The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Wen Wang - One of the best experts on this subject based on the ideXlab platform.
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identification and isolation of a Spiroplasma pathogen from diseased oriental river prawn macrobrachium nipponense in china a new freshwater crustacean host
Aquaculture, 2015Co-Authors: Yunji Xiu, Xinhe Meng, Qingguo Meng, Wen WangAbstract:Abstract Spiroplasmas are small, wall-less, helical, and motile bacteria classified within the class Mollicutes. Spiroplasma has been identified as a lethal pathogen of four freshwater crustaceans in previous studies. Here, the fifth crustacean host of Spiroplasma was found. A novel disease of oriental river prawn Macrobrachium nipponense appeared in the summer of 2012 in Jiangsu province of China. Morphological observation, molecular biological methods and infection experiments identified the pathogen as a Spiroplasma. The agent isolated from diseased prawns was able to pass through membrane filters with pores 220 nm in diameter and cultivated by R2 medium. A 16S rRNA complete sequence was cloned from the isolation and alignment results revealed that the Spiroplasmas from freshwater crustaceans were highly related. Phylogenetic analysis of these sequences showed that the five freshwater crustacean Spiroplasma strains had a close relationship with Spiroplasma mirum . The pathogenicity of the agent, evaluated by the mortalities, was determined to be 65% through a challenge experiment. The above results indicated that M. nipponense is another new Spiroplasma host in aquatic crustaceans, thus further indicating that more attention should be paid to this pathogen.
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immune responses and gene expression in hepatopancreas from macrobrachium rosenbergii challenged by a novel pathogen Spiroplasma mr 1008
Fish & Shellfish Immunology, 2013Co-Authors: Jie Du, Qingguo Meng, Jing Chen, Wei Gu, Ting Wu, Wen WangAbstract:Abstract Freshwater prawn Macrobrachium rosenbergii inoculated with 100 μl novel pathogen Spiroplasma strain MR-1008 in logarithmic phase (10 8 Spiroplasmas ml −1 ) were examined for alkaline phosphatase (AKP) activity, acid phosphatase (ACP) activity, superoxide dismutase (SOD) activity, catalase (CAT) activity, as well as expressions of 7 immune related genes in hepatopancreas after 1–28 d. Hematoxylin-eosin (HE) staining showed obvious pathological features in hepatopancreas connective and epithelial tissue. Enzyme activity analyze showed that hepatopancreas AKP and ACP activity increased markedly ( P ) when inoculated with Spiroplasma MR-1008 after 5 d and 10 d, respectively. SOD enzyme activity changed less obviously and slightly increased at 1 day post-inoculation, but CAT activity decreased significantly after 5 d inoculation. The expression levels of lipopolysaccharide and β-1,3-glucan-binding protein (LGBP), peroxinectin (PE), α2-macroglobulin (α2M), AKP, ACP, CAT, and copper/zinc SOD (Cu, Zn-SOD) genes in the hepatopancreas were examined by Real-Time PCR (qRT-PCR) and the results demonstrated that these immune related genes were induced by challenge with Spiroplasma MR-1008. The results suggested that the prawn immune responses could be activated or inhibited by Spiroplasma MR-1008, and that the hepatopancreas also plays key roles in innate immunity for defense against the pathogen.
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flow cytometry studies on the macrobrachium rosenbergii hemocytes sub populations and immune responses to novel pathogen Spiroplasma mr 1008
Fish & Shellfish Immunology, 2012Co-Authors: Huanxi Zhu, Yunji Xiu, Qingguo Meng, Qian Ren, Peng Liu, Jing Chen, Wei Yao, Wen WangAbstract:Flow cytometry provides rapid and reproducible methods for analyzing crustacean cellular immune responses to pathogens. We used this method to investigate the hemocytes sub-populations of freshwater prawn Macrobrachium rosenbergii and their immune responses to a novel pathogen Spiroplasma MR-1008. M. rosenbergii inoculated with 100 μl Spiroplasma strain MR-1008 in logarithmic phase (10(8) Spiroplasmas ml(-1)) were examined for total hemocytes count (THC) and changes in differential involvement of hemocytes sub-populations during 1-28 d after inoculation. The results showed that THC was dramatically lowered 1 d after inoculation, and it obviously increased at the 5 d after inoculation; thereafter, a high level of THC was maintained to 15 d. Three morphologically distinct hemocytes sub-populations including granular cells (GC), semigranular cells (SGC) and hyaline cells (HC) could be identified by flow cytometry, and the proportions of the 3 kinds of cell categories varied obviously during the infection of Spiroplasma suggesting differential involvement according to the pathogen. The flow cytometry used in this study confirmed that the semigranular cells were the main hemocytes involved in the cellular defense against Spiroplasma in the M. rosenbergii.
