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1.
Mem Inst Oswaldo Cruz ; 116: e200547, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34076041

RESUMO

BACKGROUND: Forty percent of the world's population live in areas where they are at risk from dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Dengue viruses are transmitted primarily by the mosquito Aedes aegypti. In Cali, Colombia, approximately 30% of field collected Ae. aegypti are naturally refractory to all four dengue serotypes. OBJECTIVES: Use RNA-sequencing to identify those genes that determine refractoriness in feral mosquitoes to dengue. This information can be used in gene editing strategies to reduce dengue transmission. METHODS: We employed a full factorial design, analyzing differential gene expression across time (24, 36 and 48 h post bloodmeal), feeding treatment (blood or blood + dengue-2) and strain (susceptible or refractory). Sequences were aligned to the reference Ae. aegypti genome for identification, assembled to visualize transcript structure, and analyzed for dynamic gene expression changes. A variety of clustering techniques was used to identify the differentially expressed genes. FINDINGS: We identified a subset of genes that likely assist dengue entry and replication in susceptible mosquitoes and contribute to vector competence. MAIN CONCLUSIONS: The differential expression of specific genes by refractory and susceptible mosquitoes could determine the phenotype, and may be used to in gene editing strategies to reduce dengue transmission.


Assuntos
Aedes , Vírus da Dengue , Dengue , Aedes/genética , Animais , Colômbia , Vírus da Dengue/genética , Mosquitos Vetores/genética , RNA , Transcriptoma/genética
2.
BMC Genomics ; 22(1): 396, 2021 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-34044772

RESUMO

BACKGROUND: Transmission of pathogens by vector mosquitoes is intrinsically linked with mosquito's reproductive strategy because anautogenous mosquitoes require vertebrate blood to develop a batch of eggs. Each cycle of egg maturation is tightly linked with the intake of a fresh blood meal for most species. Mosquitoes that acquire pathogens during the first blood feeding can transmit the pathogens to susceptible hosts during subsequent blood feeding and also vertically to the next generation via infected eggs. Large-scale gene-expression changes occur following each blood meal in various tissues, including ovaries. Here we analyzed mosquito ovary transcriptome following a blood meal at three different time points to investigate blood-meal induced changes in gene expression in mosquito ovaries. RESULTS: We collected ovaries from Aedes aegypti that received a sugar meal or a blood meal on days 3, 10 and 20 post blood meal for transcriptome analysis. Over 4000 genes responded differentially following ingestion of a blood meal on day 3, and 660 and 780 genes on days 10 and 20, respectively. Proteins encoded by differentially expressed genes (DEGs) on day 3 include odorant binding proteins (OBPs), defense-specific proteins, and cytochrome P450 detoxification enzymes. In addition, we identified 580 long non-coding RNAs that are differentially expressed at three time points. Gene ontology analysis indicated that genes involved in peptidase activity, oxidoreductase activity, extracellular space, and hydrolase activity, among others were enriched on day 3. Although most of the DEGs returned to the nonsignificant level compared to the sugar-fed mosquito ovaries following oviposition on days 10 and 20, there remained differences in the gene expression pattern in sugar-fed and blood-fed mosquitoes. CONCLUSIONS: Enrichment of OBPs following blood meal ingestion suggests that these genes may have other functions besides being part of the olfactory system. The enrichment of immune-specific genes and cytochrome P450 genes indicates that ovaries become well prepared to protect their germ line from any pathogens that may accompany the blood meal or from environmental contamination during oviposition, and to deal with the detrimental effects of toxic metabolites.


Assuntos
Aedes , Aedes/genética , Animais , Feminino , Expressão Gênica , Mosquitos Vetores/genética , Ovário , Oviposição
3.
J Vis Exp ; (170)2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33938890

RESUMO

A recently published DNA extraction protocol using magnetic beads and an automated DNA extraction instrument suggested that it is possible to extract high quality and quantity DNA from a well-preserved individual mosquito sufficient for downstream whole genome sequencing. However, reliance on an expensive automated DNA extraction instrument can be prohibitive for many laboratories. Here, the study provides a budget-friendly magnetic-bead-based DNA extraction protocol, which is suitable for low to medium throughput. The protocol described here was successfully tested using individual Aedes aegypti mosquito samples. The reduced costs associated with high quality DNA extraction will increase the application of high throughput sequencing to resource limited labs and studies.


