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Maria Luiza S Mello - One of the best experts on this subject based on the ideXlab platform.
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histone acetylation and methylation marks in chromatin of Panstrongylus megistus hemiptera reduviidae
Acta Histochemica, 2018Co-Authors: Elenice Monte Alvarenga, Vera Lucia Cortico Correa Rodrigues, Carlos Henrique L Imperador, Vanessa Bellini Bardella, Mateus Mondin, Diogo Cavalcanti Cabraldemello, Alberto S Moraes, Maria Luiza S MelloAbstract:Panstrongylus megistus, a potential vector of Chagas disease, currently occupies a wider geographic distribution in Brazil than Triatoma infestans, another member of the hemipteran Reduviidae family and a vector of the same disease. A small heterochromatic body (chromocenter) formed by the Y chromosome is evident in the somatic cells of P. megistus, differing in size and chromosome type contribution from the well-studied chromocenters present in T. infestans. While the overall distribution of histone epigenetic marks differ when comparing the heterochromatin and euchromatin territories in T. infestans, no similar data have been established for other hemipteran reduviids, including P. megistus. In the present work, histone acetylation and methylation marks were investigated in cells of Malpighian tubules of P. megistus 5th instar nymphs using immunocytochemical assays and compared to previously published data for T. infestans. Although similarities between these species were found regarding absence of acetylated H3K9, H4K8 and H4K16, and H3K9me and H3K9me2 in the chromocenter, presence of these marks in euchromatin, and presence of H3K9me3 in the chromocenter, no intimate association of acetylated H4K8 and 18S rDNA was revealed in the chromocenter of P. megistus. The elevated abundance of H3K9me2 marks at the nuclear periphery in P. megistus cells, differing from data for T. infestans, is suggested to reflect differences in the interaction of lamina-associated chromatin domains with the nuclear lamina, methyl-transferase modulation and/or association with the last DNA endoreplication step in 5th instar nymphs, which is a matter for further investigation.
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changes of nuclear phenotypes in Panstrongylus megistus hemiptera reduviidae under different stress conditions
Caryologia, 2006Co-Authors: Garcia, Simone Lopes, Vera Lucia Cortico Correa Rodrigues, Nancy L Garcia, Maria Luiza S MelloAbstract:The effect of fasting and of fasting followed by refeeding and heat shock was studied in Malpighian tu- bules of fourth instar nymphs of the blood-sucking hemipteran, Panstrongylus megistus (Burmeister). The aim was to detect different frequencies of nuclear changes (apoptosis, necrosis, heterochromatin decondensation) under conditions assumed to be stressful in blood-sucking hemipterans. The insects were fasted for up to 90 days at 28 o C and their survival was followed daily. Groups of nymphs were separated each month, with part of the group being refed and the other part kept fasting. Insects in each of these subgroups received either a heat shock at 40 o C for 1 h or were maintained at 28 o C (control for heat shock). The Malpighian tubules were removed one and seven days af- ter each assay and subjected to the Feulgen reaction for identification and counting of the various nuclear pheno- types. Insect survival was high (90%) even after 40 days of starvation but decreased thereafter. Necrosis rather than apoptosis, increased with fasting. Feeding after fasting increased the frequency of apoptosis but not of necrosis. The short heat shock as used here did not additionally affect the responses induced by fasting and refeeding. P. megistus nymphs could withstand relatively long periods of fasting although individual variation in the mean length of cell survival had been found especially after a three-month fasting. The results related to cell necrosis suggest that part of the Malpighian tubule cells may not have developed highly efficient mechanisms for dealing with fasting. For those cells resistant to fasting, feeding subsequent to fasting acted only as a mild stressing agent and heat shock was well tolerated. The ability of P. megistus nymphs to withstand and recover from periods of inadequate or poor nu- trition inclusive in association to a short heat shock as demonstrated here is certainly an important adaptation for the survival of the species.
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experimentally induced heat and cold shock tolerance in adult Panstrongylus megistus burmeister hemiptera reduviidae
Brazilian Journal of Biology, 2003Co-Authors: Simone L Garcia, Nancy L Garcia, Vera Lucia Cortico Correa Rodrigues, L R Oliveira, Maria Luiza S MelloAbstract:The survival rate of domestic male and female adult Panstrongylus megistus was studied after sequential heat and cold shocks in order to investigate shock tolerance compared to that previously reported for nymphs. Sequential shocks were such that a milder shock (0°C, 5°C, 35°C, or 40°C for 1 h) preceded a severe one (0°C or 40°C for 12 h), separated by intervals of 8, 18, 24, and 72 h at 28°C (control temperature). The preliminary thermal shock induced tolerance to the more severe one, although tolerance intensity depended on the initial shock temperature and the interval between treatments. Despite the observed tolerance, the survival rate for insects subjected to both shocks decreased when compared to that of individuals subjected to a single mild shock. When tolerance differed with sex, females showed greater values than males. In contrast to the response detected in nymphs, for which higher heat tolerance values were sustained for intervals of up to 24 h (preliminary shock, 35oC) or even longer (preliminary shock, 40oC) between sequential shocks, significant values were verified in adults only for shock intervals of up to 8 h (preliminary shock, 40oC). While findings for nymphs exhibited considerable cold-shock tolerance under conditions in which preliminary shocks were given at 5oC or 0oC and the periods between shocks were up to 72 h long, the adults were shown to be capable of acquiring a substancial tolerance response to a more severe cold shock only when the preliminary shock was given at 0oC and shock interval surpassed 18 h. It is assumed that the mechanisms involved in the cellular protection of P. megistus under sequential temperature shocks (heat shock protein action?) may loose effectiveness with insect development.