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identification and isolation of a Spiroplasma pathogen from diseased freshwater prawns macrobrachium rosenbergii in china a new freshwater crustacean host
Aquaculture, 2011Co-Authors: Tingming Liang, Qingguo Meng, Xinlun Li, Jie Du, Xuehong Dong, Jiangtao Ou, Wei Gu, Wen WangAbstract:Abstract Disease epizootics in freshwater cultured crustaceans, including freshwater prawns (Macrobrachium rosenbergii), gained high attention recently in Jiangsu, China due to intensive development of freshwater aquaculture and their susceptibility to massive mortalities. Morphological observation indicated that the pathogen in diseased M. rosenbergii had a helical morphology and lacked a cell wall. The agent could infect hemocytes and all the connective tissues of the organs such as hepatopancreas, digestive tract, and cardiac muscle. The agent was able to pass through membrane filters with pores 220 nm in diameter and could be cultivated by R2 medium. The pathogenicity of the agent was evaluated by Koch's postulate and the mortalities produced by the pathogen were determined to be 80% through experimental infection. The phylogenetic position was investigated by analysis of the 16S rRNA complete sequence. The result revealed that the pathogen had a close relationship with other freshwater Spiroplasmas and was situated in the Mirum clade together with Spiroplasma mirum in a phylogenetic tree. Taken in total, the findings demonstrated that the pathogen isolated from diseased M. rosenbergii was a Spiroplasma microorganism. This is the fourth report of a Spiroplasma pathogen in commercially exploited crustaceans and indicates that Spiroplasma pathogens have spread rapidly in aquatic crustaceans; thus, requiring more substantial research attention.
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Spiroplasma eriocheiris sp nov associated with mortality in the chinese mitten crab eriocheir sinensis
International Journal of Systematic and Evolutionary Microbiology, 2011Co-Authors: Wen Wang, Gail E. Gasparich, Qingguo Meng, Tingming Liang, Qi Feng, Jianqiong Zhang, Ying ZhangAbstract:A motile bacterium, designated strain TDA-040725-5T, was isolated from the haemolymph of a Chinese mitten crab, Eriocheir sinensis, with tremor disease. Based on 16S rRNA gene sequence analysis, the strain was phylogenetically distinct from other Spiroplasmas but was closely related to Spiroplasma mirum ATCC 29335T. Cells of strain TDA-040725-5T were variable in length and shape, helical and motile, as determined by phase-contrast light microscopy. Examination by electron microscopy revealed wall-less cells delimited by a single membrane. The strain grew in M1D or R-2 liquid media at 20–40 °C, with optimum growth at 30 °C. Doubling time at the optimal temperature was 24 h. The strain catabolized glucose and hydrolysed arginine but did not hydrolyse urea. The DNA G+C content was 29.7±1 mol%. The genome size was ~1.4–1.6 Mbp. Serological analysis, performed using the deformation test, did not reveal any reciprocal titres ≥320, indicating that strain TDA-040725-5T had minimal cross-reactivity to strains of recognized species of the genus Spiroplasma. Based on this evidence, strain TDA-040725-5T ( = CCTCC M 207170T = DSM 21848T) represents a novel species of the genus Spiroplasma, for which the name Spiroplasma eriocheiris sp. nov. is proposed, belonging to the novel Spiroplasma serological group XLIII.
Takema Fukatsu - One of the best experts on this subject based on the ideXlab platform.
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Spiroplasma as a model insect endosymbiont.
Environmental microbiology reports, 2011Co-Authors: Hisashi Anbutsu, Takema FukatsuAbstract:Summary Members of the genus Spiroplasma are actively motile and helical bacteria of the class Mollicutes, which are associated with a variety of arthropods and plants. Some Spiroplasmas cause female-biased sex ratios of their host insects as a result of selective death of the male offspring during embryogenesis. Several strains of male-killing Spiroplasmas have been successfully transfected into Drosophila melanogaster by haemolymph injection and maintained in laboratory fly stocks. Spiroplasma–Drosophila endosymbiosis represents an ideal model system for analysing the molecular mechanisms underlying host–symbiont interactions. The infection dynamics exhibited by the symbiont within the host, the effects of external and environmental factors on the symbiotic association and symbiont interactions with the host's immune system have been investigated using this system. Comparisons between a male-killing Spiroplasma strain and its non-male-killing variant revealed that, in addition to different male-killing abilities, they also differed in infection dynamics and resistance to host innate immunity. It is currently unclear whether these different phenotypes are interconnected to each other. However, if so, such pleiotropy could facilitate our understanding of the genetic and molecular mechanisms of the endosymbiotic system.