Assuntos
Aedes/genética , DNA/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de DNA/métodos , Animais , Fenômenos Magnéticos
4.
BMC Genomics ; 22(1): 253, 2021 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-33836668

RESUMO

BACKGROUND: Aedes aegypti mosquito, the principal global vector of arboviral diseases, lays eggs and undergoes larval and pupal development to become adult mosquitoes in fresh water (FW). It has recently been observed to develop in coastal brackish water (BW) habitats of up to 50% sea water, and such salinity tolerance shown to be an inheritable trait. Genomics of salinity tolerance in Ae. aegypti has not been previously studied, but it is of fundamental biological interest and important for controlling arboviral diseases in the context of rising sea levels increasing coastal ground water salinity. RESULTS: BW- and FW-Ae. aegypti were compared by RNA-seq analysis on the gut, anal papillae and rest of the carcass in fourth instar larvae (L4), proteomics of cuticles shed when L4 metamorphose into pupae, and transmission electron microscopy of cuticles in L4 and adults. Genes for specific cuticle proteins, signalling proteins, moulting hormone-related proteins, membrane transporters, enzymes involved in cuticle metabolism, and cytochrome P450 showed different mRNA levels in BW and FW L4 tissues. The salinity-tolerant Ae. aegypti were also characterized by altered L4 cuticle proteomics and changes in cuticle ultrastructure of L4 and adults. CONCLUSIONS: The findings provide new information on molecular and ultrastructural changes associated with salinity adaptation in FW mosquitoes. Changes in cuticles of larvae and adults of salinity-tolerant Ae. aegypti are expected to reduce the efficacy of insecticides used for controlling arboviral diseases. Expansion of coastal BW habitats and their neglect for control measures facilitates the spread of salinity-tolerant Ae. aegypti and genes for salinity tolerance. The transmission of arboviral diseases can therefore be amplified in multiple ways by salinity-tolerant Ae. aegypti and requires appropriate mitigating measures. The findings in Ae. aegypti have attendant implications for the development of salinity tolerance in other fresh water mosquito vectors and the diseases they transmit.


Assuntos
Aedes , Aedes/genética , Animais , Larva , Proteômica , Salinidade , Elevação do Nível do Mar , Transcriptoma
5.
Pestic Biochem Physiol ; 174: 104823, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33838716

RESUMO

Conventional and volatile pyrethroids are widely used to control the vectors of dengue arboviral diseases, Aedes albopictus in China. The development of resistance to conventional pyrethroids has become an increasing problem, potentially affecting the use of volatile pyrethroid. The Ae. albopictus dimefluthrin-resistant (R) strain by selecting the field population with dimefluthrin were investigated the multiple and cross-resistance levels between conventional and volatile pyrethroids and analyzed both target-site and metabolic resistant mechanisms to dimefluthrin compared with three volatile pyrethroids metofluthrin, meperfluthrin and esbiothrin and type II pyrethroid deltamethrin. The R strain displayed moderate to low resistance to selected pyrethroids (dimefluthrin, metofluthrin, meperfluthrin, esbiothrin and deltamethrin) associated with metabolic enzymes, but less distinctly to selected pyrethroids (dimefluthrin and metofluthrin) associated with a high frequency of sodium channel gene mutation (F1534S). Profiles of the multiple and cross-resistance of the R strain to other three volatile pyrethroids and type II pyrethroid deltamethrin were detected. Both synergistic and enzyme activity studies indicated that multifunctional oxidase (MFO) played an important role in this resistance.


Assuntos
Aedes , Inseticidas , Piretrinas , Aedes/genética , Animais , China , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mosquitos Vetores , Piretrinas/farmacologia
6.
Pest Manag Sci ; 77(7): 3450-3457, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33818874

RESUMO

BACKGROUND: In urban environments, some of the most common control tools used against the mosquito disease vector Aedes aegypti are pyrethroid insecticides applied as aerosols, fogs or residual sprays. Their efficacy is compromised by patchy deployment, aging residues, and the evolution and invasion of pyrethroid-resistant mosquitoes. A large proportion of mosquitoes in a given environment will therefore receive sublethal doses of insecticide. The potential impact of this sublethal exposure on the behaviour and biology of Ae. aegypti carrying commonly reported resistance alleles is poorly documented. RESULTS: In susceptible insects, sublethal exposure to permethrin resulted in reductions in egg viability (13.9%), blood avidity (16.7%) and male mating success (28.3%). It caused a 70% decrease in the lifespan of exposed susceptible females and a 66% decrease in the insecticide-resistant females from the parental strain. Exposure to the same dose of insecticide in the presence of the isolated kdr genotype resulted in a smaller impact on female longevity (a 58% decrease) but a 26% increase in eggs per female and a 37% increase in male mating success. Sublethal permethrin exposure reduced host-location success by 20-30% in all strains. CONCLUSION: The detrimental effects of exposure on susceptible insects were expected, but resistant insects demonstrated a less predictable range of responses, including negative effects on longevity and host-location but increases in fecundity and mating competitiveness. Overall, sublethal insecticide exposure is expected to increase the competitiveness of resistant phenotypes, acting as a selection pressure for the evolution of permethrin resistance. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Aedes , Inseticidas , Piretrinas , Aedes/genética , Animais , Feminino , Genótipo , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Masculino , Permetrina/toxicidade
7.
Biomed Res Int ; 2021: 6649038, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33763480

