| a prokaryotic dnaa sequence in drosophila melanogaster: wolbachia infection and cytoplasmic incompatibility among laboratory strains. | using oligonucleotide primers derived from the aligned polypeptide sequences of several prokaryotic dnaa genes, we amplified from drosophila melanogaster dna a 557 bp fragment containing a single open reading frame. the predicted peptide sequence shows a significant similarity to previously characterized protein sequences that are encoded by the dnaa genes of several prokaryotes. the dnaa sequences are also detectable by pcr in dna from drosophila simulans and nasonia vitripennis flies which are ... | 1994 | 7894745 |
| 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 |
| 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 |
| 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 |
| expression of cytoplasmic incompatibility in drosophila simulans and its impact on infection frequencies and distribution of wolbachia pipientis. | the aim of this study is to examine the expression of cytoplasmic incompatibility and investigate the distribution and population frequencies of wolbachia pipientis strains in drosophila simulans. nucleotide sequence data from 16s rdna and a wolbachia surface protein coding sequence and cytoplasmic incompatibility assays identify four distinct wolbachia strains: wha, wri, wma, and wau. the levels of cytoplasmic incompatibility between six lines carrying these strains of bacteria and three contro ... | 2000 | 11108593 |
| wolbachia density and virulence attenuation after transfer into a novel host. | the factors that control replication rate of the intracellular bacterium wolbachia pipientis in its insect hosts are unknown and difficult to explore, given the complex interaction of symbiont and host genotypes. using a strain of wolbachia that is known to over-replicate and shorten the lifespan of its drosophila melanogaster host, we have tracked the evolution of replication control in both somatic and reproductive tissues in a novel host/wolbachia association. after transinfection (the transf ... | 2002 | 11880639 |
| wolbachia distribution and cytoplasmic incompatibility during sperm development: the cyst as the basic cellular unit of ci expression. | the growth and distribution of the intracellular microbe wolbachia pipientis during spermatogenesis in several different host/symbiont genetic combinations in drosophila melanogaster and drosophila simulans is described. considerable intra- and inter-strain variation in wolbachia density and tissue distribution was observed. wolbachia were found inside spermatocytes and spermatids or within the somatic cyst cells surrounding the germ cells. some strains displayed both tissue distributions. high ... | 2003 | 12559491 |
| sperm chromatin remodelling and wolbachia-induced cytoplasmic incompatibility in drosophila. | wolbachia pipientis is an obligate bacterial endosymbiont, which has successfully invaded approximately 20% of all insect species by manipulating their normal developmental patterns. wolbachia-induced phenotypes include parthenogenesis, male killing, and, most notably, cytoplasmic incompatibility. in the future these phenotypes might be useful in controlling or modifying insect populations but this will depend on our understanding of the basic molecular processes underlying insect fertilization ... | 2003 | 12897857 |
| efficient procedure for purification of obligate intracellular wolbachia pipientis and representative amplification of its genome by multiple-displacement amplification. | bacteria belonging to the genus wolbachia are obligatory microendocytobionts that infect a variety of arthropods and a majority of filarial nematode species, where they induce reproductive alterations or establish a mutualistic symbiosis. although two whole genome sequences of wolbachia pipientis, for strain wmel from drosophila melanogaster and strain wbm from brugia malayi, have been fully completed and six other genome sequencing projects are ongoing (http://www.genomesonline.org/index.cgi?wa ... | 2005 | 16269725 |
| wolbachia infection reduces sperm competitive ability in an insect. | the maternally inherited bacterium wolbachia pipientis imposes significant fitness costs on its hosts. one such cost is decreased sperm production resulting in reduced fertility of male drosophila simulans infected with cytoplasmic incompatibility (ci) inducing wolbachia. we tested the hypothesis that wolbachia infection affects sperm competitive ability and found that wolbachia infection is indeed associated with reduced success in sperm competition in non-virgin males. in the second male role, ... | 2006 | 16777737 |
| wolbachia infection alters olfactory-cued locomotion in drosophila spp. | wolbachia pipientis is an endosymbiotic bacterium present in diverse insect species. although it is well studied for its dramatic effects on host reproductive biology, little is known about its effects on other aspects of host biology, despite its presence in a wide array of host tissues. this study examined the effects of three wolbachia strains on two different drosophila species, using a laboratory performance assay for insect locomotion in response to olfactory cues. the results demonstrate ... | 2008 | 18456851 |
| genetic and functional characterization of the type iv secretion system in wolbachia. | a type iv secretion system (t4ss) is used by many symbiotic and pathogenic intracellular bacteria for the successful infection of and survival, proliferation, and persistence within hosts. in this study, the presence and function of the t4ss in wolbachia strains were investigated by a combination of genetic screening and immunofluorescence microscopy. two operons of virb-vird4 loci were found in the genome of wolbachia pipientis strain watab3, from the hymenoptera asobara tabida, and strain wri, ... | 2008 | 18502862 |