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experimentally induced heat shock tolerance in Panstrongylus megistus hemiptera reduviidae
Journal of Medical Entomology, 2001Co-Authors: Simone L Garcia, Maria Luiza S Mello, Nancy L Garcia, Vera Lucia Cortico Correa RodriguesAbstract:Abstract The survival and molting incidence of fifth-instar nymphs of Panstrongylus megistus (Burmeister, 1835), a vector of Chagas’ disease, were investigated following sequential heat shocks in which a mild shock (35 or 40°C, 1 h) preceded a more drastic one (40°C, 12 h). The shocks were separated by 8-, 18- 24-, or 72-h periods at 28°C. The heat-shock tolerance response was more effective when the first shock was given at 40°C. When the period between shocks was 18 h, the tolerance to sequential shocks (in terms of specimen survival) weakened, which suggested a transient control of the process that enables the organism to circumvent the unfavorable effects of severe shock. In terms of molting incidence, the heat-shock tolerance was only demonstrated when the period between the first shock at 40°C for 1 h and the second shock at 40°C for 12 h was ≥24 h. These results are the first to demonstrate the induction of heat-shock tolerance in a blood-sucking hemipteran.
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effect of sequential cold shocks on survival and molting incidence in Panstrongylus megistus burmeister hemiptera reduviidae
Cryobiology, 2001Co-Authors: Simone L Garcia, Nancy L Garcia, Vera Lucia Cortico Correa Rodrigues, Maria Luiza S MelloAbstract:The survival and molting incidence were studied in the insect, Panstrongylus megistus, following sequential cold shocks in which a milder shock at 0 or 5 degrees C for 1 h preceded a more severe shock (0 degrees C, 12 h). The shocks were separated by intervals of 8, 18, 24, and 72 h at 28 degrees C. The survival rate after sequential shocks was identical to that of unshocked controls. Cold-shock tolerance differed from heat-shock tolerance since the latter varied with the time between shocks and was much more transient. Sequential cold shocks produced a higher molting incidence when the first shock was given at 0 compared to 5 degrees C. This response was more rapid than that to sequential heat shocks. Cold-shock tolerance in P. megistus may involve heat-shock proteins, although other protective mechanisms may also occur concurrently. This is the first report of cold-shock tolerance in a blood-sucking hemipteran.
Simone L Garcia - One of the best experts on this subject based on the ideXlab platform.
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experimentally induced heat and cold shock tolerance in adult Panstrongylus megistus burmeister hemiptera reduviidae
Brazilian Journal of Biology, 2003Co-Authors: Simone L Garcia, Nancy L Garcia, Vera Lucia Cortico Correa Rodrigues, L R Oliveira, Maria Luiza S MelloAbstract:The survival rate of domestic male and female adult Panstrongylus megistus was studied after sequential heat and cold shocks in order to investigate shock tolerance compared to that previously reported for nymphs. Sequential shocks were such that a milder shock (0°C, 5°C, 35°C, or 40°C for 1 h) preceded a severe one (0°C or 40°C for 12 h), separated by intervals of 8, 18, 24, and 72 h at 28°C (control temperature). The preliminary thermal shock induced tolerance to the more severe one, although tolerance intensity depended on the initial shock temperature and the interval between treatments. Despite the observed tolerance, the survival rate for insects subjected to both shocks decreased when compared to that of individuals subjected to a single mild shock. When tolerance differed with sex, females showed greater values than males. In contrast to the response detected in nymphs, for which higher heat tolerance values were sustained for intervals of up to 24 h (preliminary shock, 35oC) or even longer (preliminary shock, 40oC) between sequential shocks, significant values were verified in adults only for shock intervals of up to 8 h (preliminary shock, 40oC). While findings for nymphs exhibited considerable cold-shock tolerance under conditions in which preliminary shocks were given at 5oC or 0oC and the periods between shocks were up to 72 h long, the adults were shown to be capable of acquiring a substancial tolerance response to a more severe cold shock only when the preliminary shock was given at 0oC and shock interval surpassed 18 h. It is assumed that the mechanisms involved in the cellular protection of P. megistus under sequential temperature shocks (heat shock protein action?) may loose effectiveness with insect development.
