Publications

pathogens and symbionts in ticks: prevalence of anaplasma phagocytophilum (ehrlichia sp.), wolbachia sp., rickettsia sp., and babesia sp. in southern germany.	tick-transmitted diseases like tick-borne encephalitis and lyme borreliosis have been well known in germany for decades. ongoing research now gives an additional focus to a broad range of other bacteria and parasites in ticks like anaplasma phagocytophilum, former ehrlichia sp., rickettsia sp. and babesia sp. knowledge about the prevalence of these infectious agents in ticks is an important prerequisite for risk assessment of human diseases. therefore nymphs and adult ixodes ricinus ticks were c ...	2004	15146989
the sex ratio distortion in the human head louse is conserved over time.	at the turn of the 19th century the first observations of a female-biased sex ratio in broods and populations of the head louse, pediculus humanus capitis, had been reported. a study by buxton in 1940 on the sex ratio of lice on prisoners in ceylon is still today the subject of reanalyses. this sex ratio distortion had been detected in ten different countries. in the last sixty years no new data have been collected, especially on scalp infestations under economically and socially more developed ...	2004	15140268
evidence for a new feminizing wolbachia strain in the isopod armadillidium vulgare: evolutionary implications.	wolbachia are intracellular maternally inherited alpha-proteobacteria infecting a wide range of arthropods. in the common pill bug armadillidium vulgare, the known wolbachia strain is responsible for feminization of genetic males. we have investigated wolbachia diversity in 20 populations of a. vulgare from west and east europe, north africa and north america. a new wolbachia strain (wvulm) was identified through the variability of the wsp gene, distantly related to that previously known (wvulc) ...	2004	15138452
natural interspecific and intraspecific horizontal transfer of parthenogenesis-inducing wolbachia in trichogramma wasps.	the intracellular bacterium wolbachia is one of the most common symbionts in arthropods and, because of its manipulative effects on host reproduction, is assumed to be an important factor in several evolutionary processes. these bacteria are mainly vertically transmitted from mother to daughter through the egg cytoplasm, and horizontal transmission is generally assumed to be rare. here, we show natural inter- and intraspecific horizontal transfer of parthenogenesis-inducing wolbachia between par ...	2004	15129961
fitness advantage and cytoplasmic incompatibility in wolbachia single- and superinfected aedes albopictus.	wolbachia are obligate, maternally inherited, intracellular bacteria that infect numerous insects and other invertebrates. wolbachia infections have evolved multiple mechanisms to manipulate host reproduction and facilitate invasion of naive host populations. one such mechanism is cytoplasmic incompatibility (ci) that occurs in many insect species, including aedes albopictus (asian tiger mosquito). the multiple wolbachia infections that occur naturally in a. albopictus make this mosquito a usefu ...	2004	15127087
mechanisms of parasite-induced sex reversal in gammarus duebeni.	the amphipod gammarus duebeni is host to the feminising microsporidian parasite nosema granulosis that converts males into functional females. to test the hypothesis that the parasite acts through endocrine disruption we compared the morphology of the gonad and activity of the androgenic gland, which coordinates male sexual differentiation, in infected and uninfected animals. male gonad consisted of testis, seminal vesicle and vas deferens that was anchored to the genital papilla on segment 7. t ...	2004	15111096
construction of bacterial artificial chromosome libraries from the parasitic nematode brugia malayi and physical mapping of the genome of its wolbachia endosymbiont.	the parasitic nematode, brugia malayi, causes lymphatic filariasis in humans, which in severe cases leads to the condition known as elephantiasis. the parasite contains an endosymbiotic alpha-proteobacterium of the genus wolbachia that is required for normal worm development and fecundity and is also implicated in the pathology associated with infections by these filarial nematodes. bacterial artificial chromosome libraries were constructed from b. malayi dna and provide over 11-fold coverage of ...	2004	15111095
