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Hrdina A, Serra Canales M, Arias-Rojas A, Frahm D, Iatsenko I. The endosymbiont Spiroplasma poulsonii increases Drosophila melanogaster resistance to pathogens by enhancing iron sequestration and melanization. mBio 2024; 15:e0093624. [PMID: 38940615 PMCID: PMC11323552 DOI: 10.1128/mbio.00936-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 05/28/2024] [Indexed: 06/29/2024] Open
Abstract
Facultative endosymbiotic bacteria, such as Wolbachia and Spiroplasma species, are commonly found in association with insects and can dramatically alter their host physiology. Many endosymbionts are defensive and protect their hosts against parasites or pathogens. Despite the widespread nature of defensive insect symbioses and their importance for the ecology and evolution of insects, the mechanisms of symbiont-mediated host protection remain poorly characterized. Here, we utilized the fruit fly Drosophila melanogaster and its facultative endosymbiont Spiroplasma poulsonii to characterize the mechanisms underlying symbiont-mediated host protection against bacterial and fungal pathogens. Our results indicate a variable effect of S. poulsonii on infection outcome, with endosymbiont-harboring flies being more resistant to Rhyzopus oryzae, Staphylococcus aureus, and Providencia alcalifaciens but more sensitive or as sensitive as endosymbiont-free flies to the infections with Pseudomonas species. Further focusing on the protective effect, we identified Transferrin-mediated iron sequestration induced by Spiroplasma as being crucial for the defense against R. oryzae and P. alcalifaciens. In the case of S. aureus, enhanced melanization in Spiroplasma-harboring flies plays a major role in protection. Both iron sequestration and melanization induced by Spiroplasma require the host immune sensor protease Persephone, suggesting a role of proteases secreted by the symbiont in the activation of host defense reactions. Hence, our work reveals a broader defensive range of Spiroplasma than previously appreciated and adds nutritional immunity and melanization to the defensive arsenal of symbionts. IMPORTANCE Defensive endosymbiotic bacteria conferring protection to their hosts against parasites and pathogens are widespread in insect populations. However, the mechanisms by which most symbionts confer protection are not fully understood. Here, we studied the mechanisms of protection against bacterial and fungal pathogens mediated by the Drosophila melanogaster endosymbiont Spiroplasma poulsonii. We demonstrate that besides the previously described protection against wasps and nematodes, Spiroplasma also confers increased resistance to pathogenic bacteria and fungi. We identified Spiroplasma-induced iron sequestration and melanization as key defense mechanisms. Our work broadens the known defense spectrum of Spiroplasma and reveals a previously unappreciated role of melanization and iron sequestration in endosymbiont-mediated host protection. We propose that the mechanisms we have identified here may be of broader significance and could apply to other endosymbionts, particularly to Wolbachia, and potentially explain their protective properties.
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Affiliation(s)
- Alexandra Hrdina
- Research group Genetics of Host-Microbe Interactions, Max Planck Institute for Infection Biology, Berlin, Germany
- Faculty of Life Sciences, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Marina Serra Canales
- Research group Genetics of Host-Microbe Interactions, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Aranzazu Arias-Rojas
- Research group Genetics of Host-Microbe Interactions, Max Planck Institute for Infection Biology, Berlin, Germany
- Department of Biology, Chemistry, and Pharmacy, Freie Universität Berlin, Berlin, Germany
| | - Dagmar Frahm
- Research group Genetics of Host-Microbe Interactions, Max Planck Institute for Infection Biology, Berlin, Germany
| | - Igor Iatsenko
- Research group Genetics of Host-Microbe Interactions, Max Planck Institute for Infection Biology, Berlin, Germany
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2
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Huang Z, Wang D, Zhou J, He H, Wei C. The Improvement of Fluorescence In Situ Hybridization Technique Based on Explorations of Symbionts in Cicadas. Int J Mol Sci 2023; 24:15838. [PMID: 37958818 PMCID: PMC10650757 DOI: 10.3390/ijms242115838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/28/2023] [Accepted: 10/30/2023] [Indexed: 11/15/2023] Open
Abstract
Fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes is widely used for the identification of microbes in complex samples, but it suffers from some limitations resulting in the weak or even absence of fluorescence signals of microbe(s), which may lead to the underestimation or misunderstanding of a microbial community. Herein, we explored symbionts in the bacteriomes and fat bodies of cicadas using modified FISH, aiming to improve this technique. We initially revealed that the probes of Candidatus Sulcia muelleri (Sulcia) and the yeast-like fungal symbiont (YLS) are suitable for detection of these symbionts in all cicadas and some other species of Auchenorrhyncha, whereas the probe of Candidatus Hodgkinia cicadicola (Hodgkinia) is only suitable for detection of Hodgkinia in a few cicada species. The fluorescence signal of Sulcia, Hodgkinia and YLS exhibited weak intensity without the addition of unlabeled oligonucleotides (helpers) and heat shock in some cicadas; however, it can be significantly improved by the addition of both helpers and heat shock. Results of this study suggest that heat shock denaturing rRNA and proteins of related microbe(s) together with helpers binding to the adjacent region of the probe's target sites prevent the re-establishment of the native secondary structure of rRNA; therefore, suitable probe(s) can more easily access to the probe's target sites of rRNA. Our results provide new information for the significant improvement of hybridization signal intensities of microbes in the FISH experiment, making it possible to achieve a more precise understanding of the microbial distribution, community and density in complex samples.
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Affiliation(s)
- Zhi Huang
- Key Laboratory of Plant Protection Resources and Pest Management of the Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China; (Z.H.); (D.W.); (J.Z.)
- College of Forestry, Northwest A&F University, Yangling 712100, China
| | - Dandan Wang
- Key Laboratory of Plant Protection Resources and Pest Management of the Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China; (Z.H.); (D.W.); (J.Z.)
| | - Jinrui Zhou
- Key Laboratory of Plant Protection Resources and Pest Management of the Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China; (Z.H.); (D.W.); (J.Z.)
| | - Hong He
- College of Forestry, Northwest A&F University, Yangling 712100, China
| | - Cong Wei
- Key Laboratory of Plant Protection Resources and Pest Management of the Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China; (Z.H.); (D.W.); (J.Z.)
