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1.
PLoS Negl Trop Dis ; 14(4): e0008204, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32243448

RESUMO

Wolbachia are being used to reduce dengue transmission by Aedes aegypti mosquitoes around the world. To date releases have mostly involved Wolbachia strains with limited fitness effects but strains with larger fitness costs could be used to suppress mosquito populations. However, such infections are expected to evolve towards decreased deleterious effects. Here we investigate potential evolutionary changes in the wMelPop infection transferred from Drosophila melanogaster to Aedes aegypti more than ten years (~120 generations) ago. We show that most deleterious effects of this infection have persisted despite strong selection to ameliorate them. The wMelPop-PGYP infection is difficult to maintain in laboratory colonies, likely due to the persistent deleterious effects coupled with occasional maternal transmission leakage. Furthermore, female mosquitoes can be scored incorrectly as infected due to transmission of Wolbachia through mating. Infection loss in colonies was not associated with evolutionary changes in the nuclear background. These findings suggest that Wolbachia transinfections with deleterious effects may have stable phenotypes which could ensure their long-term effectiveness if released in natural populations to reduce population size.


Assuntos
Aedes/microbiologia , Evolução Molecular , Mosquitos Vetores/microbiologia , Controle Biológico de Vetores/métodos , Wolbachia/fisiologia , Animais , Dengue/prevenção & controle , Drosophila melanogaster , Feminino , Interações entre Hospedeiro e Microrganismos , Modelos Lineares , Masculino , Controle de Mosquitos , Dinâmica Populacional , Wolbachia/patogenicidade
2.
PLoS Negl Trop Dis ; 14(4): e0008157, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32302295

RESUMO

The successful establishment of the wMel strain of Wolbachia for the control of arbovirus transmission by Aedes aegypti has been proposed and is being implemented in a number of countries. Here we describe the successful establishment of the wMel strain of Wolbachia in four sites in Yogyakarta, Indonesia. We demonstrate that Wolbachia can be successfully introgressed after transient releases of wMel-infected eggs or adult mosquitoes. We demonstrate that the approach is acceptable to communities and that Wolbachia maintains itself in the mosquito population once deployed. Finally, our data show that spreading rates of Wolbachia in the Indonesian setting are slow which may reflect more limited dispersal of Aedes aegypti than seen in other sites such as Cairns, Australia.


Assuntos
Aedes/microbiologia , Mosquitos Vetores/microbiologia , Wolbachia/fisiologia , Aedes/virologia , Animais , Arbovirus , Austrália , Agentes de Controle Biológico , Transmissão de Doença Infecciosa/prevenção & controle , Feminino , Indonésia , Masculino
3.
PLoS One ; 15(3): e0229727, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32191724

RESUMO

The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), holds an impressive record of successful invasions promoted by the growth and development of international fruit trade. Hence, survival of immatures within infested fruit that are subjected to various conditions during transportation seems to be a crucial feature that promotes invasion success. Wolbachia pipientis is a common endosymbiont of insects and other arthropods generating several biological effects on its hosts. Existing information report the influence of Wolbachia on the fitness traits of insect host species, including the Mediterranean fruit fly. However, little is known regarding effects of Wolbachia infection on immature development in different host fruits and temperatures. This study was conducted to determine the development and survival of immature stages of four different Mediterranean fruit fly populations, either infected or uninfected with Wolbachia, in two hosts (apples, bitter oranges) under three constant temperatures (15, 25 and 30°C), constant relative humidity (45-55 ± 5%), and a photoperiod of 14L:10D. Our findings demonstrate both differential response of two fruit fly lines to Wolbachia infection and differential effects of the two Wolbachia strains on the same Mediterranean fruit fly line. Larva-to-pupa and larva-to-adult survival followed similar patterns and varied a lot among the four medfly populations, the two host fruits and the different temperatures. Pupation rates and larval developmental time were higher for larvae implanted in apples compared to bitter oranges. The survival rates of wildish medflies were higher than those of the laboratory adapted ones, particularly in bitter oranges. The Wolbachia infected medflies, expressed lower survival rates and higher developmental times, especially the wCer4 infected line. High temperatures constrained immature development and were lethal for the Wolbachia infected wCer4 medfly line. Lower temperatures inferred longer developmental times to immature stages of all medfly populations tested, in both host fruits. Implications on the ecology and survival of the fly in nature are discussed.


