Publications

tracking down the culprit in river blindness.		2002	12062980
could antibiotics cure river blindness?		2002	12075374
high wolbachia density in insecticide-resistant mosquitoes.	wolbachia symbionts are responsible for various alterations in host reproduction. the effects of the host genome on endosymbiont levels have often been suggested, but rarely described. here, we show that wolbachia density is strongly modified by the presence of insecticide-resistant genes in the common house mosquito, culex pipiens. the wolbachia density was estimated using a real-time quantitative pcr assay. strains harbouring different genes conferring resistance were more infected than a susc ...	2002	12079666
bacteria in ovarioles of females from maleless families of ladybird beetles adalia bipunctata l. (coleoptera: coccinellidae) naturally infected with rickettsia, wolbachia, and spiroplasma.	ovarioles were found to be infected with spiroplasma, wolbachia, and rickettsia in adalia bipunctata females with maleless progeny in different natural populations. ooplasm was infected with few wolbachia bacteria. in ooplasm infected by rickettsia, bacteria were present in small foci. spiroplasmas were found encapsulated into ooplasm from the wider intercellular spaces between epithelial and oocyte cells. the cytoplasm of follicular epithelia infected with rickettsia was heavily destroyed, but ...	2002	12095235
presence of wolbachia endosymbionts in different silkworm species and races and in their uzi fly parasites.		2002	12095241
a host parasite interaction rescues drosophila oogenesis defects.	the cytoplasmically inherited bacterium wolbachia pipientis is a widespread parasite of arthropods that manipulates the reproductive biology of its hosts, often to their detriment, in order to foster its own transmission through egg cytoplasm. here we report that infection by wolbachia restores fertility to drosophila melanogaster mutant females prevented from making eggs by protein-coding lesions in sex-lethal (sxl), the master regulator of sex determination. suppression of sterility by wolbach ...	2002	12097909
in vitro effects of antibiotics on brugia malayi worm survival and reproduction.	recent studies have suggested that intracellular wolbachia spp. endobacteria are necessary for the reproduction and survival of filarial nematodes. the effects of antibiotics that are active against related bacteria on adult worms and microfilariae (mf) of brugia malayi in vitro were investigated. antibiotics tested were doxycycline (doxy), tetracycline (tet), rifampicin (rif), azithromycin (azith), and chloramphenicol (chlor). doxy, tet, rif, and azith reduced release of mf by adult female worm ...	2002	12099435
[river blindness: not only the work of onchocerca volvulus?].		2002	12102035
[combatting river blindness by means of chemotherapy directed at the symbiotic wolbachia bacteria in the causative filariae].	in a mouse model of river blindness it was demonstrated that wolbachia bacteria, endosymbionts of filarial nematodes, play an important role in the inflammatory process leading to the disease and that this process depends on toll-like receptor 4. wolbachia is found in many arthropods and in all filariae pathogenic for man. treatment with doxycycline depletes female filariae of wolbachia and renders them infertile for at least 18 months. chemotherapy of filarial nematodes should be studied for th ...	2002	12132134
genome fragment of wolbachia endosymbiont transferred to x chromosome of host insect.	the adzuki bean beetle, callosobruchus chinensis, is triple-infected with distinct lineages of wolbachia endosymbiont, wbrucon, wbruori, and wbruaus, which were identified by their wsp (wolbachia surface protein) gene sequences. whereas wbrucon and wbruori caused cytoplasmic incompatibility of the host insect, wbruaus did not. although wbrucon and wbruori were easily eliminated by antibiotic treatments, wbruaus persisted over five treated generations and could not be eliminated. the inheritance ...	2002	12386340
field prevalence of wolbachia in the mosquito vector aedes albopictus.	the endosymbiotic bacteria in the genus wolbachia have been proposed as a potential candidate to deliver pathogen-blocking genes into natural populations of medically important insects. the successful application of wolbachia in insect vector control depends on the ability of the agent to successfully invade and maintain itself at high frequency under field conditions. here, we evaluated the prevalence of wolbachia infections in a field population of the wolbachia-superinfected mosquito aedes al ...	2002	12135259
maternal transmission efficiency of wolbachia superinfections in aedes albopictus populations in thailand.	we examined the transmission efficiency of 2 strains of wolbachia bacteria that cause cytoplasmic incompatibility in field populations of aedes albopictus by polymerase chain reaction assay. we found mainland and island populations throughout thailand to be superinfected with group a and b bacteria. of 320 wolbachia-positive adult mosquitoes, 97.5% were infected with both groups. single infected individuals of each wolbachia group were encountered in nearly equal numbers. we screened 550 offspri ...	2002	12135258
linkage disequilibria between mtdna haplotypes and chromosomal arrangements in a natural population of drosophila subobscura.	the association between mtdna haplotypes and chromosomal arrangements in a natural population of drosophila subobscura from calvia (balearic islands, spain) was studied in order to search for linkage disequilibria, in an attempt to explain the populational dynamics of the mtdna haplotypes of this species in nature. the presence of wolbachia was not detected. two main haplotypes (i and ii) were found, as well as a series of less common ones. the tajima d-test seemed to indicate some kind of seaso ...	2002	12136416
host-symbiont conflicts: positive selection on an outer membrane protein of parasitic but not mutualistic rickettsiaceae.	the rickettsiaceae is a family of intracellular bacterial symbionts that includes both vertically transmitted parasites that spread by manipulating the reproduction of their host (wolbachia in arthropods) and horizontally transmitted parasites (represented by cowdria ruminantium), and mutualists (wolbachia pipientis in nematode worms). we have investigated the nature of natural selection acting on an outer membrane protein, the wsp gene in wolbachia and its homologue map1 in cowdria, thought lik ...	2002	12140246
on the evolution of cytoplasmic incompatibility in haplodiploid species.	the most enigmatic sexual manipulation by wolbachia endosymbionts is cytoplasmic incompatibility (ci): infected males are reproductively incompatible with uninfected females. in this paper, we extend the theory on population dynamics and evolution of ci, with emphasis on haplodiploid species. first, we focus on the problem of the threshold to invasion of the wolbachia infection in a population. simulations of the dynamics of infection in small populations show that it does not suffice to assume ...	2002	12144012