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3
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Karim S, Zenzal TJ, Beati L, Sen R, Adegoke A, Kumar D, Downs LP, Keko M, Nussbaum A, Becker DJ, Moore FR. Ticks without borders: Microbial communities of immature Neotropical tick species parasitizing migratory landbirds along northern Gulf of Mexico. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.22.563347. [PMID: 37961388 PMCID: PMC10634713 DOI: 10.1101/2023.10.22.563347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
The long-distance, seasonal migrations of birds make them an effective ecological bridge for the movement of ticks. The introduction of exotic tick species to new geographical regions can lead to the emergence of novel tick-borne pathogens or the re-emergence of previously eradicated ones. This study assessed the prevalence of exotic tick species parasitizing resident, short-distance, and long-distance songbirds during spring and autumn at stopover sites in the northern Gulf of Mexico using the mitochondrial 12S rDNA gene. Birds were captured for tick collection from six different sites from late August to early November in both 2018 and 2019. The highest number of ticks were collected in the 2019 season. Most ticks were collected off the Yellow-breasted Chat (Icteria virens) and Common Yellowthroat (Geothlypis trichas), and 54% of the total ticks collected were from Grand Chenier, LA. A high throughput 16S ribosomal RNA sequencing approach was followed to characterize the microbial communities and identify pathogenic microbes in all tick samples. Tick microbial communities, diversity, and community structure were determined using quantitative insight into microbial ecology (QIIME). The sparse correlations for compositional data (SparCC) approach was then used to construct microbial network maps and infer microbial correlations. A total of 421 individual ticks in the genera Amblyomma, Haemaphysalis, and Ixodes were recorded from 28 songbird species, of which Amblyomma and Amblyomma longirostre was the most abundant tick genus and species, respectively. Microbial profiles showed that Proteobacteria was the most abundant phylum. The most abundant bacteria include the pathogenic Rickettsia and endosymbiont Francisella, Candidatus Midichloria, and Spiroplasma. BLAST analysis and phylogenetic reconstruction of the Rickettsia sequences revealed the highest similarities to pathogenic spotted and non-spotted fever groups, including R. buchneri, R. conorii, R. prowazekii, R. bellii, R. australis, R. parkeri, R. monacensis, and R. monteiroi. Permutation multivariate analysis of variance revealed that the relative abundance of Francisella and Rickettsia drives microbial patterns across the tick genera. We also observed a higher percentage of positive correlations in microbe-microbe interactions among members of the microbial communities. Network analysis suggested a negative correlation between a) Francisella and Rickettsia and, b) Francisella and Cutibacterium. Lastly, mapping the distributions of bird species parasitized during spring migrations highlighted geographic hotspots where migratory songbirds could disperse ticks and their pathogens at stopover sites or upon arrival to their breeding grounds, the latter showing means dispersal distances from 421-5003 kilometers. These findings strongly highlight the potential role of migratory birds in the epidemiology of tick-borne pathogens.
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Affiliation(s)
- Shahid Karim
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Theodore J. Zenzal
- United States Geological Survey, Wetland and Aquatic Research Center, Lafayette, LA 70506
| | - Lorenza Beati
- Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA 20460
| | - Raima Sen
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Abdulsalam Adegoke
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Deepak Kumar
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Latoyia P. Downs
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
| | - Mario Keko
- Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA 20460
| | - Ashly Nussbaum
- Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA 20460
| | - Daniel J. Becker
- Department of Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Frank R. Moore
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39406, USA
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4
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Ramirez P, Leavitt JC, Gill JJ, Mateos M. Preliminary Characterization of Phage-Like Particles from the Male-Killing Mollicute Spiroplasma poulsonii (an Endosymbiont of Drosophila). Curr Microbiol 2022; 80:6. [PMID: 36445499 DOI: 10.1007/s00284-022-03099-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 10/24/2022] [Indexed: 11/30/2022]
Abstract
Bacteriophages are vastly abundant, diverse, and influential, but with few exceptions (e.g. the Proteobacteria genera Wolbachia and Hamiltonella), the role of phages in heritable bacteria-arthropod interactions, which are ubiquitous and diverse, remains largely unexplored. Despite prior studies documenting phage-like particles in the mollicute Spiroplasma associated with Drosophila flies, genomic sequences of such phage are lacking, and their effects on the Spiroplasma-Drosophila interaction have not been comprehensively characterized. We used a density step gradient to isolate phage-like particles from the male-killing bacterium Spiroplasma poulsonii (strains NSRO and MSRO-Br) harbored by Drosophila melanogaster. Isolated particles were subjected to DNA sequencing, assembly, and annotation. Several lines of evidence suggest that we recovered phage-like particles of similar features (shape, size, DNA content) to those previously reported in Drosophila-associated Spiroplasma strains. We recovered three ~ 19 kb phage-like contigs (two in NSRO and one in MSRO-Br) containing 21-24 open reading frames, a read-alignment pattern consistent with circular permutation, and terminal redundancy (at least in NSRO). Although our results do not allow us to distinguish whether these phage-like contigs represent infective phage-like particles capable of transmitting their DNA to new hosts, their encoding of several typical phage genes suggests that they are at least remnants of functional phage. We also recovered two smaller non-phage-like contigs encoding a known Spiroplasma toxin (Ribosome Inactivating Protein; RIP), and an insertion element, suggesting that they are packaged into particles. Substantial homology of our particle-derived contigs was found in the genome assemblies of members of the Spiroplasma poulsonii clade.
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Affiliation(s)
- Paulino Ramirez
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Justin C Leavitt
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Jason J Gill
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Mariana Mateos
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA. .,Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA.
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5
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Arai H, Inoue MN, Kageyama D. Male-killing mechanisms vary between Spiroplasma species. Front Microbiol 2022; 13:1075199. [PMID: 36519169 PMCID: PMC9742256 DOI: 10.3389/fmicb.2022.1075199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 11/08/2022] [Indexed: 03/11/2024] Open
Abstract
Male-killing, a male-specific death of arthropod hosts during development, is induced by Spiroplasma (Mollicutes) endosymbionts of the Citri-Poulsonii and the Ixodetis groups, which are phylogenetically distant groups. Spiroplasma poulsonii induces male-killing in Drosophila melanogaster (Diptera) using the Spaid toxin that harbors ankyrin repeats, whereas little is known about the origin and mechanisms of male-killing induced by Spiroplasma ixodetis. Here, we analyzed the genome and the biological characteristics of a male-killing S. ixodetis strain sHm in the moth Homona magnanima (Tortricidae, Lepidoptera). Strain sHm harbored a 2.1 Mb chromosome and two potential plasmids encoding Type IV effectors, putatively involved in virulence and host-symbiont interactions. Moreover, sHm did not harbor the spaid gene but harbored 10 ankyrin genes that were homologous to those in other S. ixodetis strains. In contrast to the predominant existence of S. poulsonii in hemolymph, our quantitative PCR assays revealed a systemic distribution of strain sHm in H. magnanima, with particularly high titers in Malpighian tubules but low titers in hemolymph. Furthermore, transinfection assays confirmed that strain sHm can infect cultured cells derived from distantly related insects, namely Aedes albopictus (Diptera) and Bombyx mori (Lepidoptera). These results suggest different origins and characteristics of S. ixodetis- and S. poulsonii-induced male-killing.
