Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| dynamics of wolbachia populations in transfected lines of trichogramma. | fluorescence in situ hybridization was tested to specifically detect symbionts of the genus wolbachia in trichogramma and to allow for semiquantitative estimations of symbiont abundance. extraction solutions used for horizontal transfers of symbionts contain a high abundance of wolbachia, but wolbachia have a low and decreasing abundance in microinjected lines (transfected lines). moreover, eggs of microinjected lines were shown to be polymorphic for the infection. in naturally infected lines, w ... | 2000 | 10963399 |
| mating interactions between two biotypes of the whitefly, bemisia tabaci (hemiptera: aleyrodidae) in australia. | the biological consequences of mating interactions between indigenous and exotic biotypes of bemisia tabaci (gennadius) in australia were studied using a combination of field and laboratory experiments. the key results of the interaction between the b and eastern australian biotypes were reduced population increase, a marked increase in the proportion of male progeny, fewer eggs produced by females paired with males of different biotype and no difference in the numbers of eggs per unmated female ... | 2000 | 10948369 |
| evidence for female mortality in wolbachia-mediated cytoplasmic incompatibility in haplodiploid insects: epidemiologic and evolutionary consequences. | until now, only two wolbachia-mediated cytoplasmic incompatibility (ci) types have been described in haplodiploid species, the first in nasonia (insect) and the second in tetranychus (acari). they both induce a male-biased sex ratio in the incompatible cross. in nasonia, ci does not reduce fertility since incompatible eggs develop as haploid males, whereas in tetranychus ci leads to a partial mortality of incompatible eggs, thus reducing the fertility of females. here, we study wolbachia infecti ... | 2000 | 10937195 |
| comparative genomics of mitochondrial dna in drosophila simulans. | the current study compares the nucleotide variation among 22 complete mitochondrial genomes of the three distinct drosophila simulans haplotypes with intron 1 of the alcohol dehydrogenase-related locus. this is the first study to investigate the sequence variation of multiple complete mitochondrial genomes within distinct mitochondrial haplotypes of a single species. patterns of variation suggest distinct forces are influencing the evolution of mitochondrial dna (mtdna) and autosomal dna in d. s ... | 2000 | 10903373 |
| wolbachia infection and cytoplasmic incompatibility in the cricket teleogryllus taiwanemma. | wolbachia are cytoplasmically inherited bacteria found in many arthropods. they induce various reproductive alterations in their hosts, including cytoplasmic incompatibility, thelytokous parthenogenesis, feminization and male-killing. in this study, we examined wolbachia infection and its effects on the host cricket teleogryllus taiwanemma. in a phylogenetic study based on the wsp gene coding for a wolbachia surface protein, the wolbachia strain harboured by t. taiwanemma was clustered together ... | 2000 | 10903165 |
| macrofilaricidal activity of tetracycline against the filarial nematode onchocerca ochengi: elimination of wolbachia precedes worm death and suggests a dependent relationship. | filarial nematodes are important and widespread parasites of animals and humans. we have been using the african bovine parasite onchocerca ochengi as a chemotherapeutic model for o. volvulus, the causal organism of 'river blindness' in humans, for which there is no safe and effective drug lethal to adult worms. here we report that the antibiotic, oxytetracycline is macrofilaricidal against o. ochengi. in a controlled trial in cameroon, all adult worms (as well as microfilariae) were killed, and ... | 2000 | 10885510 |
| onchocerca ochengi infections in cattle as a model for human onchocerciasis: recent developments. | the bovine parasite onchocerca ochengi is a nodule-dwelling filarial nematode, closely related to o. volvulus, the causal agent of human river blindness, and, sharing with it, the same vector. this brief review, based on a presentation at the bsp autumn symposium 1999, describes recent work supported by the who drug development research macrofil programme and the edna mcconnell clark foundation vaccine development programme, to research the chemotherapy and immunology of onchocerciasis utilising ... | 2000 | 10874716 |
| wsp gene sequences from the wolbachia of filarial nematodes. | wolbachia endosymbiotic bacteria are widespread in arthropods and are also present in filarial nematodes. almost all filarial species so far examined have been found to harbor these endosymbionts. the sequences of only three genes have been published for nematode wolbachia (i.e., the genes coding for the proteins ftsz and catalase and for 16s rrna). here we present the sequences of the genes coding for the wolbachia surface protein (wsp) from the endosymbionts of eight species of filaria. comple ... | 2000 | 10856373 |
| male killing can select for male mate choice: a novel solution to the paradox of the lek. | in lekking species, intense directional selection is applied to aspects of the male genotype by female choice. under conventional quantitative genetics theory, the expectation is that this will lead to a rapid loss in additive genetic variance for the trait in question. however, despite female choice, male variation is maintained and hence it pays females to continue choosing. this has been termed the 'paradox of the lek'. here we present a theoretical analysis of a putative sex-role-reversed le ... | 2000 | 10853728 |
| multiple causes of male-killing in a single sample of the two-spot ladybird, adalia bipunctata (coleoptera: coccinellidae) from moscow. | thirty-six matrilines from a single muscovite sample of adalia bipunctata were assayed, using appropriate primers, for presence of the four male-killing symbionts known to infect this species of ladybird. all four, a rickettsia, a spiroplasma and two different strains of wolbachia, were found to be present. vertical transmission efficiencies were assessed from f1 and f2 families from each of the matrilines, and were found to differ significantly between symbionts. potential explanations of the p ... | 2000 | 10849086 |
| wolbachia density and host fitness components in muscidifurax uniraptor (hymenoptera: pteromalidae). | intracellular bacteria of the genus wolbachia are found in a variety of arthropod hosts, where they cause various reproductive disorders. attempts to study the fitness advantages and disadvantages of carrying these symbionts have yielded contradicting results. using various doses of the antibiotic rifampicin, we were able to manipulate the density of wolbachia in the uniparental parasitoid muscidifurax uniraptor (hymenoptera: pteromalidae). the effect of different titers of the symbiont on the f ... | 2000 | 10843833 |
