Publications

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f supergroup wolbachia in bush crickets: what do patterns of sequence variation reveal about this supergroup and horizontal transfer between nematodes and arthropods?wolbachia pipientis, an intracellular, alpha-proteobacterium, is commonly found in arthropods and filarial nematodes. most infected insects are known to harbor strains of wolbachia from supergroups a or b, whereas supergroups c and d occur only in filarial nematodes. here, we present molecular evidence from two genes (ftsz and 16s rdna) that 2 orthopterans (the bush cricket species orocharis saltator and hapithus agitator; gryllidae: eneopterinae) are infected with wolbachia from the f supergrou ...200716924406
correcting base-assignment errors in repeat regions of shotgun assembly.accurate base-assignment in repeat regions of a whole genome shotgun assembly is an unsolved problem. since reads in repeat regions cannot be easily attributed to a unique location in the genome, current assemblers may place these reads arbitrarily. as a result, the base-assignment error rate in repeats is likely to be much higher than that in the rest of the genome. we developed an iterative algorithm, euler-air, that is able to correct base-assignment errors in finished genome sequences in pub ...200717277413
onchocerca volvulus, wolbachia and river blindness.chronic infection with filarial nematodes results in development of a suppressive response to an immense parasite burden, thereby limiting pathological and clinical manifestations. however, pro-inflammatory responses to dead and degenerating onchocerca volvulus worms and release of endosymbiotic wolbachia bacteria result in corneal opacification, sacrification and visual impairment. this review discusses host and parasite factors implicated in maintaining this balance of pro- an anti-inflammator ...200717264501
cardinium symbionts cause cytoplasmic incompatibility in spider mites.intracellular symbiotic bacteria belonging to the cytophaga-flavobacterium-bacteroides lineage have recently been described and are widely distributed in arthropod species. the newly discovered bacteria, named cardinium sp, cause the expression of various reproductive alterations in their arthropod hosts, including cytoplasmic incompatibility (ci), induction of parthenogenesis and feminization of genetic males. we detected 16s ribosomal dna sequences similar to those of cardinium from seven popu ...200717035954
maintaining wolbachia in cell-free medium.in this video protocol, procedures are demonstrated to (1) purify wolbachia symbionts out of cultured mosquito cells, (2) use a fluorescent assay to ascertain the viability of the purified wolbachia and (3) maintain the now extracellular wolbachia in cell-free medium. purified wolbachia remain alive in the extracellular phase but do not replicate until re-inoculated into eukaryotic cells. extracellular wolbachia purified in this manner will remain viable for at least a week at room temperature, ...200718979021
macrofilaricidal effect of 4 weeks of treatment with doxycycline on wuchereria bancrofti.to evaluate the efficacy of doxycycline as a macrofilaricidal agent against wuchereria bancrofti.200718076549
wolbachia bacterial infection in drosophila. 200718830425
population replacement strategies for controlling vector populations and the use of wolbachia pipientis for genetic drive.in this video, jason rasgon discusses population replacement strategies to control vector-borne diseases such as malaria and dengue. "population replacement" is the replacement of wild vector populations (that are competent to transmit pathogens) with those that are not competent to transmit pathogens. there are several theoretical strategies to accomplish this. one is to exploit the maternally-inherited symbiotic bacteria wolbachia pipientis. wolbachia is a widespread reproductive parasite that ...200718979023
transfection of wolbachia pipientis into drosophila embryos.wolbachia is a genus of obligate intracellular alpha-proteobacteria represented by the type species wolbachia pipientis (dumler et al., 2001). wolbachia commonly reside within cytoplasmic vacuoles of arthropods and helminths (werren and windsor, 2000; casiraghi et al., 2004); vertebrate infections have not been identified. wolbachia are maternally transmitted from mothers to offspring though the embryonic cytoplasm. wolbachia are able to induce a diverse range of phenotypes in their invertebrate ...200718770621
[the endosymbiotic bacterium wolbachia enhances the nonspecific resistance to insect pathogens and alters behavior of drosophila melanogaster].to determine biologically important effects of the cytoplasmic endosymbiont wolbachia, two substrains of the same drosophila melanogaster strain have been studied, one of them infected with wolbachia and the other treated with tetracycline to eliminate the bacterium. female d. melanogaster infected with wolbachia are more resistant to the fungus bauveria bassiana (an insect pathogen) than uninfected females; infected females also exhibited changes in oviposition substrate preference. males infec ...200717990528
evolutionary genomics: transdomain gene transfers.biologists have until now conceded that bacterial gene transfer to multicellular animals is relatively uncommon in nature. a new study showing promiscuous insertions of bacterial endosymbiont genes into invertebrate genomes ushers in a shift in this paradigm.200717983575
[removing endosymbiotic wolbachia specifically decreases lifespan of females and competitiveness in a laboratory strain of drosophila melanogaster].to understand specific symbiotic relationships ensuring stable existing of the bacterium wolbachia in laboratory strains of drosophila melanogaster, the imago lifespan and senescence rate, as well as competitiveness, have been evaluated as components of fitness in females from the following laboratory strains: (1) inbred strain 95 infected with wolbachia; (2) two uninfected strains obtained by tetracycline treatment that were genetically similar to strain 95; and (3) two control, uninfected, wil ...200718069341
lymphatic filariasis: inflammatory response to wolbachia bacteria in filarial worms. 200718365535
host adaptation of a wolbachia strain after long-term serial passage in mosquito cell lines.the horizontal transfer of the bacterium wolbachia pipientis between invertebrate hosts hinges on the ability of wolbachia to adapt to new intracellular environments. the experimental transfer of wolbachia between distantly related host species often results in the loss of infection, presumably due to an inability of wolbachia to adapt quickly to the new host. to examine the process of adaptation to a novel host, we transferred a life-shortening wolbachia strain, wmelpop, from the fruit fly dros ...200818836024
