Dissertations / Theses: 'Aedes; Culex'

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Gonçalves, Gabriel Gazzoni Araújo. "Caracterização da resposta imunológica de Aedes aegypti e Culex quinquefasciatus à infecção pelo sorotipo 1 do Dengue vírus." Centro de Pesquisas Aggeu Magalhães, 2014. https://www.arca.fiocruz.br/handle/icict/14348.

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Fundação OSwaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, Brasil
Os insetos podem atuar como pragas agrícolas e vetores de patógenos causadores de doenças ao homem e outros animais. Investigações a respeito do sistema imunológico de Ae. aegypti e Cx. quinquefasciatus poderão contribuir para o desenvolvimento de métodos de controle das doenças veiculadas por estes insetos, principalmente a dengue, enfermidade causadora de sério problema de saúde pública no mundo. Apesar de Ae. aegypti ser a única espécie vetora confirmada na transmissão do vírus Dengue no Brasil, considera-se também importante um melhor entendimento dos mecanismos imunológicos de Cx. quinquefasciatus tido como refratário ao vírus. Neste estudo foram utilizadas linhagens de Ae. aegypti e Cx. quinquefasciatus mantidas no Insetário do Departamento de Entomologia do CPqAM/FIOCRUZ. Três grupos experimentais de fêmeas com 10 dias de idade foram formados para cada espécie. Grupo I, composto por fêmeas alimentadas com solução sacarose (10 por cento); grupo II, fêmeas alimentadas com sangue limpo e grupo III, fêmeas alimentadas com sangue infectado com o sorotipo DENV-1. De cada grupo foram obtidos hemolinfa, glândula salivar, intestino médio e corpo gorduroso para avaliação da expressão dos antimicrobianos defensina e transferrina. Essa avaliação foi realizada através de PCR em Tempo Real utilizando o kit QuantiFast SYBR Green - One-Step qRT-PCR. A avaliação da hemodinâmica foi realizada utilizando 10 microlitros de hemolinfa de cada grupo, através da contagem das células em câmara de Neubauer. Nossos resultados demonstraram que o Cx. quinquefasciatus tem um maior aumento da expressão de defensina e um maior número total de hemócitos quando infectados com DENV-1 em relação ao Ae. aegypti e a transferrina teve sua expressão alterada somente no Ae. aegypti. Em ambas as espécies estudadas, apenas a alimentação sanguínea não interfere na produção de hemócitos ou quanto na indução de defensina e transferrina. Esses dados sugerem que fêmeas de Cx. quinquefasciatus parecem apresentar uma resposta imune celular e humoral mais intensa do que Ae. aegypti quando infectados com DENV-1

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Melo, Tatiany Patrícia Romão Pompílio de. "Base molecular da interação da toxina binária do biolarvicida Bacillus shaericus com a-glicosidases de larvas de culicídios vetores." Centro de Pesquisas Aggeu Magalhães, 2010. https://www.arca.fiocruz.br/handle/icict/10521.

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Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, Brasil
O principal fator larvicida do Bacillus sphaericus (Bs) para culicídeos é a toxina binária (Bin), produzida sob a forma de um cristal, durante a esporulação. Esta toxina, ativada por meio da ação de proteases no lúmen intestinal, reconhece e liga-se a receptores específicos no intestino de larvas por meio de suasubunidade BinB, etapa crítica no seu modo de ação e essencial para a atividade larvicida. Os receptores em Culex pipiens, C. quinquefasciatus e Anopheles gambiae, denominados Cpm1, Cqm1, e Agm3, respectivamente, são alfa glicosidases de 66 kDa ligadas à membrana apical do epitélio intestinal por uma âncora de glicosilfosfatidilinositol (GPI). Larvas de Aedes aegypti expressam a alfaglicosidase Aam1, ortóloga ao receptor Cqm1 que, no entanto, não apresenta capacidade de ligação à toxina Bin. O principal objetivo deste trabalho foi caracterizar a base molecular da interação da toxina Bin do Bs com alfaglicosidases em larvas de culicídeos vetores. Para tal, a sequência protéica de Cqm1 foi alinhada a sequências ortólogas e parálogas de Ae. aegypti e An. gambiae, o que indicou trechos mais conservados na porção N-terminal e divergentes na porção C-terminal. A banálise funcional de fragmentos protéicos de 45 kDa da porção N-terminal de proteínas ortólogas e parálogas à Cqm1 sugeriu que o epitopo de ligação à toxina Bin está potencialmente localizado nesta região e que o estado conformacional nativo das proteínas é determinante para sua funcionalidade. Em seguida, foram avaliadas algumas características das alfa glicosidases Cqm1 e Aam1 de 66 kDa que podem estar envolvidas na sua capacidade de ligação à toxina Bin. Os resultados mostraram que as proteínas possuem diferenças estruturais e conformacionais que podem ter um papel determinante para a interação com a toxina Bin. Aanálise do padrão de glicosilação das proteínas revelou que a Aam1 posssui glicosilações em sua cadeia polipeptídica ao contrário da Cqm1 e que a ligação do receptor Cqm1 à toxina Bin não envolve N-glicanos. Na segunda parte do trabalho, foram investigados os motivos da subunidade BinB envolvidos na interação com o receptor Cqm1, através do estudo da funcionalidade de proteínas BinB mutantes com deleções nas regiões N- e C-terminal ou substituições de blocos de aminoácidos por alaninas. Os resultados obtidos indicam que o epitopo 147FQF149 da toxina é essencial a ligação ao receptor Cqm1 e que esta interação depende ainda do segmento N-terminal da BinB, compreendendo os primeiros 82 aminoácidos, uma região predita de segmentos não estruturados e de alfa hélices

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Oliveira, Iêda Ferreira de. "Expressão diferencial de genes que codificam peptídeos antimicrobianos de aedes aegypti em resposta`a infecção por Wuchereria bancrofti." reponame:Repositório Institucional da FIOCRUZ, 2008. https://www.arca.fiocruz.br/handle/icict/3935.

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No Brasil, a filariose linfática causada por Wuchereria bancrofti ainda é um grave problema de saúde pública. O mosquito Culex quinquefasciatus é o principal vetor nas áreas onde este nematódeo tem periodicidade noturna, enquanto Aedes aegypti é uma espécie naturalmente refratária. Os mecanismos responsáveis pela refratariedade a W. bancrofti nesta espécie de mosquito são desconhecidos. Desse modo, estudos sobre a resposta imune de Ae. aegypti à W. bancrofti são importantes para compreender os mecanismos que limitam o desenvolvimento deste patógeno nesta espécie de mosquito. O objetivo deste trabalho foi avaliar o padrão de expressão temporal dos genes defensina, cecropina e transferrina de Ae. aegypti infectados artificialmente com W. bancrofti, assim como observar o desenvolvimento do filarídeo neste mosquito comparado com Cx. quinquefasciatus. Fêmeas de Ae. aegypti Rec Lab e Cx. quinquefasciatus CqSF foram alimentadas artificialmente com amostras de sangue venoso de voluntários infectados e não infectados com W. bancrofti. Após o repasto sanguíneo, foi extraído o RNA total de pools Ae. aegypti - tanto do grupo controle, quanto do grupo infectado, coletados nos seguintes tempos: 2h, 24h, 48h, 72h e 7 dias. Os RNAs foram submetidos a reações de RT-PCR em tempo real com primers específicos para os genes da defensina, cecropina, transferrina e rpL8 (controle endógeno), separadamente e em duplicata. A expressão relativa destes genes foi calculada pelo método 2- C T. Nas observações microscópicas, a cabeça, tórax e abdômen de mosquitos Ae. aegypti e Cx. Quinquefasciatus foram dissecados durante os 15 dias pós-infecção, a fim de avaliar a migração, o desenvolvimento e o movimento dos parasitas. Os resultados mostraram que a transcrição da defensina, cecropina e transferrina aumentou em Ae. aegypti logo após a infecção com W. bancrofti, apresentou picos às 2h (cecropina) ou 24h (defensina e transferrina), e diminuiu a partir de 48h. Os picos de transcritos imunes coincidiram com o período de migração da microfilária para o tórax de Ae. aegypti, que ocorreu nas primeiras 24h. Após a migração, vermes filarídeos diferenciaram-se em larvas de primeiro estádio salsichóide, mas interromperam o desenvolvimento a partir desse momento, diferentemente de Cx. quinquefasciatus, cujo desenvolvimento de W. bancrofti foi normal. É possível que defensina, cecropina e transferrina estejam envolvidas na resposta imune de Ae. aegypti à infecção por W. bancrofti

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Mina, Petrić. "Modelling the influence of meteorological conditions on mosquito vector population dynamics (Diptera, Culicidae)." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2020. https://www.cris.uns.ac.rs/record.jsf?recordId=114757&source=NDLTD&language=en.

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Meteorological conditions have a significant influence on the time of occurrence, abundance and activity of the mosquito vector. In the current context of climate change, it is of great importance to assess the impact of shifts in climatic conditions on the suitability for the establishment and annual activity of the vector species. Moreover, changes in the variability of meteorological elements and their extremes can generate unexpected changes in the mosquito vector population which in turn have an important effect on human health. One of the ways to put these causes and effects into perspective is to simulate the activity of the vector within a processbased framework which allows for the analysis of the contribution of individual factors on the different life stages of the vector. Such analysis is presented by use of sophisticated dynamical models simulating the characteristics of the biological population, forced by observed meteorological data, capturing the localmicro-environment of the vector habitat, and validated by the observed entomology.Numerical models are being developed to model vector population dynamics and the expected circulation of the virus within a closed system. Two modelling approaches are standardly applied to modelling vector population dynamics: Mechanistic and Stochastic. The advantage of mechanistic overstatistical models is that they can provide a deterministic framework allowing for the isolated evaluation of each input parameter and their effect on the modelled system. Mechanistic dynamical models are used to describe the biophysical processes or partof the process as a response to changes in the meteorological conditions.The work carried out in this thesis can be summarized as follows: (i) Analysis of the association between the most important abiotic drivers influencing the population dynamics, annual activity and time of occurrence of Culex pipiens and Aedes aegypti; (ii) Identifying the most important climatic factors and model settings as a function of climatic characteristics of the study region; (iii) Modelling the vector population dynamics and stability analysis of the dynamical system (iv) Analysis of different verification techniques and implications in terms of model application; (v) Feasibility analysis ofimproving the model with a Land-Surface Parametrization scheme and short-range forecasting of pest population dynamics.
Meteorološki uslovi bitno utiču na vreme pojave, brojnost vektora i njihovu aktivnost. U uslovima evidentnih promene klime, od ogromne je važnosti sagledati uticaj očekivanih promena klime na pogodnost uslova na pojavu izabranih vektora.Takodje, značajne promene kolebanja meteoroloških elemenata u odnosu na višegodišnji prosek i sve češće pojave nepovoljnih vremenskih prilika dovode do neočekivanog ponašanja populacije komarca što značajno utiče na kvalitet života i zdravlje ljudi. Jedini način da se sagledaju uzroci i posledice navedenih pojava zasniva se na simulaciji aktivnosti i brojnosti vektora uz mogućnost testiranja uticaja svakog pojedinačnog faktora. Ovu mogućnost pružaju samo visoko sofistikovani dinamički modeli koju su prošli proces kalibracije i validacije zasnovanna izmerenim vrednostima meteoroloških elemenata i karakteristika biološke populacije.Sofistikovani modeli za simulaciju dinamike populacije vektora i očekivane cirkulacije vektorskih transmisivnih bolesti se koriste sa ciljem modeliranja potencijalnog rizika od zaraze i epidemije. Modeli zasimulaciju dinamike vektora mogu da se podele na dve glavne grupe: Mehanističke i Statističke. Prednost mehanističkih modela nad statističkim je što mogu da se koriste za evaluaciju uticaja izolovanog faktora na dinamički sistem i odgovarajuće promene brojnosti unutar svake faze u razvoju vektora. Mehanistički dinamički sistemi se koriste kako bi se opisao mehanizam biofizičkog procesa ili dela procesa u zavisnosti od forsirajuće veličine.Predmet istraživanja u ovom radu jeste identifikovanje najznačajnijih bioloških i fizičkih procesa kao i odgovarajućih faktora koji utiču na brojnost i aktivnost vektora roda Aedes i Culex. Ciljevi istraživanja mogu da se sumiraju na sledeći način: (i)analiza najznačajnijih meteoroloških parametara koji utiču na vreme pojave, brojnost i aktivnost vektora Aedes i Culex roda; (ii) definisanje najznačajnijih klimatskih faktora i stepena osetljivosti procesa na njih; (iii) modeliranje dinamike populacije vektora i analiza stabilnosti dinamičkog sistema; (iv) verifikacija i analiza metoda verifikacije i validacije dinamičkog modela; (v) kratkoročna prognoza dinamike populacije komarca i formulacija hidrološkog modula upotrebom SURFEX površinskešeme sa ECOCLIMAP fiziogeografskim podacima.