divergence of mitochondrial dna is not corroborated by nuclear dna, morphology, or behavior in drosophila simulans.	we ask whether the observed mitochondrial dna (mtdna) population subdivision of drosophila simulans is indicative of organismal structure or of specific processes acting on the mitochondrial genome. factors either intrinsic or extrinsic to the host genome may influence the evolutionary dynamics of mtdna. potential intrinsic factors include adaptation of the mitochondrial genome and of nucleomitochondrial gene complexes specific to the local environment. an extrinsic force that has been shown to ...	2002	11989683
searching for wolbachia (rickettsiales: rickettsiaceae) in mosquitoes (diptera: culicidae): large polymerase chain reaction survey and new identifications.	bacteria of the genus wolbachia constitute a group of intracellular and maternally inherited micro-organisms that are widespread in arthropods, inducing several reproductive disorders such as cytoplasmic incompatibility in their hosts. considering relevant biological implications related to the presence of wolbachia in several insect orders, for example its potential role as mechanism for rapid speciation and as vehicle to drive genetic markers in wild populations of vectors of medical and veter ...	2002	12144285
recent changes in phenotype and patterns of host specialization in wolbachia bacteria.	wolbachia are a genus of bacterial symbionts that are known to manipulate the reproduction of their arthropod hosts, both by distorting the host sex ratio and by inducing cytoplasmic incompatibility. previous work has suggested that some wolbachia clades specialize in particular host taxa, but others are diverse. furthermore, the frequency with which related strains change in phenotype is unknown. we have examined these issues for wolbachia bacteria from acraea butterflies, where different inter ...	2002	12144650
feminizing wolbachia in an insect, ostrinia furnacalis (lepidoptera: crambidae).	wolbachia, which forms a group of maternally inherited bacteria in arthropods, often cause reproduction alterations in their hosts, such as cytoplasmic incompatibility, parthenogenesis, male-killing, hybrid breakdown and feminization. to date, wolbachia-induced feminization has been reported only in isopods. here we report that a wolbachia strain feminizes an insect host, ostrinia furnacalis. among 79 wild females of o. furnacalis examined, wolbachia infection was detected in 13 females. twelve ...	2002	12180086
how many wolbachia supergroups exist?		2002	11861893
wolbachia density and virulence attenuation after transfer into a novel host.	the factors that control replication rate of the intracellular bacterium wolbachia pipientis in its insect hosts are unknown and difficult to explore, given the complex interaction of symbiont and host genotypes. using a strain of wolbachia that is known to over-replicate and shorten the lifespan of its drosophila melanogaster host, we have tracked the evolution of replication control in both somatic and reproductive tissues in a novel host/wolbachia association. after transinfection (the transf ...	2002	11880639
infectious disease. new culprit emerges in river blindness.		2002	11884722
the role of endosymbiotic wolbachia bacteria in the pathogenesis of river blindness.	parasitic filarial nematodes infect more than 200 million individuals worldwide, causing debilitating inflammatory diseases such as river blindness and lymphatic filariasis. using a murine model for river blindness in which soluble extracts of filarial nematodes were injected into the corneal stroma, we demonstrated that the predominant inflammatory response in the cornea was due to species of endosymbiotic wolbachia bacteria. in addition, the inflammatory response induced by these bacteria was ...	2002	11884755
the effect of wolbachia-induced cytoplasmic incompatibility on host population size in natural and manipulated systems.	obligate, intracellular bacteria of the genus wolbachia often behave as reproductive parasites by manipulating host reproduction to enhance their vertical transmission. one of these reproductive manipulations, cytoplasmic incompatibility, causes a reduction in egg-hatch rate in crosses between individuals with differing infections. applied strategies based upon cytoplasmic incompatibility have been proposed for both the suppression and replacement of host populations. as wolbachia infections occ ...	2002	11886634
history of infection with different male-killing bacteria in the two-spot ladybird beetle adalia bipunctata revealed through mitochondrial dna sequence analysis.	the two-spot ladybird beetle adalia bipunctata (coleoptera: coccinellidae) is host to four different intracellular maternally inherited bacteria that kill male hosts during embryogenesis: one each of the genus rickettsia (alpha-proteobacteria) and spiroplasma (mollicutes) and two distinct strains of wolbachia (alpha-proteobacteria). the history of infection with these male-killers was explored using host mitochondrial dna, which is linked with the bacteria due to joint maternal inheritance. two ...	2002	11901123
mutualistic wolbachia infection in aedes albopictus: accelerating cytoplasmic drive.	maternally inherited rickettsial symbionts of the genus wolbachia occur commonly in arthropods, often behaving as reproductive parasites by manipulating host reproduction to enhance the vertical transmission of infections. one manipulation is cytoplasmic incompatibility (ci), which causes a significant reduction in brood hatch and promotes the spread of the maternally inherited wolbachia infection into the host population (i.e., cytoplasmic drive). here, we have examined a wolbachia superinfecti ...	2002	11901124
parasitic sex puppeteers.		2002	11905109
deleterious wolbachia in the ant formica truncorum.	wolbachia is a maternally inherited bacterium that may manipulate the reproduction of its arthropod hosts. in insects, it is known to lead to inviable matings, cause asexual reproduction or kill male offspring, all to its own benefit, but to the detriment of its host. in social hymenoptera, wolbachia occurs widely, but little is known about its fitness effects. we report on a wolbachia infection in the wood ant formica truncorum, and evaluate whether it influences reproductive patterns. all 33 c ...	2002	11916479
wolbachia infection associated with all-female broods in hypolimnas bolina (lepidoptera: nymphalidae): evidence for horizontal transmission of a butterfly male killer.	inherited bacteria that kill male hosts during embryogenesis infect a wide range of insect species. in order to ascertain if there are patterns to host infection, with particular male killing bacteria specialising on particular taxa, we investigated the male killing trait in the butterfly hypolimnas bolina. all-female broods were first reported in this species in the 1920s. investigation of this system in the fiji islands revealed the causal agent of sex ratio distortion in h. bolina to be a mal ...	2002	11920117
dynamics of double and single wolbachia infections in drosophila simulans from new caledonia.	the bacterial symbiont wolbachia can cause cytoplasmic incompatibility in drosophila simulans flies: if an infected male mates with an uninfected female, or a female with a different strain of wolbachia, there can be a dramatic reduction in the number of viable eggs produced. here we explore the dynamics associated with double and single wolbachia infections in new caledonia. doubly infected females were compatible with all males in the population, explaining the high proportion of doubly infect ...	2002	11920119
