Publications

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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
horizontal transmission of wolbachia by strepsipteran endoparasites? a response to noda et al., 2001.		2004	14717905
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
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
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
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
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
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
endosymbiosis: lessons in conflict resolution.		2004	15024418
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
wolbachia affects oviposition and mating behaviour of its spider mite host.	wolbachia bacteria are transmitted from mother to offspring via the cytoplasm of the egg. when mated to males infected with wolbachia bacteria, uninfected females produce unviable offspring, a phenomenon called cytoplasmic incompatibility (ci). current theory predicts that 'sterilization' of uninfected females by infected males confers a fitness advantage to wolbachia in infected females. when the infection is above a threshold frequency in a panmictic population, ci reduces the fitness of uninf ...	2004	15149411
strain-specific quantification of wolbachia density in aedes albopictus and effects of larval rearing conditions.	the density of the endosymbiont wolbachia can influence the expression of the crossing sterilities known as cytoplasmic incompatibility (ci), and also its rate of maternal transmission. aedes albopictus mosquitoes contain a superinfection with the wolbachia strains walba and walbb. a strain-specific real-time quantitative pcr assay was developed and used to quantify relative wolbachia strain densities within individual mosquitoes. the walbb strain was consistently found to be at higher density t ...	2004	15157232
new environments, versatile genomes.		2004	15181901
distribution of the bacterial symbiont cardinium in arthropods.	abstract 'candidatus cardinium', a recently described bacterium from the bacteroidetes group, is involved in diverse reproduction alterations of its arthropod hosts, including cytoplasmic incompatibility, parthenogenesis and feminization. to estimate the incidence rate of cardinium and explore the limits of its host range, 99 insect and mite species were screened, using primers designed to amplify a portion of cardinium 16s ribosomal dna (rdna). these arthropods were also screened for the presen ...	2004	15189221
the contribution by mitochondrially induced oxidative damage to aging in drosophila melanogaster.	strains of drosophila melanogaster have been generated that vary in the mitochondrial genome and have a common nuclear genome. tetracycline was used to cure the strains of the endocommensal bacteria, wolbachia, which is transmitted maternally. variation in the tetracycline responsive agent contributed substantially to variation in longevity and production of metabolic oxidants. changes in diurnal cycle of activity have been investigated: such changes should be responsive to metabolism-related da ...	2004	15190188
the major surface protein of wolbachia endosymbionts in filarial nematodes elicits immune responses through tlr2 and tlr4.	more than 150 million humans in tropical countries are infected by filarial nematodes which harbor intracellular bacterial endosymbionts of the genus wolbachia (rickettsiales). these bacteria have been implicated in adverse effects of drug treatment in filariasis. the present study provides evidence that purified major wolbachia surface protein (rwsp) acts as an inducer of the innate immune system through tlr2 and tlr4: 1) recombinant, stringently purified rwsp elicited the release of tnf-alpha, ...	2004	15210803
[structural organization and distribution of symbiotic bacteria wolbachia in early embryos and ovaries of drosophila melanogaster and d. simulans].	electron microscopic and morphometric analyses of wolbachia distribution in early embryos of drosophila flies have demonstrated that the number of bacteria in the embryo remains constant from fertilization to blastoderm, and that afterwards the symbionts could be observed only in the polar cells. each bacterium has a three-layer envelope, makes contacts with microtubules and moves through the cytoplasm following the actively dividing nuclei. it has been found for the first time that wolbachia co ...	2004	15214166