efficacy of 2- and 4-week rifampicin treatment on the wolbachia of onchocerca volvulus.the microfilaricidal and temporarily sterilizing drug ivermectin is used for mass treatment of filarial infections. filariae containing wolbachia endobacteria can also be treated by the antibiotic doxycycline. the loss of wolbachia results in sterilization of onchocerca volvulus and macrofilaricidal effects. besides doxycycline, other antibiotics may be effective in depleting wolbachia. a preliminary study on the effects of rifampicin on the endobacteria, embryogenesis and microfilariae producti ...200818679718
wolbachia-based technologies for insect pest population control.wolbachia are a group of obligatory intracellular and maternally inherited bacteria found in many arthropod species, including insects, mites, spiders, springtails, crustaceans, as well as in certain nematodes. several pcr-based surveys suggest that over 20% of the arthropod species may be wolbachia-infected, rendering this bacterium the most ubiquitous intracellular symbiont yet described. wolbachia have recently attracted attention for their potential as novel and environmentally friendly bio- ...200818510018
bancroftian filariasis--absence of wolbachia after doxycycline treatment. 200818541758
heartworm and wolbachia: therapeutic implications.a safer, more effective adulticidal treatment and a safe method for reducing microfilaremia and breaking transmission of heartworm disease early in the treatment are needed. the present study evaluated efficacy of ivermectin (ivm) and doxycycline (doxy) alone or together (with or without melarsomine [mel]) in dogs with induced adult heartworm infection and assessed the ability of microfilariae from doxy-treated dogs to develop to l3 in aedes aegypti mosquitoes and subsequently to become reproduc ...200818930598
genome evolution of wolbachia strain wpip from the culex pipiens group.the obligate intracellular bacterium wolbachia pipientis strain wpip induces cytoplasmic incompatibility (ci), patterns of crossing sterility, in the culex pipiens group of mosquitoes. the complete sequence is presented of the 1.48-mbp genome of wpip which encodes 1386 coding sequences (cdss), representing the first genome sequence of a b-supergroup wolbachia. comparisons were made with the smaller genomes of wolbachia strains wmel of drosophila melanogaster, an a-supergroup wolbachia that is al ...200818550617
intense transpositional activity of insertion sequences in an ancient obligate endosymbiont.the streamlined genomes of ancient obligate endosymbionts generally lack transposable elements, such as insertion sequences (is). yet, the genome of wolbachia, one of the most abundant bacterial endosymbionts on earth, is littered with is. such a paradox raises the question as to why there are so many iss in the genome of this ancient endosymbiont. to address this question, we investigated is transpositional activity in the unculturable wolbachia by tracking the evolutionary dynamics and history ...200818562339
characterization and transcriptional analysis of two gene clusters for type iv secretion machinery in wolbachia of armadillidium vulgare.wolbachia are maternally inherited alpha-proteobacteria that induce feminization of genetic males in most terrestrial crustacean isopods. two clusters of vir genes for a type iv secretion machinery have been identified at two separate loci and characterized for the first time in a feminizing wolbachia. furthermore, we demonstrated that these operons are transcriptionally active in ovaries and in all other tissues tested, suggesting that t4ss has a significant role in wolbachia biology. these obs ...200818582562
symbionts, including pathogens, of the predatory mite metaseiulus occidentalis: current and future analysis methods.metaseiulus (= typhlodromus or galendromus) occidentalis (nesbitt) (acari: phytoseiidae) is an effective natural enemy of pest mites in a variety of crops around the world, although it is considered to be endemic in the western usa. a broad understanding of much of its biology, ecology, behavior, and genetics has been obtained over the past 60 years, but the role(s) symbionts play, which includes pathogens and other microorganisms, remains to be resolved fully. until molecular tools became avail ...200818696231
the nematoda filarioidea: critical analysis linking molecular and traditional approaches.the molecular analysis of the filarioidea and the endobacteria wolbachia is no more limited to the agents of human diseases and the diversified sampling permits a synthesis with the morphological and biological results. the validity of the genera with "uncoherent host range", such as monsonella, litomosoides and cercopithifilaria, is confirmed and, consequently, their evolution by host-switchings. dirofilaria and onchocerca, types of two subfamilies, appear more closely related than with other o ...200818814705
insights beyond wolbachia-drosophila interactions: never completely trust a model: insights from cytoplasmic incompatibility beyond wolbachia-drosophila interactions. 200818941470
curable genetic instability of a gal4 transgene in drosophila.transgenes, especially those driving production of the gal4 transcription factor in a specific spatial pattern, are a critical and widely used tool in the drosophila research community. we recently noticed loss of gal4-driven reporter gene expression in a series of crosses, and traced that loss of reporter gene expression to stochastic physical loss of the gal4 gene in the driver line. we have demonstrated that the instability of the gal4 transgene can be "cured" by treatment of the line with te ...200818820434
wolbachia genome integrated in an insect chromosome: evolution and fate of laterally transferred endosymbiont genes.recent accumulation of microbial genome data has demonstrated that lateral gene transfers constitute an important and universal evolutionary process in prokaryotes, while those in multicellular eukaryotes are still regarded as unusual, except for endosymbiotic gene transfers from mitochondria and plastids. here we thoroughly investigated the bacterial genes derived from a wolbachia endosymbiont on the nuclear genome of the beetle callosobruchus chinensis. exhaustive pcr detection and southern bl ...200818073380
the endosymbiont wolbachia pipientis induces the expression of host antioxidant proteins in an aedes albopictus cell line.wolbachia are obligate intracellular bacteria which commonly infect arthropods. they are maternally inherited and capable of altering host development, sex determination, and reproduction. reproductive manipulations include feminization, male-killing, parthenogenesis, and cytoplasmic incompatibility. the mechanism by which wolbachia avoid destruction by the host immune response is unknown. generation of antimicrobial peptides (amps) and reactive oxygen species (ros) by the host are among the fir ...200818461124
wolbachia endobacteria depletion by doxycycline as antifilarial therapy has macrofilaricidal activity in onchocerciasis: a randomized placebo-controlled study.in a randomized, placebo-controlled trial in ghana, 67 onchocerciasis patients received 200-mg/day doxycycline for 4-6 weeks, followed by ivermectin (ivm) after 6 months. after 6-27 months, efficacy was evaluated by onchocercoma histology, pcr and microfilariae determination. administration of doxycycline resulted in endobacteria depletion and female worm sterilization. the 6-week treatment was macrofilaricidal, with >60% of the female worms found dead, despite the presence of new, wolbachia-con ...200817999080
