis, a kind of sensillum with important taxonomic value was observed. The different sizes and shapes of the designs found on the posterior process of the scutellum were also of important taxonomic interest. The study of the scutellum based on SEM showed valuable characteristics, allowing the use of this structure to aid the diagnosis of triatomine species. Thus, more specimens in subsequent studies and analyses of morphometric parameters should contribute to agreement on phylogenetic aspects in this genus. A Key to eight species of Triatoma based on male scutellar morphology is presented.

Análise da relação filogenética entre Triatoma carcavalloi Jurberg, Rocha; Lent, 1998; Triatoma circummaculata Stal, 1859; Triatoma klugi Carcavallo, Jurberg, Lent; Galvão, 2001 e Triatoma rubrovaria Blanchard, 1843 (Hemiptera, Reduviidae) baseada no sequenciamento de genes do DNA mitocondrial e nuclear

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Phylogeny of Triatoma sherlocki (Hemiptera: Reduviidae: Triatominae) Inferred from Two Mitochondrial Genes Suggests Its Location Within the Triatoma brasiliensis Complex

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Description of eggs and nymphal instars of Triatoma baratai Carcavallo & Jurberg, 2000 based on optical and scanning electron microscopy (Hemiptera: Reduviidae: Triatominae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dispersion capacity of Triatoma sherlocki, Triatoma juazeirensis and laboratory-bred hybrids

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)