isolation and characterization of the bacteriophage wo from wolbachia, an arthropod endosymbiont.	wolbachia is a group of obligate symbiotic bacteria found in many insects and other arthropods. the presence of wolbachia alters reproduction in the host, but the mechanisms are unknown. molecular biological studies of wolbachia have delayed significantly, and one of the reasons is the lack of transformation techniques of this bacterium. in the present study, bacteriophage particles were isolated from wolbachia for the first time. the purified phage had an isometric head that was approximately 4 ...	2004	15094394
wolbachia infections in drosophila melanogaster and d. simulans: polymorphism and levels of cytoplasmic incompatibility.	wolbachia are endosymbiotic bacteria, widespread in terrestrial arthropods. they are mainly transmitted vertically, from mothers to offspring and induce various alterations of their hosts' sexuality and reproduction, the most commonly reported phenomenon being cytoplasmic incompatibility (ci), observed in drosophila melanogaster and d. simulans. basically, ci results in a more or less intense embryonic mortality, occurring in crosses between males infected by wolbachia and uninfected females. in ...	2004	15088646
mitochondrial dna in the drosophila melanogaster complex.	mitochondrial dna in the complex drosophila melanogaster was among the first studied in metazoans. the variability of the molecule was extensively studied using restriction enzymes, gene sequence and recently sequence of the whole coding region. within the complex, seven major haplotypes have been described, one (me) in d. melanogaster, three in d. simulans (sii, siii, siiii), two in d. mauritiana (mai, maii), and one in d. sechellia (se). the molecular distance between the haplotypes is compris ...	2004	15088645
drosophila melanogaster, drosophila simulans: so similar yet so different.	during the last two decades, the two cosmopolitan species drosophila melanogaster and drosophila simulans have been compared with regard to numerous characteristics, ranging from their geographic distribution and ecology to their dna polymorphism. various traits have been compared, including morphology, physiology, sexual behavior, allozymes and other proteins, chromosomal inversions, mitochondrial and nuclear dna, transposable elements, wolbachia etc. such comparisons reveal similarities and di ...	2004	15088643
persistence of an extreme sex-ratio bias in a natural population.	the sex ratio is a key parameter in the evolution and ecology of a species. selfish genetic elements that bias the sex ratio of affected individuals are well known and characterized, but their effect on populations has been considered limited, because either the element does not achieve high prevalence or the host rapidly evolves resistance to the distorting element, reducing its prevalence. we tested whether the host necessarily prevails by using a butterfly system where records from the early ...	2004	15087494
genetic diversity and wolbachia infection of the drosophila parasitoid leptopilina clavipes in western europe.	wolbachia are maternally transmitted bacteria that alter their arthropod hosts' reproduction in various ways, including parthenogenesis induction (pi). wolbachia-induced parthenogenesis can have drastic effects on the genetic structure of its host because it potentially reduces populations to clones without genetic exchange. however, wolbachia-induced parthenogenesis does not inevitably result in a reduction of genetic variation of infected populations vs. uninfected populations, because the par ...	2004	15078450
an initial survey for wolbachia (rickettsiales: rickettsiaceae) infections in selected california mosquitoes (diptera: culicidae).	knowledge of biogeographic variation in wolbachia infection rates and inferred susceptibility to infection among different mosquito taxa has fundamental implications for the design and successful application of wolbachia-based vector-borne disease control strategies. using a wolbachia-specific polymerase chain reaction assay, we tested 14 north american mosquito species in five genera (aedes, anopheles, culiseta, culex, and ochlerotatus) for wolbachia infection. wolbachia infections were only de ...	2004	15061286
cytology of wolbachia-induced parthenogenesis in leptopilina clavipes (hymenoptera: figitidae).	parthenogenesis induced by cytoplasmatically inherited wolbachia bacteria has been found in a number of arthropod species, mainly hymenoptera. previously, two different forms of diploidy restoration have been reported to underlie parthenogenesis induction in hymenoptera by wolbachia. both are a form of gamete duplication, but each differs in their timing. we investigated the cytology of the early embryonic development of a wolbachia-infected strain of the parasitoid wasp leptopilina clavipes and ...	2004	15060582