distribution of mosquito (diptera: culicidae) species and wolbachia (rickettsiales: rickettsiaceae) infections during the bird immigration season in pathumthani province, central thailand.mosquito distribution in the immigration bird-nested area, pathumthani province, was investigated from august to december in 2006. mosquitoes were collected by using co2-baited centers for disease control light traps in which dry ice was used as a source of co2 to attract mosquitoes. six traps were operated from 4 p.m. until 7 a.m. on each study day. four genera, which were anopheles, armigeres, culex, and mansonia with 14 species of mosquitoes were collected. culex gelidus (13.94-59.41%) and cu ...200818066693
do wolbachia-associated incompatibilities promote polyandry?the genetic incompatibility avoidance hypothesis as an explanation for the polyandrous mating strategies (mating with more than one male) of females of many species has received significant attention in recent years. it has received support from both empirical studies and a meta-analysis, which concludes that polyandrous females enjoy increased reproductive success through improved offspring viability relative to monandrous females. in this study we investigate whether polyandrous female drosoph ...200818067571
molecular identification of anaplasma marginale and rickettsial endosymbionts in blood-sucking flies (diptera: tabanidae, muscidae) and hard ticks (acari: ixodidae).in an attempt to identify the main vector and possible transmission routes of anaplasma spp. in a region of hungary with high prevalence of ovine and bovine anaplasmosis, dna was extracted from 316 haematophagous arthropods (individually or in pools), including 4 species of ixodid ticks, 6 species of tabanid flies and hornflies. midichloria-like organisms were identified with pcr (amplifying a portion of the 16s rrna gene) and sequencing from dermacentor marginatus and ixodes ricinus. significan ...200818495345
genetic and functional characterization of the type iv secretion system in wolbachia.a type iv secretion system (t4ss) is used by many symbiotic and pathogenic intracellular bacteria for the successful infection of and survival, proliferation, and persistence within hosts. in this study, the presence and function of the t4ss in wolbachia strains were investigated by a combination of genetic screening and immunofluorescence microscopy. two operons of virb-vird4 loci were found in the genome of wolbachia pipientis strain watab3, from the hymenoptera asobara tabida, and strain wri, ...200818502862
wolbachia: master manipulators of invertebrate biology.wolbachia are common intracellular bacteria that are found in arthropods and nematodes. these alphaproteobacteria endosymbionts are transmitted vertically through host eggs and alter host biology in diverse ways, including the induction of reproductive manipulations, such as feminization, parthenogenesis, male killing and sperm-egg incompatibility. they can also move horizontally across species boundaries, resulting in a widespread and global distribution in diverse invertebrate hosts. here, we ...200818794912
phylogeography and genetic diversity of a widespread old world butterfly, lampides boeticus (lepidoptera: lycaenidae).evolutionary genetics provides a rich theoretical framework for empirical studies of phylogeography. investigations of intraspecific genetic variation can uncover new putative species while allowing inference into the evolutionary origin and history of extant populations. with a distribution on four continents ranging throughout most of the old world, lampides boeticus (lepidoptera: lycaenidae) is one of the most widely distributed species of butterfly. it is placed in a monotypic genus with no ...200818973689
verified and potential pathogens of predatory mites (acari: phytoseiidae).several species of phytoseiid mites (acari: phytoseiidae), including species of the genera amblyseius, galendromus, metaseiulus, neoseiulus, phytoseiulus and typhlodromus, are currently reared for biological control of various crop pests and/or as model organisms for the study of predator-prey interactions. pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable data in mite research, as pathogens may affect the performance of their hos ...200818763041
rapidly evolving mitochondrial genome and directional selection in mitochondrial genes in the parasitic wasp nasonia (hymenoptera: pteromalidae).we sequenced the nearly complete mtdna of 3 species of parasitic wasps, nasonia vitripennis (2 strains), nasonia giraulti, and nasonia longicornis, including all 13 protein-coding genes and the 2 rrnas, and found unusual patterns of mitochondrial evolution. the nasonia mtdna has a unique gene order compared with other insect mtdnas due to multiple rearrangements. the mtdnas of these wasps also show nucleotide substitution rates over 30 times faster than nuclear protein-coding genes, indicating a ...200818653734
the genetics and cell biology of wolbachia-host interactions.wolbachia are gram-negative bacteria that are widespread in nature, carried by the majority of insect species as well as some mites, crustaceans, and filarial nematodes. wolbachia can range from parasitic to symbiotic, depending upon the interaction with the host species. the success of wolbachia is attributed to efficient maternal transmission and manipulations of host reproduction that favor infected females, such as sperm-egg cytoplasmic incompatibility (ci). much remains unknown about the me ...200818713031
the evolution of invasiveness in garden ants.it is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. ants are among the worst invasive pests, with lasius neglectus and its rapid spread through europe and asia as the most recent example of a pest ant that may become a global problem. here, we present the first integrated study on behavior, morphology, population genetics, che ...200819050762
a new cytogenetic mechanism for bacterial endosymbiont-induced parthenogenesis in hymenoptera.vertically transmitted endosymbiotic bacteria, such as wolbachia, cardinium and rickettsia, modify host reproduction in several ways to facilitate their own spread. one such modification results in parthenogenesis induction, where males, which are unable to transmit the bacteria, are not produced. in hymenoptera, the mechanism of diploidization due to wolbachia infection, known as gamete duplication, is a post-meiotic modification. during gamete duplication, the meiotic mechanism is normal, but ...200818713719
an intracellular symbiont and other microbiota associated with field-collected populations of sawflies (hymenoptera: symphyta).six species of sawfly (hymenoptera: symphyta) from four taxonomic families (agridae, diprionidae, pamphiliidae, and tenthredinidae) were collected from locations across canada and surveyed for their associated microbiota. total dna was extracted from individual insects, and polymerase chain reaction (pcr) was used to amplify the conserved 16s rrna gene from microbiota. denaturing gradient gel electrophoresis (dgge) and restriction fragment length polymorphism (rflp) were undertaken to separate b ...200818772939