Assuntos
Ceratitis capitata/crescimento & desenvolvimento , Ceratitis capitata/microbiologia , Frutas/parasitologia , Estágios do Ciclo de Vida , Temperatura , Wolbachia/fisiologia , Animais , Larva/crescimento & desenvolvimento , Modelos de Riscos Proporcionais , Pupa/crescimento & desenvolvimento , Análise de Sobrevida
4.
PLoS Negl Trop Dis ; 14(1): e0007958, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31971938

RESUMO

Aedes aegypti mosquitoes infected with the wMel strain of Wolbachia are being released into natural mosquito populations in the tropics as a way of reducing dengue transmission. High temperatures adversely affect wMel, reducing Wolbachia density and cytoplasmic incompatibility in some larval habitats that experience large temperature fluctuations. We monitored the impact of a 43.6°C heatwave on the wMel infection in a natural population in Cairns, Australia, where wMel was first released in 2011 and has persisted at a high frequency. Wolbachia infection frequencies in the month following the heatwave were reduced to 83% in larvae sampled directly from field habitats and 88% in eggs collected from ovitraps, but recovered to be near 100% four months later. Effects of the heatwave on wMel appeared to be stage-specific and delayed, with reduced frequencies and densities in field-collected larvae and adults reared from ovitraps but higher frequencies in field-collected adults. Laboratory experiments showed that the effects of heatwaves on cytoplasmic incompatibility and density are life stage-specific, with first instar larvae being the most vulnerable to temperature effects. Our results indicate that heatwaves in wMel-infected populations will have only temporary effects on Wolbachia frequencies and density once the infection has established in the population. Our results are relevant to ongoing releases of wMel-infected Ae. aegypti in several tropical countries.


Assuntos
Aedes/microbiologia , Temperatura Alta , Wolbachia/fisiologia , Animais , Austrália , Feminino , Interações Hospedeiro-Patógeno , Wolbachia/classificação
5.
Insect Mol Biol ; 29(1): 1-8, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31194893

RESUMO

Culex quinquefasciatus is an important mosquito vector of a number of viral and protozoan pathogens of humans and animals, and naturally carries the endosymbiont Wolbachia pipientis, strain wPip. Wolbachia are used in two distinct vector control strategies: firstly, population suppression caused by mating incompatibilities between mass-released transinfected males and wild females; and secondly, the spread of pathogen transmission-blocking strains through populations. Using embryonic microinjection, two novel Wolbachia transinfections were generated in C. quinquefasciatus using strains native to the mosquito Aedes albopictus: a wAlbB single infection, and a wPip plus wAlbA superinfection. The wAlbB infection showed full bidirectional cytoplasmic incompatibility (CI) with wild-type C. quinquefasciatus in reciprocal crosses. The wPipwAlbA superinfection showed complete unidirectional CI, and therefore population invasion potential. Whereas the wAlbB strain showed comparatively low overall densities, similar to the native wPip, the wPipwAlbA superinfection reached over 400-fold higher densities in the salivary glands compared to the native wPip, suggesting it may be a candidate for pathogen transmission blocking.


Assuntos
Culex/microbiologia , Wolbachia/fisiologia , Aedes/microbiologia , Animais , Feminino , Masculino , Controle de Mosquitos/métodos , Mosquitos Vetores/microbiologia , Controle Biológico de Vetores/métodos , Glândulas Salivares/microbiologia , Simbiose , Wolbachia/classificação
6.
Insect Mol Biol ; 29(1): 19-37, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31265751

RESUMO

Wolbachia and Spiroplasma are both maternally inherited endosymbionts in arthropods, and they can co-infect the same species. However, how they interact with each other in the same host is not clear. Here we investigate a co-infected Tetranychus truncatus spider mite strain that shares the same genetic background with singly infected and uninfected strains to detect the impacts of the two symbionts on their host. We found that Wolbachia-infected and Spiroplasma-infected mites can suffer significant fitness costs involving decreased fecundity, although with no effect on lifespan or development. Wolbachia induced incomplete cytoplasmic incompatibility in T. truncatus both in singly infected and doubly infected strains, resulting in female killing. In both females and males of the co-infected spider mite strain, Wolbachia density was higher than Spiroplasma density. Transcriptome analysis of female adults showed that the most differentially expressed genes were found between the co-infected strain and both the singly infected Spiroplasma strain and uninfected strain. The Wolbachia strain had the fewest differentially expressed genes compared with the co-infected strain, consistent with the higher density of Wolbachia in the co-infected strain. Wolbachia, therefore, appears to have a competitive advantage in host mites over Spiroplasma and is likely maintained in populations by cytoplasmic incompatibility despite having deleterious fitness effects.