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Rivas, Gustavo Bueno da Silva. "Análise comparativa dos ritmos de atividade locomotora e expressão circadiana de Aedes aegyptie Culex quinquefasciatus." reponame:Repositório Institucional da FIOCRUZ, 2010. https://www.arca.fiocruz.br/handle/icict/6059.

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Fundação Oswaldo Cruz.Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
A grande maioria dos seres vivos complexos apresenta um relógio endógeno, conhecido como relógio circadiano, responsável por dirigir as oscilações rítmicas de fisiologia e comportamento dentro de um período de aproximadamente 24 horas. Em insetos, as bases genéticas deste marcapasso têm sido elucidadas em Drosophila melanogaster. Diversos loci já foram identificados e o mecanismo molecular regulando o relógio circadiano consiste de alças regulatórias interligadas que controlam a expressão rítmica de muitos genes. Muitas espécies de mosquitos são vetores de doenças. Elas exibem uma variedade de padrões de atividade e hematofagia, de diurnos a crepusculares e noturnos e estes ritmos são importantes para a dinâmica da transmissãode doenças. Entretanto, apesar da sua importância epidemiológica, pouco se sabe quanto à genética molecular do relógio circadiano que controla seus ritmos de atividade. Nosso grupo tem estudado as bases moleculares do relógio circadiano em duas espécies de mosquitos, Aedes aegyptie Culex quinquefasciatus. Ambos são importantes vetores de doenças tropicais, mas com diferentes padrões de atividade. Ae. aegyptié o vetor diurno da Dengue e da Febre amarela, enquanto Cx. quinquefasciatusé o vetor noturno da Filariose e da Febre do Oeste doNilo. Análises preliminares indicaram uma conservação dos padrões de expressão entre as duas espécies em alguns dos mais importantes genes do relógio em claro-escuro e escuro constante. Entretanto, nós achamos diferenças na expressão do gene cryptochrome2(cry2), um ortólogo dos genes codificando criptocromos de mamíferos e que foi encontrado em muitos insetos, mas que não está presente em Drosophila. Nós sugerimos que cry2pode estar envolvido no controle dos padrões de atividade de Ae. aegyptie Cx. quinquefasciatus, e propusemos um modelo para explicar as diferenças na expressão de cry2. Nós também estudamos a expressão circadiana dos principais genes de relógio, além dos ritmos de atividade locomotora destas duas espécies em ciclos de temperatura. Observamos que ambas são arrastadas pela temperatura e mostram diferenças em seus comportamentos de atividade. Em ciclos de temperatura, a atividade locomotora de Ae. aegyptié mais restrita a termofase, enquanto Cx. quinquefasciatusapresenta sua atividade mais restrita a criofase. Além disso, após o arrastamento em ciclos de claro-escuro, Ae. aegypti mostrou um padrão transiente de atividade por alguns dias em escuro constante com ciclos de temperatura, enquanto Cx. quinquefasciatuspermaneceu estável nesta condição. Também foram observadas, em ciclos de temperatura, algumas diferenças espécies-específicas nos padrões de expressão de cyclee cry2. Finalmente, nós observamos diferenças na fase da expressão circadiana de Ae. aegyptiem ciclos de temperatura e escuro constante entre mosquitos criados com uma combinação de ciclos de claro-escuro e de temperaturacom mosquitos criados em ciclos de claro-escuro com temperatura constante. Isto sugere um importante papel do desenvolvimento na determinação dos padrões de expressão circadiana de insetos adultos submetidos a oscilações de temperatura.
The great majority of complex living organisms present an endogenous timekeeper, known as the circadian clock, responsible for driving rhythmic oscillations in their physiology and behaviour within a period of approximately 24 hours. In insects, the genetic bases of this pacemaker have been elucidated in Drosophila melanogaster. A number of loci have already been identified and themolecular mechanism regulating the circadian clock consists of interlocked feedback loops that control the rhythmic expression of many genes. Many species of mosquitoes are disease vectors. They show a range of activity and blood-feeding patterns, from diurnal to crepuscular and nocturnal, and these rhythms are essential for the dynamics of disease transmission. However, despite their epidemiologic importance, little is known about the molecular genetics of the circadian clock controlling their activity rhythms. Our group has been studying the molecular bases of the circadian clock in two mosquito species, Aedes aegyptiand Culex quinquefasciatus. Both are important vectors of tropical diseases but with different activitypatterns. Ae. aegyptiis a diurnal vector of Dengue and Yellow fever, while Cx. quinquefasciatusis a nocturnal vector of Filariasis and West-Nile fever. Previous analysis has indicated conserved expression patterns between the two species in some of themost important clock genes in light-dark and constant dark. However, we founddifferences in the expression in the mammalian-like cryptochrome2(cry2), a gene found in many insects but missing in Drosophila. We suggest that cry2might be involved in the control of the activity patterns in Ae. aegyptiand Cx. quinquefasciatus, and we proposed a model to explain the differences in cry2expression. We also studied the circadian expression of the main clock genes and locomotor activity rhythms of these two species under temperaturecycles. We observed that both are entrained by temperature and showed some differences in their activity behaviour. Under temperature cycles, the locomotor activity of Ae. aegyptiis more restricted to the termophase while Cx. quinquefasciatushas your activity more restricted to the cryophase. Moreover, after entrainment in light-dark cycles, Ae. aegyptishown a transient activity pattern for a few days in constant dark with temperature cycles, while Cx. quinquefasciatusremains stable in this condition. We also observed under temperature cycles some species-specific differences in cycle and cry2expression patterns. Finally, we observed differences in the phase of Ae. aegypticircadian expression in temperature cycles and constant dark between mosquitoes raised under combined light-dark and temperature cycles to those raised in light-dark cycles with constant temperature. This suggests an important role of development in determining the patterns of circadian expression of adult insects under temperature oscillations.

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Zamble, Bi Zamblé Hubert. "Biomarqueurs immuno-épidémiologiques d’exposition de l’homme aux piqûres des moustiques Aedes et Culex : application à l'évaluation du risque de transmission des arboviroses." Thesis, Université de Montpellier (2022-….), 2022. http://www.theses.fr/2022UMONT017.

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Les arboviroses, transmises par les moustiques Aedes et Culex, continuent de menacer la santé et la vie des populations des zones où elles sont endémiques et représentent des risques d’émergence dans nouveaux territoires colonisés par ces vecteurs. L’objectif principal de nos travaux était i) d’évaluer le niveau d’exposition des populations aux piqûres des Aedes aegypti et Ae. albopictus et le risque de transmission des maladies qu’ils transmettent, en milieu urbain en Afrique de l’Ouest et au Sud de la France métropolitaine et ii) d’évaluer et valider les réponses IgG anti-EGS et anti-protéine recombinante de 30 kDa de Culex quinquefasciatus comme biomarqueur d’exposition potentiel des Hommes aux piqûres des Culex. Nous avons dosé dans les sérums des individus exposés, les réponses anticorps : i) IgG anti-Nterm-34 kDa et les IgG anti- antigènes d’arbovirus (LUMINEX) chez les enfants d’Anoumabo, de Bromakoté et de Petit-Bassam, à d’Abidjan, , ii) IgG et IgM anti-Nterm-34 kDa d’Ae. aegypti à l’’Auvergne, de Corse, d’Occitanie et de PACA, en France, et iii) IgG anti-EGS et la protéine recombinante 30 kDa chez les enfants de Dar-es-Salam, N’Gattakro, Kennedy à Bouaké.A Abidjan, les IgG anti-Nterm-34 kDa étaient significativement différentes entres les quartiers d’étude avec un fort niveau à Bromakoté. Les IgG spécifiques étaient associées aux données des pièges collants. Selon la technique LUMINEX les arbovirus circulaient dans les quartiers, avec à une détection majoritaire de DENV3. Petit-Bassam était le plus affecté. L’ensemble de ces résultats démontraient que l’exposition aux Aedes et ainsi le risque de transmission étaient variables entre quartiers au sein d’une même ville africaine.En France métropolitaine, les IgG spécifiques étaient plus élevées dans les régions colonisées que dans la région non colonisée. La réponse IgG spécifique était plus élevée en Occitanie et en PACA par rapport à la Corse. Les IgM anti-peptide salivaire, indiquait une différence significative entre les régions exposées. En Occitanie, les niveaux médians des réponses IgG anti-peptide des départements 30 et 34, étaient plus élevés que celles des départements 31 et 66. En PACA, une différence significative du niveau des IgG spécifique était détectée entre le département 04 et 13 et entre les départements 05 et 13. Les IgG des départements 13 et 83 plus élevées que ceux des autres départements. Les départements colonisés entre 2010 et 2012 présentaient un taux d’IgG anti-peptide statiquement plus élevés que celui des départements non colonisés. Les IgM entre les individus des 4 régions était pratiquement nul. Ces résultats indiquaient la pertinence du biomarqueur IgG anti-peptide salivaire pour discriminer les régions et les départements les plus exposés aux piqûres d’Ae. albopictus et ainsi d’évaluer l’hétérogénéité des risques de transmission des arboviroses en France métropolitaine.Pour les Culex, les réponses IgG anti-EGS et anti-30 kDa étaient significativement plus élevées chez les enfants vivant dans les sites de forte densité de Culex quinquefasciatus. Les IgG anti-30 kDa étaient significativement plus élevées chez les enfants ne dormant pas sous les moustiquaires imprégnées d’insecticide par rapport à ceux dormant dessous. De plus, une corrélation positive a été observée entre les réponses IgG anti-EGS et les Ac IgG anti 30 kDa au sein de la population totale.Cette étude a montré que l’utilisation des biomarqueurs d’exposition aux piqûres des Aedes pourraient un outil pertinent pour l’évaluation de l’hétérogénéité d’exposition aux vecteurs d’arbovirus dans le contexte urbain africain et entre les départements d’une même région dans le Sud de la France métropolitaine. Les réponses IgG anti-EGS et anti-protéine 30 kDa représenteraient des candidats biomarqueurs potentiels aux piqûres de Culex. Toutefois, leur validation comme de ce biomarqueur d’exposition aux Culex, des études complémentaires sont nécessaires
Arboviruses, transmitted by the Aedes and Culex mosquitoes, continue to threaten the health and lives of populations in areas where they are endemic and represent risks of emergence in new territories colonised by these vectors. The main objective of our work was i) to assess the level of exposure of populations to the bites of Aedes aegypti and Ae. albopictus and the risk of transmission of the diseases they transmit, in an urban environment in West Africa and in the South of metropolitan France and ii) to evaluate and validate the anti-EGS IgG and anti-recombinant 30 kDa protein responses of Culex quinquefasciatus as a potential biomarker of human exposure to Culex bites. We measured in the sera of exposed individuals, the antibody responses: i) IgG anti-Nterm-34 kDa and IgG anti arbovirus antigens (LUMINEX) in children from Anoumabo, Bromakoté and Petit-Bassam, in Abidjan, ii) IgG and IgM anti-Nterm-34 kDa of Ae. aegypti in Auvergne, Corsica, Occitania and PACA, France, and iii) anti-EGS IgG and recombinant 30 kDa protein in children from Dar-es-Salam, N'Gattakro, Kennedy in Bouaké.In Abidjan, anti-Nterm-34 kDa IgG was significantly different between the study districts with a high level in Bromakoté. Specific IgG was associated with sticky trap data. According to the LUMINEX technique, arboviruses were circulating in the districts, with a majority detection of DENV3. Petit-Bassam was the most affected. All these results showed that exposure to Aedes and thus the risk of transmission varied between neighbourhoods within the same African city.In metropolitan France, specific IgG was higher in the colonised areas than in the uncolonised area. The specific IgG response was higher in Occitania and PACA compared to Corsica. The anti-salivary peptide IgM, indicated a significant difference between the exposed regions. In Occitanie, the median levels of anti-peptide IgG responses in departments 30 and 34 were higher than those in departments 31 and 66. In PACA, a significant difference in the level of specific IgG was detected between departments 04 and 13 and between departments 05 and 13. IgG levels in departments 13 and 83 were higher than in the other departments. Departments colonised between 2010 and 2012 had statically higher anti-peptide IgG levels than non-colonised departments. IgM between individuals in the 4 regions was practically zero. These results indicated the relevance of the salivary anti-peptide IgG biomarker to discriminate the regions and departments most exposed to Ae. albopictus bites and thus to assess the heterogeneity of arbovirosis transmission risks in metropolitan France.For Culex, anti-EGS and anti-30 kDa IgG responses were significantly higher in children living in sites of high Culex quinquefasciatus density. Anti-30 kDa IgG was significantly higher in children not sleeping under insecticide-treated nets compared to those sleeping under them. In addition, a positive correlation was observed between anti-EGS IgG responses and anti-30 kDa IgG Ac in the total population.This study showed that the use of biomarkers of exposure to Aedes bites could be a relevant tool for the assessment of heterogeneity of exposure to arbovirus vectors in the African urban context and between departments of the same region in southern France. Anti-EGS IgG and anti-30 kDa protein responses would represent potential biomarker candidates for Culex bites. However further studies are needed, to validate them as a biomarker of Culex exposure