RESUMO

Background: Genetic modification offers opportunities to introduce artificially created molecular defence mechanisms to vector mosquitoes to counter diseases causing pathogens such as the dengue virus, malaria parasite, and Zika virus. RNA interference is such a molecular defence mechanism that could be used for this purpose to block the transmission of pathogens among human and animal populations. In our previous study, we engineered a dengue-resistant transgenic Ae. aegypti using RNAi to turn off the expression of dengue virus serotype genomes to reduce virus transmission, requiring assessment of the fitness of this mosquito with respect to its wild counterpart in the laboratory and semifield conditions. Method: Developmental and reproductive fitness parameters of TM and WM have assessed under the Arthropod Containment Level 2 conditions, and the antibiotic treatment assays were conducted using co-trimoxazole, amoxicillin, and doxycycline to assess the developmental and reproductive fitness parameters. Results: A significant reduction of developmental and reproductive fitness parameters was observed in transgenic mosquito compared to wild mosquitoes. However, it was seen in laboratory-scale studies that the fitness of this mosquito has improved significantly in the presence of antibiotics such as co-trimoxazole, amoxicillin, and doxycycline in their feed. Conclusion: Our data indicate that the transgenic mosquito produced had a reduction of the fitness parameters and it may lead to a subsequent reduction of transgenic vector density over the generations in field applications. However, antibiotics of co-trimoxazole, amoxicillin, and doxycycline have shown the improvement of fitness parameters indicating the usefulness in field release of transgenic mosquitoes.


Assuntos
Animais Geneticamente Modificados , Antibacterianos/farmacologia , Vírus da Dengue/fisiologia , Aptidão Genética , Mosquitos Vetores , Replicação Viral , Aedes/genética , Aedes/virologia , Animais , Dengue/genética , Dengue/prevenção & controle , Dengue/transmissão , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , Replicação Viral/efeitos dos fármacos , Replicação Viral/genética
8.
PLoS Negl Trop Dis ; 15(2): e0008492, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33591988

RESUMO

Vector control largely relies on neurotoxic chemicals, and insecticide resistance (IR) directly threatens their effectiveness. In some cases, specific alleles cause IR, and knowledge of the genetic diversity and gene flow among mosquito populations is crucial to track their arrival, rise, and spread. Here we evaluated Aedes aegypti populations' susceptibility status, collected in 2016 from six different municipalities of Rio de Janeiro state (RJ), to temephos, pyriproxyfen, malathion, and deltamethrin. We collected eggs of Ae. aegypti in Campos dos Goytacazes (Cgy), Itaperuna (Ipn), Iguaba Grande (Igg), Itaboraí (Ibr), Mangaratiba (Mgr), and Vassouras (Vsr). We followed the World Health Organization (WHO) guidelines and investigated the degree of susceptibility/resistance of mosquitoes to these insecticides. We used the Rockefeller strain as a susceptible positive control. We genotyped the V1016I and F1534C knockdown resistance (kdr) alleles using qPCR TaqMan SNP genotyping assay. Besides, with the use of Ae. aegypti SNP-chip, we performed genomic population analyses by genotyping more than 15,000 biallelic SNPs in mosquitoes from each population. We added previous data from populations from other countries to evaluate the ancestry of RJ populations. All RJ Ae. aegypti populations were susceptible to pyriproxyfen and malathion and highly resistant to deltamethrin. The resistance ratios for temephos was below 3,0 in Cgy, Ibr, and Igg populations, representing the lowest rates since IR monitoring started in this Brazilian region. We found the kdr alleles in high frequencies in all populations, partially justifying the observed resistance to pyrethroid. Population genetics analysis showed that Ae. aegypti revealed potential higher migration among some RJ localities and low genetic structure for most of them. Future population genetic studies, together with IR data in Ae aegypti on a broader scale, can help us predict the gene flow within and among the Brazilian States, allowing us to track the dynamics of arrival and changes in the frequency of IR alleles, and providing critical information to improving vector control program.