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high and low temperatures differently affect infection density and vertical transmission of male killing Spiroplasma symbionts in drosophila hosts
Applied and Environmental Microbiology, 2008Co-Authors: Hisashi Anbutsu, Shunsuke Goto, Takema FukatsuAbstract:We investigated the vertical transmission, reproductive phenotype, and infection density of a male-killing Spiroplasma symbiont in two Drosophila species under physiological high and low temperatures through successive host generations. In both the native host Drosophila nebulosa and the nonnative host Drosophila melanogaster, the symbiont infection and the male-killing phenotype were stably maintained at 25°C, rapidly lost at 18°C, and gradually lost at 28°C. In the nonnative host, both the high and low temperatures significantly suppressed the infection density of the Spiroplasma. In the native host, by contrast, the low temperature suppressed the infection density of the Spiroplasma whereas the high temperature had little effect on the infection density. These results suggested that the low temperature suppresses both the infection density and the vertical transmission of the Spiroplasma whereas the high temperature suppresses the vertical transmission preferentially. The Spiroplasma density was consistently higher in the native host than in the nonnative host, suggesting that the host genotype may affect the infection density of the symbiont. The temperature- and genotype-dependent instability of the symbiont infection highlights a complex genotype-by-genotype-by-environment interaction and may be relevant to the low infection frequencies of the male-killing Spiroplasmas in natural Drosophila populations.
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prevalence of a non male killing Spiroplasma in natural populations of drosophila hydei
Applied and Environmental Microbiology, 2006Co-Authors: Masayoshi Watada, Masakazu Shimada, Daisuke Kageyama, Hisashi Anbutsu, Takahiro Hosokawa, Takema FukatsuAbstract:Male-killing phenotypes are found in a variety of insects and are often associated with maternally inherited endosymbiotic bacteria. In several species of Drosophila, male-killing endosymbionts of the genus Spiroplasma have been found at low frequencies (0.1 to 3%). In this study, Spiroplasma infection without causing male-killing was shown to be prevalent (23 to 66%) in Japanese populations of Drosophila hydei. Molecular phylogenetic analyses showed that D. hydei was infected with a single strain of Spiroplasma, which was closely related to male-killing Spiroplasmas from other Drosophila species. Artificial-transfer experiments suggested that the Spiroplasma genotype rather than the host genotype was responsible for the absence of the male-killing phenotype. Infection densities of the Spiroplasma in the natural host, D. hydei, and in the artificial host, Drosophila melanogaster, were significantly lower than those of the male-killing Spiroplasma NSRO, which was in accordance with the hypothesis that a threshold infection density is needed for the Spiroplasma-induced male-killing expression.
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asymmetrical interactions between wolbachia and Spiroplasma endosymbionts coexisting in the same insect host
Applied and Environmental Microbiology, 2006Co-Authors: Shunsuke Goto, Hisashi Anbutsu, Takema FukatsuAbstract:We investigated the interactions between the endosymbionts Wolbachia pipientis strain wMel and Spiroplasma sp. strain NSRO coinfecting the host insect Drosophila melanogaster. By making use of antibiotic therapy, temperature stress, and hemolymph microinjection, we established the following strains in the same host genetic background: the SW strain, infected with both Spiroplasma and Wolbachia; the S strain, infected with Spiroplasma only; and the W strain, infected with Wolbachia only. The infection dynamics of the symbionts in these strains were monitored by quantitative PCR during host development. The infection densities of Spiroplasma exhibited no significant differences between the SW and S strains throughout the developmental course. In contrast, the infection densities of Wolbachia were significantly lower in the SW strain than in the W strain at the pupal and young adult stages. These results indicated that the interactions between the coinfecting symbionts were asymmetrical, i.e., Spiroplasma organisms negatively affected the population of Wolbachia organisms, while Wolbachia organisms did not influence the population of Spiroplasma organisms. In the host body, the symbionts exhibited their own tissue tropisms: among the tissues examined, Spiroplasma was the most abundant in the ovaries, while Wolbachia showed the highest density in Malpighian tubules. Strikingly, basically no Wolbachia organisms were detected in hemolymph, the principal location of Spiroplasma. These results suggest that different host tissues act as distinct microhabitats for the symbionts and that the lytic process in host metamorphosis might be involved in the asymmetrical interactions between the coinfecting symbionts.
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Hidden from the host: Spiroplasma bacteria infecting Drosophila do not cause an immune response, but are suppressed by ectopic immune activation.
Insect molecular biology, 2003Co-Authors: Gregory D. D. Hurst, Hisashi Anbutsu, Mayako Kutsukake, Takema FukatsuAbstract:Insects and other arthropods have an effective innate immune system that can clear infections with bacteria and other microorganisms. Despite this ability, one group of bacteria, the Spiroplasmas, survive unharmed within the haemolymph of a wide range of arthropod hosts. We investigated the interaction between one member of this clade, a relative of Spiroplasma poulsonii, and the immune system of its Drosophila host. Expression of antimicrobial genes in Spiroplasma-infected flies did not differ from wild-type controls either in the naturally infected state, nor after septic shock. We therefore concluded that Spiroplasma infection did not induce an immune response in its host, but that this absence of response was unlikely to be because the bacterium inhibited response. Further experiments revealed immune reactions induced ectopically did reduce parasite titre. We therefore conclude that this bacterium has a novel form of interaction with its host, being hidden from the host immune system, but potentially suppressible by it.