| [wolbachia--a new bacteria causing sex ratio bias in the two-spot lady-bird adalia bipunctata l]. | some of the male-killing lines of the two-spot ladybird adalia bipunctata l. isolated from the populations of moscow and tomsk and having a female-biased sex ratio were found to be infected with a bacterium of the genus wolbachia. this fact is the first demonstration of the ability of wolbachia to kill males of a host insect. the coexistence of females infected with different male-killing bacteria was recorded in the population of moscow. | 2000 | 10822808 |
| infectious parthenogenesis. | parthenogenesis-inducing wolbachia bacteria are reproductive parasites that cause infected female wasps to produce daughters without mating. this manipulation of the host's reproduction enhances the transmission of wolbachia to future generations because the bacteria are passed on vertically only from mothers to daughters. males are dead ends for cytoplasmically inherited bacteria: they do not pass them on to their offspring. vertical transmission of wolbachia has been previously considered to b ... | 2000 | 10821272 |
| targeting of wolbachia endobacteria in litomosoides sigmodontis: comparison of tetracyclines with chloramphenicol, macrolides and ciprofloxacin | endobacteria of the genus wolbachia in filarial nematodes are related to rickettsiaceae and can be depleted by tetracycline antibiotics. this depletion blocks female worm development as well as early embryogenesis, in contrast to the currently used microfilaricidal ivermectin which blocks only the last stage of embryogenesis. since targeting wolbachia is becoming an area of research for the treatment of human filariases, it was investigated if antibiotics other than tetracyclines are able to dep ... | 2000 | 10810024 |
| targeting of wolbachia endobacteria in litomosoides sigmodontis: comparison of tetracyclines with chloramphenicol, macrolides and ciprofloxacin. | endobacteria of the genus wolbachia in filarial nematodes are related to rickettsiaceae and can be depleted by tetracycline antibiotics. this depletion blocks female worm development as well as early embryogenesis, in contrast to the currently used microfilaricidal ivermectin which blocks only the last stage of embryogenesis. since targeting wolbachia is becoming an area of research for the treatment of human filariases, it was investigated if antibiotics other than tetracyclines are able to dep ... | 2000 | 10810023 |
| offsetting effects of wolbachia infection and heat shock on sperm production in drosophila simulans: analyses of fecundity, fertility and accessory gland proteins. | infection in drosophila simulans with the endocellular symbiont wolbachia pipientis results in egg lethality caused by failure to properly initiate diploid development (cytoplasmic incompatibility, ci). the relationship between wolbachia infection and reproductive factors influencing male fitness has not been well examined. here we compare infected and uninfected strains of d. simulans for (1) sperm production, (2) male fertility, and (3) the transfer and processing of two accessory gland protei ... | 2000 | 10790392 |
| wolbachia bacteria of filarial nematodes: a target for control? | 2000 | 10782070 | |
| inflammatory responses induced by the filarial nematode brugia malayi are mediated by lipopolysaccharide-like activity from endosymbiotic wolbachia bacteria. | the pathogenesis of filarial disease is characterized by acute and chronic inflammation. inflammatory responses are thought to be generated by either the parasite, the immune response, or opportunistic infection. we show that soluble extracts of the human filarial parasite brugia malayi can induce potent inflammatory responses, including tumor necrosis factor (tnf)-alpha, interleukin (il)-1beta, and nitric oxide (no) from macrophages. the active component is heat stable, reacts positively in the ... | 2000 | 10770808 |
| endosymbiotic bacteria in worms as targets for a novel chemotherapy in filariasis. | endosymbiotic bacteria living in plasmodia or worm parasites are required for the homoeostasis of their host and should be excellent targets for chemotherapy of certain parasitic diseases. we show that targeting of wolbachia spp bacteria in onchocerca volvulus filariae by doxycycline leads to sterility of adult worms to an extent not seen with drugs used against onchocerciasis, a leading cause of blindness in african countries. | 2000 | 10770311 |
| tissue distribution and prevalence of wolbachia infections in tsetse flies, glossina spp. | tsetse flies glossina spp. (diptera: glossinidae) harbor three different symbiotic microorganisms, one being an intracellular rickettsia of the genus wolbachia. this bacterium infects a wide range of arthropods, where it causes a variety of reproductive abnormalities, one of which is termed cytoplasmic incompatibility (ci) that, when expressed, results in embryonic death due to disruptions in fertilization events. we report here that in colonized flies, wolbachia infections can be detected in 10 ... | 2000 | 10759311 |
| molecular evolution and phylogenetic utility of wolbachia ftsz and wsp gene sequences with special reference to the origin of male-killing. | a detailed assessment of the evolution and phylogenetic utility of two genes, ftsz and wsp, was used to investigate the origin of male-killing wolbachia, previously isolated from the ladybird adalia bipunctata and the butterfly acraea encedon. the analysis included almost all available sequences of b-group wolbachia and two outgroup taxa and showed that (1) the two gene regions differ in phylogenetic utility, (2) sequence variation is here correlated with phylogenetic information content, (3) bo ... | 2000 | 10742050 |
| the genomes of onchocerca volvulus. | onchocerca volvulus, the filarial parasite that causes onchocerciasis or river blindness, contains three distinct genomes. these include the nuclear genome, the mitochondrial genome and the genome of an intracellular endosymbiont of the genus wolbachia. the nuclear genome is roughly 1.5x10(8) bp in size, and is arranged on four chromosome pairs. analysis of expressed sequence tags from different life-cycle stages has resulted in the identification of transcripts from roughly 4000 o. volvulus gen ... | 2000 | 10731575 |
| the filarial genome project: analysis of the nuclear, mitochondrial and endosymbiont genomes of brugia malayi. | the filarial genome project (fgp) was initiated in 1994 under the auspices of the world health organisation. brugia malayi was chosen as the model organism due to the availability of all life cycle stages for the construction of cdna libraries. to date, over 20000 cdna clones have been partially sequenced and submitted to the est database (dbest). these ests define approximately 7000 new brugia genes. analysis of the est dataset provides useful information on the expression pattern of the most a ... | 2000 | 10731564 |
| do wolbachia influence fecundity in nasonia vitripennis? | this paper reports the influence of a vertically transmitted symbiont, wolbachia, on host fitness in the parasitic wasp, nasonia vitripennis. we measured fecundities of uninfected strains and strains infected with either two wolbachia variants (wav,wbv) or one (wav or wbv). preliminary tests suggested that double-infected females produce more offspring on average than uninfected females. however, further studies failed to yield consistent fitness effects. to control for host genetic effects, the ... | 2000 | 10692011 |