Assuntos
Aedes/efeitos dos fármacos , Vetores de Doenças , Resistência a Inseticidas , Inseticidas/farmacologia , Aedes/genética , Aedes/fisiologia , Animais , Bioensaio , Brasil , Perfilação da Expressão Gênica , Técnicas de Genotipagem , Cobaias , Larva/efeitos dos fármacos , Malation/farmacologia , Mutação , Nitrilas/farmacologia , Piretrinas/farmacologia , Piridinas/farmacologia , Temefós/farmacologia
9.
Mem Inst Oswaldo Cruz ; 115: e200313, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33533870

RESUMO

BACKGROUND: Aedes aegypti is the sole vector of urban arboviruses in French Guiana. Overtime, the species has been responsible for the transmission of viruses during yellow fever, dengue, chikungunya and Zika outbreaks. Decades of vector control have produced resistant populations to deltamethrin, the sole molecule available to control adult mosquitoes in this French Territory. OBJECTIVES: Our surveillance aimed to provide public health authorities with data on insecticide resistance in Ae. aegypti populations and other species of interest in French Guiana. Monitoring resistance to the insecticide used for vector control and to other molecule is a key component to develop an insecticide resistance management plan. METHODS: In 2009, we started to monitor resistance phenotypes to deltamethrin and target-site mechanisms in Ae. aegypti populations across the territory using the WHO impregnated paper test and allelic discrimination assay. FINDINGS: Eight years surveillance revealed well-installed resistance and the dramatic increase of alleles on the sodium voltage-gated gene, known to confer resistance to pyrethroids (PY). In addition, we observed that populations were resistant to malathion (organophosphorous, OP) and alpha-cypermethrin (PY). Some resistance was also detected to molecules from the carbamate family. Finally, those populations somehow recovered susceptibility against fenitrothion (OP). In addition, other species distributed in urban areas revealed to be also resistant to pyrethroids. CONCLUSION: The resistance level can jeopardize the efficiency of chemical adult control in absence of other alternatives and conducts to strongly rely on larval control measures to reduce mosquito burden. Vector control strategies need to evolve to maintain or regain efficacy during epidemics.


Assuntos
Aedes/efeitos dos fármacos , Insetos Vetores/genética , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mosquitos Vetores/efeitos dos fármacos , Piretrinas/farmacologia , Aedes/genética , Aedes/virologia , Animais , Guiana Francesa , Insetos Vetores/efeitos dos fármacos , Controle de Mosquitos/métodos , Mosquitos Vetores/virologia , Análise Espaço-Temporal
10.
Ecol Lett ; 24(4): 698-707, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33554374

RESUMO

Recurring seasonal changes can lead to the evolution of phenological cues. For example, many arthropods undergo photoperiodic diapause, a programmed developmental arrest induced by short autumnal day length. The selective mechanisms that determine the timing of autumnal diapause initiation have not been empirically identified. We quantified latitudinal clines in genetically determined diapause timing of an invasive mosquito, Aedes albopictus, on two continents. We show that variation in diapause timing within and between continents is explained by a novel application of a growing degree day (GDD) model that delineates a location-specific deadline after which it is not possible to complete an additional full life cycle. GDD models are widely used to predict spring phenology by modelling growth and development as physiological responses to ambient temperatures. Our results show that the energy accumulation dynamics represented by GDD models have also led to the evolution of an anticipatory life-history cue in autumn.


Assuntos
Aedes , Espécies Introduzidas , Aedes/genética , Animais , Clima , Fotoperíodo , Estações do Ano
11.
Nat Commun ; 12(1): 942, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33574256

RESUMO

The mosquito microbiota impacts the physiology of its host and is essential for normal larval development, thereby influencing transmission of vector-borne pathogens. Germ-free mosquitoes generated with current methods show larval stunting and developmental deficits. Therefore, functional studies of the mosquito microbiota have so far mostly been limited to antibiotic treatments of emerging adults. In this study, we introduce a method to produce germ-free Aedes aegypti mosquitoes. It is based on reversible colonisation with bacteria genetically modified to allow complete decolonisation at any developmental stage. We show that, unlike germ-free mosquitoes previously produced using sterile diets, reversibly colonised mosquitoes show no developmental retardation and reach the same size as control adults. This allows us to uncouple the study of the microbiota in larvae and adults. In adults, we detect no impact of bacterial colonisation on mosquito fecundity or longevity. In larvae, data from our transcriptome analysis and diet supplementation experiments following decolonisation suggest that bacteria support larval development by contributing to folate biosynthesis and by enhancing energy storage. Our study establishes a tool to study the microbiota in insects and deepens our knowledge on the metabolic contribution of bacteria to mosquito development.