wolbachia infection and expression of cytoplasmic incompatibility in armigeres subalbatus (diptera: culicidae).	polymerase chain reaction screening revealed that armigeres subalbatus (coquillett), a vector of filariasis, was infected with the intracellular bacteria wolbachia. laboratory crosses between infected males and uninfected females resulted in less than half the number of offspring than control crosses between uninfected individuals when young (2- to 3-d-old) males were used in the cross. however, imcompatibility was lost when old (14- to 17-d-old) males were used. field-collected females did not ...	2000	15218907
natural wolbachia infections in the drosophila yakuba species complex do not induce cytoplasmic incompatibility but fully rescue the wri modification.	in this study, we report data about the presence of wolbachia in drosophila yakuba, d. teissieri, and d. santomea. wolbachia strains were characterized using their wsp gene sequence and cytoplasmic incompatibility assays. all three species were found infected with wolbachia bacteria closely related to the wau strain, found so far in d. simulans natural populations, and were unable to induce cytoplasmic incompatibility. we injected wri, a ci-inducing strain naturally infecting d. simulans, into t ...	2004	15238531
relationship of anti-microbial activity of tetracyclines to their ability to block the l3 to l4 molt of the human filarial parasite brugia malayi.	the nematode parasites wuchereria bancrofti, brugia malayi, and b. timori cause a human disease known as lymphatic filariasis, which afflicts approximately 120 million people worldwide. these organisms are known to contain endosymbiotic bacteria (wolbachia) that are related to rickettsiae. it has been previously reported that tetracycline blocks the l3 to l4 molt of the filarial parasite b. malayi, and suggested that this was related to their known anti-rickettsial activity. however, this interp ...	2004	15238684
fitness and life-history traits of the two major mitochondrial dna haplotypes of drosophila subobscura.	mitochondrial dna restriction site analyses on natural populations of drosophila subobscura have proved the existence of two common, coexisting haplotypes (i and ii), as well as a set of less frequent ones derived from them. to explain this distribution, experiments to date point practically to all possible genetic mechanisms being involved in the changes of gene frequencies (cytonuclear coadaptation, direct natural selection on mtdna and genetic drift). in an attempt to find differences that he ...	2004	15241444
impact of population age structure on wolbachia transgene driver efficacy: ecologically complex factors and release of genetically modified mosquitoes.	wolbachia symbionts hold theoretical promise as a way to drive transgenes into insect vector populations for disease prevention. for simplicity, current models of wolbachia dynamics and spread ignore ecologically complex factors such as the age structure of vector populations and overlapping vector generations. we developed a model including these factors to assess their impact on the process of wolbachia spread into populations of three mosquito species (anopheles gambiae, aedes aegypti and cul ...	2004	15242712
wolbachia and cytoplasmic incompatibility in mosquitoes.	wolbachia are maternally inherited bacteria that induce cytoplasmic incompatibility in mosquitoes, and are able to use these patterns of sterility to spread themselves through populations. for this reason they have been proposed as a gene drive system for mosquito genetic replacement, as well as for the reduction of population size or for modulating population age structure in order to reduce disease transmission. here, recent progress in the study of mosquito wolbachia is reviewed. we now have ...	2004	15242714
sexual differentiation traits in functional males with female genital apertures (male symbol fga) in the woodlice armadillidium vulgare latr. (isopoda, crustacea).	this study reports the results of examination of the gonadal morphology and ultrastructural features of the androgenic hormone (ah)-producing androgenic gland cells of laboratory stocks of functional male woodlice, armadillidium vulgare, with female genital apertures ( male symbol fga), with and without experimentally induced infections of the sex-ratio-distorting endobacterial parasite, wolbachia. males ( male symbol fga) have been reported in wild populations containing individuals infected wi ...	2004	15242750
reproductive effects and geographical distributions of two wolbachia strains infecting the neotropical beetle, chelymorpha alternans boh. (chrysomelidae, cassidinae).	wolbachia are maternally inherited endocellular bacteria known to alter insect host reproduction to facilitate their own transmission. multiple wolbachia infections are more common in tropical than temperate insects but few studies have investigated their dynamics in field populations. the beetle, chelymorpha alternans, found throughout the isthmus of panama, is infected with two strains of wolbachia, wcalt1 (99.2% of beetles) and wcalt2 (53%). populations infected solely by the wcalt1 strain we ...	2004	15245413