| sex-ratio-distorting wolbachia causes sex-role reversal in its butterfly host. | sex-role-reversed mating systems in which females compete for males and males may be choosy are usually associated with males investing more than females in offspring. we report that sex-role reversal may also be caused by selfish genetic elements which distort the sex ratio towards females. some populations of the butterflies acraea encedon and acraea encedana are extremely female biased because over 90% of females are infected with a wolbachia bacterium that is maternally inherited and kills m ... | 2000 | 10670955 |
| high temperatures eliminate wolbachia, a cytoplasmic incompatibility inducing endosymbiont, from the two-spotted spider mite. | wolbachia can induce cytoplasmic incompatibility (ci) in the arrhenotokous two-spotted spider mite between uninfected females and infected males. cytoplasmic incompatibility is expressed through a male-biased sex ratio and a low hatchability, and can be suppressed by removing wolbachia from spider mites reared on a diet with antibiotics. here we investigated whether heat-treatment can elimate wolbachia from infected mites. using a pcr assay with a wolbachia-specific primer pair (ftsz), and by st ... | 1999 | 10668862 |
| a genetic test of the mechanism of wolbachia-induced cytoplasmic incompatibility in drosophila. | cytoplasmic bacteria of the genus wolbachia are best known as the cause of cytoplasmic incompatibility (ci): many uninfected eggs fertilized by wolbachia-modified sperm from infected males die as embryos. in contrast, eggs of infected females rescue modified sperm and develop normally. although wolbachia cause ci in at least five insect orders, the mechanism of ci remains poorly understood. here i test whether the target of wolbachia-induced sperm modification is the male pronucleus (e.g., dna o ... | 2000 | 10655228 |
| wolbachia as a speciation agent. | 2000 | 10652551 | |
| molecular evidence for multiple infections of a new subgroup of wolbachia in the european raspberry beetle byturus tomentosus. | wolbachia, a group of maternally inherited intracellular parasitic bacteria, alter host reproduction, including the induction of thelytokous parthenogenesis, feminization of genetic males, son killing and, most commonly, the induction of cytoplasmic incompatibility (ci), in a diverse array of arthropods. ci can result in infertility and has attracted attention because of its potential in biological control and as an agent in speciation. although there has been some analysis of overall infection ... | 2000 | 10652077 |
| acetone preservation: a practical technique for molecular analysis. | in attempts to establish a convenient and reliable method for field collection and archival preservation of insects and their endosymbiotic microorganisms for molecular analysis, acetone, ethanol, and other organic solvents were tested for dna preservability of the pea aphid acyrthosiphon pisum and its intracellular symbiotic bacterium buchnera sp. after 6 months' storage, not only the band of high-molecular-size dna but also the bands of rrna were well preserved in acetone, ethanol, 2-propanol, ... | 1999 | 10620236 |
| frequency of wolbachia infection in laboratory and field sand fly (diptera: psychodidae) populations. | using a polymerase chain reaction (pcr) assay with primers designed for the wolbachia 16s rrna and outer surface protein (wsp) gene, we screened 11 laboratory colonies and 4 field samples of 6 sand fly species for wolbachia infection. infection was only detected in 3 laboratory colonies of phlebotomus papatasi scopoli, originally collected in israel, egypt, and saudi arabia. | 1999 | 10612622 |
| phylogenetic evidence for horizontal transmission of wolbachia in host-parasitoid associations. | endosymbiotic wolbachia infect a number of arthropod species in which they can affect the reproductive system. while maternally transmitted, unlike mitochondria their molecular phylogeny does not parallel that of their hosts. this strongly suggests horizontal transmission among species, the mechanisms of which remain unknown. such transfers require intimate between-species relationships, and thus host-parasite associations are outstandingly appropriate for study. here, we demonstrate that hymeno ... | 1999 | 10605113 |
| germ cells colonized by endosymbiotic bacteria. | 1999 | 10591206 | |
| the wolbachia genome consortium. | 1999 | 10587943 | |
| wolbachia: why these bacteria are important to genome research. | 1999 | 10587942 | |
| wolbachia infection in the terrestrial isopod oniscus asellus: sex ratio distortion and effect on fecundity | maternally inherited wolbachia bacteria are widespread in arthropods where they are responsible for various reproductive alterations. in terrestrial isopods (woodlice), wolbachia may induce feminization or cytoplasmic incompatibility (ci), but their effect remains unknown in most host species. to increase our understanding of host/symbiont interactions in terrestrial isopods, the effect of wolbachia was investigated in the oniscidean oniscus asellus, mainly to discriminate between feminization a ... | 1999 | 10583549 |
| phylogenetic analysis of the 16s rdna of the cytoplasmic bacterium wolbachia from the novel host folsomia candida (hexapoda, collembola) and its implications for wolbachial taxonomy. | wolbachia pipientis are intracellular, transovarially inherited alpha-proteobacteria in invertebrates. four major wolbachia groups exist: a, b (contained in divergent arthropods), c and d (harbored by nematoda). by means of transmission electron microscopy, we observed wolbachia-like bacteria in a primitive insect, folsomia candida (hexapoda, collembola, isotomidae). 16s rdna analysis proved them to constitute a novel lineage, henceforth named group e, in the wolbachial phylogenetic tree. it sha ... | 1999 | 10556723 |
| sequence evolution in bacterial endosymbionts having extreme base compositions. | a major limitation on ability to reconstruct bacterial evolution is the lack of dated ancestors that might be used to evaluate and calibrate molecular clocks. vertically transmitted symbionts that have cospeciated with animal hosts offer a firm basis for calibrating sequence evolution in bacteria, since fossils of the hosts can be used to date divergence events. sequences for a functionally diverse set of genes have been obtained for bacterial endosymbionts (buchnera) from two pairs of aphid hos ... | 1999 | 10555290 |
| wolbachia pipientis: microbial manipulator of arthropod reproduction. | the alpha-proteobacterium wolbachia pipientis is a very common cytoplasmic symbiont of insects, crustaceans, mites, and filarial nematodes. to enhance its transmission, w. pipientis has evolved a large scale of host manipulations: parthenogenesis induction, feminization, and male killing. w. pipientis's most common effect is a crossing incompatibility between infected males and uninfected females. little is known about the genetics and biochemistry of these symbionts because of their fastidious ... | 1999 | 10547686 |