vertical transmission of wolbachia in tetranychus kanzawai kishida and panonychus mori yokoyama (acari: tetranychidae).	the vertical transmission of wolbachia in two species of spider mite was investigated and compared. one species, tetranychus kanzawai kishida, was infected with a modification negative strain of wolbachia while the other species, panonychus mori yokoyama, was infected with a modification positive strain. the infection showed perfect maternal transmission in the laboratory population of t. kanzawai in which wolbachia-infected females produced infected offspring regardless of whether they mated wi ...	2002	11920120
host age effect and expression of cytoplasmic incompatibility in field populations of wolbachia-superinfected aedes albopictus.	the asian tiger mosquito, aedes albopictus (skuse), is a known vector of dengue in south america and southeast asia. it is naturally superinfected with two strains of wolbachia endosymbiont that are able to induce cytoplasmic incompatibility (ci). in this paper, we report the strength of ci expression in crosses involving field-caught males. ci expression was found to be very strong in all crosses between field males and laboratory-reared uninfected or walba infected young females. in addition, ...	2002	11920134
bacterial endosymbionts of onchocerca volvulus in the pathogenesis of posttreatment reactions.	treatment of onchocerciasis with diethylcarbamazine (dec) or ivermectin is associated with a posttreatment reaction characterized by fever, tachycardia, hypotension, lymphadenopathy, and pruritus. to investigate the role of the wolbachia bacterial endosymbiont of onchocerca volvulus in these reactions, serum samples collected before and after treatment with either anthelmintic were assessed for evidence of wolbachia dna. by use of real-time quantitative polymerase chain reaction, wolbachia dna w ...	2002	11920298
the brugia malayi genome project: expressed sequence tags and gene discovery.	to advance and facilitate molecular studies of brugia malayi, one of the causative agents of human lymphatic filariasis, an expressed sequence tag (est)-based gene discovery programme has been carried out. over 22,000 ests have been produced and deposited in the public databases by a consortium of laboratories from endemic and non-endemic countries. the ests have been analysed using custom informatic tools to reveal patterns of individual gene expression that may point to potential targets for f ...	2002	11925998
does fertilization in the filarial nematode dirofilaria immitis occur through endocytosis of spermatozoa?	information on the ultrastructural details of fertilization in filarial nematodes are still unavailable. here we report new data on this process in dirofilaria immits, the heartworm of dogs and cats. electron microscopy allowed us to observe oocytes engulfing spermatozoa through an endocytosis-like process. we also observed spermatozoa inside the oocytes which still possessed their plasma membrane and which were clearly enveloped by a further membrane, likely derived from the endocytosis process ...	2002	11811805
sequencing and analysis of a 63 kb bacterial artificial chromosome insert from the wolbachia endosymbiont of the human filarial parasite brugia malayi.	wolbachia endosymbiotic bacteria are widespread in filarial nematodes and are directly involved in the immune response of the host. in addition, antibiotics which disrupt wolbachia interfere with filarial nematode development thus, wolbachia provide an excellent target for control of filariasis. a 63.1 kb bacterial artificial chromosome insert, from the wolbachia endosymbiont of the human filarial parasite brugia malayi, has been sequenced using the new england biolabs inc. genome priming system ...	2002	11812492
characterization of wolbachia host cell range via the in vitro establishment of infections.	maternally transmitted bacteria of the genus wolbachia are obligate, intracellular symbionts that are frequently found in insects and cause a diverse array of reproductive manipulations, including cytoplasmic incompatibility, male killing, parthenogenesis, and feminization. despite the existence of a broad range of scientific interest, many aspects of wolbachia research have been limited to laboratories with insect-rearing facilities. the inability to culture these bacteria outside of the invert ...	2002	11823204
[molecular diagnostic techniques of wolbachia].	wolbachia is a common and widespread group of bacteria found in reproductive tissues of arthropods. these bacteria are transmitted through the cytoplasm of eggs and have evolved various mechanisms for manipulating reproduction of their hosts. because of important relationship with some major biological issues and implication of biological control and genetic engineering, the study of wolbachia has under gone an explosive growth in recent years. a tremendous progress has been made based on the ad ...	2002	16118145
cloning and characterization of a gene encoding glutathione-regulated potassium-efflux system protein kefkl from the endosymbiont wolbachia.	the maternally inherited intracellular symbiont wolbachia is well known for inducing a variety of reproductive and developmental abnormalities in the diverse arthropod hosts it infects. it has been implicated in causing cytoplasmic incompatibility (ci), parthenogenesis, feminization of genetic males and male killing in different hosts. however, the molecular mechanisms by which this fastidious bacterium causes these abnormalities have not yet been determined. in our study, representational diffe ...	2002	12652910
male age, host effects and the weak expression or non-expression of cytoplasmic incompatibility in drosophila strains infected by maternally transmitted wolbachia.	in drosophila melanogaster, the maternally inherited endocellular microbe wolbachia causes cytoplasmic incompatibility (ci) in crosses between infected males and uninfected females. ci results in a reduction in the number of eggs that hatch. the level of ci expression in this species has been reported as varying from partial (a few eggs fail to hatch) to nonexistent (all eggs hatch). we show that male age in this host species has a large impact on the level of ci exhibited and explains much of t ...	2002	12534211
in vitro cultivation of wolbachia in insect and mammalian cell lines.	wolbachia infecting the small brown planthopper, laodelphax striatellus, were successfully maintained and cultivated in two insect and one mammalian cell lines. the bacteria with the planthopper ovary were introduced into the flasks with the cultures of the cell lines. the wolbachia proliferated in mosquito (aedes albopictus) and lepidopteran (heliothis zea) cell lines and in the mouse cell line, l929. proliferation of wolbachia was confirmed by electron microscopy and quantitative polymerase ch ...	2002	12534342