Assuntos
Spiroplasma/fisiologia , Tetranychidae/microbiologia , Wolbachia/fisiologia , Animais , Coinfecção/microbiologia , Feminino , Fertilidade , Perfilação da Expressão Gênica , Masculino , Simbiose , Tetranychidae/genética , Tetranychidae/metabolismo
7.
FEMS Microbiol Lett ; 366(23)2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31750894

RESUMO

Symbiosis between intracellular bacteria (endosymbionts) and animals are widespread. The alphaproteobacterium Wolbachia pipientis is known to maintain a variety of symbiotic associations, ranging from mutualism to parasitism, with a wide range of invertebrates. Wolbachia infection might deeply affect host fitness (e.g. reproductive manipulation and antiviral protection), which is thought to explain its high prevalence in nature. Bacterial loads significantly influence both the infection dynamics and the extent of bacteria-induced host phenotypes. Hence, fine regulation of bacterial titers is considered as a milestone in host-endosymbiont interplay. Here, we review both environmental and biological factors modulating Wolbachia titers in arthropods.


Assuntos
Artrópodes/microbiologia , Simbiose/fisiologia , Wolbachia/fisiologia , Animais , Carga Bacteriana , Meio Ambiente
8.
PLoS Biol ; 17(10): e3000438, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31600190

RESUMO

Microbial endosymbiosis is widespread in animals, with major ecological and evolutionary implications. Successful symbiosis relies on efficient vertical transmission through host generations. However, when symbionts negatively affect host fitness, hosts are expected to evolve suppression of symbiont effects or transmission. Here, we show that sex chromosomes control vertical transmission of feminizing Wolbachia endosymbionts in the isopod Armadillidium nasatum. Theory predicts that the invasion of an XY/XX species by cytoplasmic sex ratio distorters is unlikely because it leads to fixation of the unusual (and often lethal or infertile) YY genotype. We demonstrate that A. nasatum X and Y sex chromosomes are genetically highly similar and that YY individuals are viable and fertile, thereby enabling Wolbachia spread in this XY-XX species. Nevertheless, we show that Wolbachia cannot drive fixation of YY individuals, because infected YY females do not transmit Wolbachia to their offspring, unlike XX and XY females. The genetic basis fits the model of a Y-linked recessive allele (associated with an X-linked dominant allele), in which the homozygous state suppresses Wolbachia transmission. Moreover, production of all-male progenies by infected YY females restores a balanced sex ratio at the host population level. This suggests that blocking of Wolbachia transmission by YY females may have evolved to suppress feminization, thereby offering a whole new perspective on the evolutionary interplay between microbial symbionts and host sex chromosomes.


Assuntos
Isópodes/genética , Cromossomos Sexuais , Processos de Determinação Sexual , Simbiose/genética , Wolbachia/fisiologia , Alelos , Animais , Feminino , Genótipo , Homozigoto , Isópodes/microbiologia , Masculino , Modelos Genéticos , Característica Quantitativa Herdável , Razão de Masculinidade
9.
PLoS Negl Trop Dis ; 13(10): e0007771, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658265