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experimentally induced heat shock tolerance in Panstrongylus megistus hemiptera reduviidae
Journal of Medical Entomology, 2001Co-Authors: Simone L Garcia, Maria Luiza S Mello, Nancy L Garcia, Vera Lucia Cortico Correa RodriguesAbstract:Abstract The survival and molting incidence of fifth-instar nymphs of Panstrongylus megistus (Burmeister, 1835), a vector of Chagas’ disease, were investigated following sequential heat shocks in which a mild shock (35 or 40°C, 1 h) preceded a more drastic one (40°C, 12 h). The shocks were separated by 8-, 18- 24-, or 72-h periods at 28°C. The heat-shock tolerance response was more effective when the first shock was given at 40°C. When the period between shocks was 18 h, the tolerance to sequential shocks (in terms of specimen survival) weakened, which suggested a transient control of the process that enables the organism to circumvent the unfavorable effects of severe shock. In terms of molting incidence, the heat-shock tolerance was only demonstrated when the period between the first shock at 40°C for 1 h and the second shock at 40°C for 12 h was ≥24 h. These results are the first to demonstrate the induction of heat-shock tolerance in a blood-sucking hemipteran.
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effect of sequential cold shocks on survival and molting incidence in Panstrongylus megistus burmeister hemiptera reduviidae
Cryobiology, 2001Co-Authors: Simone L Garcia, Nancy L Garcia, Vera Lucia Cortico Correa Rodrigues, Maria Luiza S MelloAbstract:The survival and molting incidence were studied in the insect, Panstrongylus megistus, following sequential cold shocks in which a milder shock at 0 or 5 degrees C for 1 h preceded a more severe shock (0 degrees C, 12 h). The shocks were separated by intervals of 8, 18, 24, and 72 h at 28 degrees C. The survival rate after sequential shocks was identical to that of unshocked controls. Cold-shock tolerance differed from heat-shock tolerance since the latter varied with the time between shocks and was much more transient. Sequential cold shocks produced a higher molting incidence when the first shock was given at 0 compared to 5 degrees C. This response was more rapid than that to sequential heat shocks. Cold-shock tolerance in P. megistus may involve heat-shock proteins, although other protective mechanisms may also occur concurrently. This is the first report of cold-shock tolerance in a blood-sucking hemipteran.
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changes in nuclear phenotypes following cold shock in Panstrongylus megistus burmeister
Memorias Do Instituto Oswaldo Cruz, 2000Co-Authors: Simone L Garcia, Maria Luiza S Mello, Nancy L Garcia, Vera Lucia Cortico Correa RodriguesAbstract:The nuclear phenotypes of Malpighian tubule epithelial cells of 5th instar male nymphs of the blood-sucking insect Panstrongylus megistus were studied immediately after a short (1 h) cold shock at 0oC, and 10 and 30 days later. The objective was to compare the responses to a cold shock with those known to occur after hyperthermia in order to provide insight into the cellular effect of cold in this species. Nuclei which usually exhibited a conspicuous Y chromosome chromocenter were the most frequent phenotype in control and treated specimens. Phenotypes in which the heterochromatin was unravelled, or in which there was nuclear fusion or cell death were more abundant in the shocked specimens. Most of the changes detected have also been found in heat-shocked nymphs, except for nuclear fusion which generates giant nuclei and which appeared to be less effective or necessary than that elicited after heat shock. Since other studies showed that a short cold shock does not affect the survival of more than 14% of 5th instar nymphs of P. megistus with domestic habit and can induce tolerance to a prolonged cold shock, heat shock proteins proteins are probably the best candidates for effective protection of the cells and the insects from drastic damage caused by low temperature shocks.
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nuclear phenotype changes after heat shock in Panstrongylus megistus burmeister
Memorias Do Instituto Oswaldo Cruz, 2000Co-Authors: Simone L Garcia, Maria Luiza S Mello, Vera Lucia Cortico Correa Rodrigues, Nancy L GarciaAbstract:The nuclear phenotypes of Malpighian tubule epithelial cells of male nymphs of the blood-sucking insect, Panstrongylus megistus, subjected to short- and long-duration heat shocks at 40oC were analyzed immediately after the shock and 10 and 30 days later. Normal nuclei with a usual heterochromatic body as well as phenotypes indicative of survival (unravelled heterochromatin, giants) and death (apoptosis, necrosis) responses were observed in control and treated specimens. However, all nuclear phenotypes, except the normal ones, were more frequent in shocked specimens. Similarly altered phenotypes have also been reported in Triatoma infestans following heat shock, although at different frequencies. The frequency of the various nuclear phenotypes observed in this study suggests that the forms of cell survival observed were not sufficient or efficient enough to protect all of the Malpighian tubule cells from the deleterious effects of stress. In agreement with studies on P. megistus survival following heat shock, only long-duration shock produced strongly deleterious effects.