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Ferreira, Luana Cristina Farnesi. "Culicídeos vetoresdiferenças e semelhanças fisiológicas e estruturais relacionadas ao processo de resistência dos ovos à dessecação." reponame:Repositório Institucional da FIOCRUZ, 2014. https://www.arca.fiocruz.br/handle/icict/13047.

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Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
Diversos parasitas, agentes etiológicos de uma série de agravos, são transmitidos por mosquitos vetores em todo o mundo. A despeito de sua importância médica, ainda existem muitas lacunas no conhecimento da embriogênese desses insetos. Ovos de espécies do gênero Aedes resistem à dessecação, e são capazes de sobreviver vários meses no seco em estado de quiescência ao final da embriogênese. Entretanto, ovos de espécies de outros gêneros, como Anopheles e Culex, não possuem capacidade de resistir a longos períodos de exposição ao seco, apesar de adquirirem algum grau de impermeabilidade. Nos mosquitos Aedes aegypti e Anopheles gambiae tem sido mostrado que, durante a embriogênese, a síntese da cutícula serosa (CS), que contém quitina, coincide com a aquisição da resistência dos ovos à dessecação (ROD). O objetivo deste trabalho foi investigar, comparativamente, a embriogênese de diferentes mosquitos vetores, para elucidar semelhanças e diferenças na ROD. A maior parte do trabalho foi realizada com as espécies Ae. aegypti, An. aquasalis e Cx. quinquefasciatus. Verificamos que para An. aquasalis e Cx. quinquefasciatus a formação da CS também é simultânea à aquisição de ROD e contém quitina. O tempo requerido para a finalização da embriogênese de Ae. aegypti, An. aquasalis e Cx. quinquefasciatus é, respectivamente, 77,4, 51,3, e 34,2 horas após a postura A formação da CS ocorre em estágio embrionário equivalente para Ae. aegypti e An. aquasalis e um pouco mais tardio para Cx. quinquefasciatus. Ao final da embriogênese diferentes níveis de ROD foram detectados: alto para Ae. aegypti, médio para An. aquasalis e baixo para Cx. quinquefasciatus. Com o objetivo de entender essas diferenças, avaliamos, comparativamente, alguns aspectos físicos dos ovos: comprimento, largura, área, volume, peso e a superfície da casca. Apesar de diferenças interessantes e significativas terem sido observadas, não foi possível estabelecer correlação direta entre ROD e tais aspectos, quando avaliados individualmente. Quantificação do polissacarídeo quitina revelou tendência de maior conteúdo em cascas de ovos de espécies mais resistentes ao seco. Além disso, diferenças significativas foram encontradas no grau de melanização dos ovos das diferentes espécies, sugerindo que ovos mais melanizados são mais resistentes ao seco. Essa hipótese foi testada utilizando o mutante GORO da espécie An. quadrimaculatus. Nesta linhagem a melanização não ocorre corretamente, e as cascas de seus ovos têm aparência dourada. Em contraste, seu equivalente selvagem (WT) possui ovos de casca escura Ovos GORO possuem ROD deficiente: quando expostos ao seco por 10 horas após a formação da CS, apenas 12,3% são viáveis, em contraste com 66,5% de ovos WT. Nossos resultados confirmam de forma direta que, além da quitina da CS, a melanização da casca dos ovos é importante para a impermeabilização dos ovos de insetos
Several parasites, etiologic agents of a number of diseases, are transmitted by mosquito vectors worldwide. Despite their medical importance, many gaps in our knowledge about the embryogenesis of these insects still remain. Eggs from the Aedes genus resist to desiccation, and are able to survive several months in dry conditions in a quiescent status at the end of embryogenesis. In contrast, eggs belonging to other genera, like Anopheles and Culex, do not withstand long periods of exposure in dry conditions, although they acquire some degree of impermeability. It has already been demonstrated that, in the course of Aedes aegypti and Anopheles gambiae embryogenesis, the synthesis of the serosal cuticle (SC), which contains chitin, coincides with the acquisition of egg resistance to desiccation (ERD). The aim of the present work was to investigate, under a comparative basis, the embryogenesis of different mosquito vectors, in order to elucidate ERD similarities and differences. Most of the work was performed with Ae. aegypti, Anopheles aquasalis and Culex quinquefasciatus. We found that, for An. aquasalis and Cx. quinquefasciatus, ERD acquisition is also simultaneous to the development of SC, a layer containing chitin. Time required for embryogenesis completion is 77.4, 51.3, and 34.2 hours after egglaying for respectively Ae. aegypti, An. aquasalis and Cx. quinquefasciatus. The formation of SC occurs in an equivalent embryonic stage for Ae. aegypti and An. aquasalis, but a little later for Cx. quinquefasciatus. At the end of embryogenesis different ERD levels were detected: high for Ae. aegypti, medium for An. aquasalis and low for Cx. quinquefasciatus. In order to understand these differences, we comparatively evaluated some physical aspects of the eggs: length, width, area, volume, weight and eggshell surface appearance. Although interesting and significant differences have been observed, it was not possible to establish any direct correlation between ERD and these physical aspects, when individually considered. Quantification of chitin revealed tendency of higher amount of this polysaccharide in the eggshells of species more resistant to desiccation. Furthermore, significant differences were found in the degree of melanization of eggs from the different species, suggesting that more melanized eggs are also more resistant to dry conditions. This hypothesis was tested using the An. quadrimaculatus GORO mutant. In this strain, melanization does not occur properly, and the eggs have a golden appearance. Eggshells from the wild type (WT) strain, in contrast, are dark. GORO eggs exhibit a defective ERD: when exposed to dry conditions during 10 hours after the SC formation only 12.3% are viable, in contrast with 66.5% of WT eggs. Our results confirm, directly, that beyond the chitin present in the SC, the eggshell melanization is an important factor towards insect eggs impermeability

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Gaona, Jairo Campos. "Analise citologica de populações de Aedes aegypti (Linnaeus, 1762) e Culex quinquefasciatus Say, 1823 (Diptera, Culicinae)." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317212.