| the mosaic genome structure of the wolbachia wri strain infecting drosophila simulans. | the obligate intracellular bacterium wolbachia pipientis infects around 20% of all insect species. it is maternally inherited and induces reproductive alterations of insect populations by male killing, feminization, parthenogenesis, or cytoplasmic incompatibility. here, we present the 1,445,873-bp genome of w. pipientis strain wri that induces very strong cytoplasmic incompatibility in its natural host drosophila simulans. a comparison with the previously sequenced genome of w. pipientis strain ... | 2009 | 19307581 |
| variation in antiviral protection mediated by different wolbachia strains in drosophila simulans. | drosophila c virus (dcv) is a natural pathogen of drosophila and a useful model for studying antiviral defences. the drosophila host is also commonly infected with the widespread endosymbiotic bacteria wolbachia pipientis. when dcv coinfects wolbachia-infected d. melanogaster, virus particles accumulate more slowly and virus induced mortality is substantially delayed. considering that wolbachia is estimated to infect up to two-thirds of all insect species, the observed protective effects of wolb ... | 2009 | 19911047 |
| infection with the wmel and wmelpop strains of wolbachia leads to higher levels of melanization in the hemolymph of drosophila melanogaster, drosophila simulans and aedes aegypti. | introduction of the life-shortening strain of wolbachia pipientis, wmelpop, into the key dengue vector, aedes aegypti, and the anti-pathogen effects in wolbachia-infected hosts highlights the need for more research into its interactions with its original host, drosophila melanogaster, and the novel mosquito host. the visual difference in darkness between the eggs of wmelpop wolbachia-infected and uninfected mosquito hosts after egg deposition led to further investigation into melanization levels ... | 2010 | 21075139 |
| the bacteriophage woric is the active phage element in wri of drosophila simulans and represents a conserved class of wo phages. | the alphaproteobacterium wolbachia pipientis, the most common endosymbiont in eukaryotes, is found predominantly in insects including many drosophila species. although wolbachia is primarily vertically transmitted, analysis of its genome provides evidence for frequent horizontal transfer, extensive recombination and numerous mobile genetic elements. the genome sequence of wolbachia in drosophila simulans riverside (wri) is available along with the integrated bacteriophages, enabling a detailed e ... | 2011 | 22085419 |
| what can symbiont titres tell us about co-evolution of wolbachia and their host? | there is a long-standing prediction that associations with vertically transmitted symbionts evolve towards maximisation of host reproductive success, eventually leading to mutualist symbiosis and coadaptation. under this scenario, the regulation of symbiont titres in host tissues would be expected to be greater when partners have coevolved for a long time than when they have recently met. wolbachia pipientis, a common vertically transmitted symbiont of invertebrates, often has the capacity to sp ... | 2014 | 24594301 |
| the impact of wolbachia, male age and mating history on cytoplasmic incompatibility and sperm transfer in drosophila simulans. | most insects harbour a variety of maternally inherited endosymbionts, the most widespread being wolbachia pipientis that commonly induce cytoplasmic incompatibility (ci) and reduced hatching success in crosses between infected males and uninfected females. high temperature and increasing male age are known to reduce the level of ci in a variety of insects. in drosophila simulans, infected males have been shown to mate at a higher rate than uninfected males. by examining the impact of mating rate ... | 2014 | 24164708 |
| infection, growth and maintenance of wolbachia pipientis in clonal and non-clonal aedes albopictus cell cultures. | insect cell lines provide useful in vitro models for studying biological systems, including interactions between mosquitoes and obligate intracellular endosymbionts such as wolbachia pipientis. the aedes albopictus aa23 cell line was the first cell line developed to allow examination of wolbachia infections. however, wolbachia studies using aa23 can be complicated by the presence of different cell types in the cell line and the substantial temporal variation in infection level. two approaches we ... | 2013 | 23113940 |
| disruption of redox homeostasis leads to oxidative dna damage in spermatocytes of wolbachia-infected drosophila simulans. | molecular interactions between symbiotic bacteria and their animal hosts are, as yet, poorly understood. the most widespread bacterial endosymbiont, wolbachia pipientis, occurs in high density in testes of infected drosophila simulans and causes cytoplasmic incompatibility (ci), a form of male-derived zygotic lethality. wolbachia grow and divide within host vacuoles that generate reactive oxygen species (ros), which in turn stimulate the up-regulation of antioxidant enzymes. these enzymes appear ... | 2012 | 22831171 |
| evolution of incompatibility-inducing microbes and their hosts. | in many insect species, males infected with microbes related to wolbachia pipientis are "incompatible" with uninfected females. crosses between infected males and uninfected females produce significantly fewer adult progeny than the other three possible crosses. the incompatibility-inducing microbes are usually maternally transmitted. thus, incompatibility tends to confer a reproductive advantage on infected females in polymorphic populations, allowing these infections to spread. this paper anal ... | 1994 | 28568404 |