RESUMO

BACKGROUND: Important arboviral diseases, such as dengue, chikungunya, and Zika virus infections, are transmitted mainly by the Aedes aegypti vector. So far, controlling this vector species with current tools and strategies has not demonstrated sustainable and significant impacts. Our main objective was to evaluate whether open field release of sterile males, produced from combining the sterile insect technique using radiation with the insect incompatible technique through Wolbachia-induced incompatibility (SIT/IIT), could suppress natural populations of Ae. aegypti in semi-rural village settings in Thailand. METHODOLOGY/PRINCIPAL FINDINGS: Irradiated Wolbachia-infected Aedes aegypti males produced by the SIT/IIT approach were completely sterile and were able to compete with the wild fertile ones. Open field release of these sterile males was conducted in an ecologically isolated village in Chachoengsao Province, eastern Thailand. House-to-house visit and media reports resulted in community acceptance and public awareness of the technology. During intervention, approximately 100-200 sterile males were released weekly in each household. After 6 months of sterile male release, a significant reduction (p<0.05) of the mean egg hatch rate (84%) and the mean number of females per household (97.30%) was achieved in the treatment areas when compared to the control ones. CONCLUSIONS/SIGNIFICANCE: Our study represents the first open field release of sterile Ae. aegypti males developed from a combined SIT/IIT approach. Entomological assessment using ovitraps, adult sticky traps, and portable vacuum aspirators confirmed the success in reducing natural populations of Ae. aegypti females in treated areas. Public awareness through media resulted in positive support for practical use of this strategy in wider areas. Further study using a systematic randomized trial is needed to determine whether this approach could have a significant impact on the diseases transmitted by Ae. aegypti vector.


Assuntos
Aedes/fisiologia , Entomologia/métodos , Controle de Mosquitos/métodos , Mosquitos Vetores/fisiologia , População Rural , Aedes/microbiologia , Aedes/efeitos da radiação , Animais , Feminino , Humanos , Infertilidade Masculina , Masculino , Mosquitos Vetores/microbiologia , Mosquitos Vetores/efeitos da radiação , Dinâmica Populacional , Caracteres Sexuais , Tailândia , Wolbachia/genética , Wolbachia/fisiologia
10.
Annu Rev Genet ; 53: 93-116, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31505135

RESUMO

Wolbachia is an endosymbiotic Alphaproteobacteria that can suppress insect-borne diseases through decreasing host virus transmission (population replacement) or through decreasing host population density (population suppression). We contrast natural Wolbachia infections in insect populations with Wolbachia transinfections in mosquitoes to gain insights into factors potentially affecting the long-term success of Wolbachia releases. Natural Wolbachia infections can spread rapidly, whereas the slow spread of transinfections is governed by deleterious effects on host fitness and demographic factors. Cytoplasmic incompatibility (CI) generated by Wolbachia is central to both population replacement and suppression programs, but CI in nature can be variable and evolve, as can Wolbachia fitness effects and virus blocking. Wolbachia spread is also influenced by environmental factors that decrease Wolbachia titer and reduce maternal Wolbachia transmission frequency. More information is needed on the interactions between Wolbachia and host nuclear/mitochondrial genomes, the interaction between invasion success and local ecological factors, and the long-term stability of Wolbachia-mediated virus blocking.


Assuntos
Controle de Doenças Transmissíveis/métodos , Interações Hospedeiro-Patógeno/fisiologia , Insetos Vetores/virologia , Wolbachia/fisiologia , Animais , Evolução Biológica , Citoplasma , Meio Ambiente , Aptidão Genética , Insetos Vetores/microbiologia , Insetos/microbiologia , Insetos/virologia , Mosquitos Vetores/microbiologia , Mosquitos Vetores/virologia
11.
J Insect Physiol ; 118: 103938, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31491378

RESUMO

Wolbachia is a genus of endosymbiotic bacteria that induce a wide range of effects on their insect hosts. Cytoplasmic incompatibility (CI) is the most common phenotype mediated by Wolbachia and results in embryonic lethality when Wolbachia-infected males mate with uninfected females. Studies have revealed that bacteria can regulate many cellular processes in their hosts using small non-coding RNAs, so we investigated the involvement of small RNAs (sRNAs) in CI. Comparison of sRNA libraries between Wolbachia-infected and uninfected Drosophila melanogaster testes revealed 18 novel microRNAs (miRNAs), of which 12 were expressed specifically in Wolbachia-infected flies and one specifically in Wolbachia-uninfected flies. Furthermore, ten miRNAs showed differential expression, with four upregulated and six downregulated in Wolbachia-infected flies. Of the upregulated miRNAs, nov-miR-12 exhibited the highest upregulation in the testes of D. melanogaster. We then identified pipsqueak (psq) as the target gene of nov-miR-12 with the greatest complementarity in its 3' untranslated region (UTR). Wolbachia infection was correlated with reduced psq expression in D. melanogaster, and luciferase assays demonstrated that nov-miR-12 could downregulate psq through binding to its 3'UTR region. Knockdown of psq in Wolbachia-free fly testes significantly reduced egg hatching rate and mimicked the cellular abnormalities of Wolbachia-induced CI in embryos, including asynchronous nuclear division, chromatin bridging, and chromatin fragmentation. These results suggest that Wolbachia may induce CI in insect hosts by miRNA-mediated changes in host gene expression. Moreover, these findings reveal a potential molecular strategy for elucidating the complex interactions between endosymbionts and their insect hosts, such as Wolbachia-driven CI.