Assuntos
Interações entre Hospedeiro e Microrganismos/fisiologia , Microbiota/fisiologia , Mosquitos Vetores/microbiologia , Aedes/genética , Aedes/crescimento & desenvolvimento , Aedes/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Ácido Fólico , Alimentos Fortificados , Trato Gastrointestinal/microbiologia , Regulação da Expressão Gênica , Vida Livre de Germes , Larva/genética , Larva/crescimento & desenvolvimento , Larva/microbiologia , Metabolismo dos Lipídeos , Mosquitos Vetores/crescimento & desenvolvimento , RNA Ribossômico 16S
12.
Pest Manag Sci ; 77(6): 2887-2893, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33559956

RESUMO

BACKGROUND: Aedes aegypti is a remarkably effective mosquito vector of epidemiologically important arboviral diseases including dengue fever, yellow fever and Zika. The present spread of resistance against pyrethroids, the primary insecticides used for mosquito control, in global populations of this species is of great concern. The voltage-gated sodium channel (VGSC) in the nervous system is the known target site of pyrethroids in insects. Past studies have revealed several amino-acid substitutions in this channel that confer pyrethroid resistance, which are known as knockdown resistance (kdr) mutations. RESULTS: This study investigated a laboratory colony of Ae. aegypti, MCNaeg, established from larvae collected in Rio de Janeiro, Brazil in 2016. The MCNaeg colony showed strong resistance against pyrethroids without laboratory selection. Of the two VGSC gene haplotypes present within this colony, one harbored three known kdr mutations, V410L, V1016I, and F1534C, and the other harbored only the known F1534C mutation. In latter haplotype, we also found novel amino-acid substations including V253F. Previous molecular modeling and electrophysiological studies suggest that this residue serves a pyrethroid-sensing site in the second receptor, PyR2. Our genetical analysis showed that the haplotype harboring V253F and F1534C is associated with equal or slightly stronger resistance than the other triple kdr haplotype to both Type I and Type II pyrethroids. CONCLUSION: The novel substitution V253F is potentially involved in pyrethroid resistance in Ae. aegypti. Further studies are needed to elucidate the role of this substitution in the pyrethroid susceptibility of VGSC. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Aedes , Inseticidas , Piretrinas , Canais de Sódio Disparados por Voltagem , Infecção por Zika virus , Zika virus , Aedes/genética , Animais , Brasil , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mutação , Piretrinas/farmacologia , Canais de Sódio Disparados por Voltagem/genética
13.
Parasit Vectors ; 14(1): 12, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407824

RESUMO

BACKGROUND: Aedes albopictus is an indigenous primary vector for dengue and Zika viruses in China. Compared with its insecticide resistance, biology and vector competence, little is known about its genetic variation, which corresponds to environmental variations. Thus, the present study examines how Ae. albopictus varies among different climatic regions in China and deciphers its potential dispersal patterns. METHODS: The genetic variation and population structure of 17 Ae. albopictus populations collected from three climatic regions of China were investigated with 11 microsatellite loci and the mitochondrial coxI gene. RESULTS: Of 44 isolated microsatellite markers, 11 pairs were chosen for genotyping analysis and had an average PIC value of 0.713, representing high polymorphism. The number of alleles was high in each population, with the ne value increasing from the temperate region (3.876) to the tropical region (4.144). Twenty-five coxI haplotypes were detected, and the highest diversity was observed in the tropical region. The mean Ho value (ca. 0.557) of all the regions was significantly lower than the mean He value (ca. 0.684), with nearly all populations significantly departing from HWE and displaying significant population expansion (p value < 0.05). Two genetically isolated groups and three haplotype clades were evaluated via STRUCTURE and haplotype phylogenetic analyses, and the tropical populations were significantly isolated from those in the other regions. Most genetic variation in Ae. albopictus was detected within populations and individuals at 31.40 and 63.04%, respectively, via the AMOVA test, and a relatively significant positive correlation was observed among only the temperate populations via IBD analysis (R2 = 0.6614, p = 0.048). Recent dispersions were observed among different Ae. albopictus populations, and four major migration trends with high gene flow (Nm > 0.4) were reconstructed between the tropical region and the other two regions. Environmental factors, especially temperature and rainfall, may be the leading causes of genetic diversity in different climatic regions. CONCLUSIONS: Continuous dispersion contributes to the genetic communication of Ae. albopictus populations across different climatic regions, and environmental factors, especially temperature and rainfall, may be the leading causes of genetic variation.