Mariana Mateos - One of the best experts on this subject based on the ideXlab platform.
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differential gene expression in a tripartite interaction drosophila Spiroplasma and parasitic wasps
PeerJ, 2021Co-Authors: Victor Manuel Higareda Alvear, Mariana Mateos, Diego Cortez, Cecilia Tamborindeguy, Esperanza MartinezromeroAbstract:Background Several facultative bacterial symbionts of insects protect their hosts against natural enemies. Spiroplasma poulsonii strain sMel (hereafter Spiroplasma), a male-killing heritable symbiont of Drosophila melanogaster, confers protection against some species of parasitic wasps. Several lines of evidence suggest that Spiroplasma-encoded ribosome inactivating proteins (RIPs) are involved in the protection mechanism, but the potential contribution of the fly-encoded functions (e.g., immune response), has not been deeply explored. Methods Here we used RNA-seq to evaluate the response of D. melanogaster to infection by Spiroplasma and parasitism by the Spiroplasma-susceptible wasp Leptopilina heterotoma, and the Spiroplasma-resistant wasp Ganaspis sp. In addition, we used quantitative (q)PCR to evaluate the transcript levels of the Spiroplasma-encoded Ribosomal inactivation protein (RIP) genes. Results In the absence of Spiroplasma infection, we found evidence of Drosophila immune activation by Ganaspis sp., but not by L. heterotoma, which in turn negatively influenced functions associated with male gonad development. As expected for a symbiont that kills males, we detected extensive downregulation in the Spiroplasma-infected treatments of genes known to have male-biased expression. We detected very few genes whose expression patterns appeared to be influenced by the Spiroplasma-L. heterotoma interaction, and these genes are not known to be associated with immune response. For most of these genes, parasitism by L. heterotoma (in the absence of Spiroplasma) caused an expression change that was at least partly reversed when both L. heterotoma and Spiroplasma were present. It is unclear whether such genes are involved in the Spiroplasma-mediated mechanism that leads to wasp death and/or fly rescue. Nonetheless, the expression pattern of some of these genes, which reportedly undergo expression shifts during the larva-to-pupa transition, is suggestive of an influence of Spiroplasma on the development time of L. heterotoma-parasitized flies. One of the five RIP genes (RIP2) was consistently highly expressed independently of wasp parasitism, in two substrains of sMel. Finally, the RNAseq data revealed evidence consistent with RIP-induced damage in the ribosomal (r)RNA of the Spiroplasma-susceptible, but not the Spiroplasma-resistant, wasp. Acknowledging the caveat that we lacked adequate power to detect the majority of DE genes with fold-changes lower than 3, we conclude that immune priming is unlikely to contribute to the Spiroplasma-mediated protection against wasps, and that the mechanism by which Ganaspis sp. resists/tolerates Spiroplasma does not involve inhibition of RIP transcription.
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rapid molecular evolution of Spiroplasma symbionts of drosophila
bioRxiv, 2020Co-Authors: Michael Gerth, Mariana Mateos, Bruno Lemaitre, Humberto Martinezmontoya, Paulino Ramirez, Florent Masson, Joanne S Griffin, Rodolfo Aramayo, Stefanos Siozios, Gregory D. D. HurstAbstract:Abstract Spiroplasma are a group of Mollicutes whose members include plant pathogens, insect pathogens, and endosymbionts of animals. In arthropods, Spiroplasma are found across a broad host range, but typically with lower incidence than other bacteria with similar ecology, such as Wolbachia or Rickettsia. Spiroplasma symbionts of Drosophila are best known as male-killers and protective symbionts, and both phenotypes are mediated by Spiroplasma-encoded toxins. Spiroplasma phenotypes have been repeatedly observed to be spontaneously lost in Drosophila cultures, and several studies have documented a high genomic turnover in Spiroplasma symbionts and plant pathogens. These observations suggest that Spiroplasma evolves quickly. Here, we systematically assess evolutionary rates and patterns of Spiroplasma poulsonii, a natural symbiont of Drosophila. We analysed genomic evolution of sHy within flies, and sMel within in vitro culture over several years. We observed that S. poulsonii substitution rates are among the highest reported for any bacteria, and markedly increased compared with other symbionts. The absence of mismatch repair loci mutS and mutL is conserved across Spiroplasma and likely contributes to elevated substitution rates. Further, the closely related strains sMel and sHy (>99.5% sequence identity in shared loci) show extensive structural genomic differences, which may be explained by a higher degree of host adaptation in sHy, a protective symbiont of Drosophila hydei. Finally, comparison across diverse Spiroplasma lineages confirms previous reports of dynamic evolution of toxins, and identifies loci similar to the male-killing toxin Spaid in several Spiroplasma lineages and other endosymbionts. Overall, our results highlight the peculiar nature of Spiroplasma genome evolution, which may explain unusual features of its evolutionary ecology.