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Affiliation(s)
- Hiroshi Arai
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
| | - Maki N. Inoue
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Daisuke Kageyama
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
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6
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Su Y, Lin HC, Teh LS, Chevance F, James I, Mayfield C, Golic KG, Gagnon JA, Rog O, Dale C. Rational engineering of a synthetic insect-bacterial mutualism. Curr Biol 2022; 32:3925-3938.e6. [PMID: 35963240 PMCID: PMC10080585 DOI: 10.1016/j.cub.2022.07.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/25/2022] [Accepted: 07/14/2022] [Indexed: 10/15/2022]
Abstract
Many insects maintain mutualistic associations with bacterial endosymbionts, but little is known about how they originate in nature. In this study, we describe the establishment and manipulation of a synthetic insect-bacterial symbiosis in a weevil host. Following egg injection, the nascent symbiont colonized many tissues, including prototypical somatic and germinal bacteriomes, yielding maternal transmission over many generations. We then engineered the nascent symbiont to overproduce the aromatic amino acids tyrosine and phenylalanine, which facilitate weevil cuticle strengthening and accelerated larval development, replicating the function of mutualistic symbionts that are widely distributed among weevils and other beetles in nature. Our work provides empirical support for the notion that mutualistic symbioses can be initiated in insects by the acquisition of environmental bacteria. It also shows that certain bacterial genera, including the Sodalis spp. used in our study, are predisposed to develop these associations due to their ability to maintain benign infections and undergo vertical transmission in diverse insect hosts, facilitating the partner-fidelity feedback that is critical for the evolution of obligate mutualism. These experimental advances provide a new platform for laboratory studies focusing on the molecular mechanisms and evolutionary processes underlying insect-bacterial symbiosis.
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Affiliation(s)
- Yinghua Su
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA.
| | - Ho-Chen Lin
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Li Szhen Teh
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Fabienne Chevance
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Ian James
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Clara Mayfield
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Kent G Golic
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - James A Gagnon
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Ofer Rog
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Colin Dale
- School of Biological Sciences, University of Utah, Salt Lake City, UT 84112, USA.
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7
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Martinez J, Ant TH, Murdochy SM, Tong L, da Silva Filipe A, Sinkins SP. Genome sequencing and comparative analysis of Wolbachia strain wAlbA reveals Wolbachia-associated plasmids are common. PLoS Genet 2022; 18:e1010406. [PMID: 36121852 PMCID: PMC9560607 DOI: 10.1371/journal.pgen.1010406] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/13/2022] [Accepted: 09/02/2022] [Indexed: 11/18/2022] Open
Abstract
Wolbachia are widespread maternally-transmitted bacteria of arthropods that often spread by manipulating their host's reproduction through cytoplasmic incompatibility (CI). Their invasive potential is currently being harnessed in field trials aiming to control mosquito-borne diseases. Wolbachia genomes commonly harbour prophage regions encoding the cif genes which confer their ability to induce CI. Recently, a plasmid-like element was discovered in wPip, a Wolbachia strain infecting Culex mosquitoes; however, it is unclear how common such extra-chromosomal elements are in Wolbachia. Here we sequenced the complete genome of wAlbA, a strain of the symbiont found in Aedes albopictus, after eliminating the co-infecting and higher density wAlbB strain that previously made sequencing of wAlbA challenging. We show that wAlbA is associated with two new plasmids and identified additional Wolbachia plasmids and related chromosomal islands in over 20% of publicly available Wolbachia genome datasets. These plasmids encode a variety of accessory genes, including several phage-like DNA packaging genes as well as genes potentially contributing to host-symbiont interactions. In particular, we recovered divergent homologues of the cif genes in both Wolbachia- and Rickettsia-associated plasmids. Our results indicate that plasmids are common in Wolbachia and raise fundamental questions around their role in symbiosis. In addition, our comparative analysis provides useful information for the future development of genetic tools to manipulate and study Wolbachia symbionts.
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Affiliation(s)
- Julien Martinez
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Thomas H. Ant
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Shivan M. Murdochy
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Lily Tong
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Ana da Silva Filipe
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Steven P. Sinkins
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
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8
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Disproportionate investment in Spiralin B production limits in-host growth and favors the vertical transmission of Spiroplasma insect endosymbionts. Proc Natl Acad Sci U S A 2022; 119:e2208461119. [PMID: 35858432 PMCID: PMC9335233 DOI: 10.1073/pnas.2208461119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Insects frequently harbor endosymbionts, which are bacteria housed within host tissues. These associations are stably maintained over evolutionary timescales through vertical transmission of endosymbionts from host mothers to their offspring. Some endosymbionts manipulate host reproduction to facilitate spread within natural populations. Consequently, such infections have major impacts on insect physiology and evolution. However, technical hurdles have limited our understanding of the molecular mechanisms underlying such insect-endosymbiont interactions. Here, we investigate the nutritional interactions between endosymbiotic partners using the tractable insect Drosophila melanogaster and its natural endosymbiont Spiroplasma poulsonii. Using a combination of functional assays, metabolomics, and proteomics, we show that the abundance and amino acid composition of a single Spiroplasma membrane lectin, Spiralin B (SpiB), dictates the amino acid requirements of the endosymbiont and determines its proliferation within host tissues. Ectopically increasing SpiB levels in host tissues disrupts localization of endosymbionts in the fly egg chambers and decreases vertical transmission. We find that SpiB is likely to be required by the endosymbiont to enter host oocytes, which may explain the massive investment of S. poulsonii in SpiB synthesis. SpiB both permits vertical transmission of the symbiont and limits its growth in nutrient-limiting conditions for the host; therefore, a single protein plays a pivotal role in ensuring durability of the interaction in a variable environment.
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9
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Pollmann M, Moore LD, Krimmer E, D'Alvise P, Hasselmann M, Perlman SJ, Ballinger MJ, Steidle JL, Gottlieb Y. Highly transmissible cytoplasmic incompatibility by the extracellular insect symbiont Spiroplasma. iScience 2022; 25:104335. [PMID: 35602967 PMCID: PMC9118660 DOI: 10.1016/j.isci.2022.104335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/06/2022] [Accepted: 04/26/2022] [Indexed: 11/19/2022] Open
Abstract
Cytoplasmic incompatibility (CI) is a form of reproductive manipulation caused by maternally inherited endosymbionts infecting arthropods, like Wolbachia, whereby matings between infected males and uninfected females produce few or no offspring. We report the discovery of a new CI symbiont, a strain of Spiroplasma causing CI in the parasitoid wasp Lariophagus distinguendus. Its extracellular occurrence enabled us to establish CI in uninfected adult insects by transferring Spiroplasma-infected hemolymph. We sequenced the CI-Spiroplasma genome and did not find any homologues of any of the cif genes discovered to cause CI in Wolbachia, suggesting independent evolution of CI. Instead, the genome contains other potential CI-causing candidate genes, such as homologues of high-mobility group (HMG) box proteins that are crucial in eukaryotic development but rare in bacterial genomes. Spiroplasma's extracellular nature and broad host range encompassing medically and agriculturally important arthropods make it a promising tool to study CI and its applications.
