A influência dos ciclos de temperatura na sincronização do relógio circadiano e amplitude de atividade do mosquito Aedes aegypti

Made available in DSpace on 2016-03-01T13:50:54Z (GMT). No. of bitstreams: 2 rayane_freitas_ioc_mest_2015.pdf: 2814197 bytes, checksum: 266f348b6b9d4af76ccdbcb2de423f6a (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2016-02-23Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, BrasilMosquitos apresentam ritmos de atividade locomotora e alimentação sanguínea, que são cruciais para a transmissão de diversos patógenos e estão sob o controle de um relógio circadiano endógeno. Estímulos externos exercem uma importante modulação neste relógio, possibilitando o ajuste das funções endógenas com o ambiente. Um dos principais indicadores ambientais capaz de sincronizar o relógio circadiano são os ciclos de temperatura. Em laboratório, pesquisas no modelo Drosophila melanogaster vêm mostrando que ciclos de temperatura retangulares (com mudanças abruptas de temperatura) produzem um perfil de atividade diferente de ciclos com variações de temperatura graduais mais próximas ao natural. Assim, procuramos estabelecer um regime seminatural que fosse o mais próximo possível das variações diárias de temperatura ao longo de um dia no Rio de Janeiro. Escolhemos como modelo o mosquito Aedes aegypti, o principal vetor da dengue no Brasil. Essa espécie é conhecida por apresentar hábitos diurnos com picos de atividade durante o amanhecer e o crepúsculo. Os ciclos de temperatura graduais que produzimos foram capazes de sincronizar a atividade de Ae. aegypti, porém com um perfil diferente do que era observado em ciclos de temperatura retangulares. Na presença dos ciclos de claro/escuro, os ciclos temperatura graduais foram determinantes para amplitude dos picos de atividade e fase do pico principal (pico vespertino) As alterações nos padrões de comportamento parecem refletir alterações moleculares na expressão de genes que compõem o relógio circadiano. Possivelmente os genes da primeira alça (per, tim e cry2) seriam importante para a amplitude, enquanto genes da segunda alça (vri, Pdp1 e cyc) participariam do ajuste de fase do pico principal. Nossos resultados sugerem ainda que os ciclos de temperatura sincronizem o relógio através dos órgãos cordotonais. Mosquitos silenciados pela técnica de RNA de interferência para um gene importante no funcionamento dessas estruturas (nocte) apresentaram prejuízos na sincronização de sua atividade pelos ciclos de temperatura. Assim, concluímos que os ciclos de temperatura graduais que construímos são eficientes para a sincronização de Ae. aegypti e possivelmente poderão contribuir nos estudos de comportamento, permitindo em laboratório uma abordagem mais próxima ao natural. A utilização dos ciclos de temperatura graduais confirma a atuação desse indicador ambiental em sinergia com os ciclos de claro/escuro na promoção da completa sincronização dos ritmos de atividade e expressão circadiana dos organismosMosquitoes present locomotor activity and blood feeding rhythms, which are crucial for the transmission of many pathogens and are under the control of an endogenous circadian clock. External stimuli play an important modulation in this clock, enabling adjustment of the endogenous fun ctions with the environment. One of the main environmental indicators able to synchronize the circadian clock are temperature cycles. In laboratory, research in Drosophila melanogaster model ha s shown that rectangular temperature cycles (with abrupt temper ature changes) produce a locomotor activity pattern different from cycles with gradual temperature variations, which are closer to those organism in nature . Thus we tried to establish a semi - natural system that was as close as possible to the daily tempera ture variations observed along one day in Rio de Janeiro. We choose as model the mosquito Aedes aegypti , the main dengue vector in Brazil. This species is known to have diurnal activity with peaks at dawn and dusk. The gradual temperature cycles we produce d were able to synchronize the activity of Ae. aegypti , but with a different profile from the one observed for rectangular temperature cycles. In the presence of light / dark cycles, the gradual temperature cycles were determinat in the amplitude of the pe aks of activity and in the phase of the main peak (evening peak). Changes in the behavior patterns seem to reflect molecular alterations in the expression of the circadian clock genes. Possibly, genes from the first regulatory loop ( per , tim and cry2 ) woul d be important for the amplitude, while the genes from the second regulatory loop ( vri , Pdp1 and cyc ) would participate in the phase adjustment of the main peak. Our results also suggest that temperature cycles synchronize the clock through chordotonal org ans. Mosquitoes silenced by RNA interference assay for a n important gene in the functioning of these structures ( nocte ) presented loss in the synchronization of their activity temperature cycles. Thus, we conclude that the gradual temperature cycles we produced are effective for synchronizing Ae. aegypti and may possibly contribute to studies of behavior, allowing a more natural app roach in the laboratory. The use of gradual temperature cycles confirms the importance of this environmental indicator in synergy with the cycles of light / dark to promote full synchronization of the organisms circadian expression and activity rhythm