opposite sex-specific effects of wolbachia and interference with the sex determination of its host ostrinia scapulalis.	in the adzuki bean borer, ostrinia scapulalis, the sex ratio in most progenies is 1 : 1. females from wolbachia-infected matrilines, however, give rise to all-female broods when infected and to all-male broods when cured of the infection. these observations had been interpreted as wolbachia-induced feminization of genetic males into functional females. here, we show that the interpretation is incorrect. females from both lines have a female karyotype with a wz sex-chromosome constitution while m ...	2004	15058435
diversity, distribution and specificity of wo phage infection in wolbachia of four insect species.	the bacteriophage wo was recently characterized in wolbachia, a strictly intracellular bacterium that causes several reproductive alterations in its arthropod hosts. to gain insights into the phage-wolbachia relationships, we studied the phage presence among wolbachia infecting four insect species sharing several wolbachia strains, two drosophila and two of their parasitoid wasps. based on the phage sequence of orf7, we identified five different phages in six wolbachia strains. among these five ...	2004	15056362
presence of wolbachia endosymbionts in microfilariae of wuchereria bancrofti (spirurida: onchocercidae) from different geographical regions in india.	in view of the recent discovery of rickettsial endosymbionts, wolbachia in lymphatic filarial parasites, wuchereria bancrofti and brugia malayi and subsequently of their vital role in the survival and development of the latter, antibiotics such as tetracycline are being suggested for the treatment of lymphatic filariasis, by way of eliminating the endosymbiont. but, it is essential to assess their presence in parasites from areas endemic for lymphatic filariasis before such a new control tool is ...	2003	15049082
mapping the presence of wolbachia pipientis on the phylogeny of filarial nematodes: evidence for symbiont loss during evolution.	wolbachia pipientis is a bacterial endosymbiont associated with arthropods and filarial nematodes. in filarial nematodes, w. pipientis has been shown to play an important role in the biology of the host and in the immuno-pathology of filariasis. several species of filariae, including the most important parasites of humans and animals (e.g. onchocerca volvulus, wuchereria bancrofti and dirofilaria immitis) have been shown to harbour these bacteria. other filarial species, including an important r ...	2004	15037105
wolbachia pipientis: intracellular infection and pathogenesis in drosophila.	wolbachia pipientis is a vertically transmitted, obligate intracellular symbiont of arthropods. the bacterium is best known for its ability to manipulate host reproductive biology where it can induce cytoplasmic incompatibility, parthenogenesis, feminization and male-killing. in addition to the various reproductive phenotypes it generates through interaction with host reproductive tissue it is also known to infect somatic tissues. however, relatively little is known about the consequences of inf ...	2004	15036143
phylogenomics of the reproductive parasite wolbachia pipientis wmel: a streamlined genome overrun by mobile genetic elements.	the complete sequence of the 1,267,782 bp genome of wolbachia pipientis wmel, an obligate intracellular bacteria of drosophila melanogaster, has been determined. wolbachia, which are found in a variety of invertebrate species, are of great interest due to their diverse interactions with different hosts, which range from many forms of reproductive parasitism to mutualistic symbioses. analysis of the wmel genome, in particular phylogenomic comparisons with other intracellular bacteria, has reveale ...	2004	15024419
endosymbiosis: lessons in conflict resolution.		2004	15024418
biology of wolbachia.	wolbachia are 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, including induction of reproductive incompatibility, parthenogenesis, and feminization. wolbachia are also transmitted horizontally between arthropod species. significant recent advances have been made in the study of these interesting microorganisms. in t ...	1997	15012323
what maintains noncytoplasmic incompatibility inducing wolbachia in their hosts: a case study from a natural drosophila yakuba population.	cytoplasmic incompatibility (ci) allows wolbachia to invade hosts populations by specifically inducing sterility in crosses between infected males and uninfected females. in some species, non-ci inducing wolbachia, that are thought to derive from ci-inducing ancestors, are common. in theory, the maintenance of such infections is not possible unless the bacterium is perfectly transmitted to offspring--and/or provides a fitness benefit to infected females. the present study aims to test this view ...	2004	15009266