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independent origins of resistance or susceptibility of parasitic wasps to a defensive symbiont
Ecology and Evolution, 2016Co-Authors: Mariana Mateos, Lauryn Winter, Caitlyn Winter, Victor M Higaredaalvear, Esperanza MartinezromeroAbstract:Insect microbe associations are diverse, widespread, and influential. Among the fitness effects of microbes on their hosts, defense against natural enemies is increasingly recognized as ubiquitous, particularly among those associations involving heritable, yet facultative, bacteria. Protective mutualisms generate complex ecological and coevolutionary dynamics that are only beginning to be elucidated. These depend in part on the degree to which symbiont-mediated protection exhibits specificity to one or more members of the natural enemy community. Recent findings in a well-studied defensive mutualism system (i.e., aphids, bacteria, parasitoid wasps) reveal repeated instances of evolution of susceptibility or resistance to defensive bacteria by parasitoids. This study searched for similar patterns in an emerging model system for defensive mutualisms: the interaction of Drosophila, bacteria in the genus Spiroplasma, and wasps that parasitize larval stages of Drosophila. Previous work indicated that three divergent species of parasitic wasps are strongly inhibited by the presence of Spiroplasma in three divergent species of Drosophila, including D. melanogaster. The results of this study uncovered two additional wasp species that are susceptible to Spiroplasma and two that are unaffected by Spiroplasma, implying at least two instances of loss or gain of susceptibility to Spiroplasma among larval parasitoids of Drosophila.
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rapid spread of the defensive endosymbiont Spiroplasma in drosophila hydei under high parasitoid wasp pressure
FEMS Microbiology Ecology, 2015Co-Authors: Caitlyn Winter, Lauryn Winter, Mariana MateosAbstract:Maternally transmitted endosymbionts of insects are ubiquitous in nature and play diverse roles in the ecology and evolution of their hosts. To persist in host lineages, many symbionts manipulate host reproduction to their advantage (e.g. cytoplasmic incompatibility and male-killing), or confer fitness benefits to their hosts (e.g. metabolic provisioning and defense against natural enemies). Recent studies suggest that strains of the bacterial genus Spiroplasma protect their host (flies in the genus Drosophila ) against parasitoid attack. The Spiroplasma -conferred protection is partial and flies surviving a wasp attack have reduced adult longevity and fecundity. Therefore, it is unclear whether protection against wasps alone can counter Spiroplasma loss by imperfect maternal transmission and any possible fitness costs to harboring Spiroplasma . To address this question, we conducted a population cage study comparing Spiroplasma frequencies over time (host generations) under conditions of high wasp pressure and no wasp pressure. A dramatic increase of Spiroplasma prevalence was observed under high wasp pressure. In contrast, Spiroplasma prevalence in the absence of wasps did not change significantly over time; a pattern consistent with random drift. Thus, the defensive mechanism may contribute to the high prevalence of Spiroplasma in host populations despite imperfect vertical transmission.
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male killing Spiroplasma protects drosophila melanogaster against two parasitoid wasps
Heredity, 2014Co-Authors: Jialei Xie, S Butler, G Sanchez, Mariana MateosAbstract:Maternally transmitted associations between endosymbiotic bacteria and insects are diverse and widespread in nature. Owing to imperfect vertical transmission, many heritable microbes have evolved compensational mechanisms to enhance their persistence in host lineages, such as manipulating host reproduction and conferring fitness benefits to host. Symbiont-mediated defense against natural enemies of hosts is increasingly recognized as an important mechanism by which endosymbionts enhance host fitness. Members of the genus Spiroplasma associated with distantly related Drosophila hosts are known to engage in either reproductive parasitism (i.e., male killing) or defense against natural enemies (the parasitic wasp Leptopilina heterotoma and a nematode). A male-killing strain of Spiroplasma (strain Melanogaster Sex Ratio Organism (MSRO)) co-occurs with Wolbachia (strain wMel) in certain wild populations of the model organism Drosophila melanogaster. We examined the effects of Spiroplasma MSRO and Wolbachia wMel on Drosophila survival against parasitism by two common wasps, Leptopilina heterotoma and Leptopilina boulardi, that differ in their host ranges and host evasion strategies. The results indicate that Spiroplasma MSRO prevents successful development of both wasps, and confers a small, albeit significant, increase in larva-to-adult survival of flies subjected to wasp attacks. We modeled the conditions under which defense can contribute to Spiroplasma persistence. Wolbachia also confers a weak, but significant, survival advantage to flies attacked by L. heterotoma. The host protective effects exhibited by Spiroplasma and Wolbachia are additive and may provide the conditions for such cotransmitted symbionts to become mutualists. Occurrence of Spiroplasma-mediated protection against distinct parasitoids in divergent Drosophila hosts suggests a general protection mechanism.