USO DE Drosophila melanogaster COMO MODELO PARA O ESTUDO DO RELÓGIO CIRCADIANO EM INSETOS VETORES

The last decades have established D. melanogaster as the main multicellular model organism, and many researchers have been attracted to work with this insect due to its potential of combining a genetic and mollecular approach to investigate genetic expression, celullar biology and neurobiology. In this paper we discuss the use of this organism model in the study of the circadian clock in insect vectors

figure_S2_-_Rivas_et_al_-_30nov17 – Supplemental material for Effects of Light and Temperature on Daily Activity and Clock Gene Expression in Two Mosquito Disease Vectors

<p>Supplemental material, figure_S2_-_Rivas_et_al_-_30nov17 for Effects of Light and Temperature on Daily Activity and Clock Gene Expression in Two Mosquito Disease Vectors by Gustavo B. S. Rivas, Rayane Teles-de-Freitas, Márcio G. Pavan, José B. P. Lima, Alexandre A. Peixoto and Rafaela Vieira Bruno in Journal of Biological Rhythms</p

Figure_S1_-_Rivas_et_al_-_30nov17 – Supplemental material for Effects of Light and Temperature on Daily Activity and Clock Gene Expression in Two Mosquito Disease Vectors

<p>Supplemental material, Figure_S1_-_Rivas_et_al_-_30nov17 for Effects of Light and Temperature on Daily Activity and Clock Gene Expression in Two Mosquito Disease Vectors by Gustavo B. S. Rivas, Rayane Teles-de-Freitas, Márcio G. Pavan, José B. P. Lima, Alexandre A. Peixoto and Rafaela Vieira Bruno in Journal of Biological Rhythms</p

Zika infection decreases Aedes aegypti locomotor activity but does not influence egg production or viability