wolbachia endosymbionts of onchocerca volvulus express a putative periplasmic htra-type serine protease.	wolbachia are intracellular bacteria of many filarial nematodes. a mutualistic interaction between the endobacteria and the filarial host is likely, because the clearance of wolbachia by tetracycline leads to the obstruction of embryogenesis and larval development. databases were searched for exported molecules to identify candidates involved in this mutualism. fragments of a wolbachia serine protease from the human filarial parasite onchocerca volvulus were obtained (wol-ov-htra) by the use of ...	2004	14998511
development of genetic differentiation and postzygotic isolation in experimental metapopulations of spider mites.	we studied the development of genetic differentiation and postzygotic isolation in experimental metapopulations of the two-spotted spider mite, tetranychus urticae koch. a genetically diverse starter population was made by allowing six inbred sublines to interbreed. then three migration patterns were tested: no migration, or one or three immigrants per subpopulation per generation. variations in four traits were investigated: allozymes, acaricide resistance, diapause, and hatchability. in the al ...	2003	14974684
pathogenesis and host responses in human onchocerciasis: impact of onchocerca filariae and wolbachia endobacteria.	onchocerca volvulus is a tissue-invasive parasitic nematode causing skin and eye pathology in human onchocerciasis. the filariae habour abundant intracellular wolbachia bacteria, now recognised as obligatory symbionts, and therefore emerging as a novel target for chemotherapy. recent research demonstrates that both the filariae and endobacteria contribute to the pathogenesis of onchocerciasis, and molecules have been identified that promote inflammatory or counter-inflammatory immune mechanisms, ...	2004	14738900
immunopathogenesis of onchocerca volvulus keratitis (river blindness): a novel role for tlr4 and endosymbiotic wolbachia bacteria.	infection with the parasitic nematode onchocerca volvulus is associated with inflammation of the skin and cornea that can lead to blindness. corneal damage is thought to occur as a result of the host inflammatory responses to degenerating microfilariae in the eye. we have utilized a murine model of corneal inflammation (keratitis) to investigate the immune and inflammatory responses associated with river blindness. soluble extracts of o. volvulus, a filarial species that contains the endosymbion ...	2003	14733727
horizontal transmission of wolbachia by strepsipteran endoparasites? a response to noda et al., 2001.		2004	14717905
intracellular symbionts and other bacteria associated with deer ticks (ixodes scapularis) from nantucket and wellfleet, cape cod, massachusetts.	the diversity of bacteria associated with the deer tick (ixodes scapularis) was assessed using pcr amplification, cloning, and sequencing of 16s rrna genes originating from seven ticks collected from nantucket island and wellfleet, cape cod, mass. the majority of sequences obtained originated from gram-negative proteobacteria. four intracellular bacteria were detected including strains of ehrlichia, rickettsia, and wolbachia and an organism related to intracellular insect symbionts from the cyto ...	2004	14711698
wolbachia transfer from rhagoletis cerasi to drosophila simulans: investigating the outcomes of host-symbiont coevolution.	wolbachia is an endosymbiont of diverse arthropod lineages that can induce various alterations of host reproduction for its own benefice. cytoplasmic incompatibility (ci) is the most common phenomenon, which results in embryonic lethality when males that bear wolbachia are mated with females that do not. in the cherry fruit fly, rhagoletis cerasi, wolbachia seems to be responsible for previously reported patterns of incompatibility between populations. here we report on the artificial transfer o ...	2004	14711652
hierarchical scaffolding with bambus.	the output of a genome assembler generally comprises a collection of contiguous dna sequences (contigs) whose relative placement along the genome is not defined. a procedure called scaffolding is commonly used to order and orient these contigs using paired read information. this ordering of contigs is an essential step when finishing and analyzing the data from a whole-genome shotgun project. most recent assemblers include a scaffolding module; however, users have little control over the scaffol ...	2004	14707177