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Affiliation(s)
- Marie Pollmann
- Department of Chemical Ecology 190t, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Logan D. Moore
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Elena Krimmer
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany
| | - Paul D'Alvise
- Institute of Medical Microbiology and Hygiene, University Hospital of Tuebingen, 72016 Tuebingen, Germany
| | - Martin Hasselmann
- Department of Livestock Population Genomics 460h, Institute of Animal Science, University of Hohenheim, 70599 Stuttgart, Germany
| | - Steve J. Perlman
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada
| | - Matthew J. Ballinger
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Johannes L.M. Steidle
- Department of Chemical Ecology 190t, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany
- KomBioTa - Center of Biodiversity and Integrative Taxonomy, University of Hohenheim, 70599 Stuttgart, Germany
| | - Yuval Gottlieb
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, POB 12, Rehovot 76100, Israel
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10
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Ratcliffe NA, Furtado Pacheco JP, Dyson P, Castro HC, Gonzalez MS, Azambuja P, Mello CB. Overview of paratransgenesis as a strategy to control pathogen transmission by insect vectors. Parasit Vectors 2022; 15:112. [PMID: 35361286 PMCID: PMC8969276 DOI: 10.1186/s13071-021-05132-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 12/13/2021] [Indexed: 12/12/2022] Open
Abstract
This article presents an overview of paratransgenesis as a strategy to control pathogen transmission by insect vectors. It first briefly summarises some of the disease-causing pathogens vectored by insects and emphasises the need for innovative control methods to counter the threat of resistance by both the vector insect to pesticides and the pathogens to therapeutic drugs. Subsequently, the state of art of paratransgenesis is described, which is a particularly ingenious method currently under development in many important vector insects that could provide an additional powerful tool for use in integrated pest control programmes. The requirements and recent advances of the paratransgenesis technique are detailed and an overview is given of the microorganisms selected for genetic modification, the effector molecules to be expressed and the environmental spread of the transgenic bacteria into wild insect populations. The results of experimental models of paratransgenesis developed with triatomines, mosquitoes, sandflies and tsetse flies are analysed. Finally, the regulatory and safety rules to be satisfied for the successful environmental release of the genetically engineered organisms produced in paratransgenesis are considered.
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Affiliation(s)
- Norman A Ratcliffe
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil. .,Department of Biosciences, Swansea University, Singleton Park, Swansea, UK.
| | - João P Furtado Pacheco
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Paul Dyson
- Institute of Life Science, Medical School, Swansea University, Singleton Park, Swansea, UK
| | - Helena Carla Castro
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Marcelo S Gonzalez
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Patricia Azambuja
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
| | - Cicero B Mello
- Programa de Pós-Graduação em Ciências e Biotecnologia, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil.,Laboratório de Biologia de Insetos, Instituto de Biologia (EGB), Universidade Federal Fluminense (UFF), Niterói, Brazil
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11
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Pons I, Scieur N, Dhondt L, Renard ME, Renoz F, Hance T. Pervasiveness of the symbiont Serratia symbiotica in the aphid natural environment: distribution, diversity and evolution at a multitrophic level. FEMS Microbiol Ecol 2022; 98:6526308. [PMID: 35142841 DOI: 10.1093/femsec/fiac012] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/05/2022] [Accepted: 02/08/2022] [Indexed: 11/12/2022] Open
Abstract
Symbioses are significant drivers of insect evolutionary ecology. Despite recent findings that these associations can emerge from environmentally derived bacterial precursors, there is still little information on how these potential progenitors of insect symbionts circulate in trophic systems. Serratia symbiotica represents a valuable model for deciphering evolutionary scenarios of bacterial acquisition by insects, as its diversity includes gut-associated strains that retained the ability to live independently of their hosts, representing a potential reservoir for symbioses emergence. Here, we conducted a field study to examine the distribution and diversity of S. symbiotica found in aphid populations, and in different compartments of their surrounding environment. Twenty % of aphids colonies were infected with S. symbiotica, including a wide diversity of strains with varied tissue tropism corresponding to different lifestyle. We also showed that the prevalence of S. symbiotica is influenced by seasonal temperatures. We found that S. symbiotica was present in non-aphid species and in host plants, and that its prevalence in these samples was higher when associated aphid colonies were infected. Furthermore, phylogenetic analyses suggest the existence of horizontal transfers between the different trophic levels. These results provide a new picture of the pervasiveness of an insect symbiont in nature.
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Affiliation(s)
- Inès Pons
- Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - Nora Scieur
- Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - Linda Dhondt
- Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - Marie-Eve Renard
- Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - François Renoz
- Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
| | - Thierry Hance
- Earth and Life Institute, Biodiversity Research Centre, Université catholique de Louvain, 1348, Louvain-la-Neuve, Belgium
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12
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Massey JH, Newton ILG. Diversity and function of arthropod endosymbiont toxins. Trends Microbiol 2022; 30:185-198. [PMID: 34253453 PMCID: PMC8742837 DOI: 10.1016/j.tim.2021.06.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 02/03/2023]
Abstract
Bacterial endosymbionts induce dramatic phenotypes in their arthropod hosts, including cytoplasmic incompatibility, feminization, parthenogenesis, male killing, parasitoid defense, and pathogen blocking. The molecular mechanisms underlying these effects remain largely unknown but recent evidence suggests that protein toxins secreted by the endosymbionts play a role. Here, we describe the diversity and function of endosymbiont proteins with homology to known bacterial toxins. We focus on maternally transmitted endosymbionts belonging to the Wolbachia, Rickettsia, Arsenophonus, Hamiltonella, Spiroplasma, and Cardinium genera because of their ability to induce the above phenotypes. We identify at least 16 distinct toxin families with diverse enzymatic activities, including AMPylases, nucleases, proteases, and glycosyltransferases. Notably, several annotated toxins contain domains with homology to eukaryotic proteins, suggesting that arthropod endosymbionts mimic host biochemistry to manipulate host physiology, similar to bacterial pathogens.