the pathogenesis of filarial lymphedema: is it the worm or is it the host?	our understanding of the pathogenesis of filarial lymphedema, although evolving, is still limited. recurrent bacterial infections play a major role in the progression of lymphedema to elephantiasis, but the host and parasite factors that trigger disease development are not known. field studies in haiti show that lymphedema and host responses to parasite antigens cluster in families, consistent with the hypothesis that host genes influence lymphedema susceptibility. the recent recognition that fi ...	2002	12543723
different rates of nucleotide substitutions in wolbachia endosymbionts of arthropods and nematodes: arms race or host shifts?	the genus wolbachia encompasses intracellular bacteria found in arthropods and in filarial nematodes. in arthropods, wolbachia is primarily a reproductive parasite and shows relatively frequent horizontal transfer between host species, while in nematodes it appears to be a mutualist and is strictly vertically transmitted. we can expect that different selective pressures are acting on their genomes. here we present an analysis of three wolbachia genes, wsp, ftsz and dnaa. in wsp of arthropod wolb ...	2002	12701381
space and the persistence of male-killing endosymbionts in insect populations.	male-killing bacteria are bacteria that are transmitted vertically through the females of their insect hosts. they can distort the sex ratio of their hosts by killing infected male offspring. in nature, male-killing endosymbionts (male killers) often have a 100% efficient vertical transmission, and multiple male-killing bacteria infecting a single population are observed. we use different model formalisms to study these observations. in mean-field models a male killer with perfect transmission d ...	2002	12573064
wolbachia as a potential tool for suppressing filarial transmission.	there is currently a great deal of interest in wolbachia because of their wide distribution in arthropods and filarial nematodes and their striking effects on the biology of their hosts, including a possible role in speciation. they manipulate the reproduction of arthropod hosts through various effects on their hosts' biology, particularly cytoplasmic incompatibility (ci), to increase the proportion of infected individuals in the population, often to the point of fixation. this ability of wolbac ...	2002	12625925
pcr-based detection and identification of the filarial parasite brugia timori from alor island, indonesia.	brugia timori is widely distributed on alor island, indonesia, where it causes a high degree of morbidity. the hhai tandem repeat of b. timori was found to be identical to that of b. malayi, for which sensitive pcr-based assays have already been developed. using one of these assays, a single microfilaria (mf) of b. timori, present in a spot of dry blood on filter paper, could be detected. the assay was equally sensitive in the detection of b. timori and b. malayi. when the collected mosquitoes w ...	2002	12625936
tunga penetrans: molecular identification of wolbachia endobacteria and their recognition by antibodies against proteins of endobacteria from filarial parasites.	in search of wolbachia in human parasites, wolbachia were identified in the sand flea tunga penetrans. pcr and dna sequencing of the bacterial 16s rdna, the ftsz cell division protein, the wolbachia surface protein (wsp) and the wolbachia aspartate aminotransferase genes revealed a high similarity to the respective sequences of endosymbionts of filarial nematodes. using these sequences a phylogenetic tree was generated, that indicates a close relationship between wolbachia from t. penetrans and ...	2002	12856318
effects of wolbachia on genetic divergence between populations: mainland-island model.	cytoplasmic incompatibility (ci) induced by intracellular bacteria is a possible mechanism for speciation. growing empirical evidence suggests that bacteria of the group wolbachia may indeed act as isolating factors in recent insect speciation. wolbachia are cytoplasmically transmitted and can cause uni- or bidirectional ci. we present a mainland-island model to investigate how much impact wolbachia can have on genetic divergence between populations. in the first scenario we assume that the isla ...	2002	21708727
distribution of wolbachia within drosophila reproductive tissue: implications for the expression of cytoplasmic incompatibility.	a pcr based quantitative assay was used to determine wolbachia infection levels in three different drosophila strains. in addition, confocal microscopy was used to confirm and calibrate these results. wolbachia infection levels ranged from 2,600 to 18,500 per egg. single ovaries and testes from each of the three strains were also assayed using the calibrated quantitative pcr assay. a general correlation was found between bacterial levels in eggs and those found in ovaries and testis. these infec ...	2002	21708726
which way to manipulate host reproduction? wolbachia that cause cytoplasmic incompatibility are easily invaded by sex ratio-distorting mutants.	the bacterium wolbachia manipulates its hosts by inducing cytoplasmic incompatibility (ci), where zygotes formed from crosses between uninfected mothers and infected fathers die. in addition, it distorts the host's sex ratio via male killing, parthenogenesis induction, or feminization. here, we model transitions between these states, examining the evolution of mutants of ci strains that retain both the ability to induce and resist ci but, in addition, cause sex ratio distortion. the model shows ...	2002	18707445
the effect of wolbachia on genetic divergence between populations: models with two-way migration.	wolbachia are intracellular bacteria that cause various reproduction alterations in their hosts, including cytoplasmic incompatibility (ci), an incompatibility between sperm and egg that typically results in embryonic death. we investigate theoretically the effects of wolbachia-induced bidirectional ci on levels of divergence between two populations, where there is migration in both directions and differential selection at a single locus. the main findings are as follows: wolbachia differences i ...	2002	18707453
absence of wolbachia in nonfilariid nematodes.	intracellular bacteria of the genus wolbachia are among the most abundant endosymbionts on the planet, occurring in at least two major phyla-the arthropoda and nematoda. current surveys of wolbachia distribution have found contrasting patterns within these groups. whereas wolbachia are widespread and occur in all three major subphyla of arthropods, with estimates placing them in at least several million arthropod species, the presence of nematodes carrying wolbachia is currently confined to the ...	2003	19262760
wolbachia in the inflammatory pathogenesis of human filariasis.	filarial nematodes cause some of the most debilitating diseases in tropical medicine. recent studies, however, have implicated the parasites' endosymbiotic wolbachia bacteria, rather than the nematode, as the cause of inflammatory-mediated filarial disease. soluble extracts of a variety of filarial species stimulate innate inflammatory responses, which are absent or reduced when using extracts derived from species either devoid of bacteria, or those cleared of bacteria by antibiotics. characteri ...	2003	12860672