| wolbachia bacteria of filarial nematodes. | the finding that the intracellular bacteria of filarial nematodes are related to the wolbachia symbionts of arthropods has generated great interest. here, mark taylor and achim hoerauf review recent studies by several groups on the structure, distribution and phylogeny of these endosymbionts, and discuss the potential role for these bacteria in filarial disease and as a target for chemotherapy. | 1999 | 10511685 |
| wolbachia genomes and the many faces of symbiosis. | 1999 | 10511680 | |
| phylogeny of the arthropod endosymbiont wolbachia based on the wsp gene. | bacteria of the genus wolbachia (rickettsiae) are widespread in arthropods and can induce cytoplasmic incompatibility (ci), thelytoky (t) or feminization (f) in their host. recent research on the wsp gene of mainly ci inducing wolbachia has shown that this gene evolves at a much faster rate than previously sequenced genes such as 16s or ftsz. as a result this gene appears to be very useful in subdividing the wolbachia and twelve groups have been distinguished to date. here we extend the wolbachi ... | 1999 | 10469257 |
| mitochondrial dna variability and wolbachia infection in two sibling woodlice species | several morphological races and subspecies have been described and later included within the terrestrial isopod species porcellionides pruinosus. during our study of this species, we have worked on specimens from france, greece, tunisia and reunion island. laboratory crosses have revealed two separate groups of populations: french populations (four localities) in one group, and those from tunisia, reunion island and greece in the other. french individuals were reproductively isolated from those ... | 1999 | 10447705 |
| mitochondrial dna polymorphism, sex ratio distorters and population genetics in the isopod armadillidium vulgare. | two maternally inherited sex ratio distorters (srd) impose female-biased sex ratios on the wood louse armadillidium vulgare by feminizing putative males. these srd are (i) an intracytoplasmic bacterium of the genus wolbachia, and (ii) another non-mendelian element of unknown nature: the f element. mitochondrial dna variation was investigated in a. vulgare field populations to trace the evolution of host-srd relationships and to investigate the effect of srd on host cytoplasmic polymorphism. the ... | 1999 | 10430591 |
| gene organization of the dnaa region of wolbachia. | the dnaa region of wolbachia, an intracellular bacterial parasite of insects, is unique. a glna cognate was found upstream of the dnaa gene, while neither of the two open reading frames detected downstream of dnaa has any homologue in the database. this unusual gene arrangement may reflect requirements associated with the unique ecological niche this agent occupies. | 1999 | 10419978 |
| the first detection of the insertion sequence isw1 in the intracellular reproductive parasite wolbachia. | wolbachia are maternally inherited intracellular rickettsia-like bacteria known to infect a wide range of arthropods. they are associated with a number of different reproductive phenotypes in their hosts, such as cytoplasmic incompatibility, parthenogenesis, and feminization. we report on a novel insertion sequence (is), isw1, which was identified in the region downstream of groel of a wolbachia strain, wtai. the 573-bp-long isw1 sequence is the first is element observed in this organism, displa ... | 1999 | 10413661 |
| the structure of a glycosylated protein hormone responsible for sex determination in the isopod, armadillidium vulgare. | two glycoforms (ah1 and ah2) of androgenic hormone, and its corresponding hormone precursor derived from hplc-purified androgenic gland extract from the woodlouse armadillidium vulgare were fully characterized by microsequencing and mass spectrometry. the amino-acid sequences of the two glycoforms were identical; they consist of two peptide chains, a and b, of 29 and 44 amino acids, respectively, with chain a carrying one n-glycosylated moiety on asn18. the two chains are linked by two disulfide ... | 1999 | 10411634 |
| evolution of wolbachia pipientis transmission dynamics in insects. | wolbachia pipientis is an intracellular bacterial parasite of arthropods that enhances its transmission by manipulating host reproduction, most commonly by inducing cytoplasmic incompatibility. the discovery of isolates with modified cytoplasmic incompatibility phenotypes and others with novel virulence properties is an indication of the potential breadth of evolutionary strategies employed by wolbachia. | 1999 | 10390640 |
| a stable triple wolbachia infection in drosophila with nearly additive incompatibility effects. | drosophila simulans strains infected with three different wolbachia strains were generated by experimental injection of a third symbiont into a naturally double-infected strain. this transfer led to a substantial increase in total wolbachia density in the host strain. each of the three symbionts was stably transmitted in the presence of the other two. triple-infected males were incompatible with double-infected females. no evidence was obtained for interference between modification effects of th ... | 1999 | 10383683 |
| microbe-induced cytoplasmic incompatibility as a mechanism for introducing transgenes into arthropod populations. | many arthropods are infected with maternally transmitted, intracellular bacteria of the genus wolbachia. these infections often produce 'cytoplasmic incompatibility' (ci)--reduced egg-hatch frequencies when uninfected females mate with infected males or when males and females carrying different wolbachia strains mate. because infected females often enjoy a fitness advantage--they are effectively immune to any effects from males carrying the same wolbachia strain--wolbachia and associated cytopla ... | 1999 | 10380108 |
| distribution and phylogeny of wolbachia inducing thelytoky in rhoditini and 'aylacini' (hymenoptera: cynipidae). | wolbachia are endosymbiotic bacteria responsible for thelytoky in several parasitoid hymenopteran genera. after finding these micro-organisms in some populations of diplolepis spinosissimae (hymenoptera: cynipidae) where they are responsible for thelytoky through gamete duplication, we searched for wolbachia spp. using specific pcr primers in nineteen other species of the rhoditini tribe (rose gallwasps) and eight species of the 'aylacini' tribe (gallwasps associated with herbaceous plants). wol ... | 1999 | 10380102 |
| preliminary results on the effect of tetracycline on the embryogenesis and symbiotic bacteria (wolbachia) of dirofilaria immitis. an update and discussion. | the distribution and phylogeny of wolbachia in filarial species suggests that these endosymbiotic bacteria may be important in the biology of their filarial hosts. an experiment to falsify this hypothesis would be to treat filarial worms with antibiotics which are active against intracellular bacteria. indeed, it has already been shown that tetracycline treatment inhibits development in a model filarial species (brugia pahangi) at different stages of the life cycle, in both mosquito and mammalia ... | 1998 | 10376278 |