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Orientadores : Carlos Fernando Salgueirosa de Andrade, Shirlei Maria Recco Pimentel
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: No presente estudo foram feitas avaliações da susceptibilidade de Aedes aegypti e Culex quinquefasciatus a inseticidas organofosforados, carbamato e piretróides por meio de bioensaios. Isto permitiu monitorar a resistência em populações destas espécies em Campinas,SP, Campo Grande,MS e Cuiabá,MT. Adicionalmente, foi realizada uma avaliação citológica dos cromossomos politênicos dos túbulos de Malpighi em larvas, pupas e adultos de A. aegypti para as populações de Campinas,SP (Aea-Campus, Aea-Lab, Aea-Unicamp) e Campo Grande,MS (Aea-UFMS, Aeacemitério)- Brasil, para as populações Aea-INS-Bogotá e Aea-Palmira,VA-Colômbia, e para a linhagem padrão Rockefeller. Da mesma forma foram avaliados os cromossomos politênicos de C. quinquefasciatus em populações de Campinas,SP (UNI-R1, UNI-R2), Campo Grande,MS (UFMS-R) e Cuiabá,MT (Cuiabá-R)- Brasil, nas populações Cxq-Palmira,VA e Cxq-INS-Bogotá- Colômbia, e na linhagem padrão IAL. A partir de larvas criadas em baixas temperaturas (18-24°C), bem alimentadas e com pouco estresse por alta densidade populacional foram feitos estudos citológicos usando a técnica convencional de coloração com orceína. Os melhores resultados na obtenção e reproducibilidade dos cromossomos politênicos de A. aegypti e C. quinquefasciatus foram alcançados com túbulos de Malpighi de pupas fêmeas grandes recém formadas (0-4h/18-24°C). Lâminas adequadas também foram obtidas com imagos fêmeas e larvas de 4° estádio avançado. Pode-se considerar que as dificuldades registradas na literatura para estas espécies foram contornadas em 80% para as linhagens avaliadas neste trabalho. Mapas dos cromossomos politênicos para A. aegypti e C. quinquefasciatus foram elaborados. Isto permitiu identificar marcadores cromossômicos para uso na diferenciação dos cromossomos e caracterização citológica das espécies. Em C. quinquefasciatus as regiões centroméricas e a região organizadora do nucléolo são os principais marcadores para identificar os cromossomos, outros grupos de bandas e puffs são característicos nesta espécie como assinalado. O grau de politenia variou entre as linhagens de C. quinquefasciatus, sendo menor na linhagem padrão. Embora o padrão de bandas em C. quinquefasciatus apresente maior resolução que aquele de A. aegypti, nas duas espécies foi possível identificar marcadores cromossômicos característicos e específicos. Nos mapas das linhagens resistentes de C. quinquefasciatus, foi observado na seção 31 do cromossomo 2L, marcador cromossômico do gene amplificado para esterases já associado com a resistência aos organofosforados. Discute-se que o monitoramento de populações de mosquitos de importância médica pode ser viável por meio de bioensaios bem como citologicamente, evidenciando mudanças na susceptibilidade aos inseticidas e levantando a necessidade de vigilância da resistência nas populações avaliadas. Sugere-se que desta forma, estudos populacionais e mapeamento físico de genes poderão ser realizados com cromossomos politênicos de espécies de Culicinae
Abstract: In the present study, evaluations of the susceptibility to organophosphorus, carbamate and pirethroid insecticides of Aedes aegypti and Culex quinquefasciatus were made by means of bioassays. This allowed monitoring the resistance in populations of these species in Campinas, SP, Campo Grande, MS and Cuiabá, MT. Moreover, a cytological evaluation of the polytene chromosomes from Malpighi tubules was undertaken in larvae, pupae and adults from A. aegypti populations: Campinas, SP (Aea-campus, Aea-Lab, Aea-Unicamp) and Campo Grande, MS (AeaUFMS, Aea-cemetery) - Brazil, for the populations Aea-INS-Bogota and Aea-Palmira, VA - Colombia, and for the Rockefeller susceptible standard strain. In the same way the polytene chromosomes from C. quinquefasciatus populations were appraised: Campinas, SP (UNI-R1, UNI-R2), Campo Grande, MS (UFMS-R) and Cuiabá, MT (Cuiabá-R) - Brazil, Cxq-Palmira, VA and Cxq-INS-Bogota - Colombia, and in the IAL susceptible standard strain. Starting with larvae reared in low temperatures (18-24°C), well fed and with little stress due to overcrowding, cytological studies were made using the conventional technique of orcein staining. The best results for obtaining and reproducing the polytene chromosomes of A. aegypti and C. quinquefasciatus were reached with Malpighi tubules of recently emerged big female pupae (O to 4 h / 18-24°C). Adequate slides were also obtained with female adults and 4th advanced instar larvae. It can be considered that the difficulties registered in the literature for these species were avoided in 80% for the strains evaluated in this work. Polytene chromosome maps from A. aegypti and C. quinquefasciatus were also elaborated. This allowed identifying chromosomallandmarks for use in the differentiation of the chromosomes and cytological characterization of species. In C. quinquefasciatus the centromere regions and the nucleolar organizing region (NOR) are the main landmarks to identify the chromosomes. In this species, other groups of bands and puffs are also characteristic landmarks. The degree of politenization varied among the strains of C. quinquefasciatus, being smaller in the standard lineage. Although the pattern of bands in C. quinquefasciatus provides greater resolution than that of A. aegypti, in the two species identification of characteristic and specific chromosome landmarks was possible. In the maps of the resistant strains of C. quinquefasciatus, chromosomal marker of the amplified gene for esterase was associated with resistance to the organophosphorus insecticides and observed in section 31 of chromosome arm 2L. The monitoring of medically important mosquito populations appears to be viable by means of bioassay as well as cytological evaluations, showing changes in the susceptibility to the insecticides and demonstrating the need of surveillance of resistance in the appraised populations. It is suggested that in this way, population studies and physical mapping of genes in species of Culicinae, can be undertaken based on polytene chromosomes
Doutorado
Biologia Celular
Doutor em Biologia Celular e Estrutural

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Wright, Joshua P. "Geospatial and Negative Binomial Regression Analysis of Culex nigripalpus, Culex erraticus, Coquillettidia perturbans, and Aedes vexans Counts and Precipitation and Land use Land cover Covariates in Polk County, Florida." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6983.

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Although mosquito monitoring systems in the form of dry-ice bated CDC light traps and sentinel chickens are used by mosquito control personnel in Polk County, Florida, the placement of these are random and do not necessarily reflect prevalent areas of vector mosquito populations. This can result in significant health, economic, and social impacts during disease outbreaks. Of these vector mosquitoes Culex nigripalpus, Culex erraticus, Coquillettidia perturbans, and Aedes vexans are present in Polk County and known to transmit multiple diseases, posing a public health concern. This study seeks to evaluate the effect of Land use Land cover (LULC) unique features and precipitation on spatial and temporal distribution of Cx. nigripalpus, Cx. erraticus, Cq. perturbans, and Ae. vexans in Polk County, Florida, during 2013 and 2014, using negative binomial regression on count data from eight environmentally unique light traps retrieved from Polk County Mosquito Control. The negative binomial regression revealed a statistical association among mosquito species for precipitation and LULC features during the two-year study period, with precipitation proving to be the most significant factor in mosquito count numbers. The findings from this study can aid in more precise targeting of mosquito species, saving time and resources on already stressed public health services.

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Kurosaka, Jeffrey Allan. "Vector Competence of Aedes sierrensis and Culex pipiens complex (Diptera: Culicidae) for Dirofilaria immitis (Spirurida: Onchocercidae) in Northern California." Scholarly Commons, 2017. https://scholarlycommons.pacific.edu/uop_etds/2979.

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Dirofilaria immitis Leidy (dog heartworm) is a life-threatening parasite transmitted by mosquitoes to domestic dogs. Endemic in the eastern United States, cases have become more prevalent over the last few decades. While prevalence in California is generally low, Lake and San Joaquin Counties have reported rates comparable to the East Coast at 3.73% and 0.71%(CAPC 2017), respectively. Aedes sierrensis is thought to be responsible for transmission in California, but in some cases, it exists in inadequate quantities and temporal ranges to explain parasite activity. Based on Huang et al. (2013) and Tran (2016), bloodfeeding patterns, and other vector criteria, Culex pipiens complex and Culiseta incidens were chosen to evaluate for vector competence. Female field-caught mosquitoes were reared, infected (2.5-5 mff/μl), and decapitated at 15, 18, or 21 days post infection (dpi). Cs. incidens was reluctant to feed using an artificial feeding system and will require additional trials. On the contrary, trials on Ae. sierrensis and Cx. pipiens complex were both completed successfully. Both species were determined to be competent vectors of D. immitis. Based on our findings, more than half of Ae. sierrensis females produced emerging L3s by 21 dpi, while Cx. pipiens complex never produced L3s in more than 5% of females. In conjunction with other factors such as the detection of D. immitis in wild mosquitoes, host-seeking preferences for domestic dogs, and appropriate temporal overlap, this suggests that both Ae. sierrensis and Cx. pipiens complex may play central roles in Lake or San Joaquin Counties, CA when abundant. Targeted control efforts are necessary to reduce the incidence of canine heartworm in these areas. While Lake and San Joaquin Counties, CA were the focus of this study, our results may be applicable to the western United States when these species are relevant.

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Harris, Maria-Richetta Camille. "Forest disturbance, mosquito vector ecology and La Crosse virus dynamics in southwestern Virginia." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/64932.

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The influence of forest canopy disturbance (FCD) on La Crosse virus (LACV), leading cause of US pediatric arboviral encephalitis, is critical to understand in landscapes where forests are periodically harvested. Southwestern Virginia is part of an emerging focus of this interior forest bunyavirus. I investigated how the temperate forest mosquito community, LACV vectors, and the LACV amplifying vertebrate host (chipmunks) were impacted by logging. This research was conducted across an experimental FCD gradient (from least to most disturbed: contiguous control, fragmented control, clearcut, and high-leave shelterwood (SW)). Using gravid traps, I found that the mosquito community was resilient to logging with no significant difference in diversity or community composition across treatments. Mean number of female mosquitoes caught per trap-night declined with disturbance. FCD significantly affected the abundance of vector species in different ways. The primary LACV vector, Aedes triseriatus, and the recent invasive Ae. japonicus declined with logging. Other vectors (Ae. albopictus, Ae. canadensis, and Ae. vexans) thrived with logging. Culex pipiens/restuans was affected by disturbance but had no treatment preference. A mark-recapture study revealed that chipmunk abundance and LACV seroprevalence were greatest on the SW. In sync with Ae. triseriatus abundance but in contrast to the chipmunk results, mosquito LACV detection was significantly greater on unlogged sites. Surprisingly, LACV was detected in Ae. japonicus and Cx. pipiens/restuans. In a follow-up study, I isolated LACV from field-collected Ae. japonicus. Although LACV was previously isolated from Cx. pipiens, the vector competence was unknown. Therefore, I examined the vector competence of Cx. pipiens and Cx. restuans. Although poor vectors, I did detect LACV in the saliva of both species. An additional experiment found that nutritionally-stressed Cx. restuans were better vectors than those in the control group, indicating that environmental stressors (e.g., FCD) may alter the ability of accessory vectors to spread LACV. The influence of FCD on LACV is complex. Because logging decreases Ae. triseriatus abundance, human LACV risk is likely lowered by decreased transovarial vertical transmission. However, high chipmunk seroprevalence on disturbed sites suggest horizontal transmission with accessory vectors plays a larger role in LACV risk on recently logged sites.
Ph. D.

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Burkett, Nathan Daniel Mullen Gary R. "Comparative study of gravid-trap infusions for capturing blood-fed mosquitoes (diptera : culicidae) of the genera Aedes, Ochlerotatus, and Culex." Auburn, Ala., 2005. http://repo.lib.auburn.edu/2005%20Summer/master's/BURKETT_NATHAN_18.pdf.

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Silva, Joelma Soares da. "Seleção de isolados de Bacillus thuringiensis Berliner, 1911 ativos para larvas de Aedes aegypti Linnaeus, 1762, Anopheles darlingi Root, 1926 e Culex quinquefasciatus Say, 1823 (Diptera: Culicidae) e caracterização das toxinas mosquitocidas." Instituto Nacional de Pesquisas da Amazônia, 2017. http://bdtd.inpa.gov.br/handle/tede/2473.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The diversity of Bacillus thuringiensis obtained from three Brazilian biomes with pathogenic action for Ae. aegypti, An. darlingi and Cx. quinquefasciatus. Aspects as characterization of the active strains and the importance of the cyt1Aa gene also were analyzed.
Estudou-se a diversidade de Bacillus thuringiensis obtidos de três biomas brasileiros com ação patogênica para larvas de Ae. aegypti, An. darlingi e Cx. quinquefasciatus. Aspectos como caracterização molecular das linhagens ativas e a importância do gene cyt1Aa também foram analisados.

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Zettel, Nalen Catherine M. "Comparitive [sic] behavioral analysis of oviposition behavior in Aedes and Culex mosquitoes and the impact of pathogen infection on oviposition behavior." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024842.

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Veloso, André Borges. "Caracterização de serina peptidases e identificação do perfil proteico em intestino de Culex quinquefasciatus, Anopheles albitarsis s.s e Aedes aegypti (Diptera: Culicidae)." reponame:Repositório Institucional da FIOCRUZ, 2015. https://www.arca.fiocruz.br/handle/icict/14072.