molecular and electron microscopic identification of wolbachia in culex pipiens complex populations from the upper rhine valley, germany, and cebu city, philippines.	we detected wolbachia infections in culex pipiens complex mosquitoes from the upper rhine valley, germany, and cebu city, philippines, with the use of polymerase chain reaction (pcr) amplification of the 16s rdna of the bacteria and further confirmation by electron microscopy. species of 5 different autogenous and anautogenous populations of culex pipiens from germany and 1 population of culex quinquefasciatus from the philippines were used in this study. larvae were sampled from different local ...	2003	14524541
analysis of 16s rrna gene sequences of ehrlichia canis, anaplasma platys, and wolbachia species from canine blood in japan.	in the present study, three canine blood samples from japan, that were suspected to be ehrlichia positive were examined. after sequencing the 16s rrna genes, each dog was found to be infected either with ehrlichia canis (kagoshima 1), anaplasma platys (okinawa 1), or wolbachia sp. (okinawa 2). phylogenic analysis was performed on these sequences. the nearly entire 16s rrna sequence of kagoshima 1 was found to be most similar to the sequences from oklahoma and venezuela e. canis strains (1 base p ...	2003	12860708
trans-species transfer of wolbachia: microinjection of wolbachia from litomosoides sigmodontis into acanthocheilonema viteae.	intracellular bacteria of the genus wolbachia are found in most filarial nematodes, but are lacking in some species like acanthocheilonema viteae. due to their symbiotic nature and their role in the pathology of filarial infections they are considered to be potential targets for intervention against filarial infections in man. infection of a. viteae (a species which does not naturally carry wolbachia) with wolbachia bacteria could allow comparative studies on the effect of the endobacterium on t ...	2003	12866789
the effects of host age, host nuclear background and temperature on phenotypic effects of the virulent wolbachia strain popcorn in drosophila melanogaster.	because of their obligate endosymbiotic nature, wolbachia strains by necessity are defined by their phenotypic effects upon their host. nevertheless, studies on the influence of host background and environmental conditions upon the manifestation of wolbachia effects are relatively uncommon. here we examine the behavior of the overreplicating wolbachia strain popcorn in four different drosophila melanogaster backgrounds at two temperatures. unlike other strains of wolbachia in drosophila, popcorn ...	2003	12871912
wolbachia-induced mortality as a mechanism to modulate pathogen transmission by vector arthropods.	insecticide resistance and absence of clinical cures or vaccines for many vector-borne diseases has stimulated interest in using genetically modified arthropod vectors for disease control. current transgenic strategies focus on vector susceptibility to pathogen infection, which is an inefficient target for pathogen transmission interference. manipulation of vector survival is theoretically more effective, resulting in larger reductions in the expected number of human infections. a hypothetical m ...	2003	12693838
molecular evidence for novel tick-associated spotted fever group rickettsiae from thailand.	ticks are of considerable medical and veterinary importance because they directly harm the host through their feeding action and indirectly through vectoring many bacterial pathogens. despite many ticks being known from thailand, very little is known about the bacteria they may harbor. we report here the results of a survey of tick-associated bacteria in thailand. a total of 334 individuals representing 14 species of ticks in five genera were collected from 10 locations in thailand and were exam ...	2003	12693853
evolution 2003 meeting. genetic deficiency blamed on bacteria.		2003	12881548
sperm chromatin remodelling and wolbachia-induced cytoplasmic incompatibility in drosophila.	wolbachia pipientis is an obligate bacterial endosymbiont, which has successfully invaded approximately 20% of all insect species by manipulating their normal developmental patterns. wolbachia-induced phenotypes include parthenogenesis, male killing, and, most notably, cytoplasmic incompatibility. in the future these phenotypes might be useful in controlling or modifying insect populations but this will depend on our understanding of the basic molecular processes underlying insect fertilization ...	2003	12897857
characterization of antibody responses to wolbachia surface protein in humans with lymphatic filariasis.	symbiotic wolbachia organisms of filarial nematodes have received much attention as possible chemotherapy targets and disease-causing organisms. in order to further investigate the association between anti-wolbachia immune responses and chronic filarial disease in humans, antibody responses to wolbachia surface protein (wsp) were assayed in serum samples collected from 232 individuals living in leogane, haiti, an area where wuchereria bancrofti infection is endemic, and from 67 north americans w ...	2003	12933853
wolbachia distribution and cytoplasmic incompatibility based on a survey of 42 spider mite species (acari: tetranychidae) in japan.	wolbachia are a group of maternally inherited bacteria that infect a wide range of arthropods. wolbachia infections are known to result in the expression of various abnormal reproductive phenotypes, the best known being cytoplasmic incompatibility. the first systematic survey of 42 spider mite species in japan revealed that seven species (16.7%) were infected with wolbachia. wolbachia in the spider mites were grouped into three subgroups in supergroup b by phylogenetic analyses of the wsp gene. ...	2003	12939620
removal of wolbachia from brugia pahangi is closely linked to worm death and fecundity but does not result in altered lymphatic lesion formation in mongolian gerbils (meriones unguiculatus).	approximately 30 years ago, researchers reported intracellular bacteria in filarial nematodes. these bacteria are relatives of the arthropod symbiont wolbachia and occur in many filarial nematodes, including brugia pahangi and brugia malayi. wolbachia bacteria have been implicated in a variety of roles, including filaria development and fecundity and the pathogenesis of lymphatic lesions associated with filarial infections. however, the role of the bacteria in worm biology or filarial disease is ...	2003	14638788
identification of wolbachia--host interacting factors through cytological analysis.	manipulation of host reproduction and efficient maternal transmission have facilitated the global spread of wolbachia through millions of insect species. cytological studies of the most common wolbachia-induced phenotype, cytoplasmic incompatibility (ci), demonstrate that wolbachia induce ci by altering host cell cycle timing. cytological analyses also suggest that microtubules and motor proteins may play a role in the maternal and somatic transmission of wolbachia.	2003	12941392