| four intracellular genomes direct weevil biology: nuclear, mitochondrial, principal endosymbiont, and wolbachia. | cell physiology in the weevil sitophilus oryzae is coordinated by three integrated genomes: nuclear, mitochondrial, and the "s. oryzae principal endosymbiont" (sope). sope, a cytoplasmic bacterium (2 x 10(3) bacteria per specialized bacteriocyte cell and 3 x 10(6) bacteria per weevil) that belongs to the proteobacteria gamma3-subgroup, is present in all weevils studied. we discovered a fourth prokaryotic genome in somatic and germ tissues of 57% of weevil strains of three species, s. oryzae, sit ... | 1999 | 10359795 |
| effects of tetracycline on the filarial worms brugia pahangi and dirofilaria immitis and their bacterial endosymbionts wolbachia. | wolbachia endosymbiotic bacteria have been shown to be widespread among filarial worms and could thus play some role in the biology of these nematodes. indeed, tetracycline has been shown to inhibit both the development of adult worms from third-stage larvae and the development of the microfilaraemia in jirds infected with brugia pahangi. the possibility that these effects are related to the bacteriostatic activity of tetracycline on wolbachia symbionts should be considered. here we show that te ... | 1999 | 10221636 |
| horizontal transfer of wolbachia between phylogenetically distant insect species by a naturally occurring mechanism. | wolbachia is a genus of alpha-proteobacteria found in obligate intracellular association with a wide variety of arthropods, including an estimated 10-20% of all insect species [1]. wolbachia represents one of a number of recently identified 'reproductive parasites' [2] which manipulate the reproduction of their hosts in ways that enhance their own transmission [3] [4] [5] [6] [7] [8] [9]. the influence of wolbachia infection on the dynamics of host populations has focused considerable interest o ... | 1999 | 10209097 |
| wolbachia infections are distributed throughout insect somatic and germ line tissues. | wolbachia are intracellular microorganisms that form maternally-inherited infections within numerous arthropod species. these bacteria have drawn much attention, due in part to the reproductive alterations that they induce in their hosts including cytoplasmic incompatibility (ci), feminization and parthenogenesis. although wolbachia's presence within insect reproductive tissues has been well described, relatively few studies have examined the extent to which wolbachia infects other tissues. we h ... | 1999 | 10196738 |
| cross-order transfer of wolbachia from muscidifurax uniraptor (hymenoptera: pteromalidae) to drosophila simulans (diptera: drosophilidae). | bacteria of the genus wolbachia are widespread in arthropods and can induce different effects on the host such as cytoplasmic incompatibility (ci), thelytoky (t) or feminization (f). in some wolbachia-infected hosts, no effect (n) has been found. successful transfer of wolbachia by microinjection from one host to an uninfected one has been established with ci, f, n-wolbachia but not with t-wolbachia. in this paper a transfer experiment of t-wolbachia from the parasitoid muscidifurax uniraptor to ... | 1999 | 10098265 |
| 16s rdna phylogeny and ultrastructural characterization of wolbachia intracellular bacteria of the filarial nematodes brugia malayi, b. pahangi, and wuchereria bancrofti. | 1999 | 10092480 | |
| spacer 2 region and 5s rdna variation of wolbachia strains involved in cytoplasmic incompatibility or sex-ratio distortion in arthropods. | bacteria in the genus wolbachia are widespread in arthropods and can induce sex-ratio distortion or cytoplasmic incompatibility in their hosts. the phylogeny of wolbachia has been studied using 16s rdna and the cell cycle gene ftsz, but sequence variation of those genes is limited. the spacer 2 region (sr2) was amplified to determine whether this region would improve phylogenetic resolution. the sr2 of wolbachia is 66 bp long, shows higher variation than ftsz and has very low homology with close ... | 1999 | 10030026 |
| tissue tropism, transmission and expression of foreign genes in vivo in midgut symbionts of tsetse flies. | tsetse flies (diptera: glossinidae) harbour three different symbiotic organisms in addition to the pathogenic african trypanosomes they transmit. the two gut-associated symbionts (primary, p; secondary, s) are enteric and are nutritionally required, whereas the third microorganism wolbachia (family rickettsiaceae) affects the reproductive biology of the insects it infects. the bacteriome-associated p-symbiont (wigglesworthia glossinidia) displays a concordant phylogeny with its host tsetse speci ... | 1999 | 9927181 |
| phylogenetic status of a fecundity-enhancing wolbachia that does not induce thelytoky in trichogramma. | wolbachia are widespread bacteria which infect a number of species of insects and other arthropods. they manipulate the reproduction of their hosts at their own advantage. in trichogramma species all wolbachia known so far induce thelytoky and form a monophyletic group in the b subdivision of wolbachia. here we show that some strains of the arrhenotokous species trichogramma bourarachae harbour wolbachia symbionts that locate in the a subdivision, and which do not induce thelytoky. although the ... | 1999 | 9927175 |
| phylogeny of wolbachia in filarial nematodes. | intracellular bacteria have been observed in various species of filarial nematodes (family onchocercidae). the intracellular bacterium of the canine filaria dirofilaria immitis has been shown to be closely related to wolbachia, a rickettsia-like micro-organism that is widespread among arthropods. however, the relationships between endosymbionts of different filariae, and between these and the arthropod wolbachiae, appear not to have been studied. to address these issues we have examined ten spec ... | 1998 | 9921679 |
| tetracycline therapy targets intracellular bacteria in the filarial nematode litomosoides sigmodontis and results in filarial infertility. | intracellular bacteria have been described in several species of filarial nematodes, but their relationships with, and effects on, their nematode hosts have not previously been elucidated. in this study, intracellular bacteria were observed in tissues of the rodent parasite litomosoides sigmodontis by transmission electron microscopy and by immunohistochemistry using antiendobacterial heat shock protein-60 antisera. molecular phylogenetic analysis of the bacterial 16s ribosomal rna gene, isolate ... | 1999 | 9884329 |
| concordant evolution of a symbiont with its host insect species: molecular phylogeny of genus glossina and its bacteriome-associated endosymbiont, wigglesworthia glossinidia. | many arthropods with restricted diets rely on symbiotic associations for full nutrition and fecundity. tsetse flies (diptera: glossinidae) harbor three symbiotic organisms in addition to the parasitic african trypanosomes they transmit. two of these microorganisms reside in different gut cells, while the third organism is harbored in reproductive tissues and belongs to the genus wolbachia. the primary symbiont (genus wigglesworthia glossinidia) lives in differentiated epithelial cells (bacterioc ... | 1999 | 9873076 |