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Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Rio de Janeiro, RJ, Brasil
Os dípteros Aedes aegypti, Anopheles albitarsis e Culex quinquefasciatus pertencem à família Culicidae e são considerados um problema de saúde pública quando atuam como vetores de parasitos e/ou arboviroses. O regime de alimentação de fêmeas dos mosquitos anautógenos influencia os processos que ocorrem no intestino e regula os genes envolvidos na reprodução. Além disso, apesar dos ciclos de vida dos parasitos veiculados por essas espécies de vetores serem distintos, todos eles são ingeridos durante a hematofagia e expostos ao ambiente do intestino médio (estômago) para em seguida atravessar o epitélio intestinal e chegarem ao tecido apropriado para seu desenvolvimento e/ou transmissão para um novo hospedeiro vertebrado. Neste trabalho, utilizamos uma abordagem proteômica para a identificação de proteínas totais, bem como ensaios em solução e enzimografia em gel copolimerizado com substrato para identificação de peptidases ativas presentes no intestino de fêmeas de Cx. quinquefasciatus e An. albitarsis s.s sob regime de alimentação com açúcar. As técnicas de enzimografia também foram utilizadas aqui para a caracterização de peptidases ativas de intestinos de fêmeas de Ae. aegypti alimentadas com açúcar ou sangue. Foi observado que o intestino de fêmeas das três espécies alimentadas com açúcar apresenta um complexo perfil de peptidases ativas, do tipo tripsina, composto por bandas migrando nas regiões entre ~ 24 a 40 kDa e em regiões de alto peso molecular Atividades proteolíticas foram detectadas entre pH 3,5 \2013 10, revelando diferenças quantitativas e qualitativas entre os perfis proteolíticos das três espécies. Em fêmeas de Ae. aegypti, o regime de alimentação com açúcar ou sangue alterou o perfil de SPtrip ativas do intestino de forma qualitativa e quantitativa. Um total de oito tripsinas em Cx. quinquefasciatus e dez tripsinas em An. albitarsis, foram identificadas por SDS-PAGE acoplado a LC-MS/MS. Apesar dessas SPtrip identificadas apresentarem características comuns às tripsinas digestivas de invertebrados, foram observadas diferenças nas sequências de aminoácidos, como por exemplo, em regiões de especificidade ao substrato e de ativação do zimogênio. Foi observado que os genes codificadores para SPtrip possuem diferentes tamanhos e organização, tais como, diferenças no número de éxons/introns. Com relação à composição de proteínas totais solúveis do intestino de fêmeas de Cx. quinquefasciatus e An. albitarsis, análise por LC-MS/MS e bioinformática revelou a presença de proteínas envolvidas em processos fisiológicos importantes, como exopeptidaes, glicosidades, enzimas detoxificantes e proteínas relacionadas com a interação parasito/vetor Em Cx. quinquefasciatus, foram identificadas 1397 proteínas, distribuídas em 1090 grupos, representando um total de ~ 7,5% das proteínas codificadas pelo genoma dessa espécie. Em An. albitarsis foram identificadas 916 proteínas distribuídas em 748 grupos. As centenas de proteínas presentes no intestino de fêmeas alimentadas com açúcar, de ambas as espécies, foram classificadas segundo sua ontologia gênica e o papel de algumas famílias de proteínas historicamente importante em mosquitos foram discutidas. Finalmente, foi demonstrado que abordagem proteômica combinada à enzimografia e bioinformática é uma ferramenta que pode auxiliar na anotação funcional dos genes de tripsinas expressos no intestino de fêmeas alimentadas com açúcar, bem como auxilia no mapeamento do repertório de proteínas totais presentes no intestino de Cx. quinquefasciatus e An. albitarsis
Culex quinquefasciatus, Anopheles albitarsis and Aedes aegypti are hematophagous insect from the Culicidae family that feeds on the blood of humans, dogs, birds and livestock. These species transmit a wide variety of pathogens between humans and animals. The midgut environment is the first location of pathogen-vector interaction for blood-feeding mosquitoes and the expression of specific peptidases in the early stages of feeding could influence the outcome of the infection. Trypsin-like serine peptidases belong to a multi-gene family that can be expressed in different isoforms under distinct physiological conditions. However, the confident assignment of the trypsin genes that are expressed under each condition is still a challenge due to the large number of trypsin-coding genes in the Culicidae family and most likely because they are low abundance proteins. We used zymography for the biochemical characterization of the peptidase profile of the midgut from Cx. quinquefasciatus, An. albitarsis, and Ae. aegypti females fed on sugar. We also caracterized the peptidses profile of the midgut from Ae. aegypti fed on blood, during different moments after fedding. Protein samples were also submitted to SDS-PAGE followed by liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis for peptidase identification. The peptidases sequences were analyzed by bioinformatics tools to assess their distinct features. Zymography revealed that trypsin-like serine peptidases were responsible for the proteolytic activity in the midgut of females fed on sugar or blood diet. In addition, we observed that the profile is influenced by the blood ingestion. After fractionation in SDS-PAGE, eight and ten trypsin-like serine peptidases were identified by LC-MS/MS in Cx. quinquefasciatus and An. albitarsis, respectively. Peptidases from Cx. quinquefasciatus were also analysed with bioinformatic tools revealing that they have structural features typical of invertebrate digestive trypsin peptidases but exhibited singularities at the protein sequence level such as: the presence of different amino acids at the autocatalytic motif and substrate binding regions as well as different number of disulfide bounds. Data mining revealed a group of trypsin-like serine peptidases that are specific to C. quinquefasciatus when compared to the culicids genomes sequenced so far. We demonstrated that proteomics approaches combined with bioinformatics tools and zymographic analysis can lead to the functional annotation of trypsin-like serine peptidases coding genes and aid in the understanding of the complexity of peptidase expression in mosquitoes.
2016-10-11

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OLIVEIRA, Iêda Ferreira de. "Caracterização molecular de membros de glutationa s-transferase da classe epsilon em processos biológicos de Aedes aegypti e Culex quinquefasciatus (Diptera: Culicidae)." Universidade Federal de Pernambuco, 2014. https://repositorio.ufpe.br/handle/123456789/11884.

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CNPq; PAPES VI
As glutationas S-transferase (GSTs) constituem uma superfamília de enzimas envolvida em diversos processos biológicos, por exemplo, detoxificação metabólica, transporte intracelular de substratos hidrofóbicos e proteção contra radicais livres. Em artrópodes, as classes delta e epsilon destacam-se por sua função no metabolismo de inseticidas. Até o momento, pouco se conhece sobre a diversidade dos genes GSTs dentro e entre as populações, assim como a função desses genes em outros processos biológicos, tais como no desenvolvimento e na resposta ao estresse. Este trabalho teve o objetivo de analisar a diversidade genética e padrões de transcrição de genes GSTs em Aedes aegypti e Culex quinquefasciatus. Sequências de DNA foram obtidas por amplificação e sequenciamento, enquanto a expressão gênica foi realizada por experimentos de RT-PCRq. Os resultados revelaram ausência de polimorfismo nos genes GSTE2 e GSTE3 de Ae. aegypti, além de assinaturas de seleção em três populações de Cx. quinquefasciatus. Após a infecção com o vírus Dengue (DENV), Ae. aegypti mostrou regulação gênica tecido-específica para os quatro genes avaliados ao longo do tempo, com destaque para GSTO e GSTX1. A expressão dos genes GSTE2 e GSTE3 em Cx. quinquefasciatus variou de acordo com o tecido, o estágio de vida e o sexo analisado. A partir dos resultados observados, pode-se concluir que: 1) os genes GSTEs provavelmente estão sendo selecionados ao longo do tempo, indicando que eles desempenham importante papel na sobrevivência desses culicídeos na natureza; 2) os mosquitos Ae. aegypti e Cx. quinquefasciatus são capazes de regular a expressão dos genes GSTs, no tempo e no espaço, de acordo com a natureza do estímulo.

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Yang, Fan. "Optimization of Cytogenetic and Physical mapping of Culicinae genomes." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/76948.

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Understanding chromosome structure and genome organization of Culicine mosquitoes can potentially contribute to the development of novel approaches to vector control. However, because of highly repetitive nature of the Aedes and Culex genomes, the structure of their polytene chromosomes is damaged by ectopic contacts that make the analysis difficult. Mitotic chromosomes from imaginal discs of 4th instar larvae of Aedes aegypti were tested as a source for the physical genome mapping for this mosquito. Chromosomes in imaginal discs are 10 times more abundant than chromosomes in nervous ganglia, and they do not accumulate chromosomal mutation as cell line chromosomes do. Prometaphase chromosomes in imaginal discs of Ae. aegypti are 4-5 times longer than metaphase chromosomes and can provide higher resolution for physical mapping. Cold temperature (+16°C) was proven to increase the number of the chromosomes. Hypotonic solution treatment of live larvae was proven to elongate chromosomes and improve banding patterns. We differentially stained these mitotic chromosomes with Giemsa and YOYO-1 to revile the banding pattern. We applied fluorescent in situ hybridization (FISH) procedure developed for human chromosomes to Ae. aegypti chromosomes. A strain from Culex pipiens, Cx. quinquefasciatus and their hybrids from the natural population in Virginia was successfully colonized in the laboratory. This strain can be used as a reliable source for cytogenetic studies.
Master of Science in Life Sciences

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18

Hunt, Sophia Katherine. "Climate- and habitat-mediation of predator-prey interactions in an invasion context." Thesis, University of Canterbury. Biological Sciences, 2015. http://hdl.handle.net/10092/11036.

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Ecosystems across the globe are facing a range of anthropogenically-driven changes, including biotic invasions, urbanisation and land-use alterations, which can affect ecosystem structure and stability. To manage both native species decline and invasive species spread it is imperative that we can accurately predict how current global environmental change will affect biotic communities. I examined effects of different land uses at both landscape- and habitat-scales on native (Culex pervigilans) and exotic (Aedes notoscriptus) mosquito distributions in lentic (standing water) freshwater habitats. Because of the importance of land use on habitat characteristics, I expected different land uses would contain different biotic communities, and that mosquitoes would more likely be present in simple communities with fewer predators. Moreover, because habitat disturbance and modification can significantly influence community structure, I expected less diverse pond communities in habitats within highly modified urban and pasture land uses would also be more likely to contain mosquitoes. I found land use affects mosquito presence, and was likely strongly linked with land-use effects on predator presence and taxon richness. Predators were more common in habitats within native forest and tussock grassland, and mosquitoes were almost entirely restricted to urban and pasture habitats. Moreover, local habitat characteristics had a strong influence on both mosquito and predator presence, with deeper and more open habitats supporting greater predator abundance, thereby excluding mosquito larvae. To further investigate the global of climate change on predator-prey interactions involving Ae. notoscriptus and Cx. pervigilans, I conducted two experiments. Firstly, I measured effects of habitat warming and short- and long-term habitat drying on interactions between the two mosquito species and three predatory invertebrates, Anisops wakefieldi backswimmers, Austrolestes colensonis damselflies, and Procordulia smithii dragonflies, which represented predators characteristic of different habitat drying regimes. A second experiment further tested interactions between A. wakefieldi and the two mosquito species in a wider range of temperatures. There was little evidence that short-term habitat drying affected interaction strengths of any of the predator-prey combinations, but strong evidence for the importance of temperature-mediated predation rates which depended on both predator and prey identities. Here, predators characteristic of more temporary hydroperiods showed temperature-mediated predation responses on the two mosquito species: increasing temperature resulted in greater predation on native Cx. pervigilans but not effect on predation on exotic Ae. notoscriptus. The second experiment revealed, again, that predation depended on both temperature and mosquito species with higher predation occurring at increased temperature, but also indicated life history traits could mediate the overall effect of temperature-mediated predation. Overall, I have shown that interactions between temperature, predator identity and mosquito species will be very important in determining the potential for mosquitoes to invade under a changing climate. Considering effects of both climate change and land-use-driven habitat modification on the invasion potential of mosquitoes in freshwater communities will therefore be important for managing both native species decline and spread of invaders. Moreover, research and management decisions on critical species like mosquitoes will need to encompass multiple drivers of climate change at both global and local scales.