Assuntos
Citoplasma/genética , Drosophila melanogaster/microbiologia , Regulação da Expressão Gênica no Desenvolvimento , Wolbachia/fisiologia , Regiões 3' não Traduzidas , Animais , Citoplasma/patologia , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Masculino , MicroRNAs/genética , Pequeno RNA não Traduzido , Simbiose , Testículo
12.
Insect Biochem Mol Biol ; 113: 103211, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31425852

RESUMO

Wolbachia are intracellular bacteria that manipulate host reproduction by several mechanisms including cytoplasmic incompatibility (CI). However, the underlying mechanisms of Wolbachia-induced CI are not entirely clear. Here, we monitored the Wolbachia distribution in the male gonads of the small brown planthopper (Laodelphax striatellus, SBPH) at different development stages, and investigated the influence of Wolbachia on male gonads by a quantitative proteomic analysis. A total of 276 differentially expressed proteins were identified, with the majority of them participating in metabolism, modification, and reproduction. Knocking down the expression of outer dense fiber protein (ODFP) and venom allergen 5-like (VA5L) showed decreased egg reproduction, and these two genes might be responsible for Wolbachia improved fecundity in infected L. striatellus; whereas knocking down the expression of cytosol amino-peptidase-like (CAL) significantly decreased the egg hatch rate in Wolbachia-uninfected L. striatellus, but not in the Wolbachia-infected one. Considering that the mRNA/protein level of CAL was downregulated by Wolbachia infection and dsCAL treatment closely mimicked Wolbachia-induced CI, we presumed that CAL might be one of the factors determining the CI phenotype.


Assuntos
Hemípteros/fisiologia , Proteínas de Insetos/genética , Wolbachia/fisiologia , Animais , Gônadas/crescimento & desenvolvimento , Gônadas/microbiologia , Hemípteros/genética , Hemípteros/crescimento & desenvolvimento , Proteínas de Insetos/metabolismo , Masculino , Ninfa/genética , Ninfa/crescimento & desenvolvimento , Proteoma , Proteômica , Reprodução
13.
Nat Microbiol ; 4(11): 1832-1839, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31451771

RESUMO

The dengue, Zika and chikungunya viruses are transmitted by the mosquito Aedes aegypti and pose a substantial threat to global public health. Current vaccines and mosquito control strategies have limited efficacy, so novel interventions are needed1,2. Wolbachia are bacteria that inhabit insect cells and have been found to reduce viral infection-a phenotype that is referred to as viral 'blocking'3. Although not naturally found in A. aegypti4, Wolbachia were stably introduced into this mosquito in 20114,5 and were shown to reduce the transmission potential of dengue, Zika and chikungunya6,7. Subsequent field trials showed Wolbachia's ability to spread through A. aegypti populations and reduce the local incidence of dengue fever8. Despite these successes, the evolutionary stability of viral blocking is unknown. Here, we utilized artificial selection to reveal genetic variation in the mosquito that affects Wolbachia-mediated dengue blocking. We found that mosquitoes exhibiting weaker blocking also have reduced fitness, suggesting the potential for natural selection to maintain blocking. We also identified A. aegypti genes that affect blocking strength, shedding light on a possible mechanism for the trait. These results will inform the use of Wolbachia as biocontrol agents against mosquito-borne viruses and direct further research into measuring and improving their efficacy.