| gene structure, activity and localization of a catalase from intracellular bacteria in onchocerca volvulus. | within the context of studies on the antioxidant enzymes in onchocerca volvulus, dna clones encoding catalase (cat) were isolated from an o. volvulus adult lambda zapii cdna library. analysis of their nucleotide and encoded amino acid sequences revealed that they derive from intracellular bacteria, rather than the o. volvulus nuclear genome. the endobacterial cat gene was found to lie in a gene cluster, followed by a ferritin gene and an excinuclease gene. the endobacterial cat gene encodes a fu ... | 1998 | 9851608 |
| wolbachia in two insect host-parasitoid communities. | wolbachia form a group of intracellular bacteria that alter reproduction in their arthropod hosts. two major phylogenetic subdivisions (a and b) of wolbachia occur. using a polymerase chain reaction assay we surveyed for the a and b group wolbachia in 82 insect species from two temperate host-parasitoid communities (food webs) and a general collection of lepidoptera caught at a light trap. one host-parasitoid community was based around leaf-mining lepidoptera, and the other around aphids. we fou ... | 1998 | 9819901 |
| western blotting analysis of heat shock proteins of rickettsiales and other eubacteria. | heat shock proteins (hsp) of four rickettsia species, three bartonella species, two ehrlichia species, orientia tsutsugamushi and seventeen other eubacterial species were characterized by the enhanced chemiluminescence western blotting (wb) technique with antibodies raised against recombinant hsp from escherichia coli and purified groes from r. typhi. although e. coli dnak and groel have epitopes that are highly conserved among the homologous proteins found in rickettsia, ehrlichia, o. tsutsugam ... | 1998 | 9809424 |
| dynamics of cytoplasmic incompatability with multiple wolbachia infections. | wolbachia infections occur in many arthropods. these matrilineally inherited bacteria cause cytoplasmic incompatibility, in which a cross produces no offspring when between an infected male and an uninfected female. some populations harbour multiple wolbachia strains. females fail to produce offspring when crossed to a male with a strain that the female lacks. prior theoretical work showed that a panmictic population cannot maintain polymorphism for different strains when each female carries onl ... | 1998 | 9735249 |
| wolbachia transfer from drosophila melanogaster into d. simulans: host effect and cytoplasmic incompatibility relationships. | wolbachia are maternally transmitted endocellular bacteria causing a reproductive incompatibility called cytoplasmic incompatibility (ci) in several arthropod species, including drosophila. ci results in embryonic mortality in incompatible crosses. the only bacterial strain known to infect drosophila melanogaster (wdm) was transferred from a d. melanogaster isofemale line into uninfected d. simulans isofemale lines by embryo microinjections. males from the resulting transinfected lines induce >9 ... | 1998 | 9725842 |
| phylogenetic analysis of parthenogenesis-inducing wolbachia in the genus aphytis (hymenoptera: aphelinidae). | parthenogenesis-inducing intracellular bacteria of the genus wolbachia are found in a variety of parasitoid wasp genera. the presence of wolbachia in the uniparental aphytis species a. lingnanensis compere, a. diaspidis (howard), a. chilensis howard, and a. chrysomphali (mercet) was tested using primers specific for the ftsz gene. the symbiont was detected in all of these species. wolbachia ftsz genes that were sequenced from the four hosts show a high degree of similarity. both the pcr with spe ... | 1998 | 9723877 |
| widespread occurrence of the micro-organism wolbachia in ants. | for more than 20 years, sex allocation in hymenopteran societies has been a major topic in insect sociobiology. a recurring idea was that relatedness asymmetrics arising from their haplodiploid sex determination system would lead to various parent-offspring conflicts over optimal reproduction. a possible weakness of existing theory is that only interests of nuclear genes are properly accounted for. yet, a diversity of maternally transmitted elements manipulate the reproduction of their host in m ... | 1998 | 9721689 |
| cloning and characterization of multigenes encoding the immunodominant 30-kilodalton major outer membrane proteins of ehrlichia canis and application of the recombinant protein for serodiagnosis. | a 30-kda major outer membrane protein of ehrlichia canis, the agent of canine ehrlichiosis, is the major antigen recognized by both naturally and experimentally infected dog sera. the protein cross-reacts with a serum against a recombinant 28-kda protein (rp28), one of the outer membrane proteins of a gene (omp-1) family of ehrlichia chaffeensis. two dna fragments of e. canis were amplified by pcr with two primer pairs based on the sequences of e. chaffeensis omp-1 genes, cloned, and sequenced. ... | 1998 | 9705412 |
| wolbachia as a possible means of driving genes into populations. | cytoplasmic incompatibility consists of sterility in cross matings, the crossing type being maternally inherited. it can be explained by the action of wolbachia symbionts which are transmitted through the egg cytoplasm and leave an imprint on the sperm which prevents it fertilizing unless it is 'rescued' by the action of the same type of wolbachia in the egg. thus matings between infected males and uninfected females are sterile, but the reciprocal matings are fertile. hence uninfected females a ... | 1998 | 9695115 |
| horizontal transfer of parasitic sex ratio distorters between crustacean hosts. | parasitic sex distorters were artificially transferred within and between crustacean host species in order to study the effects of parasitism on host fitness and sex determination and to investigate parasite host specificity. implantation of nosema sp. to uninfected strains of its gammarus duebeni host resulted in an active parasite infection in the gonad of recipient females and subsequent transovarial parasite transmission. the young of artificially infected females were feminized by the paras ... | 1998 | 9695096 |
| evidence for widespread wolbachia infection in isopod crustaceans: molecular identification and host feminization. | wolbachia are maternally inherited, intracellular, alpha proteobacteria that infect a wide range of arthropods. they cause three kinds of reproductive alterations in their hosts: cytoplasmic incompatibility, parthenogenesis and feminization. there have been many studies of the distribution of wolbachia in arthropods, but very few crustacean species are known to be infected. we investigated the prevalence of wolbachia in 85 species from five crustacean orders. twenty-two isopod species were found ... | 1998 | 9684374 |