Assuntos
Aedes/genética , Distribuição Animal , Genética Populacional , Aedes/virologia , Animais , China/epidemiologia , Clima , Dengue/transmissão , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes de Insetos , Variação Genética , Repetições de Microssatélites/genética , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , Filogenia , Polimorfismo Genético , Infecção por Zika virus/transmissão
14.
PLoS Negl Trop Dis ; 15(1): e0008351, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33481791

RESUMO

The Asian tiger mosquito, Aedes albopictus (Ae. albopictus), is an important vector that transmits arboviruses such as dengue (DENV), Zika (ZIKV) and Chikungunya virus (CHIKV). Long noncoding RNAs (lncRNAs) are known to regulate various biological processes. Knowledge on Ae. albopictus lncRNAs and their functional role in virus-host interactions are still limited. Here, we identified and characterized the lncRNAs in the genome of an arbovirus vector, Ae. albopictus, and evaluated their potential involvement in DENV and ZIKV infection. We used 148 public datasets, and identified a total of 10, 867 novel lncRNA transcripts, of which 5,809, 4,139, and 919 were intergenic, intronic and antisense respectively. The Ae. albopictus lncRNAs shared many characteristics with other species such as short length, low GC content, and low sequence conservation. RNA-sequencing of Ae. albopictus cells infected with DENV and ZIKV showed that the expression of lncRNAs was altered upon virus infection. Target prediction analysis revealed that Ae. albopictus lncRNAs may regulate the expression of genes involved in immunity and other metabolic and cellular processes. To verify the role of lncRNAs in virus infection, we generated mutations in lncRNA loci using CRISPR-Cas9, and discovered that two lncRNA loci mutations, namely XLOC_029733 (novel lncRNA transcript id: lncRNA_27639.2) and LOC115270134 (known lncRNA transcript id: XR_003899061.1) resulted in enhancement of DENV and ZIKV replication. The results presented here provide an important foundation for future studies of lncRNAs and their relationship with virus infection in Ae. albopictus.


Assuntos
Aedes/genética , Aedes/virologia , Vírus da Dengue/fisiologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Zika virus/fisiologia , Aedes/metabolismo , Animais , Sistemas CRISPR-Cas , Linhagem Celular , Dengue/virologia , Vírus da Dengue/genética , Regulação da Expressão Gênica , Genoma , Interações entre Hospedeiro e Microrganismos/genética , Interações entre Hospedeiro e Microrganismos/fisiologia , Mosquitos Vetores/genética , Mosquitos Vetores/virologia , Transcriptoma , Zika virus/genética , Infecção por Zika virus/virologia
15.
PLoS Negl Trop Dis ; 15(1): e0009036, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33497375

RESUMO

BACKGROUND: In the absence of vaccines or drugs, insecticides are the mainstay of Aedes-borne disease control. Their utility is challenged by the slow deployment of resources, poor community compliance and inadequate household coverage. Novel application methods are required. METHODOLOGY AND PRINCIPAL FINDINGS: A 10% w/w metofluthrin "emanator" that passively disseminates insecticide from an impregnated net was evaluated in a randomized trial of 200 houses in Mexico. The devices were introduced at a rate of 1 per room and replaced at 3-week intervals. During each of 7 consecutive deployment cycles, indoor resting mosquitoes were sampled using aspirator collections. Assessments of mosquito landing behaviours were made in a subset of houses. Pre-treatment, there were no differences in Aedes aegypti indices between houses recruited to the control and treatment arms. Immediately after metofluthrin deployment, the entomological indices between the trial arms diverged. Averaged across the trial, there were significant reductions in Abundance Rate Ratios for total Ae. aegypti, female abundance and females that contained blood meals (2.5, 2.4 and 2.3-times fewer mosquitoes respectively; P<0.001). Average efficacy was 60.2% for total adults, 58.3% for females, and 57.2% for blood-fed females. The emanators also reduced mosquito landings by 90% from 12.5 to 1.2 per 10-minute sampling period (P<0.05). Homozygous forms of the pyrethroid resistant kdr alleles V410L, V1016L and F1534C were common in the target mosquito population; found in 39%, 24% and 95% of mosquitoes collected during the trial. CONCLUSIONS/SIGNIFICANCE: This is the first randomized control trial to evaluate the entomological impact of any volatile pyrethroid on urban Ae. aegypti. It demonstrates that volatile pyrethroids can have a sustained impact on Ae. aegypti population densities and human-vector contact indoors. These effects occur despite the presence of pyrethroid-resistant alleles in the target population. Formulations like these may have considerable utility for public health vector control responses.


Assuntos
Aedes/efeitos dos fármacos , Ciclopropanos/farmacologia , Fluorbenzenos/farmacologia , Inseticidas/farmacologia , Controle de Mosquitos/métodos , Mosquitos Vetores/efeitos dos fármacos , Aedes/genética , Animais , Comportamento Animal , Dengue/transmissão , Entomologia , Características da Família , Feminino , Humanos , Resistência a Inseticidas/efeitos dos fármacos , Resistência a Inseticidas/genética , México , Mosquitos Vetores/genética , Prevalência , Piretrinas/farmacologia , Projetos de Pesquisa
16.
BMC Genomics ; 22(1): 71, 2021 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-33478394