iswpi1 from wolbachia pipientis defines a novel group of insertion sequences within the is5 family.insertion sequences are transposable elements that can represent substantial proportions of prokaryotic genomes and play a substantial role in shaping host genome evolution. as such, evaluating and understanding insertion sequence diversity is an important task to fulfill, because it is expected to yield new insight into the evolution of bacterial transposable elements and contribute to improve genome annotations. here, i characterized an insertion sequence, termed iswpi1, for which the taxonomi ...200818155858
insight into the routes of wolbachia invasion: high levels of horizontal transfer in the spider genus agelenopsis revealed by wolbachia strain and mitochondrial dna diversity.the pandemic distribution of wolbachia (alpha-proteobacteria) across arthropods is largely due to the ability of these maternally inherited endosymbionts to successfully shift hosts across species boundaries. yet it remains unclear whether wolbachia has preferential routes of transfer among species. here, we examined populations of eight species of the north american funnel-web spider genus agelenopsis to evaluate whether wolbachia show evidence for host specificity and the relative contribution ...200818179432
the mitochondrial heat shock protein 60 (hsp60) is up-regulated in onchocerca volvulus after the depletion of wolbachia.wolbachia, a genus of endosymbiotic bacteria of filarial worms, represent novel targets for anti-filarial therapy. the efficacy of compounds against wolbachia has been evaluated using antiserum raised against the 60 kda heat shock protein (hsp60) which binds specifically to this protein in both wolbachia and mitochondria. it has been shown that wolbachia stains (using such specific probes) stronger than the mitochondria in untreated onchocerca volvulus, whereas after the depletion of wolbachia ( ...200818205985
novel rna sequences associated with late male killing in homona magnanima.maternally inherited female-biased sex ratios have been documented in many invertebrate species. one cause of such biased sex ratios is male killing, i.e. only males die. in most species, male killing occurs during embryonic stages (early male killing) and is associated with cytoplasmic bacteria, including wolbachia, spiroplasma, rickettsia, flavobacteria and gamma proteobacteria. however, the oriental tea tortrix, homona magnanima, is one of the few species in which male death occurs in the lar ...200818302997
protein profiling of hemocytes from the terrestrial crustacean armadillidium vulgare.to establish and maintain a successful infection, microbial pathogens have evolved various strategies to infect the host in the face of a functional immune system. in this context, the alpha-proteobacteria wolbachia capacities to infect new host species have been greatly evidenced. indeed, in terrestrial isopods, experimentally transferred wolbachia invade all host tissues, including immune cells such as hemocytes. to investigate mechanisms that have to be avoided by bacteria to maintain themsel ...200818329099
infection of the intermediate mite host with wolbachia-depleted litomosoides sigmodontis microfilariae: impaired l1 to l3 development and subsequent sex-ratio distortion in adult worms.the rodent filaria litomosoides sigmodontis harbour wolbachia, endosymbionts essential for worm embryogenesis, larval development and adult survival. to study the effect of tetracycline, which depletes wolbachia, on the development of microfilariae (l1s, mf) to l3 in the intermediate host ornithonyssus bacoti, and to observe the development of wolbachia-depleted l3s in mongolian gerbils (meriones unguiculatus); microfilaremic gerbils were treated orally with tetracycline for 6 weeks (primary inf ...200818282572
natural death of adult onchocerca volvulus and filaricidal effects of doxycycline induce local foxp3+/cd4+ regulatory t cells and granzyme expression.immunosuppression in human filarial disease involves regulatory t cells. we hypothesized that natural or worm antigen-induced foxp3 regulatory t cells could be involved locally, suppressing effector cells via granzymes. natural and treatment-induced death of worms implies enhanced exposure to worm antigens. therefore, we examined foxp3+t cells and granzyme expression in onchocercomas harbouring adult onchocerca volvulus worms, with respect to worm viability, productivity, the patient's immune st ...200818339571
sex chromosomes and sex determination in lepidoptera.the speciose insect order lepidoptera (moths and butterflies) and their closest relatives, trichoptera (caddis flies), share a female-heterogametic sex chromosome system. originally a z/zz (female/male) system, it evolved by chromosome rearrangement to a wz/zz (female/male) system in the most species-rich branch of lepidoptera, a monophyletic group consisting of ditrysia and tischeriina, which together comprise more than 98% of all species. further sporadic rearrangements created multi-sex chrom ...200818391545
the diversity of reproductive parasites among arthropods: wolbachia do not walk alone.inherited bacteria have come to be recognised as important components of arthropod biology. in addition to mutualistic symbioses, a range of other inherited bacteria are known to act either as reproductive parasites or as secondary symbionts. whilst the incidence of the alpha-proteobacterium wolbachia is relatively well established, the current knowledge of other inherited bacteria is much weaker. here, we tested 136 arthropod species for a range of inherited bacteria known to demonstrate reprod ...200818577218
[wolbachia extensively harbored by bemisia tabaci in china].wolbachia are a group of maternally inherited bacteria harbored by a variety of arthropods and can manipulate the reproductivity of their hosts. eighteen populations of whiteflies were collected from hebei, xinjiang, beijing, shandong, zhejiang, guangxi, hainan, guangzhou and fujian provinces, china. these whiteflies were molecularly identified using internal transcribed spacer 1 its1 rdna sequences. they were then detected for wolbachia infection using wolbachia-specific primers designed based ...200818338578
standardization of a colorimetric method to quantify growth and metabolic activity of wolbachia-infected mosquito cells.the aedes albopictus aa23 cell line, which is persistently infected with wolbachia pipientis strain walbb, tends to grow as aggregated clusters of cells that are difficult to disperse for conventional quantification based on cell number. we used a. albopictus c7-10 cells to validate conversion of methylthiazole tetrazolium (mtt) to a colored formazan product with respect to incubation time, cell number over a 40-fold range, and metabolic activity as cells enter stationary phase. using this assay ...200818622662