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Masri, Reem Abed. "Chromosome and Genome Evolution in Culicinae Mosquitoes." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/104175.

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The Culicinae is the most extensive subfamily among the Culicidae family of mosquitoes. Two genera, Culex and Aedes, from this subfamily have world-wide distribution and are responsible for transmitting of several deadly diseases including Zika, West Nile fevers, chikungunya, dengue, and Rift Valley fevers. Developing high-quality genome assembly for mosquitoes, studying their population structure, and evolution can help to facilitate the development of new strategies for vector control. Studies on Aedes albopitcus as well as on species from the Culex pipiens complex, which are widely spread in the United States, provide excellent models on these topics. Ae. albopictus is one of the most dangerous invasive mosquito species in the world that transmits more than 20 arboviruses. This species has highly repetitive genome that is the largest among mosquito genomes sequenced so far. Thus, sequencing and assembling of such genome is extremally challenging. As a result, the lack of high-quality Ae. albopictus genome assembly has delayed the progress in understanding its biology. To produce a high-quality genome assembly, it was important to anchor genomic scaffolds to the cytogenetic map creating a physical map of the genome assembly. We first developed a new gene-based approach for the physical mapping of repeat-rich mosquito genomes. The approach utilized PCR amplification of the DNA probes based on complementary DNA (cDNA) that does not include repetitive DNA sequences. This method was then used for the development of a physical map for Ae. albopictus based on the in situ hybridization of fifty cDNA fragments or gene exons from twenty-four scaffolds to the mitotic chromosomes from imaginal discs. This study resulted in the construction of a first physical map of the Ae. albopictus genome as well as mapping viral integration and polyphenol oxidase genes. Moreover, comparing our present Ae. albopictus physical map to the current Ae. aegypti assembly indicated the presence of multiple chromosomal inversions between them. To better understand population structure and chromosome evolution in Culicinae mosquitoes, especially in the Culex pipiens complex, we studied genomic and chromosomal differentiation between two subspecies Cx. pipiens pipiens and Cx. pipiens molestus. For the species responsible for the spread of human diseases, understanding the population dynamics and processes of taxa diversification is important for an effective mosquito control . Two vectors of West Nile virus, Cx. p. pipiens and Cx. p. molestus, exhibit epidemiologically important behavioral and physiological differences, but the whole-genome divergence between them was unexplored. The first goal of this study was to better understand the level of genomic differentiation and population structures of Cx. p. pipiens and Cx. p. molestus from different continents. We sequenced and compared whole genomes of 40 individual mosquitoes from two locations in Eurasia and two in North America. Principal Component, ADMIXTURE, and neighbor joining analyses of the nuclear genomes identified two major intercontinental, monophyletic clusters of Cx. p. pipiens and Cx. p. molestus. The level of genomic differentiation between the subspecies was uniform along chromosomes. The ADMIXTURE analysis determined signatures of admixture in Cx. p. pipens populations, but not in Cx. p. molestus populations. Thus, our study identified that Cx. p. molestus and Cx. p. pipiens represent different evolutionary units with monophyletic origin that have undergone incipient ecological speciation. The second goal was to study differences at the chromosome level between these two organisms. We first measured whole chromosome and chromosome arm length differences between Cx. p. molestus and Cx. p. pipiens as a basic cytogenetic approach. In addition, we used the novel Hi-C approach to detect chromosomal rearrangements between them since Hi-C was successful in detecting a known inversion in Cx. quinquefasciatus. Cx. p. molestus and Cx. p. pipiens embryos were used to perform the Hi-C technique. Analysis of the Hi-C data showed the presence of two different inversions in Cx. p. pipiens and Cx. p. molestus heatmap, which could explain their different physiology and adaptation in nature. Developing modern genomic and cytogenetic tools is important to enhance the quality of genome assemblies, improve gene annotation, and provide a better framework for comparative and population genomics of mosquitoes; also it is the foundation for the development of novel genome-based approaches for vector control.
Doctor of Philosophy
Mosquitoes are medically important insects because they vector a range of diseases that infect humans. The subfamily Culicinae is responsible for transmitting such diseases as Zika, dengue, and West Nile fevers, which have triggered fatal infections and epidemics in multiple parts of the world. Since 2010-2016, studies have reported exceeding levels of insecticide resistance that slows the disease elimination process. Novel transgenic techniques have a tremendous potential for more efficiently minimizing mosquito-borne diseases and transmission. Availability of high-quality genome assemblies for mosquitoes may help to better understand their population structure and to develop effective and safe vector-control approaches that we urgently need. For the development of high-quality genome assemblies, we need to construct a physical genome map, that shows the physical locations of genes or other DNA sequences of interest along the chromosomes. For this reason, we developed a new gene-based approach for the physical mapping of the mosquito genomes. This method was then used for the development of a physical map for Ae. albopictus. This study resulted in the generation of the first physical map of the Ae. albopictus genome. To understand population structure in Culicinae mosquitoes, we used mosquitoes from the Culex pipiens complex. Species in this complex transmit different arthropod-borne viruses or arboviruses. Notable is the West Nile Virus, which has triggered fatal infections and epidemics in Eastern and Central Europe, North America and is also known in Asia, Australia, Africa, and the Caribbean. We specifically focused on two subspecies in this complex, Cx. pipiens pipiens and Cx. pipiens molestus that are morphologically identical, but are different physiologically and behaviorally. Although they are spread globally in temperate regions, their population structure and taxonomic status remains unclear. The first goal of this study was to better understand the level of genomic differentiation of Cx. p. pipiens and Cx. p. molestus from different continents. We sequenced and compared the whole genomes of 40 individual mosquitoes from two locations in Eurasia and two in North America. Our study identified that Cx. p. molestus and Cx. p. pipiens represent different evolutionary units that are currently undergoing ecological speciation. The second goal was to study differences at the chromosome level between them. Using the Hi-C approach we detected presence of two different inversions in Cx. p. pipiens and Cx. p. molestus, which could potentially explain their different physiology and adaptation.

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Ferreira, Lígia Maria. "Análise da refratariedade do Aedes aegypti à toxina binária do biolarvicida Bacillus sphaericus." Centro de Pesquisas Aggeu Magalhães, 2009. http://beta.arca.fiocruz.br/handle/icict/14535.

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Fundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Recife, PE, Brasil
O principal fator larvicida do Bacillus sphaericus (Bsp) para culicídeos é a protoxina Bin, produzida sob a forma de um cristal, durante a esporulação. Quando ingerido pelas larvas o cristal é processado e a toxina Bin reconhece e liga-se a receptores específicos do epitélio intestinal. O receptor em Culex quinquefasciatus é uma alfa-glicosidase de 60 kDa, ligada à membrana intestinal por uma âncora GPI, denominado Cqm1. Larvas de Aedes aegypti são consideradas refratárias ao Bsp, pois a toxina Bin não reconhece receptores no microvilli intestinal. No entanto, a análise do genoma do Ae. aegypti, revelou a presença do gene aam1, que codificaria uma proteína ortóloga e com 83 por cento de similaridade ao receptor Cqm1. O principal objetivo deste estudo foi elucidar a base molecular da refratariedade do Ae. aegypti ao Bsp, determinada pela ausência de ligação da toxina Bin ao epitélio intestinal das larvas. Para tal, foi feita uma investigação da expressão da proteína Aam1 e do perfil de alfa-glicosidases de Ae. aegypti, tendo como referência o receptor Cqm1. Os resultados mostraram que larvas e adultos de Ae. aegypti expressam uma ?-glicosidase de membrana de 70 kDa, reconhecida pelo anticorpo anti-Cqm1, e que provavelmente trata-se da proteína Aam1. Tal proteína é expressa no microvilli intestinal das larvas em níveis superiores à Cqm1, no entanto, não apresenta capacidade de ligação à toxina Bin. Em uma segunda etapa, a avaliação de proteínas Aam1 e Cqm1 recombinantes, produzidas em lisado de reticulócitos de coelho, mostrou que ambas não foram capazes de se ligar específicamente à toxina Bin. A falha na ligação da proteína Cqm1 à toxina Bin pode ser decorrente da ausência do processamento pós-traducional adequado neste sistema de expressão, indicando que certas modificações podem ser críticas para a sua funcionalidade. O tratamento da proteína Cqm1 nativa à temperatura de 100 °C aboliu a sua capacidade de ligação à toxina Bin, indicando que a conformação da proteína pode ser essencial para a sua funcionalidade. Os resultados obtidos demonstram que, apesar dos altos níveis de expressão da Aam1 nas larvas de Ae. aegypti, a proteína não é capaz de ligar-se à toxina Bin. Tal fato estar relacionado a outros fatores críticos para sua funcionalidade, tais como diferenças conformacionais e/ou modificações pós-traducionais que determinem o status de refratariedade do Ae. aegypti

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Goudreau, Réal. "Effet de la compétition intraspécifique et interspécifique chez des populations larvaires de deux espèces de moustiques : Aedes triseriatus (Say) et Culex restuans Theobald (Diptera : Culicidae), dans les pneus abandonnés." Thèse, Université du Québec à Trois-Rivières, 1988. http://depot-e.uqtr.ca/5749/1/000569511.pdf.

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Skiles, Andrea Glenn. "EVALUATION OF PYRIPROXYFEN APPLIED IN BARRIER SPRAYS FOR MOSQUITO SUPPRESSION." UKnowledge, 2017. http://uknowledge.uky.edu/entomology_etds/36.

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Despite advances in mosquito management, mosquito-borne disease in the United States is still of relevant public health concern and vector control is a top priority in preventing transmission of pathogens. Insecticide barrier sprays have become a common tool for suppression of mosquitoes in single-homeowner backyards. The application of the synthetic pyrethroid, lambda-cyhalothrin to perimeter vegetation with a backpack sprayer has been shown to significantly suppress mosquito levels for around 6 weeks. In an attempt to lengthen the effective duration of treatment, the IGR, pyriproxyfen, was added to a backpack mist blower with lambda-cyhalothrin, as adult mosquitoes exposed to pyriproxyfen have been shown to disseminate it to oviposition sites and to experience lowered fecundity. This treatment was compared to lambda-cyhalothrin alone and to a water control. Mosquito populations were sampled using CO2-baited CDC light traps, CDC gravid traps, human landing rates, and ovitraps. Leaf bioassays were performed. The following summer, the same treatments were applied with a truck-mounted mist blower to tree lines in Central Kentucky, to test the efficacy of an application method that could be used on large properties. Finally, bioassays were performed with water sampled from pyriproxyfen-treated containers, exposed to field conditions to test for residual efficacy.