Gregory D. D. Hurst - One of the best experts on this subject based on the ideXlab platform.
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symbiont mediated fly survival is independent of defensive symbiont genotype in the drosophila melanogaster Spiroplasma wasp interaction
Journal of Evolutionary Biology, 2020Co-Authors: Jordan E Jones, Gregory D. D. HurstAbstract:When a parasite attacks an insect, the outcome is commonly modulated by the presence of defensive heritable symbionts residing within the insect host. Previous studies noted markedly different strengths of Spiroplasma-mediated fly survival following attack by the same strain of wasp. One difference between the two studies was the strain of Spiroplasma used. We therefore performed a laboratory experiment to assess whether Spiroplasma-mediated protection depends upon the strain of Spiroplasma. We perform this analysis using the two strains of male-killing Spiroplasma used previously, and examined response to challenge by two strains of Leptopilina boulardi and two strains of Leptopilina heterotoma wasp. We found no evidence Spiroplasma strain affected fly survival following wasp attack. In contrast, analysis of the overall level of protection, including the fecundity of survivors of wasp attack, did indicate the two Spiroplasma strains tested varied in protective efficiency against three of the four wasp strains tested. These data highlight the sensitivity of symbiont-mediated protection phenotypes to laboratory conditions, and the importance of common garden comparison. Our results also indicate that Spiroplasma strains can vary in protective capacity in Drosophila, but these differences may exist in the relative performance of survivors of wasp attack, rather than in survival of attack per se.
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symbiont mediated fly survival is independent of defensive symbiont genotype in the drosophila melanogaster Spiroplasma wasp interaction
bioRxiv, 2020Co-Authors: Jordan E Jones, Gregory D. D. HurstAbstract:When a parasite attacks an insect, the outcome is commonly modulated by the presence of defensive heritable symbionts residing within the insect host. Previous studies noted markedly different strengths of Spiroplasma-mediated fly survival following attack by the same strain of wasp. One difference between the two studies was the strain of Spiroplasma used. We therefore performed a common garden laboratory experiment to assess whether Spiroplasma-mediated protection depends upon the strain of Spiroplasma. We perform this analysis using the two strains of male-killing Spiroplasma used previously, and examined response to challenge by two strains of Leptopilina boulardi and two strains of Leptopilina heterotoma wasp. We found no evidence Spiroplasma strain affected fly survival following wasp attack. In contrast, analysis of the overall level of protection, including the fecundity of survivors of wasp attack, did indicate the two Spiroplasma strains tested varied in protective efficiency against three of the four wasp strains tested. These data highlight the sensitivity of symbiont-mediated protection phenotypes to laboratory conditions, and the importance of common garden comparison. Our results also indicate that Spiroplasma strains can vary in protective capacity in Drosophila, but these differences may exist in the relative performance of survivors of wasp attack, rather than in survival of attack per se.
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rapid molecular evolution of Spiroplasma symbionts of drosophila
bioRxiv, 2020Co-Authors: Michael Gerth, Mariana Mateos, Bruno Lemaitre, Humberto Martinezmontoya, Paulino Ramirez, Florent Masson, Joanne S Griffin, Rodolfo Aramayo, Stefanos Siozios, Gregory D. D. HurstAbstract:Abstract Spiroplasma are a group of Mollicutes whose members include plant pathogens, insect pathogens, and endosymbionts of animals. In arthropods, Spiroplasma are found across a broad host range, but typically with lower incidence than other bacteria with similar ecology, such as Wolbachia or Rickettsia. Spiroplasma symbionts of Drosophila are best known as male-killers and protective symbionts, and both phenotypes are mediated by Spiroplasma-encoded toxins. Spiroplasma phenotypes have been repeatedly observed to be spontaneously lost in Drosophila cultures, and several studies have documented a high genomic turnover in Spiroplasma symbionts and plant pathogens. These observations suggest that Spiroplasma evolves quickly. Here, we systematically assess evolutionary rates and patterns of Spiroplasma poulsonii, a natural symbiont of Drosophila. We analysed genomic evolution of sHy within flies, and sMel within in vitro culture over several years. We observed that S. poulsonii substitution rates are among the highest reported for any bacteria, and markedly increased compared with other symbionts. The absence of mismatch repair loci mutS and mutL is conserved across Spiroplasma and likely contributes to elevated substitution rates. Further, the closely related strains sMel and sHy (>99.5% sequence identity in shared loci) show extensive structural genomic differences, which may be explained by a higher degree of host adaptation in sHy, a protective symbiont of Drosophila hydei. Finally, comparison across diverse Spiroplasma lineages confirms previous reports of dynamic evolution of toxins, and identifies loci similar to the male-killing toxin Spaid in several Spiroplasma lineages and other endosymbionts. Overall, our results highlight the peculiar nature of Spiroplasma genome evolution, which may explain unusual features of its evolutionary ecology.