Vera Lucia Cortico Correa Rodrigues - One of the best experts on this subject based on the ideXlab platform.
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histone acetylation and methylation marks in chromatin of Panstrongylus megistus hemiptera reduviidae
Acta Histochemica, 2018Co-Authors: Elenice Monte Alvarenga, Vera Lucia Cortico Correa Rodrigues, Carlos Henrique L Imperador, Vanessa Bellini Bardella, Mateus Mondin, Diogo Cavalcanti Cabraldemello, Alberto S Moraes, Maria Luiza S MelloAbstract:Panstrongylus megistus, a potential vector of Chagas disease, currently occupies a wider geographic distribution in Brazil than Triatoma infestans, another member of the hemipteran Reduviidae family and a vector of the same disease. A small heterochromatic body (chromocenter) formed by the Y chromosome is evident in the somatic cells of P. megistus, differing in size and chromosome type contribution from the well-studied chromocenters present in T. infestans. While the overall distribution of histone epigenetic marks differ when comparing the heterochromatin and euchromatin territories in T. infestans, no similar data have been established for other hemipteran reduviids, including P. megistus. In the present work, histone acetylation and methylation marks were investigated in cells of Malpighian tubules of P. megistus 5th instar nymphs using immunocytochemical assays and compared to previously published data for T. infestans. Although similarities between these species were found regarding absence of acetylated H3K9, H4K8 and H4K16, and H3K9me and H3K9me2 in the chromocenter, presence of these marks in euchromatin, and presence of H3K9me3 in the chromocenter, no intimate association of acetylated H4K8 and 18S rDNA was revealed in the chromocenter of P. megistus. The elevated abundance of H3K9me2 marks at the nuclear periphery in P. megistus cells, differing from data for T. infestans, is suggested to reflect differences in the interaction of lamina-associated chromatin domains with the nuclear lamina, methyl-transferase modulation and/or association with the last DNA endoreplication step in 5th instar nymphs, which is a matter for further investigation.
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analise da fonte alimentar de Panstrongylus megistus hemiptera reduviidae triatominae e sua atual importância como vetor do trypanosoma cruzi no estado de minas gerais
Revista Da Sociedade Brasileira De Medicina Tropical, 2010Co-Authors: Marcos Marreiro Villela, Vera Lucia Cortico Correa Rodrigues, Claudio Casanova, Joao Carlos Pinto DiasAbstract:INTRODUCTION: Investigation of the food source of triatomines helps in understanding the biology of these insects, and also helps to infer their importance in transmitting Trypanosoma cruzi to humans. METHODS: The present study aimed to use the precipitin reaction to record the food source of triatomines from 54 municipalities in the central-western region of the State of Minas Gerais, as well as their natural infection by flagellates similar to Trypanosoma cruzi. RESULTS: From July 2003 to March 2007, 416 insects were evaluated, all from the species Panstrongylus megistus. Among all these occurrences, birds (70%) and humans (22.5%) were the major blood sources. Sixteen (3.8%) of the insects were found to be positive for flagellates similar to Trypanosoma cruzi, and eight performed hematophagia on humans. CONCLUSIONS: The results show the need to increase the entomological surveillance in this region, given that the possibility of new cases of Chagas disease occurring through vector transmission was detected.
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changes of nuclear phenotypes in Panstrongylus megistus hemiptera reduviidae under different stress conditions
Caryologia, 2006Co-Authors: Garcia, Simone Lopes, Vera Lucia Cortico Correa Rodrigues, Nancy L Garcia, Maria Luiza S MelloAbstract:The effect of fasting and of fasting followed by refeeding and heat shock was studied in Malpighian tu- bules of fourth instar nymphs of the blood-sucking hemipteran, Panstrongylus megistus (Burmeister). The aim was to detect different frequencies of nuclear changes (apoptosis, necrosis, heterochromatin decondensation) under conditions assumed to be stressful in blood-sucking hemipterans. The insects were fasted for up to 90 days at 28 o C and their survival was followed daily. Groups of nymphs were separated each month, with part of the group being refed and the other part kept fasting. Insects in each of these subgroups received either a heat shock at 40 o C for 1 h or were maintained at 28 o C (control for heat shock). The Malpighian tubules were removed one and seven days af- ter each assay and subjected to the Feulgen reaction for identification and counting of the various nuclear pheno- types. Insect survival was high (90%) even after 40 days of starvation but decreased thereafter. Necrosis rather than apoptosis, increased with fasting. Feeding after fasting increased the frequency of apoptosis but not of necrosis. The short heat shock as used here did not additionally affect the responses induced by fasting and refeeding. P. megistus nymphs could withstand relatively long periods of fasting although individual variation in the mean length of cell survival had been found especially after a three-month fasting. The results related to cell necrosis suggest that part of the Malpighian tubule cells may not have developed highly efficient mechanisms for dealing with fasting. For those cells resistant to fasting, feeding subsequent to fasting acted only as a mild stressing agent and heat shock was well tolerated. The ability of P. megistus nymphs to withstand and recover from periods of inadequate or poor nu- trition inclusive in association to a short heat shock as demonstrated here is certainly an important adaptation for the survival of the species.