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Affiliation(s)
| | - Irene L. G. Newton
- Department of Biology, Indiana University, Bloomington, Indiana, USA,Corresponding author,
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13
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Masson F, Pierrat X, Lemaitre B, Persat A. The wall-less bacterium Spiroplasma poulsonii builds a polymeric cytoskeleton composed of interacting MreB isoforms. iScience 2021; 24:103458. [PMID: 34888500 PMCID: PMC8634037 DOI: 10.1016/j.isci.2021.103458] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/03/2021] [Accepted: 11/11/2021] [Indexed: 11/20/2022] Open
Abstract
A rigid cell wall defines the morphology of most bacteria. MreB, a bacterial homologue of actin, plays a major role in coordinating cell wall biogenesis and defining cell shape. Spiroplasma are wall-less bacteria that robustly grow with a characteristic helical shape. Paradoxal to their lack of cell wall, the Spiroplasma genome contains five homologs of MreB (SpMreBs). Here, we investigate the function of SpMreBs in forming a polymeric cytoskeleton. We found that, in vivo, Spiroplasma maintain a high concentration of all MreB isoforms. By leveraging a heterologous expression system that bypasses the poor genetic tractability of Spiroplasma, we found that SpMreBs produced polymeric filaments of various morphologies. We characterized an interaction network between isoforms that regulate filament formation and patterning. Therefore, our results support the hypothesis where combined SpMreB isoforms would form an inner polymeric cytoskeleton in vivo that shapes the cell in a wall-independent manner. The five Spiroplasma MreB isoforms are extremely abundant proteins in vivo Each isoform produces filaments when expressed in a heterologous system SpMreBs form an interaction network that regulates filament length and shape
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Affiliation(s)
- Florent Masson
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Corresponding author
| | - Xavier Pierrat
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Alexandre Persat
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
- Corresponding author
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14
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Maire J, Blackall LL, van Oppen MJH. Intracellular Bacterial Symbionts in Corals: Challenges and Future Directions. Microorganisms 2021; 9:2209. [PMID: 34835335 PMCID: PMC8619543 DOI: 10.3390/microorganisms9112209] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 02/07/2023] Open
Abstract
Corals are the main primary producers of coral reefs and build the three-dimensional reef structure that provides habitat to more than 25% of all marine eukaryotes. They harbor a complex consortium of microorganisms, including bacteria, archaea, fungi, viruses, and protists, which they rely on for their survival. The symbiosis between corals and bacteria is poorly studied, and their symbiotic relationships with intracellular bacteria are only just beginning to be acknowledged. In this review, we emphasize the importance of characterizing intracellular bacteria associated with corals and explore how successful approaches used to study such microorganisms in other systems could be adapted for research on corals. We propose a framework for the description, identification, and functional characterization of coral-associated intracellular bacterial symbionts. Finally, we highlight the possible value of intracellular bacteria in microbiome manipulation and mitigating coral bleaching.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
| | - Linda L. Blackall
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
| | - Madeleine J. H. van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia
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15
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Masson F, Rommelaere S, Marra A, Schüpfer F, Lemaitre B. Dual proteomics of Drosophila melanogaster hemolymph infected with the heritable endosymbiont Spiroplasma poulsonii. PLoS One 2021; 16:e0250524. [PMID: 33914801 PMCID: PMC8084229 DOI: 10.1371/journal.pone.0250524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/07/2021] [Indexed: 11/19/2022] Open
Abstract
Insects are frequently infected with heritable bacterial endosymbionts. Endosymbionts have a dramatic impact on their host physiology and evolution. Their tissue distribution is variable with some species being housed intracellularly, some extracellularly and some having a mixed lifestyle. The impact of extracellular endosymbionts on the biofluids they colonize (e.g. insect hemolymph) is however difficult to appreciate because biofluid composition can depend on the contribution of numerous tissues. Here we investigate Drosophila hemolymph proteome changes in response to the infection with the endosymbiont Spiroplasma poulsonii. S. poulsonii inhabits the fly hemolymph and gets vertically transmitted over generations by hijacking the oogenesis in females. Using dual proteomics on infected hemolymph, we uncovered a weak, chronic activation of the Toll immune pathway by S. poulsonii that was previously undetected by transcriptomics-based approaches. Using Drosophila genetics, we also identified candidate proteins putatively involved in controlling S. poulsonii growth. Last, we also provide a deep proteome of S. poulsonii, which, in combination with previously published transcriptomics data, improves our understanding of the post-transcriptional regulations operating in this bacterium.
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Affiliation(s)
- Florent Masson
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Samuel Rommelaere
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Alice Marra
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Fanny Schüpfer
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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16
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Vera-Ponce León A, Dominguez-Mirazo M, Bustamante-Brito R, Higareda-Alvear V, Rosenblueth M, Martínez-Romero E. Functional genomics of a Spiroplasma associated with the carmine cochineals Dactylopius coccus and Dactylopius opuntiae. BMC Genomics 2021; 22:240. [PMID: 33823812 PMCID: PMC8025503 DOI: 10.1186/s12864-021-07540-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 03/18/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Spiroplasma is a widely distributed endosymbiont of insects, arthropods, and plants. In insects, Spiroplasma colonizes the gut, hemolymph, and reproductive organs of the host. Previous metagenomic surveys of the domesticated carmine cochineal Dactylopius coccus and the wild cochineal D. opuntiae reported sequences of Spiroplasma associated with these insects. However, there is no analysis of the genomic capabilities and the interaction of this Spiroplasma with Dactylopius. RESULTS Here we present three Spiroplasma genomes independently recovered from metagenomes of adult males and females of D. coccus, from two different populations, as well as from adult females of D. opuntiae. Single-copy gene analysis showed that these genomes were > 92% complete. Phylogenomic analyses classified these genomes as new members of Spiroplasma ixodetis. Comparative genome analysis indicated that they exhibit fewer genes involved in amino acid and carbon catabolism compared to other spiroplasmas. Moreover, virulence factor-encoding genes (i.e., glpO, spaid and rip2) were found incomplete in these S. ixodetis genomes. We also detected an enrichment of genes encoding the type IV secretion system (T4SS) in S. ixodetis genomes of Dactylopius. A metratranscriptomic analysis of D. coccus showed that some of these T4SS genes (i.e., traG, virB4 and virD4) in addition to the superoxide dismutase sodA of S. ixodetis were overexpressed in the ovaries. CONCLUSION The symbiont S. ixodetis is a new member of the bacterial community of D. coccus and D. opuntiae. The recovery of incomplete virulence factor-encoding genes in S. ixodetis of Dactylopius suggests that this bacterium is a non-pathogenic symbiont. A high number of genes encoding the T4SS, in the S. ixodetis genomes and the overexpression of these genes in the ovary and hemolymph of the host suggest that S. ixodetis use the T4SS to interact with the Dactylopius cells. Moreover, the transcriptional differences of S. ixodetis among the gut, hemolymph and ovary tissues of D. coccus indicate that this bacterium can respond and adapt to the different conditions (e.g., oxidative stress) present within the host. All this evidence proposes that there is a strong interaction and molecular signaling in the symbiosis between S. ixodetis and the carmine cochineal Dactylopius.
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Affiliation(s)
- Arturo Vera-Ponce León
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico. .,Present Address: Faculty of Biotechnology, Chemistry and Food Science, Norwegian University of Life Sciences, 1433, Ås, Norway.
| | - Marian Dominguez-Mirazo
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.,Present Address: School of Biology, Georgia Institute of Technology, Atlanta, GA, USA
| | - Rafael Bustamante-Brito
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Víctor Higareda-Alvear
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mónica Rosenblueth
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Esperanza Martínez-Romero
- Programa de Ecología Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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17
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Higareda Alvear VM, Mateos M, Cortez D, Tamborindeguy C, Martinez-Romero E. Differential gene expression in a tripartite interaction: Drosophila, Spiroplasma and parasitic wasps. PeerJ 2021; 9:e11020. [PMID: 33717711 PMCID: PMC7937342 DOI: 10.7717/peerj.11020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/06/2021] [Indexed: 12/13/2022] Open
Abstract
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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Affiliation(s)
| | - Mariana Mateos
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA
| | - Diego Cortez
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México
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18
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Abstract
Bacteriophages (phages) are ubiquitous in nature. These viruses play a number of central roles in microbial ecology and evolution by, for instance, promoting horizontal gene transfer (HGT) among bacterial species. The ability of phages to mediate HGT through transduction has been widely exploited as an experimental tool for the genetic study of bacteria. As such, bacteriophage P1 represents a prototypical generalized transducing phage with a broad host range that has been extensively employed in the genetic manipulation of Escherichia coli and a number of other model bacterial species. Here we demonstrate that P1 is capable of infecting, lysogenizing, and promoting transduction in members of the bacterial genus Sodalis, including the maternally inherited insect endosymbiont Sodalis glossinidius. While establishing new tools for the genetic study of these bacterial species, our results suggest that P1 may be used to deliver DNA to many Gram-negative endosymbionts in their insect host, thereby circumventing a culturing requirement to genetically manipulate these organisms. IMPORTANCE A large number of economically important insects maintain intimate associations with maternally inherited endosymbiotic bacteria. Due to the inherent nature of these associations, insect endosymbionts cannot be usually isolated in pure culture or genetically manipulated. Here we use a broad-host-range bacteriophage to deliver exogenous DNA to an insect endosymbiont and a closely related free-living species. Our results suggest that broad-host-range bacteriophages can be used to genetically alter insect endosymbionts in their insect host and, as a result, bypass a culturing requirement to genetically alter these bacteria.