effects of 6-week azithromycin treatment on the wolbachia endobacteria of onchocerca volvulus.the effects of azithromycin treatment on the presence of wolbachia endobacteria and on the embryogenesis and microfilariae production of onchocerca volvulus were studied. in 2002, in an endemic area in ghana, 37 onchocerciasis patients were treated for 6 weeks with azithromycin: 23 patients received 250 mg every day, and 14 took 1,200 mg once a week. after 6 and/or 12 months, all palpable worm nodules were extirpated from 31 treated and nine additional untreated patients, and the presence of wol ...200818421478
multiple rescue factors within a wolbachia strain.wolbachia-induced cytoplasmic incompatibility (ci) is expressed when infected males are crossed with either uninfected females or females infected with wolbachia of different ci specificity. in diploid insects, ci results in embryonic mortality, apparently due to the the loss of the paternal set of chromosomes, usually during the first mitotic division. the molecular basis of ci has not been determined yet; however, several lines of evidence suggest that wolbachia exhibits two distinct sex-depen ...200818430940
transfection of feminizing wolbachia endosymbionts of the butterfly, eurema hecabe, into the cell culture and various immature stages of the silkmoth, bombyx mori.wolbachia are maternally inherited endosymbiotic bacteria of invertebrates that can manipulate the reproductive systems of their arthropod hosts in a variety of ways. to establish a useful model system for investigating the mechanism of wolbachia-induced host feminization, we conducted the following series of experiments: (1) feminizing wolbachia of the butterfly, eurema hecabe, were transferred into cell cultures of the silkmoth, bombyx mori, and (2) the transfected wolbachia in cell cultures w ...200818458997
wolbachia plays no role in the one-way reproductive incompatibility between the hybridizing field crickets gryllus firmus and g. pennsylvanicus.wolbachia are cytoplasmically inherited alpha-proteobacteria that can cause cytoplasmic incompatibility (ci) in insects. this incompatibility between sperm and egg is evident when uninfected females mate with infected males. wolbachia-driven reproductive incompatibilities are of special interest because they may play a role in speciation. however, the presence of wolbachia does not always imply incompatibility. the field crickets gryllus firmus and g. pennsylvanicus exhibit a very clear unidirec ...200818685571
an rgs-containing sorting nexin controls drosophila lifespan.the pursuit of eternal youth has existed for centuries and recent data indicate that fat-storing tissues control lifespan. in a d. melanogaster fat body insertional mutagenic enhancer trap screen designed to isolate genes that control longevity, we identified a regulator of g protein signaling (rgs) domain containing sorting nexin, termed snazarus (sorting nexin lazarus, snz). flies with insertions into the 5' utr of snz live up to twice as long as controls. transgenic expression of uas-snz from ...200818478054
relative wolbachia density of field-collected aedes albopictus mosquitoes in thailand.female aedes albopictus mosquitoes from natural populations of different geographical regions of thailand were collected and allowed to oviposit to determine relative wolbachia a and wolbachia b densities of their offspring (f1) by using real-time quantitative pcr (rtq-pcr). an important aspect of this work is that all aedes albopictus mosquitoes were collected from the field. twenty-seven offspring were from diverse areas of thailand (songkhla, konkaen, chantaburi, and kanchanaburi). the range ...200818697321
heartworm disease in animals and humans.heartworm disease due to dirofilaria immitis continues to cause severe disease and even death in dogs and other animals in many parts of the world, even though safe, highly effective and convenient preventatives have been available for the past two decades. moreover, the parasite and vector mosquitoes continue to spread into areas where they have not been reported previously. heartworm societies have been established in the usa and japan and the first european dirofilaria days (fedd) conference ...200818486691
origins of asexuality in bryobia mites (acari: tetranychidae).obligate asexual reproduction is rare in the animal kingdom. generally, asexuals are considered evolutionary dead ends that are unable to radiate. the phytophagous mite genus bryobia contains a large number of asexual species. in this study, we investigate the origin and evolution of asexuality using samples from 111 populations in europe, south africa and the united states, belonging to eleven bryobia species. we also examine intraspecific clonal diversity for one species, b. kissophila, by gen ...200818489749
molecular identification of wolbachia from the filarial nematode mansonella perstans.wolbachiae are bacterial endosymbionts of insects and many filarial nematodes whose products trigger inflammation in filarial infections. the dependence of the parasites on their endosymbionts has also led to the use of antibiotics directed against the wolbachiae, therapy that has been demonstrated to have a profound salutary effect on filarial infections. the identification of wolbachiae in mansonella species has been conclusively shown for mansonella ozzardi (mo), but not for mansonella persta ...200818538871
the wolbachia endosymbiont of brugia malayi has an active pyruvate phosphate dikinase.genome analysis of the glycolytic/gluconeogenic pathway in the wolbachia endosymbiont from the filarial parasite brugia malayi (wbm) has revealed that wbm lacks pyruvate kinase (pk) and may instead utilize the enzyme pyruvate phosphate dikinase (ppdk; atp:pyruvate, orthophosphate phosphotransferase, ec 2.7.9.1). ppdk catalyses the reversible conversion of amp, ppi and phosphoenolpyruvate (pep) into atp, pi and pyruvate. the glycolytic pathway of most organisms, including mammals, contains exclus ...200818539347
exploring the transcriptome of the burrowing nematode radopholus similis.radopholus similis is an important nematode pest on fruit crops in the tropics. unraveling the transcriptome of this migratory plant-parasitic nematode can provide insight in the parasitism process and lead to more efficient control measures. for the first high throughput molecular characterization of this devastating nematode, 5,853 expressed sequence tags from a mixed stage population were generated. adding 1,154 tags from the est division of genbank for subsequent analysis, resulted in a tota ...200818386064
stochastic spread of wolbachia.wolbachia are very common, maternally transmitted endosymbionts of insects. they often spread by a mechanism termed cytoplasmic incompatibility (ci) that involves reduced egg hatch when wolbachia-free ova are fertilized by sperm from wolbachia-infected males. because the progeny of wolbachia-infected females generally do not suffer ci-induced mortality, infected females are often at a reproductive advantage in polymorphic populations. deterministic models show that wolbachia that impose no costs ...200818755670