infection of new- and old-world aedes albopictus (diptera: culicidae) by the intracellular parasite wolbachia: implications for host mitochondrial dna evolution.	wolbachia are cytoplasmically inherited, endosymbiotic bacteria known to infect a wide variety of arthropods. polymerase chain reaction (pcr) amplification of the wolbachia surface protein (wsp) gene was used to assay the infection of geographically disparate populations of aedes albopictus (skuse) by wolbachia. nine north american, four south american, one hawaiian, and four old world populations of a. albopictus were all doubly infected with both the walba and walbb strains of wolbachia. a 365 ...	2003	12943116
incidence of a new sex-ratio-distorting endosymbiotic bacterium among arthropods.	many intracellular micro-organisms are now known to cause reproductive abnormalities and other phenomena in their hosts. the endosymbiont wolbachia is the best known of these reproductive manipulators owing to its extremely high incidence among arthropods and the diverse host effects it has been implicated as causing. however, recent evidence suggests that another intracellular bacterium, a cytophaga-like organism (clo), may also induce several reproductive effects in its hosts. here, we present ...	2003	12964989
variable male potential rate of reproduction: high male mating capacity as an adaptation to parasite-induced excess of females?	numerous animals are known to harbour intracytoplasmic symbionts that gain transmission to a new host generation via female eggs and not male sperm. bacteria of the genus wolbachia are a typical example. they infect a large range of arthropod species and manipulate host reproduction in several ways. in terrestrial isopods (woodlice), wolbachia are responsible for converting males into females (feminization (f)) in some species, or for infertility in certain host crosses in other species (cytopla ...	2003	12965021
infection density of wolbachia and level of cytoplasmic incompatibility in the mediterranean flour moth, ephestia kuehniella.	wolbachia, a causative agent of various reproductive changes in arthropods, induces cytoplasmic incompatibility (ci) in the mediterranean flour moth, ephestia kuehniella. two strains of e. kuehniella, yokohama and tsuchiura, harbor closely related wolbachia, but the yokohama strain expresses stronger ci than the tsuchiura strain. a transinfected e. kuehniella strain that harbors the wolbachia derived from the almond moth cadra cautella, expresses weak ci at a similar level to the tsuchiura strai ...	2003	13678706
the potential of virulent wolbachia to modulate disease transmission by insects.	a virulent strain of wolbachia has recently been identified in drosophila that drastically reduces adult lifespan. it has been proposed that this phenotype might be introduced into insect disease vector populations to reduce pathogen transmission. here we model the requirements for spread of such an agent and the associated reduction in disease transmission. first, a simulation of mosquito population age structure was used to describe the age distribution of mosquitoes transmitting dengue virus. ...	2003	13678709
control of filarial infections: not the beginning of the end, but more research is needed.	infections with the filarial nematodes affect more than 150 million people mainly in the tropics. the very successful efforts to control filarial infections, however, have to be sustained by new tools that require long-term commitment to research. this review, focusing on reports from 2002 and 2003, highlights recent advances in research on immunology, understanding of pathogenesis and drug development in lymphatic filariasis and onchocerciasis research with potential relevance to the generation ...	2003	14501992
evidence against wolbachia symbiosis in loa loa.	background: the majority of filarial nematode species are host to wolbachia bacterial endosymbionts, although a few including acanthocheilonema viteae, onchocerca flexuosa and setaria equina have been shown to be free of infection. comparisons of species with and without symbionts can provide important information on the role of wolbachia symbiosis in the biology of the nematode hosts and the contribution of the bacteria to the development of disease. previous studies by electron microscopy and ...	2003	12816546
the invasion and coexistence of competing wolbachia strains.	cytoplasmic incompatibility between arthropods infected with different strains of wolbachia has been proposed as an important mechanism for speciation. however, a basic requirement for this mechanism is the coexistence of different strains in neighbouring populations. here we test whether this required coexistence is possible in a spatial context. continuous-time models for the behaviour of one and two strains of wolbachia within a single well-mixed population demonstrate the allee effect and fo ...	2003	14512953
diversity of wolbachia endosymbionts in heteropteran bugs.	an extensive survey of wolbachia endosymbionts in japanese terrestrial heteropteran bugs was performed by pcr detection with universal primers for wsp and ftsz genes of wolbachia, cloning of the pcr products, restriction fragment length polymorphism analysis of infecting wolbachia types, and molecular phylogenetic characterization of all the detected wolbachia strains. of 134 heteropteran species from 19 families examined, wolbachia infection was detected in 47 species from 13 families. from the ...	2003	14532065
no variation for wolbachia-induced hybrid breakdown in two populations of a spider mite.	wolbachia are cytoplasmically transmitted bacteria that infect several species of mites. in the two-spotted spider mite tetranychus urticae koch this symbiont can induce reproductive incompatibility. wolbachia-induced reproductive incompatibility is observed in crosses between wolbachia-infected (w) males and uninfected (u) females. this incompatibility is expressed in f1 broods as male-biased sex ratios, an effect called cytoplasmic incompatibility (ci). however, in the two-spotted spider mite, ...	2003	14580056
immunological role of the endosymbionts of dirofilaria immitis: the wolbachia surface protein activates canine neutrophils with production of il-8.	filarial nematodes, including dirofilaria immitis and d. repens, harbour intracellular bacteria belonging to the genus wolbachia. these bacteria have been implicated in the pathogenesis of filarial diseases, possibly through their endotoxins. recent studies have shown that a major surface protein of wolbachia (wsp) induces a specific igg response in hosts infected by d. immitis. wsp from the wolbachia of d. immitis was produced in recombinant form. the purified protein was used in stimulation as ...	2003	14597281
bacterial diversity in worker adults of apis mellifera capensis and apis mellifera scutellata (insecta: hymenoptera) assessed using 16s rrna sequences.	high-fidelity pcr of 16s rrna sequences was used to identify bacteria associated with worker adults of the honeybee subspecies apis mellifera capensis and apis mellifera scutellata. an expected approximately 1.5-kb dna band, representing almost the entire length of the 16s rrna gene, was amplified from both subspecies and cloned. ten unique sequences were obtained: one sequence each clustered with bifidobacterium (gram-positive eubacteria), lactobacillus (gram-positive eubacteria), and gluconace ...	2003	14615218