Submitted by Sandra Infurna ([email protected]) on 2018-07-12T11:39:17Z No. of bitstreams: 1 ricardo_oliveira_etal_IOC_2018.pdf: 642918 bytes, checksum: 2318904ea236de527d7ed2042dd7b648 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-07-12T11:52:39Z (GMT) No. of bitstreams: 1 ricardo_oliveira_etal_IOC_2018.pdf: 642918 bytes, checksum: 2318904ea236de527d7ed2042dd7b648 (MD5)Made available in DSpace on 2018-07-12T11:52:39Z (GMT). No. of bitstreams: 1 ricardo_oliveira_etal_IOC_2018.pdf: 642918 bytes, checksum: 2318904ea236de527d7ed2042dd7b648 (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Insetos. Rio de Janeiro, RJ. Brasil / Universidade Federal do Rio de Janeiro. Instituto de Bioquímica Médica Leopoldo de Meis. Laboratório de Bioquímica de Insetos Hematófagos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Insetos. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Instituto de Bioquímica Médica Leopoldo de Meis. Laboratório de Bioquímica de Insetos Hematófagos. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Insetos. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Instituto de Bioquímica Médica Leopoldo de Meis. Laboratório de Bioquímica de Insetos Hematófagos. Rio de Janeiro, RJ, Brasil / Instituto Nacional de Ciência e Tecnologia em Entomologia Médica. CNPQ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil / Instituto Nacional de Ciência e Tecnologia em Entomologia Médica. CNPQ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Insetos. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular de Insetos. Rio de Janeiro, RJ. Brasil / Instituto Nacional de Ciência e Tecnologia em Entomologia Médica. CNPQ, Brasil.Zika has emerged as a new public health threat after the explosive epidemic in Brazil in 2015. It is an arboviroses transmitted mainly by Ae. aegypti mosquitoes. The knowledge of physiological, behavioral and biological features in virus-infected vectors may help the understanding of arbovirus transmission dynamics and elucidate their influence in vector capacity. Here, we aimed to investigate the effects of Zika virus (ZIKV) infection in the behavior of Ae. aegypti females by analyzing the locomotor activity, egg production and viability. Ae. aegypti females were orally infected with ZIKV through an artificial feeder to access egg production, egg viability and locomotor activity. For egg production and viability assays, females were kept in cages containing an artificial site for oviposition and eggs were counted. No significant difference in the number of eggs laid per females neither in their viability were found between ZIKV infected and non-infected females, regardless the tested pair of mosquito population and virus strain and the gonotrophic cycles. Locomotor activity assays were performed in activity monitors, an average of 5th, 6th and 7th days after infective feeding was calculated and a significant decrease in the locomotor activity in ZIKV infected females was observed. These results suggest that even when mosquitoes are infected with ZIKV, in places where there are many oviposition sites, they are able to maintain the dissemination of the vector population. Besides, the decreased locomotor activity does not seem to influence negatively in ZIKV transmission and may explain case clustering within households reported during Zika outbreaks such as in Rio de Janeiro 2015. High mosquito infestation index and abundant vector breeding sites may also influence this disease transmission

ANÁLISE ESPACIAL DA REDUÇÃO DE CASOS NOVOS DE LEISHMANIOSE VISCERAL NO BRASIL NO PRIMEIRO ANO DA PANDEMIA DE COVID-19

Introdução/objetivo: A leishmaniose visceral (LV) é uma doença tropical negligenciada e potencialmente letal. Ao considerar que o Brasil é responsável pela notificação de mais de 90% dos casos da América Latina, a vigilância epidemiológica possibilita a caracterização espacial, sazonal e cíclica dos novos casos. Como a covid-19 demandou a reorganização dos sistemas de saúde, hipotetizamos que houve redução da notificação de casos de LV na pandemia. Diante disso, este trabalho teve como objetivo analisar a dinâmica espacial da notificação de casos novos LV no Brasil em 2020, no contexto da pandemia da covid-19. Métodos: Trata-se de um estudo ecológico de série temporal que utilizou análise espacial, cujas unidades de análise foram os 5.570 municípios brasileiros e a população os casos novos de LV registrados entre 2015 e 2020 no Sistema de Informação de Agravos de Notificação (SINAN). O p-score foi calculado para estimar a variação percentual dos registros de casos novos de LV. Os índices de Moran global e local univariados foram utilizados na análise espacial para a identificação de padrões espaciais por meio da aglomeração de municípios com taxas semelhantes. Resultados: No Brasil, entre 2010 e 2019, a incidência de LV apresentou progressiva redução. Além disso, a análise da distribuição mensal dos casos novos de LV por estado no ano de 2020 mostrou que a maioria dos estados vinham sofrendo redução na incidência da doença. No entanto, a partir de maio, tal redução se tornou acentuada em diversos estados, especialmente na região Nordeste e Sudeste. Ademais, o índice de Moran global univariado foi utilizado na análise da autocorrelação espacial, a qual evidenciou a existência de dependência espacial na ocorrência de novos casos de LV, tanto no período de 2015-2019 (I = 0,491; p < 0,001), quanto no ano de 2020 (I = 0,031; p = 0,009). Conclusão: A distribuição da LV no Brasil mostrou-se dependente do território analisado, formando clusters espaciais de alto risco compostos por municípios da região Nordeste, Norte e Centro-oeste. Entretanto, embora as reduções expressivas na detecção dos casos de LV possam parecer um bom cenário, são uma preocupação importante para a saúde pública, pois a sobreposição geográfica entre covid-19 e LV e a sobrecarga do sistema de notificações podem ter contribuído para a diminuição dos registros. Sendo assim, a redução significativa na incidência de LV em 2020 deve alertar para o fortalecimento do sistema de vigilância epidemiológica