increased fecundity associated with infection by a cytophaga-like intracellular bacterium in the predatory mite, metaseiulus occidentalis.	the endosymbiont wolbachia has gained widespread notoriety over the past decade because of its high infection frequency among arthropods, and the unique heterogeneity of the host reproductive effects that it has been implicated as causing to enhance its own spread. recently, another endosymbiotic bacterium from the cytophaga-flavobacterium-bacteroides phylum has been shown to be widespread among arthropods and manipulate its hosts' reproduction to enhance its own spread. we show that infection b ...	2004	15252981
bacteriophage flux in endosymbionts (wolbachia): infection frequency, lateral transfer, and recombination rates.	the highly specialized genomes of bacterial endosymbionts typically lack one of the major contributors of genomic flux in the free-living microbial world-bacteriophages. this study yields three results that show bacteriophages have, to the contrary, been influential in the genome evolution of the most prevalent bacterial endosymbiont of invertebrates, wolbachia. first, we show that bacteriophage wo is more widespread in wolbachia than previously recognized, occurring in at least 89% (35/39) of t ...	2004	15254259
multiple displacement amplification in combination with high-fidelity pcr improves detection of bacteria from single females or eggs of metaseiulus occidentalis (nesbitt) (acari: phytoseiidae).	amplifying microbial dna by the polymerase chain reaction (pcr) from single phytoseiid mites has been difficult, perhaps due to the low titer of bacteria and to interference by the relatively larger amounts of mite genomic dna. in this paper we evaluate the efficiency of standard and high-fidelity pcr protocols subsequent to amplification of the whole genome by a multiple displacement amplification (mda) procedure developed by dean et al. dna from the phytoseiid phytoseiulus persimilis (athias-h ...	2004	15261775
ultrastructural evidence of the degenerative events occurring during embryogenesis of the filarial nematode brugia pahangi after tetracycline treatment.	intracellular bacteria belonging to the genus wolbachia have been described in filarial nematodes and these microorganisms appear to have evolved an obligatory mutualistic association with their filarial hosts. in fact, antibiotic treatment leads to the clearance of bacteria from worms resulting in a block in embryogenesis and, eventually, death of adult filariae. currently, the antifilarial action of antibiotic treatment is interpreted as a secondary consequence of the bacteriostatic activity a ...	2003	15267003
dnaa gene sequences from wolbachia pipientis support subdivision into supergroups and provide no evidence for recombination in the lineages infecting nematodes.	wolbachia pipientis is an intracellular bacterial endosymbiont of arthropods and filarial nematodes. six main supergroups of w. pipientis have been described: supergroups a, b, e, and f encompass arthropod wolbachiae; supergroups c and d encompass nematode wolbachiae. the description of these six supergroups has been based on the analysis of only two genes (ftsz and 16s rdna) and before decisions are taken on the taxonomic status of the six supergroups, analysis of further genes is required. in ...	2003	15270538
distribution and prevalence of wolbachia in japanese populations of lepidoptera.	wolbachia are cytoplasmically inherited bacteria that are reported to infect at least 18-30% of all insect species. our survey of lepidoptera indicated that 44.9% of forty-nine species and 77.8% of nine families tested positive for wolbachia using pcr with wsp primers. nineteen species had not been described previously as infected. in particular, although pieris rapae, which is a common species in japan, is infected by wolbachia, the prevalence was very low (3.4%) and there were some localities ...	2004	15271207
molecular discrimination of wolbachia in the culex pipiens complex: evidence for variable bacteriophage hyperparasitism.	the medically important members of the culex pipiens species complex provide an enigma for systematists, evolutionary biologists, and vector biologists. the species complex is composed of forms that differ in their ecology, behaviour, physiology and vector competence. cytoplasmic incompatibility (ci) caused by endosymbiotic wolbachia bacteria is thought to play an important role in restricting gene flow and the evolution of the culex complex. here we describe the first molecular marker useful fo ...	2004	15271208
wolbachia pipientis: symbiont or parasite?		1995	15275347