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19
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Gerth M, Martinez-Montoya H, Ramirez P, Masson F, Griffin JS, Aramayo R, Siozios S, Lemaitre B, Mateos M, Hurst GDD. Rapid molecular evolution of Spiroplasma symbionts of Drosophila. Microb Genom 2021; 7:000503. [PMID: 33591248 PMCID: PMC8208695 DOI: 10.1099/mgen.0.000503] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/22/2021] [Indexed: 12/21/2022] Open
Abstract
Spiroplasma is a genus of Mollicutes whose members include plant pathogens, insect pathogens and endosymbionts of animals. 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 in comparison to other insect symbionts. 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 around two orders of magnitude higher compared with other inherited arthropod endosymbionts. 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 potentially indicates 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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Affiliation(s)
- Michael Gerth
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
- Present address: Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | - Humberto Martinez-Montoya
- Laboratorio de Genética y Genómica Comparativa, Unidad Académica Multidisciplinaria Reynosa Aztlán, Universidad Autónoma de Tamaulipas, Reynosa, Mexico
| | - Paulino Ramirez
- Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Florent Masson
- Global Health Institute, School of Life Sciences, Swiss Federal Institute of Technology Lausanne (École Polytechnique Fédérale de Lausanne), Lausanne, Switzerland
| | - Joanne S. Griffin
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Rodolfo Aramayo
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - Stefanos Siozios
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, Swiss Federal Institute of Technology Lausanne (École Polytechnique Fédérale de Lausanne), Lausanne, Switzerland
| | - Mariana Mateos
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA
| | - Gregory D. D. Hurst
- Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, UK
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20
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Masson F, Lemaitre B. Growing Ungrowable Bacteria: Overview and Perspectives on Insect Symbiont Culturability. Microbiol Mol Biol Rev 2020; 84:e00089-20. [PMID: 33177190 PMCID: PMC7667007 DOI: 10.1128/mmbr.00089-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Insects are often involved in endosymbiosis, that is, the housing of symbiotic microbes within their tissues or within their cells. Endosymbionts are a major driving force in insects' evolution, because they dramatically affect their host physiology and allow them to adapt to new niches, for example, by complementing their diet or by protecting them against pathogens. Endosymbiotic bacteria are, however, fastidious and therefore difficult to manipulate outside of their hosts, especially intracellular species. The coevolution between hosts and endosymbionts leads to alterations in the genomes of endosymbionts, limiting their ability to cope with changing environments. Consequently, few insect endosymbionts are culturable in vitro and genetically tractable, making functional genetics studies impracticable on most endosymbiotic bacteria. However, recently, major progress has been made in manipulating several intracellular endosymbiont species in vitro, leading to astonishing discoveries on their physiology and the way they interact with their host. This review establishes a comprehensive picture of the in vitro tractability of insect endosymbiotic bacteria and addresses the reason why most species are not culturable. By compiling and discussing the latest developments in the design of custom media and genetic manipulation protocols, it aims at providing new leads to expand the range of tractable endosymbionts and foster genetic research on these models.
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Affiliation(s)
- Florent Masson
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bruno Lemaitre
- Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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21
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Abstract
Tsetse flies are the insect vectors of T. brucei, the causative agent of African sleeping sickness—a zoonotic disease that inflicts a substantial economic cost on a broad region of sub-Saharan Africa. Notably, tsetse flies can be infected with the bacterium S. glossinidius to establish an asymptomatic chronic infection. This infection can be inherited by future generations of tsetse flies, allowing S. glossinidius to spread and persist within populations. To this effect, S. glossinidius has been considered a potential expression platform to create flies which reduce T. brucei stasis and lower overall parasite transmission to humans and animals. However, the efficient genetic manipulation of S. glossinidius has remained a technical challenge due to its complex growth requirements and uncharacterized physiology. Here, we exploit a natural mechanism of DNA transfer among bacteria and develop an efficient technique to genetically manipulate S. glossinidius for future studies in reducing trypanosome transmission. Stable associations between insects and bacterial species are widespread in nature. This is the case for many economically important insects, such as tsetse flies. Tsetse flies are the vectors of Trypanosoma brucei, the etiological agent of African trypanosomiasis—a zoonotic disease that incurs a high socioeconomic cost in regions of endemicity. Populations of tsetse flies are often infected with the bacterium Sodalis glossinidius. Following infection, S. glossinidius establishes a chronic, stable association characterized by vertical (maternal) and horizontal (paternal) modes of transmission. Due to the stable nature of this association, S. glossinidius has been long sought as a means for the implementation of anti-Trypanosoma paratransgenesis in tsetse flies. However, the lack of tools for the genetic modification of S. glossinidius has hindered progress in this area. Here, we establish that S. glossinidius is amenable to DNA uptake by conjugation. We show that conjugation can be used as a DNA delivery method to conduct forward and reverse genetic experiments in this bacterium. This study serves as an important step in the development of genetic tools for S. glossinidius. The methods highlighted here should guide the implementation of genetics for the study of the tsetse-Sodalis association and the evaluation of S. glossinidius-based tsetse fly paratransgenesis strategies. IMPORTANCE Tsetse flies are the insect vectors of T. brucei, the causative agent of African sleeping sickness—a zoonotic disease that inflicts a substantial economic cost on a broad region of sub-Saharan Africa. Notably, tsetse flies can be infected with the bacterium S. glossinidius to establish an asymptomatic chronic infection. This infection can be inherited by future generations of tsetse flies, allowing S. glossinidius to spread and persist within populations. To this effect, S. glossinidius has been considered a potential expression platform to create flies which reduce T. brucei stasis and lower overall parasite transmission to humans and animals. However, the efficient genetic manipulation of S. glossinidius has remained a technical challenge due to its complex growth requirements and uncharacterized physiology. Here, we exploit a natural mechanism of DNA transfer among bacteria and develop an efficient technique to genetically manipulate S. glossinidius for future studies in reducing trypanosome transmission.