| cloning and characterization of a gene encoding the major surface protein of the bacterial endosymbiont wolbachia pipientis. | the maternally inherited intracellular symbiont wolbachia pipientis is well known for inducing a variety of reproductive abnormalities in the diverse arthropod hosts it infects. it has been implicated in causing cytoplasmic incompatibility, parthenogenesis, and the feminization of genetic males in different hosts. the molecular mechanisms by which this fastidious intracellular bacterium causes these reproductive and developmental abnormalities have not yet been determined. in this paper, we repo ... | 1998 | 9573188 |
| phylogeny and pcr-based classification of wolbachia strains using wsp gene sequences. | wolbachia are a group of intracellular inherited bacteria that infect a wide range of arthropods. they are associated with a number of different reproductive phenotypes in their hosts, such as cytoplasmic incompatibility, parthenogenesis and feminization. while it is known that the bacterial strains responsible for these different host phenotypes form a single clade within the alpha-proteobacteria, until now it has not been possible to resolve the evolutionary relationships between different wol ... | 1998 | 9569669 |
| effects of a and b wolbachia and host genotype on interspecies cytoplasmic incompatibility in nasonia. | wolbachia endosymbionts cause postmating reproductive isolation between the sibling species nasonia vitripennis and n. giraulti. most nasonia are doubly infected with a representative from each of the two major wolbachia groups (a and b). this study investigates the role of single (a or b) and double (a and b) wolbachia infections in interspecies cytoplasmic incompatibility (ci) and host genomic influences on the incompatibility phenotype. results show that the single a wolbachia harbored in n. ... | 1998 | 9560398 |
| allozyme polymorphism and geographic variation in the small brown planthopper, laodelphax striatellus (homoptera: delphacidae). | the small brown planthopper, laodelphax striatellus, immigrates annually into japan over the east china sea from the asian mainland. it is not known whether this long-distance dispersal has any effect on the genetic structure of japanese l. striatellus populations. the dispersal of l. striatellus is suspected to be relevant to the population dynamics of infection with the parasitic bacterium wolbachia, which causes cytoplasmic incompatibility in l. striatellus. wolbachia infection has spread wit ... | 1997 | 9559095 |
| screening mollusks for wolbachia infection. | we screened 38 species of mollusks for infection by wolbachia, a bacterium that is a common endosymbiont in arthropods, where it induces alterations in reproduction. using a pcr assay, we could not detect the symbiont in any of the samples, indicating that, in mollusks, it might be absent. | 1998 | 9538033 |
| analysis of wolbachia protein synthesis in drosophila in vivo. | intracellular wolbachia infections are extremely common in arthropods and exert profound control over the reproductive biology of the host. however, very little is known about the underlying molecular mechanisms which mediate these interactions with the host. we examined protein synthesis by wolbachia in a drosophila host in vivo by selective metabolic labelling of prokaryotic proteins and subsequent analysis by 1d and 2d gel electrophoresis. using this method we could identify the major protein ... | 1998 | 9535156 |
| overcoming cytoplasmic incompatibility in drosophila. | the endocellular microbe wolbachia pipientis infects a wide variety of invertebrate species, in which its presence is closely linked to a form of reproductive failure termed cytoplasmic incompatibility (ci). ci renders infected males unable to father offspring when mated to uninfected females. because ci can dramatically affect fitness in natural populations, mechanisms that abate ci can have equally large impacts on fitness. we have discovered that repeated copulation by wolbachia-infected male ... | 1998 | 9523438 |
| ultrastructural differentiation of the genogroups in the genus ehrlichia. | ultrastructural characteristics of 15 strains and isolates of ehrlichiae belonging to three genogroups, or clades of genetically related organisms united in the genera ehrlichia, cowdria, anaplasma, neorickettsia and a strain of wolbachia pipientis which represents a fourth genogroup in this cluster of species, were studied in continuous cell culture or in vivo: e. canis (oklahoma strain and vhe isolate), e. muris (as 145), e. chaffeensis (arkansas, 91he17 and sapulpa), human granulocytic ehrlic ... | 1998 | 9511829 |
| rescuing wolbachia have been overlooked. | 1998 | 9495337 | |
| population dynamics of the wolbachia infection causing cytoplasmic incompatibility in drosophila melanogaster. | field populations of drosophila melanogaster are often infected with wolbachia, a vertically transmitted microorganism. under laboratory conditions the infection causes partial incompatibility in crosses between infected males and uninfected females. here we examine factors influencing the distribution of the infection in natural populations. we show that the level of incompatibility under field conditions was much weaker than in the laboratory. the infection was not transmitted with complete fi ... | 1998 | 9475734 |
| phylogenetically distant intracellular symbionts in termites. | cockroaches are known to harbour intracellular bacteria in specialised cells (mycetocytes, or bacteriocytes) of the fat body. in termites, mycetocyte bacteria have been observed only in mastotermes darwiniensis. these symbionts are thought to have originated from a bacterium that infected an ancestor common to cockroaches and termites. thus, loss of the infection should have occurred during evolution in all termite lineages, with the exception of that leading to m. darwiniensis. one might suspec ... | 1997 | 9419851 |
| distribution of parthenogenesis-inducing symbionts in ovaries and eggs of aphytis (hymentoptera: aphelinidae). | in parasitic hymenoptera, severe sex ratio distortions are sometimes associated with the presence of symbiotic microorganisms. symbiont-induced uniparental reproduction is found in several species of the genus aphytis and is suspected in others. these intracellular bacteria (called wolbachia) reside within the egg cytoplasm. in order to follow their vertical transmission, the distribution pattern of the symbionts in ovaries and eggs of two uniparental lines (a. lingnanensis and a. yanonensis) wa ... | 1998 | 9405738 |
| groe-homologous operon of wolbachia, an intracellular symbiont of arthropods: a new approach for their phylogeny. | wolbachia, a member of rickettsia found in the cells of many arthropod species, are cytoplasmically inherited bacteria which interfere with host's sexuality and reproduction. wolbachia strains have been phylogenetically divided into a and b groups based on the nucleotide sequences of their ftsz genes. in an attempt to further define the phylogenetical relationship among these endosymbionts, we cloned and sequenced the entire length of the groe operon of a wolbachia harbored by a cricket. the ope ... | 1997 | 9401467 |