cloning, expression, purification and characterization of a dsba-like protein from wolbachia pipientis.wolbachia pipientis are obligate endosymbionts that infect a wide range of insect and other arthropod species. they act as reproductive parasites by manipulating the host reproduction machinery to enhance their own transmission. this unusual phenotype is thought to be a consequence of the actions of secreted wolbachia proteins that are likely to contain disulfide bonds to stabilize the protein structure. in bacteria, the introduction or isomerization of disulfide bonds in proteins is catalyzed b ...200818387819
combined ivermectin and doxycycline treatment has microfilaricidal and adulticidal activity against dirofilaria immitis in experimentally infected dogs.there is still a pressing need for effective adulticide treatment for human and animal filarial infections. like many filarial nematodes, dirofilaria immitis, the causative agent of canine heartworm disease, harbours the bacterial endosymbiont wolbachia, which has been shown to be essential for worm development, fecundity and survival. here the authors report the effect of different treatment regimens in dogs experimentally infected with adult d. immitis on microfilariemia, antigenemia, worm rec ...200818433753
phylogenetic analyses of ribosomal dna-containing bacterioplankton genome fragments from a 4000 m vertical profile in the north pacific subtropical gyre.high-throughput identification of rrna gene-containing clones in large insert metagenomic libraries is difficult, because of the high background of host ribosomal rna (rrna) and rrna genes. to address this challenge, a membrane hybridization method was developed to identify all bacterial small subunit rrna-containing fosmid clones of microbial community dna from seven different depths in the north pacific subtropical gyre. out of 101,376 clones screened, 751 rdna-containing clones were identifie ...200818494796
first detection of wolbachia spp., including a new genotype, in sand flies collected in marseille, france.pooled sand fly samples collected in marseille, france, in july 2005 were examined by polymerase chain reaction amplification and sequencing of the 16s rrna gene of the anaplasmataceae. two different sequences of the 16s rrna gene were obtained that are similar to bacteria belonging to the genus wolbachia. these findings were confirmed by amplification, sequencing, and phylogenetic analysis of the wsp gene of the genus wolbachia. the wolbachia species from sergentomyia minuta has been named "wol ...200818533441
the secretome of the filarial parasite, brugia malayi: proteomic profile of adult excretory-secretory products.the secretome of a parasite in its definitive host can be considered to be its genome in trans, to the extent that secreted products encoded by the parasite fulfill their function in the host milieu. the 'extended phenotype' of the filarial parasite, brugia malayi, is of particular interest because of the evidence that infection results in potent down-modulation of the host immune response. we collected b. malayi 'excretory-secretory' (bes) proteins from adult parasites and using a combination o ...200818439691
using predictive models to optimize wolbachia-based strategies for vector-borne disease control.the development of resistance to insecticides by vector arthropods, the evolution of resistance to chemotherapeutic agents by parasites and the lack of clinical cures or vaccines for many diseases has stimulated a high-profile effort to develop vector-borne disease control strategies based on release of genetically-modified mosquitoes. because transgenic insects are likely to be less fit than their wild-type counterparts, transgenic traits must be actively driven into the population in spite of ...200818510019
modifying insect population age structure to control vector-borne disease.age is a critical determinant of the ability of most arthropod vectors to transmit a range of human pathogens. this is due to the fact that most pathogens require a period of extrinsic incubation in the arthropod host before pathogen transmission can occur. this developmental period for the pathogen often comprises a significant proportion of the expected lifespan of the vector. as such, only a small proportion of the population that is oldest contributes to pathogen transmission. given this, st ...200818510020
absence of wolbachia endobacteria in the non-filariid nematodes angiostrongylus cantonensis and a. costaricensis.abstract: the majority of filarial nematodes harbour wolbachia endobacteria, including the major pathogenic species in humans, onchocerca volvulus, brugia malayi and wuchereria bancrofti. these obligate endosymbionts have never been demonstrated unequivocally in any non-filariid nematode. however, a recent report described the detection by pcr of wolbachia in the metastrongylid nematode, angiostrongylus cantonensis (rat lungworm), a leading cause of eosinophilic meningitis in humans. to address ...200818801163
genetic and cytogenetic analysis of the fruit fly rhagoletis cerasi (diptera: tephritidae).the european cherry fruit fly, rhagoletis cerasi, is a major agricultural pest for which biological, genetic, and cytogenetic information is limited. we report here a cytogenetic analysis of 4 natural greek populations of r. cerasi, all of them infected with the endosymbiotic bacterium wolbachia pipientis. the mitotic karyotype and detailed photographic maps of the salivary gland polytene chromosomes of this pest species are presented here. the mitotic metaphase complement consists of 6 pairs of ...200818545272
wolbachia modification of sperm does not always require residence within developing sperm.wolbachia are maternally inherited intracellular bacteria known to manipulate the reproduction of their arthropod hosts. wolbachia commonly affect the sperm of infected arthropods. wolbachia-modified sperm cannot successfully fertilize unless the female is infected with the same wolbachia type. a study of spermatogenesis in the parasitic wasp nasonia vitripennis reveals that wolbachia are not required in individual spermatocytes or spermatids to modify sperm. in n. vitripennis, wolbachia modify ...200818648384
wolbachia mediate variation of host immunocompetence.after decades during which endosymbionts were considered as silent in their hosts, in particular concerning the immune system, recent studies have revealed the contrary. in the present paper, we addressed the effect of wolbachia, the most prevalent endosymbiont in arthropods, on host immunocompetence. to this end, we chose the a. vulgare-wolbachia symbiosis as a model system because it leads to compare consequences of two wolbachia strains (wvulc and wvulm) on hosts from the same population. mor ...200818818770
wolbachia in dirofilaria repens causing human subcutaneous dirofilariosis.human subcutaneous dirofilariosis is an increasingly reported zoonosis caused by several filarial species, in particular by dirofilaria (nochtiella) repens. like many filarial worms, d. repens harbours the bacterial endosymbiont wolbachia that has been implicated in the inflammatory features of filarial infection. immunohistochemical staining against the wolbachia surface protein (wsp) was carried out on 14 skin nodules and showed numerous bacteria within the intact worms and occasional positive ...200818576857