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experimentally induced heat and cold shock tolerance in adult Panstrongylus megistus burmeister hemiptera reduviidae
Brazilian Journal of Biology, 2003Co-Authors: Simone L Garcia, Nancy L Garcia, Vera Lucia Cortico Correa Rodrigues, L R Oliveira, Maria Luiza S MelloAbstract:The survival rate of domestic male and female adult Panstrongylus megistus was studied after sequential heat and cold shocks in order to investigate shock tolerance compared to that previously reported for nymphs. Sequential shocks were such that a milder shock (0°C, 5°C, 35°C, or 40°C for 1 h) preceded a severe one (0°C or 40°C for 12 h), separated by intervals of 8, 18, 24, and 72 h at 28°C (control temperature). The preliminary thermal shock induced tolerance to the more severe one, although tolerance intensity depended on the initial shock temperature and the interval between treatments. Despite the observed tolerance, the survival rate for insects subjected to both shocks decreased when compared to that of individuals subjected to a single mild shock. When tolerance differed with sex, females showed greater values than males. In contrast to the response detected in nymphs, for which higher heat tolerance values were sustained for intervals of up to 24 h (preliminary shock, 35oC) or even longer (preliminary shock, 40oC) between sequential shocks, significant values were verified in adults only for shock intervals of up to 8 h (preliminary shock, 40oC). While findings for nymphs exhibited considerable cold-shock tolerance under conditions in which preliminary shocks were given at 5oC or 0oC and the periods between shocks were up to 72 h long, the adults were shown to be capable of acquiring a substancial tolerance response to a more severe cold shock only when the preliminary shock was given at 0oC and shock interval surpassed 18 h. It is assumed that the mechanisms involved in the cellular protection of P. megistus under sequential temperature shocks (heat shock protein action?) may loose effectiveness with insect development.
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experimentally induced heat shock tolerance in Panstrongylus megistus hemiptera reduviidae
Journal of Medical Entomology, 2001Co-Authors: Simone L Garcia, Maria Luiza S Mello, Nancy L Garcia, Vera Lucia Cortico Correa RodriguesAbstract:Abstract The survival and molting incidence of fifth-instar nymphs of Panstrongylus megistus (Burmeister, 1835), a vector of Chagas’ disease, were investigated following sequential heat shocks in which a mild shock (35 or 40°C, 1 h) preceded a more drastic one (40°C, 12 h). The shocks were separated by 8-, 18- 24-, or 72-h periods at 28°C. The heat-shock tolerance response was more effective when the first shock was given at 40°C. When the period between shocks was 18 h, the tolerance to sequential shocks (in terms of specimen survival) weakened, which suggested a transient control of the process that enables the organism to circumvent the unfavorable effects of severe shock. In terms of molting incidence, the heat-shock tolerance was only demonstrated when the period between the first shock at 40°C for 1 h and the second shock at 40°C for 12 h was ≥24 h. These results are the first to demonstrate the induction of heat-shock tolerance in a blood-sucking hemipteran.
Joao Aristeu Da Rosa - One of the best experts on this subject based on the ideXlab platform.
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first report of Panstrongylus megistus hemiptera reduviidae triatominae in the state of acre and rondonia amazon brazil
Acta Tropica, 2018Co-Authors: Jader De Oliveira, Joao Aristeu Da Rosa, Gabriela Vieira De Souza Castro, Mariane Albuquerque Lima Ribeiro Castro, Janis Lunier De Souza, Claudio Rodrigues De Souza, Leandro Jose Ramos, Luis Marcelo Aranha CamargoAbstract:Abstract Introduction This article reports, for the first time, the occurrence of Panstrongylus megistus in the Brazilian Western Amazon. Methods Specimens of P. megistus were collected in the cities of Rio Branco, Acre and Extrema, Rondonia. Results The number of triatomine species in the State of Acre increased from eight to nine and in Rondonia from seven to eight. This was also the first report of P. megistus in the Brazilian Western Amazon. Conclusion The occurrence of P. megistus in the Western Amazon evidences an epidemiological alert, since it is an important vector of T. cruzi.