Assuntos
Aedes/genética , Vírus da Dengue/patogenicidade , Proteínas de Insetos/genética , Wolbachia/fisiologia , Aedes/microbiologia , Aedes/virologia , Animais , Vírus da Dengue/genética , Evolução Molecular , Feminino , Frequência do Gene , Aptidão Genética , Genoma Bacteriano , Masculino , Mosquitos Vetores/fisiologia , Polimorfismo de Nucleotídeo Único
14.
PLoS Negl Trop Dis ; 13(8): e0007636, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31381563

RESUMO

Depletion of Wolbachia endosymbionts of human pathogenic filariae using 4-6 weeks of doxycycline treatment can lead to permanent sterilization and adult filarial death. We investigated the anti-Wolbachia drug candidate ABBV-4083 in the Litomosoides sigmodontis rodent model to determine Wolbachia depletion kinetics with different regimens. Wolbachia reduction occurred in mice as early as 3 days after the initiation of ABBV-4083 treatment and continued throughout a 10-day treatment period. Importantly, Wolbachia levels continued to decline after a 5-day-treatment from 91.5% to 99.9% during a 3-week washout period. In jirds, two weeks of ABBV-4083 treatment (100mg/kg once-per-day) caused a >99.9% Wolbachia depletion in female adult worms, and the kinetics of Wolbachia depletion were recapitulated in peripheral blood microfilariae. Similar to Wolbachia depletion, inhibition of embryogenesis was time-dependent in ABBV-4083-treated jirds, leading to a complete lack of late embryonic stages (stretched microfilariae) and lack of peripheral microfilariae in 5/6 ABBV-4083-treated jirds by 14 weeks after treatment. Twice daily treatment in comparison to once daily treatment with ABBV-4083 did not significantly improve Wolbachia depletion. Moreover, up to 4 nonconsecutive daily treatments within a 14-dose regimen did not significantly erode Wolbachia depletion. Within the limitations of an animal model that does not fully recapitulate human filarial disease, our studies suggest that Wolbachia depletion should be assessed clinically no earlier than 3-4 weeks after the end of treatment, and that Wolbachia depletion in microfilariae may be a viable surrogate marker for the depletion within adult worms. Furthermore, strict daily adherence to the dosing regimen with anti-Wolbachia candidates may not be required, provided that the full regimen is subsequently completed.


Assuntos
Antibacterianos/farmacologia , Filarioidea/microbiologia , Microfilárias/microbiologia , Wolbachia/efeitos dos fármacos , Wolbachia/fisiologia , Animais , Doxiciclina/farmacologia , Feminino , Filariose , Filarioidea/efeitos dos fármacos , Gerbillinae , Cinética , Camundongos , Camundongos Endogâmicos BALB C , Microfilárias/efeitos dos fármacos , Microfilárias/embriologia , Modelos Animais
15.
PLoS Pathog ; 15(7): e1007942, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31323076

RESUMO

Exotic invasive species can influence the behavior and ecology of native and resident species, but these changes are often overlooked. Here we hypothesize that the ghost ant, Tapinoma melanocephalum, living in areas that have been invaded by the red imported fire ant, Solenopsis invicta, displays behavioral differences to interspecific competition that are reflected in both its trophic position and symbiotic microbiota. We demonstrate that T. melanocephalum workers from S. invicta invaded areas are less aggressive towards workers of S. invicta than those inhabiting non-invaded areas. Nitrogen isotope analyses reveal that colonies of T. melanocephalum have protein-rich diets in S. invicta invaded areas compared with the carbohydrate-rich diets of colonies living in non-invaded areas. Analysis of microbiota isolated from gut tissue shows that T. melanocephalum workers from S. invicta invaded areas also have different bacterial communities, including a higher abundance of Wolbachia that may play a role in vitamin B provisioning. In contrast, the microbiota of workers of T. melanocephalum from S. invicta-free areas are dominated by bacteria from the orders Bacillales, Lactobacillales and Enterobacteriales that may be involved in sugar metabolism. We further demonstrate experimentally that the composition and structure of the bacterial symbiont communities as well as the prevalence of vitamin B in T. melanocephalum workers from S. invicta invaded and non-invaded areas can be altered if T. melanocephalum workers are supplied with either protein-rich or carbohydrate-rich food. Our results support the hypothesis that bacterial symbiont communities can help hosts by buffering behavioral changes caused by interspecies competition as a consequence of biological invasions.