RESUMO

BACKGROUND: In the light of dengue being the fastest growing transmissible disease, there is a dire need to identify the mechanisms regulating the behaviour of the main vector Aedes aegypti. Disease transmission requires the female mosquito to acquire the pathogen from a blood meal during one gonotrophic cycle, and to pass it on in the next, and the capacity of the vector to maintain the disease relies on a sustained mosquito population. RESULTS: Using a comprehensive transcriptomic approach, we provide insight into the regulation of the odour-mediated host- and oviposition-seeking behaviours throughout the first gonotrophic cycle. We provide clear evidence that the age and state of the female affects antennal transcription differentially. Notably, the temporal- and state-dependent patterns of differential transcript abundance of chemosensory and neuromodulatory genes extends across families, and appears to be linked to concerted differential modulation by subsets of transcription factors. CONCLUSIONS: By identifying these regulatory pathways, we provide a substrate for future studies targeting subsets of genes across disparate families involved in generating key vector behaviours, with the goal to develop novel vector control tools.


Assuntos
Aedes , Dengue , Aedes/genética , Animais , Dengue/genética , Feminino , Humanos , Insetos Vetores/genética , Mosquitos Vetores/genética , Transcriptoma
17.
PLoS One ; 16(1): e0243992, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33428654

RESUMO

Insecticide resistance is a worldwide threat for vector control around the world, and Aedes aegypti, the main vector of several arboviruses, is a particular concern. To better understand the mechanisms of resistance, four isofemale strains originally from French Guiana were isolated and analysed using combined approaches. The activity of detoxification enzymes involved in insecticide resistance was assayed, and mutations located at positions 1016 and 1534 of the sodium voltage-gated channel gene, which have been associated with pyrethroid resistance in Aedes aegypti populations in Latin America, were monitored. Resistance to other insecticide families (organophosphates and carbamates) was evaluated. A large-scale proteomic analysis was performed to identify proteins involved in insecticide resistance. Our results revealed a metabolic resistance and resistance associated with a mutation of the sodium voltage-gated channel gene at position 1016. Metabolic resistance was mediated through an increase of esterase activity in most strains but also through the shifts in the abundance of several cytochrome P450 (CYP450s). Overall, resistance to deltamethrin was linked in the isofemale strains to resistance to other class of insecticides, suggesting that cross- and multiple resistance occur through selection of mechanisms of metabolic resistance. These results give some insights into resistance to deltamethrin and into multiple resistance phenomena in populations of Ae. aegypti.


Assuntos
Aedes/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Canais de Sódio Disparados por Voltagem/genética , Aedes/efeitos dos fármacos , Aedes/genética , Animais , Esterases/metabolismo , Feminino , Guiana Francesa , Técnicas de Silenciamento de Genes , Genótipo , Inativação Metabólica/genética , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/metabolismo , Inseticidas/farmacologia , Mucosa Intestinal/metabolismo , Nitrilas/farmacologia , Oligonucleotídeos/metabolismo , Polimorfismo de Nucleotídeo Único , Proteoma/análise , Proteômica , Piretrinas/farmacologia , Canais de Sódio Disparados por Voltagem/química , Canais de Sódio Disparados por Voltagem/metabolismo
18.
PLoS One ; 16(1): e0245694, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33465164

RESUMO

Autophagy is a conserved cellular process playing a role in maintenance of cellular homeostasis and response to changing nutrient conditions via degradation and recirculation of cellular redundant components. Autophagy-related proteins (Atg) play important function in autophagy pathway. Aedes albopictus mosquito is an effective vector transmitting multiple viruses which cause serious human diseases. Moreover, Aedes albopictus mosquito is becoming a serious threat to human health due to its widening distribution in recent years and thus worth of more research attention. It was reported that autophagy might play a role in viral infection in Aedes mosquito. To better understand the interaction between autophagy and arbovirus infection in mosquito system, it is necessary to identify autophagy pathway in the system. However, autophagy in Aedes albopictus mosquito is still poorly understood so far. We recently identified AaAtg8, the first Atg protein reported in Aedes albopictus mosquito. This work further identified twelve atg genes in Aedes albopictus mosquito. Sequence and phylogenetic analysis of the twelve atg genes were performed. Expression profiles of all the twelve Aaatg genes in different developmental stages and genders of Aedes albopictus mosquito were conducted. Effects of chemicals inhibiting or inducing autophagy on the levels of eight identified AaAtg proteins were examined. The function of two identified AaAtg proteins AaAtg6 and AaAtg16 and their response to arbovirus SINV infection were studied preliminarily. Taken together, this work systematically identified Aedes albopictus atg genes and provided basic information which might help to elucidate the autophagy pathway and the role of autophagy in arbovirus infection in Aedes mosquito system.