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Hambrick, Bethany Lynn. "Population Dynamics and Community Structure of Mosquitoes (Diptera: Culicidae) Recorded in Denton, Texas from 2005 to 2015." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157552/.

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A population survey was conducted on the mosquito species recorded in Denton, Texas for the years of 2005 to 2015. Data used in this project were obtained from an ongoing, long-term surveillance program led by the City of Denton and conducted through the University of North Texas. Research focused on the population dynamics and community structure of mosquitoes collected within urban areas of Denton, Texas in relation to certain environmental variables. A total of 80,837 female mosquitoes were captured and represented 38 species found under the following genera: Aedes, Anopheles, Coquillettidia, Culex, Culiseta, Mansonia, Orthopodomyia, Psorophora, Toxorhynchites, and Uranotaenia. Culex quinquefasciatus was the most abundant species followed by Aedes vexans. Seasonal patterns of the most abundant species revealed high variability throughout the study. Container breeders were most abundant in August and those that breed in floodwaters were most abundant in the months of May and September. Samples were tested for arbovirus presence through the Texas Department of State Health Services in Austin, Texas and multiple pools tested positive for West Nile virus throughout the study. Stepwise multiple regression and Spearman's rank correlation analyses were performed to examine the relationship between the mosquito community and environmental variables. Data revealed that temperature, precipitation, and dew point were the most important variables influencing the mosquito population in the City of Denton.

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Vazeille, Marie-Christine. "Etude de quelques virus de dipteres comme modele pour la transmission verticale des arbovirus chez les insectes." Clermont-Ferrand 2, 1987. http://www.theses.fr/1987CLF21064.

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Rey, Delphine. "Un exemple de coévolution plante-arthropode : étude de la phytotoxicité des composés phénoliques de la litière d'Alnus glutinosa (Bétulacées) et perspectives d'application en démoustication." Université Joseph Fourier (Grenoble), 2000. http://www.theses.fr/2000GRE10074.

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Dans les gites a moustiques de l'avant-pays alpin, les composes phenoliques issus de la decomposition de la litiere de la vegetation ripariale sont impliques dans la segregation ecologique de la faune arthropodienne detritivore. Cette relation plante-arthropode a ete exploree au niveau ecotoxicologique, evolutif et applique. Des bioessais comparatifs sur des larves de dipteres et des crustaces planctoniques ont confirme la sensibilite differentielle des animaux aux composes phenoliques de l'acide tannique et de la litiere decomposee d'aulne. Cette sensibilite est en rapport avec le potentiel enzymatique detoxifiant de chaque espece (ou ecotype), notamment au niveau des mono-oxygenases a p 450, esterases et gst. L'acquisition de ce potentiel de detoxication a permis aux especes (ou ecotypes) resistants de coloniser des gites fermes, a litiere riche en composes phenoliques (type aulne). L'effet toxique de ces xenobiotiques vegetaux s'exerce sur l'epithelium du mesenteron selon un scenario deletere comparable a celui induit par le bacterio-insecticide bacillus thuringiensis var israelensis (bti). Le pouvoir toxique est lie a la litiere qui doit subir un long processus de decomposition in natura. Une analyse phytochimique preliminaire a permis de le localiser, apres extraction selective, dans une fraction phenolique insoluble du materiel vegetal correspondant a la paroi. L'absence de correlation entre phylogenie moleculaire et sensibilite larvaire aux composes phenoliques, suggere que la coevolution (non reciproque) plante-moustique dans les hydrosystemes alpins est un phenomene recent, associe a une radiation evolutive rapide. La comparaison des potentialites insecticides des composes phenoliques vegetaux a celles de deux insecticides conventionnels (bti et temephos) suggere la possibilite d'utilisation de ces composes naturels en demoustication de zones anthropisees, riches en especes invasives, vulnerantes et vectrices (type culex pipiens, aedes aegypti, a. Albopictus).

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Charles, Jean-François. "Bacillus thuringiensis sérotype H 14 et bacillus sphaericus : sporulation, biogenèse des cristaux larvicides et cytopathologie sur larves de moustiques (diptères; culicidae)." Paris 6, 1987. http://www.theses.fr/1987PA066303.

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Lin, Chang-Chi, and 林昌棋. "Expression and characterization of two mosquito STATs from Aedes albopictus and Culex tritaeniorhynchus." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/85644792921138466951.

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博士
國防醫學院
生命科學研究所
92
Two mosquito STATs, AaSTAT and CtSTAT, have been cloned from Aedes albopictus and Culex tritaeniorhynchus mosquitoes, respectively. These two STATs are more similar to those of Drosophila, Anopheles, and mammalian STAT5 in the DNA binding and SH2 domains. The mRNA transcripts are expressed at all developmental stages, and the proteins are present prominently at the pupal and adult stages in both mosquitoes. Stimulation with LPS resulted in the increase of tyrosine phosphorylation and DNA binding activity and nuclear translocations in fat body cells of AaSTAT and CtSTAT as well as the increase of luciferase activity of a reporter gene containing Drosophila STAT binding motif in mosquito C6/36 cells. After infected with Japanese encephalitis virus, nuclear extracts of C6/36 cells revealed the decrease of tyrosine phosphorylation and DNA binding activity of AaSTAT that could be restored by sodium orthovanadate treatment. Furthermore, sodium orthovanadate treatment could decrease the synthesis of viral protein in C6/36 cells. Taken all the data together, this is the first report to clone and characterize two mosquito STATs with 81% identity and to demonstrate different response of tyrosine phosphorylation and DNA binding of these two STATs by LPS treatment and by JEV infection. This study also provided clues to understanding the possible pathogenesis of JEV, and another approaches to development new vaccines and drugs for flaviviruses.

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Liu, Yen-Ming, and 劉彥明. "Phylogeny of culex and aedes inferred from sequences of mitochondrial COI and ATPase6 genes." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/64286572028733391420.

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Pan, Hsuan-Jen, and 潘宣任. "Evaluation on vector competence of Culex tritaeniorhynchus and Aedes albopictus for Bovine ephemeral fever virus." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/41415717129984736278.

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碩士
國立臺灣大學
昆蟲學研究所
100
Bovine ephemeral fever is caused by Bovine ephemeral fever virus (BEFV) that belongs to the genus Ephemerovirus of the family Rhabdoviridae. This disease causes significant economic loses through loss in milk production, loss of condition in beef herd and high cost of medication. Although BEFV has been isolated from field collected biting midges (Culicoides spp.), but the disparity of bovine ephemeral fever epidemic area and distribution of biting midges suggests that vectors other than Culicoides may be involved in the transmission of BEFV. The objective of this research was to investigate the susceptibility and transmission potential of mosquitoes to BEFV. Artificial bloodmeal or intra-thoracic injection was used to let mosquitoes acquire the virus. The infection of BEFV in mosquitoes was examined by immunofluorescence assay and confocal laser scanning microscopy. To examine the BEFV transmission potential of virus-infected mosquitoes, the saliva of mosquito was used to infect baby hamster cells. Results showed that BEFV infected many organs and tissues of Culex tritaeniorhynchus Giles and Aedes albopictus Skuse after oral infection through artificial bloodmeal, and the major infection was detected in posterior midgut, salivary glands and brain. Intra-thoracic injection helped BEFV to escape from the midgut barriers of Cx. tritaeniorhynchus and Ae. albopictus, and it increased virus infection rate, promote infection progress and enhance infection intensity. The susceptibility of Cx. tritaeniorhynchus to BEFV was always higher than that of Ae. albopictus no matter using oral infection or virus injection. Only the saliva collected from BEFV-infected Cx. tritaeniorhynchus had cytopathogenic effect in baby hamster cells that implies Cx. tritaeniorhynchus may be the vector of BEFV. Neither through oral infection nor intra-thoracic injection of BEFV, the saliva collected from virus-infected Ae. albopictus did not infect baby hamster cells that implies Ae. albopictus is a non-vector of BEFV. According to the ecological data from field surveys and our results, geography distribution, population dynamic, blood-feeding preference and serological preference well support the hypothesis that Cx. tritaeniorhynchus may transmit BEFV in Taiwan. This study identified Cx. tritaeniorhynchus as a potential vector of BEFV, and the information would be helpful to prevent the disease by environmental management and insecticide application.

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Weng, Ling-Wei, and 翁淩維. "Effects of Salts on the Eggshell Structure of Aedes aegypti, Culex quinquefasciatus and Forcipomyia taiwana." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/99mrnk.

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碩士
國立臺灣大學
昆蟲學研究所
107
Aedes aegypti (Linnaeus), Culex quinquefasciatus Say and Forcipomyia taiwana (Shiraki) are important nuisance pests in Taiwan. All of them would make people allergic reaction through the bloodsucking and Ae. aegypti and Cx. quinquefasciatus also can spread diseases and harm human healthy. The control strategies always focus on larval and adult stage instead of the egg stage. Previous study suggested that eggs laid on the NaCl-containing medium are unable to melanize. When laid on MgSO4-containing medium, the eggs of Ae. aegypti and F. taiwana but not Cx. quinquefasciatus, are able to melanize. This study further investigates the effect of NaCl and MgSO4 solutions on the surface of eggs, structure of eggshell and serosal cuticle which contribute the eggs resistance to desiccation on Ae. aegypti, Cx. quinquefasciatus and F. taiwana. Our results showed that the unmelanization group of salt-treated eggs become shorter in length, outer chorionic cell decreased in area or tubercle increased in area ratio. These results indicate the egg become shrunk due to the failure of melanization. Moreover, the serosal cuticle only existed in the naturally laid and melanized eggs. Transection of NaCl-treated Ae. aegypti eggs showed that the eggshell had two intact layers (exochorion and endochorion) and the width of endochorion showed significantly wider (0.4-0.5 μm). The major prophenoloxidase gene (proPO5) responsible for egg melanization was expressed in all treatments, however, the expression level was significantly decreased in MgSO4-treated naturally laid eggs and NaCl-treated dissected eggs. The reason of salts influence egg chorion melanization is still unknown and deserves further investigation.

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"Prospecção de estirpes de Bacillus thuringiensis e Bacillus sphaericus tóxicas contra Aedes aegypti e Culex quinquefasciatus." Tese, Biblioteca Digital de Teses e Dissertações da UCB, 2002. http://www.bdtd.ucb.br/tede/tde_busca/arquivo.php?codArquivo=119.

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"Analise citologica de populações de Aedes aegypti (Linnaeus, 1762) e Culex quinquefasciatus Say, 1823 (Diptera, Culicinae)." Tese, Biblioteca Digital da Unicamp, 2002. http://libdigi.unicamp.br/document/?code=vtls000272471.

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Spencer, Jennifer Ann. "The effect of different diets on the reproduction of two species of mosquitoes, Aedes aegypti and Culex pipiens." Thesis, 1987. http://hdl.handle.net/10413/9966.