the role of endosymbiotic wolbachia bacteria in filarial disease.	in this review, we describe the pathogenic role of wolbachia endosymbiotic bacteria in filarial diseases, focusing on the host innate immune responses to filarial and wolbachia products. a description of the host pathogen recognition and early inflammatory responses including tlr4-mediated signalling, chemokine and cytokine responses and inflammatory cell recruitment is provided from human studies and from animal models of filarial disease. finally, the impact of the discovery and characterizati ...	2004	14706096
wolbachia and cytoplasmic incompatibility in the california culex pipiens mosquito species complex: parameter estimates and infection dynamics in natural populations.	before maternally inherited bacterial symbionts like wolbachia, which cause cytoplasmic incompatibility (ci; reduced hatch rate) when infected males mate with uninfected females, can be used in a program to control vector-borne diseases it is essential to understand their dynamics of infection in natural arthropod vector populations. our study had four goals: (1) quantify the number of wolbachia strains circulating in the california culex pipiens species complex, (2) investigate wolbachia infect ...	2003	14704183
influence of two wolbachia strains on population structure of east african drosophila simulans.	drosophila simulans is hypothesized to have originated in continental east africa or madagascar. in this study, we investigated evolutionary forces operating on mitochondrial dna (mtdna) in populations of d. simulans from zimbabwe, malawi, tanzania, and kenya. variation in mtdna may be affected by positive selection, background selection, demographic history, and/or any maternally inherited factor such as the bacterial symbiont wolbachia. in east africa, the wri and wma wolbachia strains associa ...	2003	14704179
most of the response elicited against wolbachia surface protein in filarial nematode infection is due to the infective larval stage.	immune responses to the intracellular wolbachia bacteria of filarial nematodes are thought to contribute to the pathologic process of filarial infection. here, we compare antibody responses of subjects living in an area where lymphatic filariasis is endemic with antibody responses elicited in a murine model of filarial infection, to provide evidence that the infective larval stage (l3), not adult nematodes, are the primary inducer of responses against wolbachia. in human subjects, antibody respo ...	2004	14702162
detection and phylogenetic analysis of wolbachia in collembola.	wolbachia are obligatory, cytoplasmatically inherited alpha-proteobacteria which are known for infecting the reproductive tissues of many arthropods. their prevalence in the large group of collembola, however, is not known, except for pcr detection in the parthenogenetically reproducing species folsomia candida (order: entomobryomorpha; family: isotomidae). in this study, fluorescence in situ hybridization on microscopic sections of f. candida specimens indicated that wolbachia-related bacteria ...	2004	14686939
sexual mosaics induced by tetracycline treatment in the wolbachia-infected adzuki bean borer, ostrinia scapulalis.	wolbachia-infected ostrinia scapulalis (lepidoptera: crambidae) females generate all-female or nearly all-female broods. curing the infection by tetracycline treatment during larval stages results in the generation of all-male broods in the next generation. here we show that sexually mosaic offspring are produced by wolbachia-infected females treated with tetracycline at the adult stage. the sexual mosaics had wings that were composed of distinctive female and male sectors. besides wings, the se ...	2003	14663517
two kinds of sex ratio distorters in a moth, ostrinia scapulalis.	we surveyed female-biased sex ratio traits (sr traits) in a moth, ostrinia scapulalis (lepidoptera: crambidae) from six geographic locations in japan. a small proportion (8.3%) of females showed the sr trait. about half of them were associated with a wolbachia infection (srw+), whereas the remaining ones were not (srw-). no significant differences in frequencies were detected among locations and years for either srw+ or srw- females. in srw+ matrilines, the sr trait was inherited. curing the wol ...	2003	14663516
culture and phenotypic characterization of a wolbachia pipientis isolate.	the recent isolation of wolbachia pipientis in the continuous cell line aa23, established from eggs of a strain of the asian tiger mosquito aedes albopictus, allowed us to perform extensive characterization of the isolate. bacterial growth could be obtained in c6/36, another a. albopictus cell line, at 28 degrees c and in a human embryonic lung fibroblast monolayer at 28 and 37 degrees c, confirming that its host cell range is broader than was initially thought. the bacteria were best visualized ...	2003	14662922