| wolbachia, normally a symbiont of drosophila, can be virulent, causing degeneration and early death. | wolbachia, a maternally transmitted microorganism of the rickettsial family, is known to cause cytoplasmic incompatibility, parthenogenesis, or feminization in various insect species. the bacterium-host relationship is usually symbiotic: incompatibility between infected males and uninfected females can enhance reproductive isolation and evolution, whereas the other mechanisms enhance progeny production. we have discovered a variant wolbachia carried by drosophila melanogaster in which this cozy ... | 1997 | 9380712 |
| characterization of an endosymbiont infecting wood ticks, dermacentor andersoni, as a member of the genus francisella. | a microorganism (dermacantor andersoni symbiont [das]) infecting rocky mountain wood ticks (d. andersoni) collected in the bitterroot mountains of western montana was characterized as an endosymbiont belonging to the genus francisella. previously described as wolbachia like, the organism's dna was amplified from both naturally infected tick ovarial tissues and vero cell cultures by pcr assay with primer sets derived from eubacterial 16s ribosomal dna (rdna) and francisella membrane protein genes ... | 1997 | 9327558 |
| endosymbionts of ticks and their relationship to wolbachia spp. and tick-borne pathogens of humans and animals. | the presence, internal distribution, and phylogenetic position of endosymbiotic bacteria from four species of specific-pathogen-free ticks were studied. these included the hard ticks ixodes scapularis (the black-legged tick), rhipicephalus sanguineus (the brown dog tick), and haemaphysalis longicornis and the african soft tick ornithodoros moubata. pcr assays for bacteria, using two sets of general primers for eubacterial 16s and 23s rrna genes (rdnas) and seven sets of specific primers for wolb ... | 1997 | 9327557 |
| the role of wolbachia bacteria in reproductive incompatibilities and hybrid zones of diabrotica beetles and gryllus crickets. | a rickettsial bacterium in the genus wolbachia is the cause of a unidirectional reproductive incompatibility observed between two major beetle pests of maize, the western corn rootworm, diabrotica virgifera virgifera, and the mexican corn rootworm, d. v. zeae. these subspecies are allopatric except for two known regions of sympatry in texas and mexico. we demonstrate that populations of d. v. virgifera, with the exception of two populations in southern arizona, are infected with a strain of wolb ... | 1997 | 9326628 |
| wolbachia run amok. | 1997 | 9326576 | |
| phylogenetic characterization of two transovarially transmitted endosymbionts of the bedbug cimex lectularius (heteroptera:cimicidae). | two different inherited bacterial symbionts from ovary tissue of the bedbug cimex lectularius were characterized by gene amplification and sequencing analysis of their 16s rdna gene. the first bacterium belongs to the wolbachia subgroup of the alpha-proteobacteria, the second is a member of the gamma-subdivision, and is closely related to the bacterial parasite of the leafhopper euscelidius variegatus (bev) which was shown to be capable of transovarial transmission. the high similarity (> 97%) b ... | 1997 | 9272448 |
| molecular evidence for single wolbachia infections among geographic strains of the flour beetle tribolium confusum. | infections with the rickettsial microorganism wolbachia are cytoplasmically inherited and occur in a wide range of insect species and several other arthropods. wolbachia infection often results in unidirectional cytoplasmic incompatibility (ci): crosses between infected males and uninfected females are incompatible and show a reduction of progeny or complete inviability. unidirectional ci can also occur when males harbouring two incompatible wolbachia strains are crossed with females infected wi ... | 1997 | 9263471 |
| horizontal transmission of parthenogenesis-inducing microbes in trichogramma wasps. | complete parthenogenesis (thelytoky) in species of the parasitic wasp trichogramma is usually caused by the cytoplasmically inherited bacterium wolbachia. this symbiont induces gamete duplication, which, in these haplodiploid organisms, results in all-female broods. antibiotic treatment "cures' this condition, restoring normal sexual reproduction. phylogenetic analysis of wolbachia has shown that, in contrast with the strains in other host organisms (where the symbiont also induces different rep ... | 1997 | 9107051 |
| phylogeny and potential transmission routes of midgut-associated endosymbionts of tsetse (diptera:glossinidae). | many tsetse species (diptera: glossinidae) harbour two morphologically different intracellular endosymbiotic microorganisms associated with gut tissue: primary (p) and secondary (s) endosymbionts. the p-endosymbionts of tsetse (wigglesworthia glossinidia) are sequestered in specialized epithelial cells, bacteriocytes, which form a structure (bacteriome) in the anterior portion of the gut. phylogenetic characterization of p-endsymbionts from the three subgenera of genus glossina has shown that th ... | 1997 | 9099582 |
| phylogeny of the nasonia species complex (hymenoptera: pteromalidae) inferred from an internal transcribed spacer (its2) and 28s rdna sequences. | the phylogeny of the cryptic species complex of wasps in the genus nasonia was inferred by analysis of nucleotide sequences of an rdna internal transcribed spacer (its2) and the d2 region of 28s rdna. phylogenetic analysis showed that n. vitripennis descended from a theoretical common ancestor with that of a lineage that diverged into n. longicornis and n. giraulti. differences in the its2 regions clearly distinguished two strains of n. giraulti. another member of the dibrachys group, trichomalo ... | 1993 | 9087560 |
| contrasting levels of variability between cytoplasmic genomes and incompatibility types in the mosquito culex pipiens. | reproductive incompatibilities called cytoplasmic incompatibilities are known to affect a large number of arthropod species and are mediated by wolbachia, a maternally transmitted microorganism. the crossing relationships between strains of potential hosts define their incompatibility types and it is generally assumed that differences between strains of wolbachia induce different crossing types. among all the described host species, the mosquito, culex pipiens, displays the greatest variability ... | 1997 | 9061971 |
| birefringent crystals and abdominal discoloration in the predatory mite phytoseiulus persimilis (acari: phytoseiidae) | in response to grower complaints of poor performance of phytoseiulus persimilis, mites from 14 commercial insectaries and research colonies were examined for pathogens. some were found to have abdominal discolorations, manifested initially as two white stripes along the dorsal sides of the body within the malpighian tubules. advanced signs appeared as a large, centrally located, white spot or u-shaped discoloration in the distal opisthosoma within the rectum/anal atrium. white material often acc ... | 1997 | 9056458 |