Assuntos
Formigas/microbiologia , Formigas/fisiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Espécies Introduzidas , Microbiota/fisiologia , Adaptação Fisiológica , Animais , Dieta , Ecossistema , Comportamento Alimentar , Especificidade da Espécie , Simbiose/fisiologia , Complexo Vitamínico B/metabolismo , Wolbachia/fisiologia
16.
Curr Opin Insect Sci ; 33: 84-90, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31358201

RESUMO

Endosymbionts play important roles in protecting hosts from environmental stress, such as natural enemies, heat, and toxins. Many insects are infected with the facultative nonessential endosymbionts Wolbachia and Rickettsia, which are the crux in this review, although other relevant symbiont genera will also be treated. Insecticide resistance of hosts can be related to infections with Wolbachia and Rickettsia. These endosymbionts commonly increase host susceptibility to chemical insecticides, but cases of increased resistance also exist. The symbiont-mediated insecticide resistance/susceptibility varies with species of insect, species of symbiont, and chemical compound. Changes in insecticide resistance levels of insects can be associated with fluctuations in population density of endosymbionts. Effects of endosymbionts on host fitness, metabolism, immune system, and gene expression may determine how endosymbionts influence insecticide resistance. A clearer understanding of these interactions can improve our knowledge about drivers of decreasing insecticide resistance.


Assuntos
Insetos/microbiologia , Resistência a Inseticidas , Rickettsia/fisiologia , Wolbachia/fisiologia , Animais , Inativação Metabólica , Insetos/fisiologia , Inseticidas/toxicidade , Simbiose
18.
J Parasitol ; 105(4): 555-566, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31348717

RESUMO

Dispersal influences the evolution and adaptation of organisms, but it can be difficult to detect. Host-specific parasites provide information about the dispersal of their hosts and may be valuable for examining host dispersal that does not result in gene flow or that has low signals of gene flow. We examined the population connectivity of the buffy flower bat, Erophylla sezekorni (Chiroptera: Phyllostomidae), and its associated obligate ectoparasite, Trichobius frequens (Diptera: Streblidae), across a narrow oceanic channel in The Bahamas that has previously been implicated as a barrier to dispersal in bats. Due to the horizontal transmission of T. frequens, we were able to test the hypothesis that bats are dispersing across this channel, but this dispersal does not result in gene flow, occurs rarely, or started occurring recently. We developed novel microsatellite markers for the family Streblidae in combination with previously developed markers for bats to genotype individuals from 4 islands in The Bahamas. We provide evidence for a single population of the host, E. sezekorni, but 2 populations of its bat flies, potentially indicating a recent reduction of gene flow in E. sezekorni, rare dispersal, or infrequent transportation of bat flies with their hosts. Despite high population differentiation in bat flies indicated by microsatellites, mitochondrial DNA shows no polymorphism, suggesting that bacterial reproductive parasites may be contributing to mitochondrial DNA sweeps. Parasites, including bat flies, provide independent information about their hosts and can be used to test hypotheses of host dispersal that may be difficult to assess using host genetics alone.


Assuntos
Distribuição Animal/fisiologia , Quirópteros/fisiologia , Quirópteros/parasitologia , Dípteros/fisiologia , Ectoparasitoses/veterinária , Algoritmos , Alelos , Animais , Bahamas , Teorema de Bayes , Análise por Conglomerados , Sequência Consenso , DNA Mitocondrial/química , Dípteros/genética , Dípteros/microbiologia , Ectoparasitoses/parasitologia , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Interações Hospedeiro-Parasita , Cadeias de Markov , Alinhamento de Sequência/veterinária , Wolbachia/fisiologia
19.
BMC Genomics ; 20(1): 608, 2019 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-31340757