molecular evidence of wolbachia infection in natural populations of tropical odonates.	wolbachia are endosymbiotic bacteria that cause reproductive alterations in numerous arthropod species. using a pcr-based method, we found that, out of 33 odonate species, four species were infected with wolbachia. this finding represents the first record of wolbachia infection in tropical odonates. identical wsp gene sequences were found in the wolbachia-infected common odonate species, agriocnemis f. femina, collected from different locations in thailand. the infection frequencies in several n ...	2003	14629013
strain-specific regulation of intracellular wolbachia density in multiply infected insects.	vertically transmitted symbionts suffer a severe reduction in numbers when they pass through host generations, resulting in genetic homogeneity or even clonality of their populations. wolbachia endosymbionts that induce cytoplasmic incompatibility in their hosts depart from this rule, because cytoplasmic incompatibility actively maintains multiple infection within hosts. hosts and symbionts are thus probably under peculiar selective pressures that must shape the way intracellular bacterial popul ...	2003	14629360
the distribution and evolutionary history of wolbachia infection in native and introduced populations of the invasive argentine ant (linepithema humile).	wolbachia pipientis is a maternally transmitted bacterium that often alters the life history of its insect host to maximize transmission to subsequent generations. here we report on the frequency and distribution of wolbachia infection in a widespread invasive species, the argentine ant (linepithema humile). we screened 1175 individual argentine ants from 89 nests on five continents and several islands, including numerous locations in both the native (south american) and introduced ranges. we de ...	2003	14629385
sorting out the effects of wolbachia, genotype and inbreeding on life-history traits of a spider mite.	wolbachia bacteria manipulate host reproduction by inducing cytoplasmic incompatibility (ci) and sex ratio distortion. wolbachia are transmitted from mother to offspring through the cytoplasm of the egg. therefore, reproduction of wolbachia is tightly coupled to reproduction of its host. mathematical analysis predicts that in the course of evolution, traits that reduce the physiological costs of the infection will be selectively favored. for a wolbachia-host system to evolve, traits under select ...	2003	14635812
host-specific wolbachia strains in widespread populations of phlebotomus perniciosus and p. papatasi (diptera: psychodidae), and prospects for driving genes into these vectors of leishmania.	a single strain of wolbachia (alpha-proteobacteria, rickettsiales) was found in widespread geographical populations of each of two phlebotomus species, within which there was no indication of 'infectious speciation'. the two strains were identified by sequencing a fragment of wsp (a major surface protein gene), amplified by polymerase chain reaction from dna extracted from the body parts of individual sandflies. infection rates were high in the males and females of both sandflies, but they were ...	2003	14641977
development of a physical and genetic map of the virulent wolbachia strain wmelpop.	we report here the construction of a physical and genetic map of the virulent wolbachia strain, wmelpop. this map was determined by ordering 28 chromosome fragments that resulted from digestion with the restriction endonucleases fsei, apai, smai, and asci and were resolved by pulsed-field gel electrophoresis. southern hybridization was done with 53 wolbachia-specific genes as probes in order to determine the relative positions of these restriction fragments and use them to serve as markers. comp ...	2003	14645266
mitochondrial and wolbachia markers for the sandfly phlebotomus papatasi: little population differentiation between peridomestic sites and gerbil burrows in isfahan province, iran.	in iran, phlebotomus papatasi (scopoli) (diptera: psychodidae) is the main vector of leishmania major yakimoff & schokhor (kinetoplastida: trypanosomatidae), the causative agent of rural zoonotic cutaneous leishmaniasis. this sandfly is abundant both in villages and in the burrows of the main reservoir host, the gerbil rhombomys opimus (licht.) (rodentia: gerbillidae). populations of p. papatasi were sampled from the edges of villages in isfahan province, using cdc miniature light traps in perid ...	2003	14651648
canine onchocercosis in greece: report of further 20 cases and molecular characterization of the parasite and its wolbachia endosymbiont.	recently, sporadic cases of subconjunctival onchocerca infection have been reported in dogs in greece and hungary. herein we report further cases from greece and the results of the molecular analysis of onchocerca sp. removed from greek dogs and its wolbachia endosymbionts. twenty dogs of various breeds, 1-11 years of age with subconjunctival onchocercosis (4 cases each in right or left eye, 12 cases in both eyes) were presented having similar manifestations. periorbital swelling, exophthalmos, ...	2003	14651884
immunohistochemical/immunogold detection and distribution of the endosymbiont wolbachia of dirofilaria immitis and brugia pahangi using a polyclonal antiserum raised against wsp (wolbachia surface protein).	intracellular bacteria in filarial nematodes were described as early as the 1970s, yet it was only with the work on dirofilaria immitis, the agent of canine and feline heartworm disease, that these microorganisms were identified as belonging to wolbachia, a genus known for encompassing bacteria infecting insects and other arthropods. the implications for the presence of intracellular bacteria in filarial nematodes is now the subject of intense research, particularly regarding their role in the i ...	2003	12632152
wolbachia segregation dynamics and levels of cytoplasmic incompatibility in drosophila sechellia.	in drosophila sechellia, the endocellular bacterium wolbachia induces cytoplasmic incompatibility (ci): in crosses involving infected males, a partial or complete embryonic mortality occurs unless the female bears the same wolbachia. d. sechellia is known to harbour two wolbachia variants, namely wsh and wsn, closely related to wha and wno, respectively, two strains infecting the populations of d. simulans from the seychelles archipelago and new caledonia. strikingly, the two species show simila ...	2003	12634822
molecular detection of bartonella quintana, b. koehlerae, b. henselae, b. clarridgeiae, rickettsia felis, and wolbachia pipientis in cat fleas, france.	the prevalences of bartonella, rickettsia, and wolbachia were investigated in 309 cat fleas from france by polymerase chain reaction (pcr) assay and sequencing with primers derived from the glta gene for rickettsia, the its and pap31 genes for bartonella, and the 16s rrna gene for anaplasmataceae. positive pcr results were confirmed by using the lightcycler and specific primers for the rompb of rickettsia and glta of bartonella. r. felis was detected in 25 fleas (8.1%), w. pipientis, an insect s ...	2003	12643829