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how do insects react to novel inherited symbionts a microarray analysis of drosophila melanogaster response to the presence of natural and introduced Spiroplasma
Molecular Ecology, 2011Co-Authors: Kate J Hutchence, Bettina Fischer, Steve Paterson, Gregory D. D. HurstAbstract:Maternally inherited endosymbionts are found in numerous insect species and have various effects on host ecology. New symbioses are most commonly established following lateral transfer of an existing symbiont from one host species to another. Laboratory study has demonstrated that symbionts commonly perform poorly in novel hosts, with weak vertical transmission and maladaptive pathogenicity being observed in the generations following transfer. This poor performance probably limits symbiont occurrence. We here use microarray technology to test whether poor symbiont performance observed following 1 year of vertical transmission through a new host is associated with alteration in host gene expression or whether it occurs independently of this. We utilize the Drosophila melanogaster--Spiroplasma interaction and test the response of the host in the presence of both natural Spiroplasma infections and novel Spiroplasma infections transinfected previously from other host species. None of the Spiroplasma infections investigated produced upregulation in host haemolymph/fat body-based immune responses, and we therefore rejected the hypothesis that failure to thrive was associated with immune upregulation. One infection was associated with a downregulation of genes associated with egg production compared to uninfected controls, indicative of damage to the host. The Spiroplasma infection showed that the weakest vertical transmission showed no significant disturbance to host gene expression compared to uninfected controls. We conclude that the failure of Spiroplasma in novel host species is associated either with causing harm to their new hosts or through a failure to thrive in the new host that occurs independently of host responses to infection.
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Hidden from the host: Spiroplasma bacteria infecting Drosophila do not cause an immune response, but are suppressed by ectopic immune activation.
Insect molecular biology, 2003Co-Authors: Gregory D. D. Hurst, Hisashi Anbutsu, Mayako Kutsukake, Takema FukatsuAbstract:Insects and other arthropods have an effective innate immune system that can clear infections with bacteria and other microorganisms. Despite this ability, one group of bacteria, the Spiroplasmas, survive unharmed within the haemolymph of a wide range of arthropod hosts. We investigated the interaction between one member of this clade, a relative of Spiroplasma poulsonii, and the immune system of its Drosophila host. Expression of antimicrobial genes in Spiroplasma-infected flies did not differ from wild-type controls either in the naturally infected state, nor after septic shock. We therefore concluded that Spiroplasma infection did not induce an immune response in its host, but that this absence of response was unlikely to be because the bacterium inhibited response. Further experiments revealed immune reactions induced ectopically did reduce parasite titre. We therefore conclude that this bacterium has a novel form of interaction with its host, being hidden from the host immune system, but potentially suppressible by it.
Gail E. Gasparich - One of the best experts on this subject based on the ideXlab platform.
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complete genome sequence of Spiroplasma citri strain r8 a2t causal agent of stubborn disease in citrus species
Genome Announcements, 2017Co-Authors: R E Davis, Gail E. Gasparich, Jonathan Shao, Yan Zhao, Brady J. Gaynor, Nicole M. DonofrioAbstract:ABSTRACT Spiroplasma citri causes stubborn disease in Citrus spp. and diseases in other plants. Here, we report the nucleotide sequence of the 1,599,709-bp circular chromosome and two plasmids of S. citri strain R8-A2T. This information will facilitate analyses to understand Spiroplasmal pathogenicity and evolutionary adaptations to lifestyles in plants and arthropod hosts.
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Complete Genome Sequence of Spiroplasma turonicum Strain Tab4cT, a Parasite of a Horse Fly, Haematopota sp. (Diptera: Tabanidae).
Genome announcements, 2015Co-Authors: Robert E. Davis, Gail E. Gasparich, Jonathan Shao, Yan Zhao, Brady J. Gaynor, Nicole M. DonofrioAbstract:ABSTRACT Spiroplasma turonicum was isolated from a Haematopota sp. fly in France. We report the nucleotide sequence of the circular chromosome of strain Tab4cT. The genome information will facilitate evolutionary studies of Spiroplasmas, including symbionts of insects and ticks and pathogens of plants, insects, crustaceans, and humans.