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homogeneidade cromossomica em diferentes populacoes de Panstrongylus megistus do brasil
Journal of Basic and Applied Pharmaceutical Sciencies, 2015Co-Authors: Kaio Cesar Chaboli Alevi, Joao Aristeu Da Rosa, Giovana Menezes Nunes, Maria Tercilia Vilela De Azeredo OliveiraAbstract:Os triatomineos sao insetos vetores do protozoario Trypanosoma cruzi, agente etiologico da doenca de Chagas. Existem seis especies de maior importância vetorial, a saber, Triatoma infestans, Panstrongylus megistus, T. brasiliensis, T. sordida, T. pseudomaculata e Rhodnius neglectus. P. megistus apresenta grande distribuicao geografica e ja foi coletada em 22 Estados brasileiros. Variacoes cromossomicas intraespecificas ja foram detectadas na subfamilia Triatominae. Assim, o presente trabalho teve como objetivo analisar as caracteristicas cromossomicas de P. megistus provenientes de sete diferentes Estados brasileiros (Rio Grande do Norte, Rio Grande do Sul, Parana, Sao Paulo, Minas Gerais, Bahia e Santa Catarina), por meio de tecnicas citogeneticas classicas. Todos os insetos analisados apresentaram as mesmas caracteristicas cromossomicas: 21 cromossomos, sistema de determinacao do sexo do tipo X1X2Y, tamanho relativo dos autossomos com pequena variacao, tamanho relativo dos cromossomos sexuais (Y>X1>X2), cromocentro na profase meiotica formado apenas pelos cromossomos sexuais e presenca de heterocromatina apenas no cromossomo sexual Y. Sendo assim, o presente trabalho apresenta dados evolutivos sobre as populacoes de P. megistus do Brasil, demonstrando que as populacoes de diferentes Estados brasileiros apresentam homogeneidade cromossomica. Palavras-chave: Citogenetica. Cariotipo. Bandamento C. Subfamilia Triatominae. ABSTRACT The triatomines are insects vectors of the protozoan Trypanosoma cruzi, etiologic agent of Chagas disease. There are six species of greatest importance vector, out more, Triatoma infestans, Panstrongylus megistus, T. brasiliensis, T. sordida, Rhodnius neglectus and T. pseudomaculata. P. megistus presents great geographic distribution and has been collected in 22 Brazilian states. Intraspecific chromosomal variations have been detected in Triatominae. Thus, the present study aimed to analyze the chromosomal characteristics of P. megistus from seven different Brazilian states (Rio Grande do Norte, Rio Grande do Sul, Parana, Sao Paulo, Minas Gerais, Bahia and Santa Catarina) by means of classical cytogenetic techniques. All insects analyzed showed the same chromosomal characteristics: 21 chromosomes, sex determination system the type X1X2Y, relative size of autosomes with little variation, relative size of the sex chromosomes (Y>X1>X2), chromocenter in meiotic prophase formed only by sex chromosomes and the presence of heterochromatin only in sex chromosome Y. Thus, this paper presents evolutionary data on the populations of P. megistus of Brazil demonstrating that populations from different Brazilian states have chromosomal homogeneity. Keywords: Cytogenetics. Karyotype. C-banding. Triatominae subfamily.
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Homogeneidade cromossômica em diferentes populações de Panstrongylus megistus do Brasil
Universidade Estadual Paulista, 2015Co-Authors: Kaio Cesar Chaboli Alevi, Joao Aristeu Da Rosa, Giovana Menezes Nunes, Maria Tercilia Vilela De Azeredo OliveiraAbstract:Os triatomíneos são insetos vetores do protozoário Trypanosoma cruzi, agente etiológico da doença de Chagas. Existem seis espécies de maior importância vetorial, a saber, Triatoma infestans, Panstrongylus megistus, T. brasiliensis, T. sordida, T. pseudomaculata e Rhodnius neglectus. P. megistus apresenta grande distribuição geográfica e já foi coletada em 22 Estados brasileiros. Variações cromossômicas intraespecíficas já foram detectadas na subfamília Triatominae. Assim, o presente trabalho teve como objetivo analisar as características cromossômicas de P. megistus provenientes de sete diferentes Estados brasileiros (Rio Grande do Norte, Rio Grande do Sul, Paraná, São Paulo, Minas Gerais, Bahia e Santa Catarina), por meio de técnicas citogenéticas clássicas. Todos os insetos analisados apresentaram as mesmas características cromossômicas: 21 cromossomos, sistema de determinação do sexo do tipo X1X2Y, tamanho relativo dos autossomos com pequena variação, tamanho relativo dos cromossomos sexuais (Y>X1>X2), cromocentro na prófase meiótica formado apenas pelos cromossomos sexuais e presença de heterocromatina apenas no cromossomo sexual Y. Sendo assim, o presente trabalho apresenta dados evolutivos sobre as populações de P. megistus do Brasil, demonstrando que as populações de diferentes Estados brasileiros apresentam homogeneidade cromossômica.Palavras-chave: Citogenética. Cariótipo. Bandamento C. Subfamília Triatominae. ABSTRACT The triatomines are insects vectors of the