life stages and reproductive components of the marmorkrebs (marbled crayfish), the first parthenogenetic decapod crustacean.	recently, we briefly reported on the first case of parthenogenesis in the decapod crustacea which was found in the marmorkrebs or marbled crayfish, a cambarid species of unknown geographic origin and species identity. curiously, this animal is known only from aquarium populations, where it explosively propagates. by means of light and electron microscopic techniques we have now investigated the reproductive components of this crayfish, using more than 100 specimens ranging from hatchling to repe ...	2004	15281058
population dynamics of wolbachia bacterial endosymbionts in brugia malayi.	the human filarial nematode brugia malayi contains an endosymbiotic bacterium, wolbachia. we used real-time quantitative polymerase chain reaction (qpcr) and microscopy to investigate the population dynamics of the bacterium-nematode association. two wolbachia (wsp and ftsz) and one nematode (gst) genes were amplified from all life-cycle stages of b. malayi and results expressed as gene copies per worm and as wolbachia/nematode ratios. since the genes were single copy and there was one genome pe ...	2004	15287587
wolbachia replication and host cell division in aedes albopictus.	wolbachia pipientis is an obligate intracellular endosymbiont of a range of arthropod species. the microbe is best known for its manipulations of host reproduction that include inducing cytoplasmic incompatibility, parthenogenesis, feminization, and male-killing. like other vertically transmitted intracellular symbionts, wolbachia's replication rate must not outpace that of its host cells if it is to remain benign. the mosquito aedes albopictus is naturally infected both singly and doubly with d ...	2004	15297923
variable fitness effects of wolbachia infection in drosophila melanogaster.	maternally inherited wolbachia bacteria are extremely widespread among insects and their presence is usually associated with parasitic modifications of host fitness. wolbachia pipientis infects drosophila melanogaster populations from all continents, but their persistence in this species occurs despite any strong parasitic effects. here, we have investigated the symbiosis between wolbachia and d. melanogaster and found that wolbachia infection can have significant survival and fecundity effects. ...	2004	15305172
[ultrastructural basis of interactions between prokaryotes and eukaryotes in different symbiotic models].	this paper reviews the author's contribution to the knowledge of the ultrastructural basis of the prokaryote-eukaryote interactions in different models assessed by an ultrastructural approach. in agreement with the hypothesis of the origin of eukaryotic cells, which are chimeras of several prokaryotes with different morpho-functional specializations, symbiosis had major consequence for evolution of life. in arthropods, one of the most successful lifestyles, the presence of endosymbiotic prokaryo ...	2004	15305681
multiple infection with wolbachia inducing different reproductive manipulations in the butterfly eurema hecabe.	wolbachia are rickettsial intracellular symbionts of arthropods and nematodes. in arthropods, they act as selfish genetic elements and manipulate host reproduction, including sex-ratio distortion and cytoplasmic incompatibility (ci). previous studies showed that infection of feminizing wolbachia and ci wolbachia sympatrically occurred in the butterfly eurema hecabe. we demonstrate that feminization-infecting individuals can rescue sperm modified by ci-infecting males. phylogenetic analysis revea ...	2004	15306297
use of wolbachia to drive nuclear transgenes through insect populations.	wolbachia is an inherited intracellular bacterium found in many insects of medical and economic importance. the ability of many strains to spread through populations using cytoplasmic incompatibility, involving sperm modification and rescue, provides a powerful mechanism for driving beneficial transgenes through insect populations, if such transgenes could be inserted into and expressed by wolbachia. however, manipulating wolbachia in this way has not yet been achieved. here, we demonstrate theo ...	2004	15306342
differential fitness of mitochondrial dna in perturbation cage studies correlates with global abundance and population history in drosophila simulans.	mitochondria are often referred to as the powerhouse of the cell. however, research linking intraspecific differences in organismal fitness with genotypic mitochondrial dna (mtdna) variation has been hampered by the lack of variation in experimentally tractable species. this study examines whether fly lines harbouring three distinct drosophila simulans mtdna types (sii, -ii and -iii) exhibit differential fitness in laboratory perturbation cages. comparison of the pre-perturbation and post-pertur ...	2004	15306370