Frequency of co-seropositivities for certain pathogens and their relationship with clinical and histopathological changes and parasite load in dogs infected with Leishmania infantum.

In canine leishmaniosis caused by the protozoan Leishmania infantum, little is known about how co-infections with or co-seropositivities for other pathogens can influence aggravation of this disease. Therefore, the objectives of this study were to evaluate the frequency of co-infections with or co-seropositivities for certain pathogens in dogs seropositive for L. infantum and their relationship with clinical signs, histological changes and L. infantum load. Sixty-six L. infantum-seropositive dogs were submitted to clinical examination, collection of blood and bone marrow, culling, and necropsy. Antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and Toxoplasma gondii and Dirofilaria immitis antigens were investigated in serum. Samples from different tissues were submitted to histopathology and immunohistochemistry for the detection of Leishmania spp. and T. gondii. Quantitative real-time PCR was used to assess the L. infantum load in spleen samples. For detection of Coxiella burnetii, conventional PCR and nested PCR were performed using bone marrow samples. All 66 dogs tested positive for L. infantum by qPCR and/or culture. Fifty dogs (76%) were co-seropositive for at least one pathogen: T. gondii (59%), Ehrlichia spp., (41%), and Anaplasma spp. (18%). Clinical signs were observed in 15 (94%) dogs monoinfected with L. infantum and in 45 (90%) dogs co-seropositive for certain pathogens. The L. infantum load in spleen and skin did not differ significantly between monoinfected and co-seropositive dogs. The number of inflammatory cells was higher in the spleen, lung and mammary gland of co-seropositive dogs and in the mitral valve of monoinfected dogs. These results suggest that dogs infected with L. infantum and co-seropositive for certain pathogens are common in the region studied. However, co-seropositivities for certain pathogens did not aggravate clinical signs or L. infantum load, although they were associated with a more intense inflammatory reaction in some organs

Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World

Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites. The leishmaniases are a group of neglected tropical diseases caused by protist parasites from the Genus Leishmania. Different Leishmania species present a wide clinical profile, ranging from mild, often self-resolving cutaneous lesions that can lead to protective immunity, to severe metastatic mucosal disease, to visceral disease that is ultimately fatal. Leishmania parasites are transmitted by the bites of sand flies, and as no approved human vaccine exists, available drugs are toxic and/or expensive and parasite resistance to them is emerging, new dual control strategies to combat these diseases must be developed, combining interventions on human infections and integrated sand fly population management. Effective vector control requires a comprehensive understanding of the biology of sand flies. To this end, we sequenced and annotated the genomes of two sand fly species that are important leishmaniasis vectors from the Old and New Worlds. These genomes allow us to better understand, at the genetic level, processes important in the vector biology of these species, such as finding hosts, blood-feeding, immunity, and detoxification. These genomic resources highlight the driving forces of evolution of two major Leishmania vectors and provide foundations for future research on how to better prevent leishmaniasis by control of the sand fly vectors

Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World.

Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites

<i>Phlebotomus papatasi</i> circadian rhythm pathway annotation.

Phlebotomus papatasi circadian rhythm pathway annotation.</p