wolbachia in two populations of melittobia digitata dahms (hymenoptera: eulophidae).we investigated two populations of melittobia digitata dahms, a gregarious parasitoid (primarily upon a wide range of solitary bees, wasps, and flies), in search of wolbachia infection. the first population, from xalapa, mexico, was originally collected from and reared on mexican fruit fly pupae, anastrepha ludens loew (diptera: tephritidae); the other, from athens, georgia, was collected from and reared on prepupae of mud dauber wasps, trypoxylon politum say (hymenoptera: crabronidae). pcr stud ...200819169549
wolbachia and virus protection in insects.wolbachia pipientis bacteria are common endosymbionts of insects that are best known for their ability to increase their prevalence in populations by manipulating host reproductive systems. however, there are examples of wolbachia that exist in nature that seem to induce no reproductive parasitism trait and yet are able to invade populations. we demonstrate a fitness benefit for wolbachia-infected insects that may explain this paradox. drosophila melanogaster flies infected with wolbachia are le ...200818974344
evaluation of reproductive compatibility of interstrain matings among plum curculio populations in the eastern united states.reproductive compatibility of interstrain matings in plum curculio, conotrachelus nenuphar (herbst), was studied during the summers of 2004 and 2006. there was a unidirectional incompatibility in the cross-matings along a rough north to south transect of the range of plum curculio (4 x 4 two-factorial design). there was significantly lower fertility in west virginia males mated with new york and virginia females (40 and 29%, respectively), and florida males had a significantly lower fertility wi ...200819036199
genomics and evolution of heritable bacterial symbionts.insect heritable symbionts have proven to be ubiquitous, based on molecular screening of various insect lineages. recently, molecular and experimental approaches have yielded an immensely richer understanding of their diverse biological roles, resulting in a burgeoning research literature. increasingly, commonalities and intermediates are being discovered between categories of symbionts once considered distinct: obligate mutualists that provision nutrients, facultative mutualists that provide pr ...200818983256
no resistance to male-killing wolbachia after thousands of years of infection.maternally transmitted male-killing endosymbionts can exert strong and relentless selection pressure on their hosts to evolve resistance to these infections. surveys of current infection prevalence and mtdna diversity indicate that drosophila innubila is and has been infected with male-killing wolbachia at moderate frequencies for extended evolutionary periods. here, we use coalescent simulations to infer the minimum age of the wolbachia infection in this species, and estimate that the infection ...200818717746
wolbachia in dirofilaria repens, an agent causing human subcutaneous dirofilariasis.human subcutaneous dirofilariasis is an increasingly reported zoonosis caused by several filarial species, in particular by dirofilaria (nochtiella) repens. like many filarial worms, d. repens harbors the bacterial endosymbiont wolbachia that has been implicated in the inflammatory features of filarial infection. immunohistochemical staining against the wolbachia surface protein (wsp) was carried out on 14 skin nodules and showed numerous bacteria within the intact worms and occasional positive ...200819127968
natural enemies of mass-reared predatory mites (family phytoseiidae) used for biological pest control.predatory mites of the family phytoseiidae are valued natural enemies that provide effective pest control in greenhouses and on agricultural crops. mass-reared phytoseiids are occasionally associated with microorganisms and although their effects are not always apparent, some are pathogenic and reduce host fitness. invertebrate pathogens are encountered more frequently in mass production systems than in nature because rearing environments often cause overcrowding and other stresses that favour p ...200818726699
prevalence of the endosymbiont wolbachia in heartworms (dirofilaria immitis). 200818931357
nonrandom wolbachia infection status of drosophila melanogaster strains with different mtdna haplotypes.wolbachia are maternally inherited bacteria, which typically spread in the host population by inducing cytoplasmic incompatibility (ci). in drosophila melanogaster, wolbachia is quite common but ci is variable, with most of the studies reporting low levels of ci. surveying mitochondrial dna (mtdna) variation and infection status in a worldwide d. melanogaster collection, we found that the wolbachia infection was not randomly distributed among flies with different mtdna haplotypes. this preferent ...200818780877
wolbachia and its influence on the pathology and immunology of dirofilaria immitis infection.since the definitive identification in 1995 of the bacterial endosymbiont wolbachia that resides in different tissues of the filarial worm dirofilaria immitis, there has been increasing interest to understand whether and what role it plays in the pathogenesis of and immune response to heartworm infection. the present study evaluated the effects of treatments on lung pathology in 20 beagle dogs experimentally infected with d. immitis. dogs in group 1 were treated with doxycycline (10 mg/kg/day) o ...200818947926
[high temperature initiates changes of wolbachia ultrastructure in the ovaries and early embryos of drosophila melanogaster].electron microscopic analysis of drosophila melanogaster (w1118) ovarian cells has demonstrated that stressful heat treatment of flies results in the appearance of electron dense granules and large lysosomes in the cytoplasm of ovarian cells, which is not related with the presence of wolbachia, as these changes are observed in both the infected and uninfected flies. high temperature initiates essential envelope defects and other structural changes of symbiotic bacteria in the cytoplasm of ovaria ...200819198544
filariasis: new drugs and new opportunities for lymphatic filariasis and onchocerciasis.chemotherapy against onchocerciasis and lymphatic filariasis has been discussed mainly within the framework of mass drug administration with diethylcarbamazine, ivermectin and albendazole. although strong reductions in infection prevalence were achieved, the regimes for these drugs do not fully cover needs of individual patients who seek treatment because of symptoms. chemotherapy against filarial wolbachia endosymbionts with doxycycline showed higher antiparasitic efficacy in onchocerciasis and ...200818978537