Assuntos
Aedes/metabolismo , Infecções por Arbovirus/metabolismo , Proteínas Relacionadas à Autofagia/metabolismo , Autofagia/efeitos dos fármacos , Autofagia/genética , Adenina/análogos & derivados , Adenina/farmacologia , Aedes/genética , Aedes/crescimento & desenvolvimento , Aedes/virologia , Animais , Infecções por Arbovirus/genética , Arbovírus/efeitos dos fármacos , Proteínas Relacionadas à Autofagia/genética , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Linhagem Celular , Cloroquina/farmacologia , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Masculino , Filogenia , RNA Interferente Pequeno , Reação em Cadeia da Polimerase em Tempo Real
19.
PLoS Negl Trop Dis ; 14(12): e0008971, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33338046

RESUMO

Aedes aegypti is a vector of dengue, chikungunya, and Zika viruses. Current vector control strategies such as community engagement, source reduction, and insecticides have not been sufficient to prevent viral outbreaks. Thus, interest in novel strategies involving genetic engineering is growing. Female mosquitoes rely on flight to mate with males and obtain a bloodmeal from a host. We hypothesized that knockout of genes specifically expressed in female mosquitoes associated with the indirect flight muscles would result in a flightless female mosquito. Using CRISPR-Cas9 we generated loss-of-function mutations in several genes hypothesized to control flight in mosquitoes, including actin (AeAct-4) and myosin (myo-fem) genes expressed specifically in the female flight muscle. Genetic knockout of these genes resulted in 100% flightless females, with homozygous males able to fly, mate, and produce offspring, albeit at a reduced rate when compared to wild type males. Interestingly, we found that while AeAct-4 was haplosufficient, with most heterozygous individuals capable of flight, this was not the case for myo-fem, where about half of individuals carrying only one intact copy could not fly. These findings lay the groundwork for developing novel mechanisms of controlling Ae. aegypti populations, and our results suggest that this mechanism could be applicable to other vector species of mosquito.


Assuntos
Aedes/genética , Sistemas CRISPR-Cas , Inseticidas/farmacologia , Controle de Mosquitos , Mosquitos Vetores/genética , Infecção por Zika virus/prevenção & controle , Zika virus/fisiologia , Aedes/fisiologia , Aedes/virologia , Animais , Feminino , Voo Animal , Técnicas de Inativação de Genes , Humanos , Masculino , Mosquitos Vetores/fisiologia , Mosquitos Vetores/virologia , Fenótipo , Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia
20.
BMC Genet ; 21(Suppl 2): 142, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339503

RESUMO

BACKGROUND: Aedes aegypti is the primary vector of arthropod-borne viruses and one of the most widespread and invasive mosquito species. Due to the lack of efficient specific drugs or vaccination strategies, vector population control methods, such as the sterile insect technique, are receiving renewed interest. However, availability of a reliable genetic sexing strategy is crucial, since there is almost zero tolerance for accidentally released females. Development of genetic sexing strains through classical genetics is hindered by genetic recombination that is not suppressed in males as is the case in many Diptera. Isolation of naturally-occurring or irradiation-induced inversions can enhance the genetic stability of genetic sexing strains developed through genetically linking desirable phenotypes with the male determining region. RESULTS: For the induction and isolation of inversions through irradiation, 200 male pupae of the 'BRA' wild type strain were irradiated at 30 Gy and 100 isomale lines were set up by crossing with homozygous 'red-eye' (re) mutant females. Recombination between re and the M locus and the white (w) gene (causing a recessive white eye phenotype when mutated) and the M locus was tested in 45 and 32 lines, respectively. One inversion (Inv35) reduced recombination between both re and the M locus, and wand the M locus, consistent with the presence of a rather extended inversion between the two morphological mutations, that includes the M locus. Another inversion (Inv5) reduced recombination only between w and the M locus. In search of naturally-occurring, recombination-suppressing inversions, homozygous females from the red eye and the white eye strains were crossed with seventeen and fourteen wild type strains collected worldwide, representing either recently colonized or long-established laboratory populations. Despite evidence of varying frequencies of recombination, no combination led to the elimination or substantial reduction of recombination. CONCLUSION: Inducing inversions through irradiation is a feasible strategy to isolate recombination suppressors either on the M or the m chromosome for Aedes aegypti. Such inversions can be incorporated in genetic sexing strains developed through classical genetics to enhance their genetic stability and support SIT or other approaches that aim to population suppression through male-delivered sterility.


Assuntos
Aedes/genética , Aedes/efeitos da radiação , Infertilidade/genética , Recombinação Genética/efeitos da radiação , Animais , Feminino , Raios gama , Genes de Insetos , Marcadores Genéticos , Controle de Insetos , Masculino , Mosquitos Vetores/genética , Mosquitos Vetores/efeitos da radiação
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