protozoan Trypanosoma cruzi, etiologic agent of Chagas disease. There are six species of greatest importance vector, out more, Triatoma infestans, Panstrongylus megistus, T. brasiliensis, T. sordida, Rhodnius neglectus and T. pseudomaculata. P. megistus presents great geographic distribution and has been collected in 22 Brazilian states. Intraspecific chromosomal variations have been detected in Triatominae. Thus, the present study aimed to analyze the chromosomal characteristics of P. megistus from seven different Brazilian states (Rio Grande do Norte, Rio Grande do Sul, Paraná, São Paulo, Minas Gerais, Bahia and Santa Catarina) by means of classical cytogenetic techniques. All insects analyzed showed the same chromosomal characteristics: 21 chromosomes, sex determination system the type X1X2Y, relative size of autosomes with little variation, relative size of the sex chromosomes (Y>X1>X2), chromocenter in meiotic prophase formed only by sex chromosomes and the presence of heterochromatin only in sex chromosome Y. Thus, this paper presents evolutionary data on the populations of P. megistus of Brazil demonstrating that populations from different Brazilian states have chromosomal homogeneity.Keywords: Cytogenetics. Karyotype. C-banding. Triatominae subfamily.
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genetic variability and geographical diversity of the main chagas disease vector Panstrongylus megistus hemiptera triatominae in brazil based on ribosomal dna intergenic sequences
Journal of Medical Entomology, 2014Co-Authors: Francelisse Bridi Cavassin, D R Klisiowicz, Luiz Gustavo Rodrigues Oliveira, Christian Collins Kuehn, Rogerio Luiz Kopp, Vanette Thomazsoccol, Joao Aristeu Da RosaAbstract:ABSTRACT Studies were made on the ribosomal DNA intergenic region, comprising complete internal transcribed spacer (ITS)-1, 5.8S, and ITS-2 sequences, of populations of the triatomine Panstrongylus megistus, the most important vector of Chagas' disease in Brazil since Triatoma infestans eradication. Specimens were from 26 localities of Rio Grande do Sul, Santa Catarina, Parana, Sao Paulo, Minas Gerais, Bahia, and Sergipe states. In total, 21 ITS-1 and 12 ITS-2 haplotypes were found. Nucleotide differences were higher in ITS-1 (3.00%) than in ITS-2 (1.33%). The intergenic region was 1,513–1,522-bp-long (mean 1,516.9 bp), providing 26 combined haplotypes. The combination of microsatellites found in both ITSs may be of applied usefulness, to assess interpopulation specimen exchange and potential recolonizations after vector elimination by control implementation. Network results suggest that Sao Paulo maybe considered one of the spreading centers of this species. Molecular clock datation suggests that P. megi...
Lileia Diotaiuti - One of the best experts on this subject based on the ideXlab platform.
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identification and characterization of microsatellite markers for population genetic studies of Panstrongylus megistus burmeister 1835 triatominae reduviidae
Parasites & Vectors, 2021Co-Authors: Flavio Campos Ferreira, Lileia Diotaiuti, Leilane Oliveira Goncalves, Jeronimo C Ruiz, Leonardo B Koerich, Fabiano Sviatopolkmirsky Pais, Carlota Josefovicz BelisarioAbstract:Panstrongylus megistus is the most important vector of Chagas disease in Brazil. Studies show that the principal factor hindering the control of triatomines is reinfestation of houses previously treated with insecticides. Studies at the microgeographic level are therefore necessary to better understand these events. However, an efficient molecular marker is not yet available for carrying out such analyses in this species. The aim of the present study was to identify and characterize microsatellite loci for future population genetic studies of P. megistus. This study work consisted of five stages: (i) sequencing of genomic DNA; (ii) assembly and selection of contigs containing microsatellites; (iii) validation of amplification and evaluation of polymorphic loci; (iv) standardization of the polymorphic loci; and (v) verification of cross-amplification with other triatomine species. Sequencing of males and females generated 7,908,463 contigs with a total length of 2,043,422,613 bp. A total of 2,043,690 regions with microsatellites in 1,441,091 contigs were obtained, with mononucleotide repeats being the most abundant class. From a panel of 96 loci it was possible to visualize polymorphisms in 64.55% of the loci. Of the 20 loci genotyped, the number of alleles varied from two to nine with an average of 4.9. Cross-amplification with other species of triatomines was observed in 13 of the loci. Due to the high number of alleles encountered, polymorphism and the capacity to amplify from geographically distant populations, the microsatellites described here show promise for utilization in population genetic studies of P. megistus.