the bacterial symbiont wolbachia induces resistance to rna viral infections in drosophila melanogaster.wolbachia are vertically transmitted, obligatory intracellular bacteria that infect a great number of species of arthropods and nematodes. in insects, they are mainly known for disrupting the reproductive biology of their hosts in order to increase their transmission through the female germline. in drosophila melanogaster, however, a strong and consistent effect of wolbachia infection has not been found. here we report that a bacterial infection renders d. melanogaster more resistant to drosophi ...200819222304
dirofilaria immitis and wolbachia-derived antigens: its effect on endothelial mammal cells.antigens of both dirofilaria immitis and wolbachia symbiont bacteria are implicated in the inflammatory pathology of heartworm infection. the aim of the present study was to compare the stimulatory capacity of in vitro cultures of vascular endothelial cells by the adult somatic antigens of d. immitis (disa) and the recombinant form of the wolbachia surface protein (rwsp), during the first 24h of stimulation. our results indicate a different stimulatory activity of the two antigens. both the disa ...200818922634
galectin and aldolase-like molecules are responsible for the specific ige response in humans exposed to dirofilaria immitis.dirofilaria immitis is the agent of the heartworm disease in canids and felids, and of pulmonary dirofilariosis in man. like other filariae, d. immitis harbours endosymbion wolbachia bacteriae. in this work we analyse the response of specific ige antibodies against both d. immitis antigens and the wolbachia surface protein (wsp) in two groups of persons living in an area of canine endemia, one presenting high levels of total ige (group 1) and other with normal levels (group 2). infections with d ...200819067840
'til death do us part': coming to terms with symbiotic relationships. forward.symbiotic interactions of microorganisms are widespread in nature, and support fundamentally important processes in diverse areas of biology that range from health and disease to ecology and the environment. here, david relman discusses the selection of articles in this focus issue, which reflects the exciting advances in our understanding of intimate partnerships between organisms and their environments.200819086265
microbiology. rogue insect immunity. 200819023073
widespread mito-nuclear discordance with evidence for introgressive hybridization and selective sweeps in lycaeides.we investigated the extent and potential cause(s) of mitochondrial introgression within the polytypic north american lycaeides species complex (lepidoptera). by comparing population genetic structure based on mitochondrial dna (coi and coii) and nuclear dna (251 polymorphic amplified fragment length polymorphism markers), we detected substantial mito-nuclear discordance, primarily involving a single mitochondrial haplotype (h01), which is likely due to mitochondrial introgression between differe ...200819120997
chikungunya-wolbachia interplay in aedes albopictus.a severe chikungunya (chik) outbreak recently hit several countries of the indian ocean. on la réunion island, aedes albopictus was incriminated as the major vector. this mosquito species is naturally co-infected with two distinct strains of the endosymbiont wolbachia, namely walba and walbb, which are increasingly attracting interest as potential tools for vector control. a pcr quantitative assay was developed to investigate wolbachia/mosquito host interactions. we show that wolbachia densities ...200819133077
first detection of wolbachia in arrhenotokous populations of thrips species (thysanoptera: thripidae and phlaeothripidae) and its role in reproduction.insects in the order thysanoptera are known for their haplodiploid reproduction, with most species reproducing by arrhenotoky. a few species, however, have only female populations and reproduce by thelytoky. seven thrips species reproducing either by arrhenotoky [frankliniella occidentalis (pergande), echinothrips americanus morgan, suocerathrips linguis mound and marullo, gynaikothrips ficorum (marchal)] or thelytoky [hercinothrips femoralis (o.m. reuter) and parthenothrips dracaenae (heeger)] ...200819161685
genome-wide analysis of the interaction between the endosymbiotic bacterium wolbachia and its drosophila host.intracellular wolbachia bacteria are obligate, maternally-inherited, endosymbionts found frequently in insects and other invertebrates. the success of wolbachia can be attributed in part to an ability to alter host reproduction via mechanisms including cytoplasmic incompatibility (ci), parthenogenesis, feminization and male killing. despite substantial scientific effort, the molecular mechanisms underlying the wolbachia/host interaction are unknown.200818171476
wolbachia infection alters olfactory-cued locomotion in drosophila spp.wolbachia pipientis is an endosymbiotic bacterium present in diverse insect species. although it is well studied for its dramatic effects on host reproductive biology, little is known about its effects on other aspects of host biology, despite its presence in a wide array of host tissues. this study examined the effects of three wolbachia strains on two different drosophila species, using a laboratory performance assay for insect locomotion in response to olfactory cues. the results demonstrate ...200818456851
coexistence of cytoplasmic incompatibility and male-killing-inducing endosymbionts, and their impact on host gene flow.male-killing (mk) and cytoplasmic incompatibility (ci) inducing bacteria are among the most common endosymbionts of arthropods. previous theoretical research has demonstrated that these two types of endosymbionts cannot stably coexist within a single unstructured host population if no doubly infected host individuals occur. here, we analyse a model of two host subpopulations connected by migration. we demonstrate that coexistence of mk- and ci-inducing endosymbionts is possible if migration rate ...200817915272
cytological properties of an aedes albopictus mosquito cell line infected with wolbachia strain walbb.in vitro production of the obligate intracellular bacterium, wolbachia pipientis, is essential to its manipulation as a genetic tool to spread transgenes within vector populations. we have adapted the wolbachia-infected aa23 aedes albopictus mosquito cell line to eagle's minimal medium, supplemented with nonessential amino acids, glutamine, and 20% fetal bovine serum. when plated at low densities, aa23e cells grew as patchy monolayers, comprised of non-contiguous clusters of cells that gave rise ...200818401667
molecular and functional characterization of granulin-like molecules of insects.granulins are a group of highly conserved growth factors that have been described from a variety of organisms spanning the metazoa. here, we report on the identification of two partial transcripts encoding granulin-like molecules from aa23 embryonic cells of aedes albopictus and primary haemocytes from manduca sexta. both these partial transcripts had the characteristic 12-cysteine motif that is a hallmark of the granulin family and they represent the first granulin mrna transcripts identified f ...200818405836
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