proinflammatory cytokines dominate the early immune response to filarial parasites.	although the early human immune response to the infective-stage larvae (l3) of brugia malayi has not been well-characterized in vivo (because of the inability to determine the precise time of infection), the consensus has been that it must involve a predominant th2 environment. we have set up an in vitro system to study this early immune response by culturing pbmc from unexposed individuals with live l3 of b. malayi. after 24 h of culture, t cell responses were examined by flow cytometry and by ...	2003	14662876
sequential evolution of a symbiont inferred from the host: wolbachia and drosophila simulans.	this study aims to unravel the biogeography of a model symbiont/host system by exploiting the prediction that a symbiont will leave a signature of infection on the host. specifically, a global sample of 1,442 drosophila simulans from 33 countries and 64 sampling localities was employed to infer the phylogeography of the maternally inherited alpha-proteobacteria wolbachia. phylogenetic analyses, from three symbiont genes and 24 mtdna genomes (excluding the a + t-rich region), showed that each of ...	2004	14660690
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
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
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
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
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
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
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
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
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
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
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
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
a bacterial symbiont in the bacteroidetes induces cytoplasmic incompatibility in the parasitoid wasp encarsia pergandiella.	vertically transmitted symbionts of arthropods have been implicated in several reproductive manipulations of their hosts. these include cytoplasmic incompatibility (ci), parthenogenesis induction in haplodiploid species (pi), feminization and male killing. one symbiont lineage in the alpha-proteobacteria, wolbachia, is the only bacterium known to cause all of these effects, and has been thought to be unique in causing ci, in which the fecundity of uninfected females is reduced after mating with ...	2003	14561283
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
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
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
wolbachia infection and the expression of cytoplasmic incompatibility in sandflies (diptera: psychodidae) from egypt.	a pcr-based method was used to screen four laboratory colonies of sandflies for wolbachia infection. the colonies - one of phlebotomus langeroni, one of p. bergeroti and two of p. papatasi - were all derived from sandflies collected in egypt. only one of the colonies, derived from p. papatasi collected in sinai, was found infected. the sequence of the pcr product for this colony was identical to that previously reported for the wolbachia in p. papatasi from israel. the induction with tetracyclin ...	2003	14511562
wolbachia infections of the whitefly bemisia tabaci.	we report the first systematic survey for the presence of wolbachia endosymbionts in aphids and whiteflies, particularly different populations and biotypes of bemisia tabaci. additional agriculturally important species included were predator species, leafhoppers, and lepidopterans. we used a polymerase chain reaction (pcr)-based detection assay with ribosomal 16s rdna and wolbachia cell surface protein (wsp) gene primers. wolbachia were detected in a number of whitefly populations and species, w ...	2003	14506854
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
studies on the cell envelope of wolbachia persica.		1964	14144721
lipid metabolism of the rickettsialike microorganism wolbachia persica. iii. comparison with other metabolic activities.		1964	14118048
lipid metabolism of the rickettsialike microorganism wolbachia persica. ii. studies with labeled nonlipid substrates.		1964	14118047
lipid metabolism of the rickettsialike microorganism wolbachia persica. i. incorporation of long chain fatty acids into phosphatides.		1964	14118046
respiration of a rickettsialike microorganism, wolbachia persica.		1962	14005862