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comparative genome analysis of Spiroplasma melliferum ipmb4a a honeybee associated bacterium
BMC Genomics, 2013Co-Authors: Lingling Chen, Gail E. Gasparich, Chihhorng Kuo, Wanchia ChungAbstract:Background: The genus Spiroplasma contains a group of helical, motile, and wall-less bacteria in the class Mollicutes. Similar to other members of this class, such as the animal-pathogenic Mycoplasma and the plant-pathogenic ‘Candidatus Phytoplasma’, all characterized Spiroplasma species were found to be associated with eukaryotic hosts. While most of the Spiroplasma species appeared to be harmless commensals of insects, a small number of species have evolved pathogenicity toward various arthropods and plants. In this study, we isolated a novel strain of honeybee-associated S. melliferum and investigated its genetic composition and evolutionary history by whole-genome shotgun sequencing and comparative analysis with other Mollicutes genomes. Results: The whole-genome shotgun sequencing of S. melliferum IPMB4A produced a draft assembly that was ~1.1 Mb in size and covered ~80% of the chromosome. Similar to other Spiroplasma genomes that have been studied to date, we found that this genome contains abundant repetitive sequences that originated from plectrovirus insertions. These phage fragments represented a major obstacle in obtaining a complete genome sequence of Spiroplasma with the current sequencing technology. Comparative analysis of S. melliferum IPMB4A with other Spiroplasma genomes revealed that these phages may have facilitated extensive genome rearrangements in these bacteria and contributed to horizontal gene transfers that led to species-specific adaptation to different eukaryotic hosts. In addition, comparison of gene content with other Mollicutes suggested that the common ancestor of the SEM (Spiroplasma, Entomoplasma, and Mycoplasma) clade may have had a relatively large genome and flexible metabolic capacity; the extremely reduced genomes of present day Mycoplasma and ‘Candidatus Phytoplasma’ species are likely to be the result of independent gene losses in these lineages. Conclusions: The findings in this study highlighted the significance of phage insertions and horizontal gene transfer in the evolution of bacterial genomes and acquisition of pathogenicity. Furthermore, the inclusion of Spiroplasma in comparative analysis has improved our understanding of genome evolution in Mollicutes. Future improvements in the taxon sampling of available genome sequences in this group are required to provide further insights into the evolution of these important pathogens of humans, animals, and plants.
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Spiroplasma eriocheiris sp nov associated with mortality in the chinese mitten crab eriocheir sinensis
International Journal of Systematic and Evolutionary Microbiology, 2011Co-Authors: Wen Wang, Gail E. Gasparich, Qingguo Meng, Tingming Liang, Qi Feng, Jianqiong Zhang, Ying ZhangAbstract:A motile bacterium, designated strain TDA-040725-5T, was isolated from the haemolymph of a Chinese mitten crab, Eriocheir sinensis, with tremor disease. Based on 16S rRNA gene sequence analysis, the strain was phylogenetically distinct from other Spiroplasmas but was closely related to Spiroplasma mirum ATCC 29335T. Cells of strain TDA-040725-5T were variable in length and shape, helical and motile, as determined by phase-contrast light microscopy. Examination by electron microscopy revealed wall-less cells delimited by a single membrane. The strain grew in M1D or R-2 liquid media at 20–40 °C, with optimum growth at 30 °C. Doubling time at the optimal temperature was 24 h. The strain catabolized glucose and hydrolysed arginine but did not hydrolyse urea. The DNA G+C content was 29.7±1 mol%. The genome size was ~1.4–1.6 Mbp. Serological analysis, performed using the deformation test, did not reveal any reciprocal titres ≥320, indicating that strain TDA-040725-5T had minimal cross-reactivity to strains of recognized species of the genus Spiroplasma. Based on this evidence, strain TDA-040725-5T ( = CCTCC M 207170T = DSM 21848T) represents a novel species of the genus Spiroplasma, for which the name Spiroplasma eriocheiris sp. nov. is proposed, belonging to the novel Spiroplasma serological group XLIII.
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Spiroplasma-like organisms closely associated with the gut in five leafhopper species (Hemiptera: Cicadellidae)
Archives of Microbiology, 2011Co-Authors: El-desouky Ammar, Gail E. Gasparich, David G. Hall, Saskia A. HogenhoutAbstract:Spiroplasmas are bacteria in the Class Mollicutes that are frequently associated with insects and/or plants. Here, we describe the ultrastructure, localization, and occurrence of apparent commensal/symbiotic Spiroplasma-like organisms (SLOs) in the midgut and hindgut of five leafhopper species from laboratory-reared colonies. Those found in Dalbulus elimatus, Endria inimica , and Macrosteles quadrilineatus were long and tubular shaped, whereas those in Dalbulus maidis and Graminella nigrifrons were shorter and mostly rod-shaped in their host organisms. These SLOs were found in great numbers in the gut lumen frequently associated with the gut microvilli, but unlike the plant-pathogenic mollicutes, they did not seem to invade the gut epithelium or other tissues in any of these five leafhopper species. Large accumulations of these gut-associated organisms were more commonly found by confocal laser scanning microscopy in males than in females and in crowded than in singly reared leafhoppers. Ultrastructural evidence suggests that these SLOs may be horizontally transmitted between leafhoppers by contamination of the mouth parts with leafhopper excretions.