RESUMO

BACKGROUND: Cytoplasmic incompatibility (CI) is the most common phenotype induced by endosymbiont Wolbachia and results in embryonic lethality when Wolbachia-modified sperm fertilize eggs without Wolbachia. However, eggs carrying the same strain of Wolbachia can rescue this embryonic death, thus producing viable Wolbachia-infected offspring. Hence Wolbachia can be transmitted mainly by hosts' eggs. One of the models explaining CI is "titration-restitution", which hypothesized that Wolbachia titrated-out some factors from the sperm and the Wolbachia in the egg would restitute the factors after fertilization. However, how infected eggs rescue CI and how hosts' eggs ensure the proliferation and transmission of Wolbachia are not well understood. RESULTS: By RNA-seq analyses, we first compared the transcription profiles of Drosophila melanogaster adult ovaries with and without the wMel Wolbachia and identified 149 differentially expressed genes (DEGs), of which 116 genes were upregulated and 33 were downregulated by Wolbachia infection. To confirm the results obtained from RNA-seq and to screen genes potentially associated with reproduction, 15 DEGs were selected for quantitative RT-PCR (qRT-PCR). Thirteen genes showed the same changing trend as RNA-seq analyses. To test whether these genes are associated with CI, we also detected their expression levels in testes. Nine of them exhibited different changing trends in testes from those in ovaries. To investigate how these DEGs were regulated, sRNA sequencing was performed and identified seven microRNAs (miRNAs) that were all upregulated in fly ovaries by Wolbachia infection. Matching of miRNA and mRNA data showed that these seven miRNAs regulated 15 DEGs. Wolbachia-responsive genes in fly ovaries were involved in biological processes including metabolism, transportation, oxidation-reduction, immunity, and development. CONCLUSIONS: Comparisons of mRNA and miRNA data from fly ovaries revealed 149 mRNAs and seven miRNAs that exhibit significant changes in expression due to Wolbachia infection. Notably, most of the DEGs showed variation in opposite directions in ovaries versus testes in the presence of Wolbachia, which generally supports the "titration-restitution" model for CI. Furthermore, genes related to metabolism were upregulated, which may benefit maximum proliferation and transmission of Wolbachia. This provides new insights into the molecular mechanisms of Wolbachia-induced CI and Wolbachia dependence on host ovaries.


Assuntos
Drosophila melanogaster/microbiologia , Ovário/microbiologia , Wolbachia/fisiologia , Animais , Citosol , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Masculino , MicroRNAs/genética , RNA Mensageiro/genética , RNA-Seq , Testículo/microbiologia , Transcriptoma , Regulação para Cima
20.
BMC Genomics ; 20(1): 465, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174466

RESUMO

BACKGROUND: The Neotropical fruit fly Drosophila paulistorum (Diptera: Drosophilidae) is a species complex in statu nascendi comprising six reproductively isolated semispecies, each harboring mutualistic Wolbachia strains. Although wild type flies of each semispecies are isolated from the others by both pre- and postmating incompatibilities, mating between semispecies and successful offspring development can be achieved once flies are treated with antibiotics to reduce Wolbachia titer. Here we use RNA-seq to study the impact of Wolbachia on D. paulistorum and investigate the hypothesis that the symbiont may play a role in host speciation. For that goal, we analyze samples of heads and abdomens of both sexes of the Amazonian, Centro American and Orinocan semispecies of D. paulistorum. RESULTS: We identify between 175 and 1192 differentially expressed genes associated with a variety of biological processes that respond either globally or according to tissue, sex or condition in the three semispecies. Some of the functions associated with differentially expressed genes are known to be affected by Wolbachia in other species, such as metabolism and immunity, whereas others represent putative novel phenotypes involving muscular functions, pheromone signaling, and visual perception. CONCLUSIONS: Our results show that Wolbachia affect a large number of biological functions in D. paulistorum, particularly when present in high titer. We suggest that the significant metabolic impact of the infection on the host may cause several of the other putative and observed phenotypes. We also speculate that the observed differential expression of genes associated with chemical communication and reproduction may be associated with the emergence of pre- and postmating barriers between semispecies, which supports a role for Wolbachia in the speciation of D. paulistorum.


Assuntos
Drosophila/genética , Drosophila/microbiologia , Especiação Genética , Simbiose , Wolbachia/fisiologia , Aminoácidos/metabolismo , Animais , Metabolismo dos Carboidratos/genética , Drosophila/metabolismo , Feminino , Imunidade/genética , Metabolismo dos Lipídeos/genética , Masculino , Músculos/metabolismo , Feromônios/metabolismo , Proteólise , RNA-Seq , Reprodução/genética , Transcriptoma
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