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identification and characterization of microsatellite markers for population genetic studies of Panstrongylus megistus burmeister 1835 triatominae reduviidae
Parasites & Vectors, 2021Co-Authors: Flavio Campos Ferreira, Lileia Diotaiuti, Leilane Oliveira Goncalves, Jeronimo C Ruiz, Leonardo B Koerich, Fabiano Sviatopolkmirsky Pais, Carlota Josefovicz BelisarioAbstract:Background Panstrongylus megistus is the most important vector of Chagas disease in Brazil. Studies show that the principal factor hindering the control of triatomines is reinfestation of houses previously treated with insecticides. Studies at the microgeographic level are therefore necessary to better understand these events. However, an efficient molecular marker is not yet available for carrying out such analyses in this species. The aim of the present study was to identify and characterize microsatellite loci for future population genetic studies of P. megistus. Methods This study work consisted of five stages: (i) sequencing of genomic DNA; (ii) assembly and selection of contigs containing microsatellites; (iii) validation of amplification and evaluation of polymorphic loci; (iv) standardization of the polymorphic loci; and (v) verification of cross-amplification with other triatomine species. Results Sequencing of males and females generated 7,908,463 contigs with a total length of 2,043,422,613 bp. A total of 2,043,690 regions with microsatellites in 1,441,091 contigs were obtained, with mononucleotide repeats being the most abundant class. From a panel of 96 loci it was possible to visualize polymorphisms in 64.55% of the loci. Of the 20 loci genotyped, the number of alleles varied from two to nine with an average of 4.9. Cross-amplification with other species of triatomines was observed in 13 of the loci. Conclusions Due to the high number of alleles encountered, polymorphism and the capacity to amplify from geographically distant populations, the microsatellites described here show promise for utilization in population genetic studies of P. megistus.
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occurrence of Panstrongylus megistus burmeister 1835 in an area under entomological surveillance in the southeast region of brazil
Revista Da Sociedade Brasileira De Medicina Tropical, 2021Co-Authors: Joao Victor Leite Dias, Lileia Diotaiuti, Rita De Cassia Moreira De Souza, Janice Maria Borba De Souza, Raquel Aparecida FerreiraAbstract:Introduction Panstrongylus megistus is the main triatomine involved in the human transmission of Trypanosoma cruzi in Minas Gerais, Brazil. We analyzed the occurrence of triatomines in the Itauna micro-regions for healthcare. Methods Data were collected as part of routine entomological surveillance activities, including the species identity, capture site, developmental stage, and trypanosome infection. Results In total, 503 specimens from five species were captured (495 P. megistus). Adults were mainly captured by residents inside their homes, whereas nymphs were mostly captured by public health professionals outside. Conclusions The epidemiologically important triatomine, P. megistus, continues to persist in our study region.
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first report of Panstrongylus megistus sylvatic focus in municipality of bambui state of minas gerais brazil
Memorias Do Instituto Oswaldo Cruz, 2011Co-Authors: Jose Eloy Dos Santos, Lileia Diotaiuti, Joao Carlos Pinto DiasAbstract:In 1943, the Center for the Study and Prophylaxis of Chagas Disease, Oswaldo Cruz Foundation, state of Minas Gerais (MG), was created in the municipality of Bambui to carry out studies related to Chagas disease in the mid-western region of MG. Since that time, several investigations have been conducted to determine the natural habitat of triatomines, but Panstrongylus megistus colonies have never been found in this region. This paper records the first finding of a P. megistus sylvatic colony in 69 years of research. The characteristics of this ecotope and its implications for the epidemiology of Chagas disease are discussed.
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variability of the salivary proteins of 20 brazilian populations of Panstrongylus megistus hemiptera reduviidae triatominae
Acta Tropica, 2004Co-Authors: Silvia Ermelinda Barbosa, Lileia Diotaiuti, Erika Martins Braga, Marcos H PereiraAbstract:Abstract The objective of the present study was to study variability in the salivary proteins of 20 Panstrongylus megistus populations from different ecotopes and verify whether this variability influenced the intensity of the response to specific anti-saliva antibodies. Electrophoretic analysis of P. megistus saliva showed a complex protein composition and great interpopulation variability. A higher concentration of bands was observed in the 17–29 kDa region. The phenogram constructed from the electrophoretic profiles of the P. megistus study populations revealed the existence of two main groups. However, there was no evident relationship between these groups and geographical regions, ecotopes or hosts. Saliva inoculated by P. megistus during feeding elicited production of low level of anti-saliva antibodies in rabbit. The homologous and heterologous salivary proteins were recognised by serum of rabbit sensitised with saliva from only one population. Qualitative and quantitative differences were observed for recognised bands in the saliva of all eight populations studied by Western blot analysis. The most recognised bands were those of greatest molecular weight (68.0–97.4 kDa).