reversing wolbachia-based population replacement.	genetic manipulation that reduces the competence of a vector population to transmit pathogens would provide a useful tool to complement current control strategies, which are based primarily on the reduction/exclusion of vector populations and the prophylactic/therapeutic treatment of the vertebrate host population. genetic drive is an important component of vector population replacement strategies, facilitating the replacement of natural populations with a genetically modified population. geneti ...	2003	12643996
cytoplasmic incompatibility and sperm cyst infection in different drosophila-wolbachia associations.	wolbachia are a group of maternally transmitted obligatory intracellular alpha-proteobacteria that infect a wide range of arthropod and nematode species. wolbachia infection in drosophila in most cases is associated with the induction of cytoplasmic incompatibility (ci), manifested as embryonic lethality of offspring in a cross between infected males and uninfected females. while the molecular basis of ci is still unknown, it has been suggested that two bacterial functions are involved: mod (for ...	2003	12807775
regulation of wolbachia density in the mediterranean flour moth, ephestia kuehniella, and the almond moth, cadra cautella.	the mediterranean flour moth, ephestia kuehniella, is infected with a-group wolbachia (wkue), and the almond moth, cadra cautella, is doubly infected with a- and b-group wolbachia, which are designated as wcaua and wcaub, respectively. in both insects, the wolbachia populations increased greatly during embryonic and larval stages. the wolbachia population doubled every 3.6 days on average in e. kuehniella larvae, whereas those of wcaua and wcaub doubled every 2.1 days in c. cautella larvae. the ...	2003	12655178
the cytogenetics of thelytoky in a predominantly asexual parasitoid wasp with covert sex.	asexual lineages in the parasitoid wasp lysiphlebus fabarum (hymenoptera: braconidae: aphidiinae) have previously been shown to have occasionally undergone sexual reproduction and recombination with males from related sexual populations. in the present study, the cytogenetic system of asexual females in this species is shown by 4',6-diamidino-2-phenylindole dihydrochloride (dapi) staining to be central fusion automixis. this system has the potential to allow occasional sex and recombination with ...	2003	12669810
genetic conflicts over sex ratio: mite-endosymbiont interactions.	nucleocytoplasmic genetic conflicts arise as a result of asymmetric transmission of cytoplasmic and nuclear genes. spread of a cytoplasmic element promoting female-biased sex ratios creates selection on nuclear genes for mechanisms that decrease the bias. here we investigate the conflict over sex ratio between the cytoplasmic bacterium wolbachia and the two-spotted spider mite tetranychus urticae koch. we show that, first, infected females produce significantly more female-biased sex ratios than ...	2003	12675371
high levels of multiple wolbachia infection and recombination in the ant formica exsecta.	wolbachia bacteria are intracellular symbionts of many arthropod species. their spread through host populations is promoted by drastic alterations imposed on their hosts' reproductive physiology. in the present study, we analyzed the association between wolbachia strains and host mitochondrial haplotypes in a swiss population of the ant formica exsecta. in this species, female dispersal is extremely limited and the mitochondrial haplotypes are strongly differentiated between and within subpopula ...	2003	12679529
between- and within-host species selection on cytoplasmic incompatibility-inducing wolbachia in haplodiploids.	the most common effect of the endosymbiont wolbachia is cytoplasmic incompatibility (ci), a form of postzygotic reproductive isolation that occurs in crosses where the male is infected by at least one wolbachia strain that the female lacks. we revisited two puzzling features of wolbachia biology: how wolbachia can invade a new species and spread among populations, and how the association, once established in a host species, can evolve, with emphasis on the possible process of infection loss. the ...	2003	12683537
evolutionary consequences of wolbachia infections.	the past decade has revealed the bacterium wolbachia as the most widespread symbiont of arthropods and nematodes. behind this evolutionary success is an remarkable variety of effects on host biology, ranging from manipulation of reproduction in favor of females to more classical mutualistic interactions. here we discuss the potential of wolbachia for promoting evolutionary changes in its hosts.	2003	12683975
doxycycline as a novel strategy against bancroftian filariasis-depletion of wolbachia endosymbionts from wuchereria bancrofti and stop of microfilaria production.	chemotherapy of onchocerciasis by doxycycline, which targets symbiotic wolbachia endobacteria, has been shown to result in a long-term sterility of adult female worms and corresponding absence of microfilariae. it represents an additional chemotherapeutic approach. the aim of this study was to determine whether a similar regimen would also show efficacy against wuchereria bancrofti. ghanaian individuals ( n=93) with lymphatic filariasis and a minimum microfilaremia of 40 microfilariae/ml were in ...	2003	12684759
wolbachia pipientis growth kinetics and susceptibilities to 13 antibiotics determined by immunofluorescence staining and real-time pcr.	wolbachia spp. are strict intracellular bacteria that infect a wide range of arthropods and filarial nematodes. filarial nematodes are important causes of human diseases. there is increasing evidence that wolbachia spp. influence important functions in the biology of the hosts, specifically, infertility. preliminary experiments with humans and animals have suggested that antibiotics with activity against wolbachia may help to treat filariasis. in this study, we determined using a real-time quant ...	2003	12709338
th1 response in balb/c mice immunized with dirofilaria immitis soluble antigens: a possible role for wolbachia?	the immune response to filarial infection has been shown to be of both the th1 and th2 types. studies aimed at developing immunization strategies against dirofilaria immitis infection in dogs have shown that protection against larval challenge is of the th2 type and that several proteins are recognized by immunized or infected animals. the bacterial endosymbiont wolbachia, harbored by many filarial species including d. immitis, has recently been shown to interact with the host immune system. spe ...	2003	12581590
involvement of toll-like receptor 4 in the embryogenesis of the rodent filaria litomosoides sigmodontis.	to examine the role that lipopolysaccharide (lps)-like molecules from the filarial intracellular endobacteria wolbachia might play in the development of filarial infections, a natural infection in the lps-nonresponsive c3h/hej mouse strain was compared to that of the lps-responsive c3h/hen mouse strain. c3h/hen mice have been shown to be susceptible to the rodent filarial nematode litomosoides sigmodontis, with the development of adult worms including females containing mature microfilariae (fir ...	2003	12592564