molecular (sub) grouping of endosymbiont wolbachia infection among mosquitoes of taiwan.	wolbachia are maternally inherited bacteria that infect a wide range of arthropods as well as filarial worms. the infection usually results in reproductive distortions of the host, primarily cytoplasmic incompatibility, parthenogenesis, and feminization. this study showed that wolbachia infection (15/29; 51.72%) was prevalent among field-caught mosquitoes in taiwan. three mosquito species were identified as having wolbachia a infection, eight species as having wolbachia b, and four other species ...	2004	15311460
the bacterial catalase from filarial dna preparations derives from common pseudomonad contaminants and not from wolbachia endosymbionts.	wolbachia are obligatory endosymbionts in many species of filarial nematodes. certain bacterial molecules induce antibody responses in mammalian hosts infected with filariae, while others activate inflammatory responses that contribute to pathology. these findings, coupled with antibiotic studies demonstrating the dependence of filarial embryogenesis on the presence of wolbachia, have intensified research on wolbachia-nematode interactions, and the effects of wolbachia molecules on the mammalian ...	2004	15322925
cytogenetic mechanism and genetic consequences of thelytoky in the wasp trichogramma cacoeciae.	in hymenoptera, complete parthenogenesis, that is thelytoky, is a common phenomenon where virgin females produce only daughters. thelytoky is often induced by bacteria of the genus wolbachia, but can also be genetically determined by the insect itself, as in the genus trichogramma where both forms exist. in order to compare these two forms of thelytoky, chromosome behaviour analysis in young eggs and genetic analysis of microsatellite markers were carried out in the wasp trichogramma cacoeciae, ...	2004	15329666
parasites and sexual reproduction in psychid moths.	persistence of sexual reproduction among coexisting asexual competitors has been a major paradox in evolutionary biology. the number of empirical studies is still very limited, as few systems with coexisting sexual and strictly asexual lineages have been found. we studied the ecological mechanisms behind the simultaneous coexistence of a sexually and an asexually reproducing closely related species of psychid moth in central finland between 1999 and 2001. the two species compete for the same res ...	2004	15341153
heads or tails: host-parasite interactions in the drosophila-wolbachia system.	wolbachia strains are endosymbiotic bacteria typically found in the reproductive tracts of arthropods. these bacteria manipulate host reproduction to ensure maternal transmission. they are usually transmitted vertically, so it has been predicted that they have evolved a mechanism to target the host's germ cells during development. through cytological analysis we found that wolbachia strains display various affinities for the germ line of drosophila. different wolbachia strains show posterior, an ...	2004	15345422
a cost of wolbachia-induced sex reversal and female-biased sex ratios: decrease in female fertility after sperm depletion in a terrestrial isopod.	a number of parasites are vertically transmitted to new host generations via female eggs. in such cases, host reproduction is an intimate component of parasite fitness and no cost of the infection on host reproduction is expected to evolve. a number of these parasites distort host sex ratios towards females, thereby increasing either parasite fitness or the proportion of the host that transmit the parasite. in terrestrial isopods (woodlice), wolbachia bacteria are responsible for sex reversion a ...	2004	15347518
a new form of symbiotic bacteria wolbachia found in the endoplasmic reticulum of early embryos of drosophila melanogaster.		2004	15354833
coexistence of wolbachia with buchnera aphidicola and a secondary symbiont in the aphid cinara cedri.	intracellular symbiosis is very common in the insect world. for the aphid cinara cedri, we have identified by electron microscopy three symbiotic bacteria that can be characterized by their different sizes, morphologies, and electrodensities. pcr amplification and sequencing of the 16s ribosomal dna (rdna) genes showed that, in addition to harboring buchnera aphidicola, the primary endosymbiont of aphids, c. cedri harbors a secondary symbiont (s symbiont) that was previously found to be associat ...	2004	15375144
quantification of wolbachia bacteria in brugia malayi through the nematode lifecycle.		2004	15383308