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
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
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
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
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
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
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
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
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
evolution 2003 meeting. genetic deficiency blamed on bacteria.		2003	12881548
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
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
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
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
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
endosymbiotic bacterium wolbachia pipientis in synanthropic populations of the mosquito culex pipiens pipiens l. (diptera, culicidae).		2003	12854423
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
brugia pahangi and wolbachia: the kinetics of bacteria elimination, worm viability, and host responses following tetracycline treatment.	wolbachia spp., first reported from filariae nearly 30 years ago, have been suggested to contribute to the pathogenesis associated with human filarial infection. tetracycline has been used to cure filariae of wolbachia, as a novel means of chemotherapeutic treatment for both ocular and lymphatic filariasis. tetracycline treatment of l4 or adult brugia pahangi in vivo resulted in wolbachia clearance. less tetracycline was required to clear wolbachia when treatment began at the l4 stage, compared ...	2003	12810042
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
wolbachia and genetic variability in the birdnest blowfly protocalliphora sialia.	wolbachia are widespread cytoplasmically inherited bacteria that induce various reproductive alterations in host arthropods, including cytoplasmic incompatibility (ci), an incompatibility between sperm and egg that typically results in embryonic death. ci has been invoked as a possible mechanism for reproductive isolation and speciation in arthropods, by restricting gene flow and promoting maintenance (and evolution) of genetic divergence between populations. here we investigate patterns of wolb ...	2003	12803636
effects of wolbachia on mtdna variation in two fire ant species.	wolbachia are endosymbiotic bacteria that infect arthropods. as they are maternally transmitted, the spread of wolbachia variants within host populations may affect host mtdna evolution. we sequenced a portion of the mitochondrial cytochrome oxidase i gene from numerous individuals of two wolbachia-infected fire ant species, solenopsis invicta and s. richteri, to determine how these bacteria influence patterns of mtdna variation. as predicted, there was a strong association between wolbachia str ...	2003	12803629
obligatory symbiotic wolbachia endobacteria are absent from loa loa.	background: many filarial nematodes harbour wolbachia endobacteria. these endobacteria are transmitted vertically from one generation to the next. in several filarial species that have been studied to date they are obligatory symbionts of their hosts. elimination of the endobacteria by antibiotics interrupts the embryogenesis and hence the production of microfilariae. the medical implication of this being that the use of doxycycline for the treatment of human onchocerciasis and bancroftian filar ...	2003	12801420
wolbachia endosymbionts in fleas (siphonaptera).	intracellular endosymbionts, wolbachia spp., have been reported in many different orders of insects and in nematodes but not previously in fleas. this is the first conclusive report of wolbachia spp. within members of the siphonaptera. using nested polymerase chain reaction (pcr) targeting of the 16s ribosomal rna gene, we screened for wolbachia spp. in fleas collected from 3 counties in georgia and 1 in new york. the prevalence of wolbachia spp. detected varied among the 6 different species scr ...	2003	12760642
antibiotic therapy in murine filariasis (litomosoides sigmodontis): comparative effects of doxycycline and rifampicin on wolbachia and filarial viability.	the symbiosis of filarial nematodes and rickettsial wolbachia endobacteria has been exploited as a target for antibiotic therapy of filariasis. depletion of wolbachia after tetracycline treatment results in filarial sterility because of interruption of embryogenesis and inhibits larval development and adult worm viability. the aim of this study was to investigate if antibiotic intervention of balb/c mice infected with the rodent filaria litomosoides sigmodontis with rifampicin or the combination ...	2003	12753632