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Phenotypic Response of Wolbachia pipientis in a Cell-Free Medium. Microorganisms 2020; 8:microorganisms8071060. [PMID: 32708688 PMCID: PMC7409048 DOI: 10.3390/microorganisms8071060] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/30/2020] [Accepted: 07/14/2020] [Indexed: 12/22/2022] Open
Abstract
Wolbachia, an obligate intracellular bacterium estimated to infect millions of arthropod species worldwide, is currently being utilized in novel control strategies to limit the transmission of Dengue and Zika viruses. A limitation for Wolbachia-based control approaches is the difficulty of transferring Wolbachia to novel hosts and the lack of tools for the genetic transformation of Wolbachia due to the inability to culture Wolbachia outside the insect host cell in an axenic media. Here, we applied extracellular Wolbachia to phenotypic microarrays to measure the metabolic response of Wolbachia in media formulations with different pH levels and supplementation with Casamino acids. Results suggested a pH of 6.5–6.8 and showed that the supplementation of 1 mg/mL casamino acids increased the survival and longevity of Wolbachia in an axenic medium. In addition, phenotypic microarrays are a useful tool to measure the phenotypic response of Wolbachia under different media conditions, as well as determine specific components that may be required for an axenic medium. This study is an initial step toward the development of a potential Wolbachia axenic culture system.
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Transformation of the Drosophila Sex-Manipulative Endosymbiont Spiroplasma poulsonii and Persisting Hurdles for Functional Genetic Studies. Appl Environ Microbiol 2020; 86:AEM.00835-20. [PMID: 32444468 DOI: 10.1128/aem.00835-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/12/2020] [Indexed: 01/07/2023] Open
Abstract
Insects are frequently infected by bacterial symbionts that greatly affect their physiology and ecology. Most of these endosymbionts are, however, barely tractable outside their native host, rendering functional genetics studies difficult or impossible. Spiroplasma poulsonii is a facultative bacterial endosymbiont of Drosophila melanogaster that manipulates the reproduction of its host by killing its male progeny at the embryonic stage. S. poulsonii, although a very fastidious bacterium, is closely related to pathogenic Spiroplasma species that are cultivable and genetically modifiable. In this work, we present the transformation of S. poulsonii with a plasmid bearing a fluorescence cassette, leveraging techniques adapted from those used to modify the pathogenic species Spiroplasma citri We demonstrate the feasibility of S. poulsonii transformation and discuss approaches for mutant selection and fly colonization, which are persisting hurdles that must be overcome to allow functional bacterial genetics studies of this endosymbiont in vivo IMPORTANCE Dozens of bacterial endosymbiont species have been described and estimated to infect about half of all insect species. However, only a few them are tractable in vitro, which hampers our understanding of the bacterial determinants of the host-symbiont interaction. Developing a transformation method for S. poulsonii is a major step toward genomic engineering of this symbiont, which will foster basic research on endosymbiosis. This could also open the way to practical uses of endosymbiont engineering through paratransgenesis of vector or pest insects.
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Masson F, Calderon‐Copete S, Schüpfer F, Vigneron A, Rommelaere S, Garcia‐Arraez MG, Paredes JC, Lemaitre B. Blind killing of both male and female Drosophila embryos by a natural variant of the endosymbiotic bacterium Spiroplasma poulsonii. Cell Microbiol 2020; 22:e13156. [PMID: 31912942 PMCID: PMC7187355 DOI: 10.1111/cmi.13156] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 02/07/2023]
Abstract
Spiroplasma poulsonii is a vertically transmitted endosymbiont of Drosophila melanogaster that causes male-killing, that is the death of infected male embryos during embryogenesis. Here, we report a natural variant of S. poulsonii that is efficiently vertically transmitted yet does not selectively kill males, but kills rather a subset of all embryos regardless of their sex, a phenotype we call 'blind-killing'. We show that the natural plasmid of S. poulsonii has an altered structure: Spaid, the gene coding for the male-killing toxin, is deleted in the blind-killing strain, confirming its function as a male-killing factor. Then we further investigate several hypotheses that could explain the sex-independent toxicity of this new strain on host embryos. As the second non-male-killing variant isolated from a male-killing original population, this new strain raises questions on how male-killing is maintained or lost in fly populations. As a natural knock-out of Spaid, which is unachievable yet by genetic engineering approaches, this variant also represents a valuable tool for further investigations on the male-killing mechanism.
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Affiliation(s)
- Florent Masson
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Sandra Calderon‐Copete
- Center for Integrative GenomicsLausanne Genomic Technologies FacilityLausanneSwitzerland
| | - Fanny Schüpfer
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Aurélien Vigneron
- Department of Epidemiology of Microbial DiseasesYale School of Public HealthNew HavenConnecticut
| | - Samuel Rommelaere
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Mario G. Garcia‐Arraez
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
| | - Juan C. Paredes
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
- Present address:
International Centre of Insect Physiology and Ecology (ICIPE)KasaraniNairobiKenya
| | - Bruno Lemaitre
- Global Health Institute, School of Life SciencesÉcole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland
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Arai H, Lin SR, Nakai M, Kunimi Y, Inoue MN. Closely Related Male-Killing and Nonmale-Killing Wolbachia Strains in the Oriental Tea Tortrix Homona magnanima. MICROBIAL ECOLOGY 2020; 79:1011-1020. [PMID: 31820073 DOI: 10.1007/s00248-019-01469-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 11/25/2019] [Indexed: 06/10/2023]
Abstract
Wolbachia are inherited intracellular bacteria that cause male-specific death in some arthropods, called male-killing. To date, three Wolbachia strains have been identified in the oriental tea tortrix Homona magnanima (Tortricidae, Lepidoptera); however, none of these caused male-killing in the Japanese population. Here, we describe a male-killing Wolbachia strain in Taiwanese H. magnanima. From field-collected H. magnanima, two female-biased host lines were established, and antibiotic treatments revealed Wolbachia (wHm-t) as the causative agent of male-killing. The wsp and MLST genes in wHm-t are identical to corresponding genes in the nonmale-killing strain wHm-c from the Japanese population, implying a close relationship of the two strains. Crossing the Japanese and Taiwanese H. magnanima revealed that Wolbachia genotype rather than the host genetic background was responsible for the presence of the male-killing phenotype. Quantitative PCR analyses revealed that the density of wHm-t was higher than that of other Wolbachia strains in H. magnanima, including wHm-c. The densities of wHm-t were also heterogeneous between host lines. Notably, wHm-t in the low-density and high-density lines carried identical wsp and MLST genes but had distinct lethal patterns. Furthermore, over 90% of field-collected lines of H. magnanima in Taiwan were infected with wHm-t, although not all host lines harboring wHm-t showed male-killing. The host lines that showed male-killing harbored a high density of Wolbachia compared to the host lines that did not show male-killing. Thus, the differences in the phenotypes appear to be dependent on biological and genetic characteristics of closely related Wolbachia strains.