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Larvae of Culex quinquefasciatus and Aedes aegypti were raised on five different diets and the effects thereof on various parameters was studied. The diets used were: A = Pronutro and Tastee wheat, B = Epo 1 rat cubes, C= Breeder's Dogmor puppy chunks, D = Vital Brewer's yeast powder and E (the control) = Vital dessicated liver. The following results were obtained. 1. Fecundity appeared not to be affected by diet in both species. 2. Fertility did not appear to be affected by diet either. 3. Diets C and D significantly shortened the duration of the larval stage in C. quinquefasciatus when compared with the control Diet E. In A. aegypti diets B, C and D produced larval periods that were significantly shorter than the control. 4. The pupal stage in C. quinquefasciatus in diets C and D was also. Significantly shorter than that of the control diet E. In A. aegypti only diet B produced a pupal stage that was significantly shorter than the control. 5. Larval mortality was significantly higher than the control diet E in C. quinquefasciatus in diet group A. There was no significant differences between the experimental diet groups A to D and the control, in A. aegypti. 6. Pupa 1 mortality appeared to be unaffected by larval diet in both species. 7. Larval diet did not affect adult mortality either. 8. In C. quinquefasciatus the size of the ovaries was significantly smaller than the control in diet group B. Ovary size appeared to be unaffected by larval diet in A. aegypti. 9. Sex ratio appeared to be greatly affected by larval diet. There were significantly more males than females in diets D and E in Culex quinquefasciatus and in diets C and E in Aedes aegypti. 10. Oogenesis also appeared to be affected by larval diet. In C. quinquefasciatus oogenesis was found to be slower from 36 hours PBM in diet A. In A. aegypti oogenesis was slower in diets A and B from 60 hours PBM. The rate of oogenesis in C. quinquefasciatus was also found to be slower, than that in A. aegypti.
Thesis (M.Sc.)-University of Durban-Westville, 1987.

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Mahood, Thomas. "Differential innate immunity responses to West Nile virus and bacterial infections in mosquitoes." 2013. http://hdl.handle.net/1993/16594.

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Identifying the molecular interactions of pathogens in different mosquito species is critical for understanding how mosquitoes transmit diseases. In this study, the role of the Jak-STAT immune signalling pathway in two different mosquito species, (Aedes aegypti L.) and (Culex quinquefasciatus L.) was assessed. Using in silico analysis tools, cell culture, and molecular techniques, changes in gene expression were assessed during lipopolysaccharide (LPS) challenge and West Nile virus (WNV) infection in the two species. It was found that activation of the Jak-STAT pathway occurred more quickly in Ae. aegypti cells compared to Cx. quinquefasciatus cells during LPS exposure. During WNV infections, no significant differences were observed, although preliminary evidence suggests that differential activation of the Jak-STAT pathway may exist between the two species. This research extends our understanding of the mosquito immune system while demonstrating the critical importance of vector-virus interactions across different mosquito species.

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Tranchida, María Cecilia. "Estudio y evaluación de depredadores y bacterias entomopatógenas de Aedes aegypti (L.) y Culex pipiens (L.), como potenciales agentes de control." Tesis, 2010. http://hdl.handle.net/10915/4304.

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Aedes aegypti y Culex pipiens se encuentran entre las principales especies de mosquitos vectores de enfermedades a nivel mundial. Ambas, son de gran importancia sanitaria en la Argentina. Aedes aegypti, es el principal vector del dengue y la fiebre amarilla. Está presente en la Argentina desde 1983, cuando fue confirmada su reemergencia en nuestro país. A partir de entonces comenzaron a detectarse casos de dengue hasta que el último brote de esta enfermedad en 2009 produjo 24.720 casos autóctonos confirmados por la OPS a nivel nacional. Culex pipiens es vector de algunas filariasis, y de importantes arbovirosis como la ocasionada por el virus del Nilo Occidental. La actividad vectorial de este mosquito se ve incrementada en zonas donde la densidad de zanjas de desagüe domiciliario es elevada, ya que este tipo de ambiente constituye un lugar propicio para su desarrollo. De su importancia sanitaria nace la necesidad de controlar su actividad vectorial, manteniendo las poblaciones en bajas densidades. El objetivo de este trabajo fue desarrollar estrategias para el control de A. aegypti y C. pipiens, basadas en métodos biológicos, eficaces, permanentes y seguros para el ambiente, mediante el empleo de enemigos naturales presentes en las poblaciones de ambas especies. En este trabajo, fueron evaluados copépodos, turbelarios y peces como depredadores; y bacterias entomopatógenas (α-protobacterias y bacterias esporulantes). El estudio de los copépodos, tuvo como objetivo identificar a la comunidad de copépodos larvívoros que se desarrolla en los criaderos de mosquitos, ubicados en los alrededores de la ciudad de La Plata, para identificar nuevas especies capaces de depredar mosquitos que habitan recipientes artificiales (A. aegypti y C. pipiens). La diversidad de copépodos larvívoros fue mayor en los cuerpos de agua permanentes. Acanthocyclops robustus, Diacyclops uruguayensis, Macrocyclops albidus y Mesocyclops longisetus fueron seleccionados por su capacidad depredadora. En el laboratorio fueron evaluadas: la capacidad de depredación de ambos sexos y diferentes estadios, preferencia de especie presa, y la tasa de depredación diaria. Las hembras de estas especies de copépodos presentaron mayor capacidad depredadora. No se detectó preferencia de los copépodos hacia ninguna de las especies de mosquitos. También se evaluó la tolerancia a la desecación y la capacidad de vivir en el agua que se acumula en los recipientes artificiales. Diacyclops uruguayensis y A. robustus sobrevivieron en las condiciones de sequía ensayadas en este estudio, pero D. uruguayensis mostró una menor supervivencia en el agua de recipientes artificiales. Macrocyclops albidus no sobrevivió en condiciones de sequía ni toleró el agua extraída de los recipientes artificiales. La supervivencia de M. longisetus ante estas condiciones, fue reducida. Se concluyó que las especies D. uruguayensis y A. robustus podrían ser buenos candidatos para el control de especies de mosquitos que crían en recipientes artificiales.

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Ulvedal, Carolina. "Infectividad de Heterorhabditis bacteriophora (aislado 4) (Nematoda: Heterorhabditidae) en larvas de Aedes aegypti (L.) y Culex quinquefasciatus Say en condiciones de laboratorio." Bachelor's thesis, 2013. http://hdl.handle.net/11086/22831.

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Aedes aegypti y Culex quinquefasciatus son reconocidos vectores de los virus Dengue y Encefalitis de San Luis en nuestro país, respectivamente. Un método alternativo al control químico, que se aplica actualmente con estos dípteros, es el empleo de insecticidas biológicos, como los nematodos entomopatógenos. El objetivo general de este trabajo fue evaluar la infectividad de Heterorhabditis bacteriophora (aislado 4) proveniente de la ciudad de Córdoba, en larvas de Cx. quinquefasciatus y Ae. aegypti en condiciones de laboratorio. Se emplearon 30 larvas de segundo estadio de cada especie de mosquito y se expusieron a diferentes dosis de nematodos: 1:1, 5:1, 15:1, 100:1, 500:1, 750:1 y 1500:1 Juveniles infectivos del nematodo por larva de mosquito (JIs/larva). Se realizaron 4 réplicas con los correspondientes controles por dosis y por especie de mosquito. Los resultados obtenidos se analizaron mediante ANOVA. Los valores de parasitismo variaron entre 2,5 y 80% en Cx. quinquefasciatus y entre 4,2 y 92,5% en Ae. aegypti, detectándose diferencias significativas entre las dosis ensayadas (p < 0,0001). Se estimaron las DL50 que resultaron 160,8 JIs/larva para Cx. quinquefasciatus y 113,6 JIs/larva para Ae. aegypti. Independientemente de las dosis de aplicación, en ambas especies de mosquitos, el tercer estadio larval resultó el más parasitado, difiriendo significativamente de los estadios restantes (p < 0,0001). El número total de nematodos que ingresaron en las larvas fue significativamente mayor a partir de la dosis 100:1 y 500:1 para Cx. quinquefasciatus y Ae. aegypti, respectivamente (p < 0,0001). En ambas especies hospedadoras, se encontraron nematodos adultos en dosis superiores a 5:1 y los valores más altos se registraron a partir de la dosis 500:1, observándose diferencias significativas entre las dosis (p < 0,0001). En Ae. aegypti, el desarrollo de nematodos adultos fue mayor en todas las dosis evaluadas. Al finalizar el ciclo parasitario se observó la emergencia de nuevos JIs a partir de la dosis 100:1 y las superiores a ésta en Ae. aegypti y sólo en la dosis 1500:1 en Cx. quinquefasciatus. Los porcentajes de JIs melanizados superaron en todas las dosis el 94% y se observaron principalmente en el tórax en Cx. quinquefasciatus. En tanto que, en Ae. aegypti en dosis mayores a 15:1 no superaron el 50% y se encontraron principalmente en el tórax y abdomen de las larvas, observándose diferencias significativas entre las regiones corporales en ambas especies (p < 0,0001). Se pone en evidencia por primera vez la susceptibilidad de estas dos especies de mosquitos al parasitismo en condiciones de laboratorio de un aislado autóctono de H. bacteriophora y su potencial como bioreguladores para el manejo de estos mosquitos plaga.
Fil: Ulvedal, Carolina. Universidad Nacional de Córdoba Facultad de Ciencias Exactas, Físicas y Naturales. Ciencias Biológicas. Cátedra de Parasitología; Argentina.
Otras Ciencias Biológicas

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Ali, Mushal Allam Mohamed Alhaj. "Identification and characterization of microRNAs and their putative target genes in Anopheles funestus s.s." 2013. http://hdl.handle.net/11394/3949.

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Philosophiae Doctor - PhD
The discovery of microRNAs (miRNAs) is one of the most exciting scientific breakthroughs in the last decade. miRNAs are short RNA molecules that do not encode proteins but instead, regulate gene expression. Over the past several years, thousands of miRNAs have been identified in various insect genomes through cloning and sequencing, and even by computational prediction. However, information concerning possible roles of miRNAs in mosquitoes is limited. Within this context, we report here the first systematic analysis of these tiny RNAs and their target mRNAs in one of the principal African malaria vectors, Anopheles funestus s.s. Firstly, to extend the known repertoire of miRNAs expressed in this insect, the small RNAs from the four developmental stages (egg, larvae, pupae and the adult females), were sequenced using next generation sequencing technology. A total of 98 miRNAs were identified, which included 65 known Anopheles miRNAs, 25 miRNAs conserved in other insects and 8 novel miRNAs that had not been reported in any species. We further characterized new variants for miR-2 and miR-927 and stem-loop precursors for miR-286 and miR-2944. The analysis showed that many miRNAs have stage-specific expression, and co-transcribed and co-regulated during development. Secondly, for a better understanding of the molecular details of the miRNAs function, we identified the target genes for the Anopheles miRNAs using a novel approach that identifies overlap genes among three target prediction tools followed by filtering genes based on functional enrichment of GO terms and KEGG pathways. We found that most of the miRNAs are metabolic regulators. Moreover, the results suggest implication of some miRNAs not only in the development but also in insect-parasite interaction. Finally, we developed the InsecTar database (http://insectar.sanbi.ac.za) for miRNA targets in the three mosquito species; Anopheles gambiae, Aedes aegypti, and Culex quinquefasciatus, which incorporates prediction and the functional analysis of these target genes. The proposed database will undoubtedly assist to explore the roles of these regulatory molecules in insects. This type of analysis is a key step towards improving our understanding of the complexity and regulationmode of miRNAs in mosquitoes. Moreover, this study opens the door for exploration of miRNA in regulation of critical physiological functions specific to vector arthropods which may lead to novel approaches to combat mosquito-borne infectious diseases.

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Dissertations / Theses on the topic 'Aedes; Culex'

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