wolbachia infection complexity among insects in the tropical rice-field community.	wolbachia are a group of intracellular bacteria that cause reproductive alterations in their arthropod hosts. widely discordant host and wolbachia phylogenies indicate that horizontal transmission of these bacteria among species sometimes occurs. a likely means of horizontal transfer is through the feeding relations of organisms within communities. feeding interactions among insects within the rice-field insect community have been well documented in the past. here, we present the results of a po ...	2003	12753223
host genotype determines cytoplasmic incompatibility type in the haplodiploid genus nasonia.	in haplodiploid species, wolbachia-induced cytoplasmic incompatibility (ci) can be expressed in one of two ways: as a "conversion" of diploid fertilized eggs into haploid males or as embryonic mortality. here we describe ci-type variation within the parasitic wasp genus nasonia and genetically analyze the basis of this variation. we reach four main conclusions: (i) ci is expressed primarily as conversion in n. vitripennis, but as embryonic mortality in the sibling species n. giraulti and n. long ...	2003	12750334
male-killing wolbachia and mitochondrial dna: selective sweeps, hybrid introgression and parasite population dynamics.	mitochondrial dna (mtdna) sequences are widely used as neutral genetic markers in insects. however, patterns of mtdna variability are confounded by the spread of maternally transmitted parasites, which are genetically linked to the mitochondria. we have investigated these effects in the butterflies acraea encedon (which is host to two strains of male-killing wolbachia bacteria) and a. encedana (which is host to one strain). within a population, the mitochondria are in linkage disequilibrium with ...	2003	12750316
no evidence of wolbachia endosymbiosis with loa loa and mansonella perstans.	endosymbiotic wolbachia bacteria from different filarial species, including major pathogens of humans such as wuchereria bancrofti, brugia malayi and onchocerca volvulus, seem to play an important role in the development, viability and fertility of these worms. wolbachia trigger inflammatory host responses as well as adverse reactions against standard treatment regimens and are therefore under investigation as novel treatment targets. we investigated whether wolbachia are also endosymbiotic in l ...	2003	12748849
an aspartate aminotransferase of wolbachia endobacteria from onchocerca volvulus is recognized by igg1 antibodies from residents of endemic areas.	wolbachia are intracellular alpha-proteobacteria, closely related to rickettsia, that infect various arthropods and filarial parasites. in the present study, the cdna encoding the aspartate aminotransferase (aspat) of wolbachia from the human pathogenic filarial parasite onchocerca volvulus (ov-wolaspat) was identified. at the amino acid level, the identity of the ov-wolaspat was 56% to rickettsia prowazekii aspat and 54% to the aspat of the nitrogen-fixing bacterium sinorhizobium meliloti, but ...	2003	12743802
[possible bacterial etiologies for diseases of unknown origin].		2003	12717985
rna polymerase beta-subunit-based phylogeny of ehrlichia spp., anaplasma spp., neorickettsia spp. and wolbachia pipientis.	sequence analysis of rpob, the gene encoding the beta-subunit of rna polymerase, was used in a phylogenetic investigation of nine species from the genera ehrlichia, neorickettsia, wolbachia and anaplasma. the complete nucleotide sequences obtained for anaplasma phagocytophilum (hge agent), ehrlichia chaffeensis, neorickettsia sennetsu, neorickettsia risticii, anaplasma marginale and wolbachia pipientis were amongst the longest rpob sequences in genbank and ranged from 4074 bp for n. sennetsu to ...	2003	12710612
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
doxycycline in the treatment of human onchocerciasis: kinetics of wolbachia endobacteria reduction and of inhibition of embryogenesis in female onchocerca worms.	recently, experts have warned that mass treatment with ivermectin alone may not interrupt the transmission of onchocerca. hence, additional drugs are needed, such as antibiotics acting on symbiotic endobacteria of the filariae, the causative agents of onchocerciasis. based on animal experiments, human onchocerciasis was treated with doxycycline, and preliminary observations published in 2001 in the lancet showed sterility in female worms by depletion and marked reduction in symbiotic wolbachia e ...	2003	12706439
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