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Affiliation(s)
- Hiroshi Arai
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo, 183-8509, Japan
| | - Shiou Ruei Lin
- Department of Tea Agronomy Tea Research and Extension Station, 324 Chung-Hsing RD., Yangmei, Taoyuan, Taiwan
| | - Madoka Nakai
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo, 183-8509, Japan
| | - Yasuhisa Kunimi
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo, 183-8509, Japan
| | - Maki N Inoue
- Department of Applied Biological Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo, 183-8509, Japan.
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Patel V, Chevignon G, Manzano-Marín A, Brandt JW, Strand MR, Russell JA, Oliver KM. Cultivation-Assisted Genome of Candidatus Fukatsuia symbiotica; the Enigmatic "X-Type" Symbiont of Aphids. Genome Biol Evol 2020; 11:3510-3522. [PMID: 31725149 PMCID: PMC7145644 DOI: 10.1093/gbe/evz252] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2019] [Indexed: 12/19/2022] Open
Abstract
Heritable symbionts are common in terrestrial arthropods and often provide beneficial services to hosts. Unlike obligate, nutritional symbionts that largely persist under strict host control within specialized host cells, heritable facultative symbionts exhibit large variation in within-host lifestyles and services rendered with many retaining the capacity to transition among roles. One enigmatic symbiont, Candidatus Fukatsuia symbiotica, frequently infects aphids with reported roles ranging from pathogen, defensive symbiont, mutualism exploiter, and nutritional co-obligate symbiont. Here, we used an in vitro culture-assisted protocol to sequence the genome of a facultative strain of Fukatsuia from pea aphids (Acyrthosiphon pisum). Phylogenetic and genomic comparisons indicate that Fukatsuia is an aerobic heterotroph, which together with Regiella insecticola and Hamiltonella defensa form a clade of heritable facultative symbionts within the Yersiniaceae (Enterobacteriales). These three heritable facultative symbionts largely share overlapping inventories of genes associated with housekeeping functions, metabolism, and nutrient acquisition, while varying in complements of mobile DNA. One unusual feature of Fukatsuia is its strong tendency to occur as a coinfection with H. defensa. However, the overall similarity of gene inventories among aphid heritable facultative symbionts suggests that metabolic complementarity is not the basis for coinfection, unless playing out on a H. defensa strain-specific basis. We also compared the pea aphid Fukatsuia with a strain from the aphid Cinara confinis (Lachninae) where it is reported to have transitioned to co-obligate status to support decaying Buchnera function. Overall, the two genomes are very similar with no clear genomic signatures consistent with such a transition, which suggests co-obligate status in C. confinis was a recent event.
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Affiliation(s)
- Vilas Patel
- Department of Entomology, University of Georgia
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27
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Frank AC. Molecular host mimicry and manipulation in bacterial symbionts. FEMS Microbiol Lett 2019; 366:5342066. [PMID: 30877310 DOI: 10.1093/femsle/fnz038] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 02/18/2019] [Indexed: 12/17/2022] Open
Abstract
It is common among intracellular bacterial pathogens to use eukaryotic-like proteins that mimic and manipulate host cellular processes to promote colonization and intracellular survival. Eukaryotic-like proteins are bacterial proteins with domains that are rare in bacteria, and known to function in the context of a eukaryotic cell. Such proteins can originate through horizontal gene transfer from eukaryotes or, in the case of simple repeat proteins, through convergent evolution. Recent studies of microbiomes associated with several eukaryotic hosts suggest that similar molecular strategies are deployed by cooperative bacteria that interact closely with eukaryotic cells. Some mimics, like ankyrin repeats, leucine rich repeats and tetratricopeptide repeats are shared across diverse symbiotic systems ranging from amoebae to plants, and may have originated early, or evolved independently in multiple systems. Others, like plant-mimicking domains in members of the plant microbiome are likely to be more recent innovations resulting from horizontal gene transfer from the host, or from microbial eukaryotes occupying the same host. Host protein mimics have only been described in a limited set of symbiotic systems, but are likely to be more widespread. Systematic searches for eukaryote-like proteins in symbiont genomes could lead to the discovery of novel mechanisms underlying host-symbiont interactions.
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Affiliation(s)
- A Carolin Frank
- Life and Environmental Sciences, 5200 North Lake Rd, University of California Merced, Merced, CA 95343, USA.,Sierra Nevada Research Institute, School of Natural Sciences, 5200 North Lake Rd, University of California Merced, Merced, CA 95343, USA
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Spiroplasma eriocheiris Enters Drosophila Schneider 2 Cells and Relies on Clathrin-Mediated Endocytosis and Macropinocytosis. Infect Immun 2019; 87:IAI.00233-19. [PMID: 31451616 DOI: 10.1128/iai.00233-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 08/15/2019] [Indexed: 11/20/2022] Open
Abstract
Spiroplasma eriocheiris causes great economic losses in the crustacean aquaculture industry. However, the mechanism of S. eriocheiris infecting host cells has been poorly studied. We established a Spiroplasma-infected Drosophila Schneider 2 (S2) cell model and investigated its pathogenic mechanism. First, S. eriocheiris induced S2 cell apoptosis and necrosis, seriously decreased cell viability, and increased the production of intracellular reactive oxygen species. Further research showed that S. eriocheiris can invade S2 cells, and the number of copies of intracellular spiroplasmas is sharply increased by 12 h postinfection. In addition, S. eriocheiris can cause S2 cells to form typical inclusion bodies and exhibit large vacuoles. Second, S. eriocheiris is internalized into S2 cells and strongly inhibited through blocking clathrin-mediated endocytosis using chlorpromazine and dynasore. Inhibitors of macropinocytosis, protein kinase C and myosin II, cause a significant reduction in S. eriocheiris in S2 cells. In contrast, disruption of cellular cholesterol by methyl-β-cyclodextrin and nystatin has no effect on S. eriocheiris infection. These results suggest that the entry of S. eriocheiris into S2 cells relies on clathrin-dependent endocytosis and macropinocytosis, but not via the caveola-mediated endocytic pathway. In addition, the intracellular numbers of S. eriocheiris are dramatically reduced after S2 cells are treated with cytoskeleton-depolymerizing agents, including nocodazole and cytochalasin B. Thus, cellular infection by S. eriocheiris is related to microtubules and actin filaments. This research successfully shows for the first time that S. eriocheiris can invade Drosophila S2 cells and provides a process for S. eriocheiris infection.
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29
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Nadal-Jimenez P, Griffin JS, Davies L, Frost CL, Marcello M, Hurst GDD. Genetic manipulation allows in vivo tracking of the life cycle of the son-killer symbiont, Arsenophonus nasoniae, and reveals patterns of host invasion, tropism and pathology. Environ Microbiol 2019; 21:3172-3182. [PMID: 31237728 PMCID: PMC6771839 DOI: 10.1111/1462-2920.14724] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 12/17/2022]
Abstract
Maternally heritable symbionts are common in arthropods and represent important partners and antagonists. A major impediment to understanding the mechanistic basis of these symbioses has been lack of genetic manipulation tools, for instance, those enabling transgenic GFP expression systems for in vivo visualization. Here, we transform the ‘son‐killer’ reproductive parasite Arsenophonus nasoniae that infects the parasitic wasp Nasonia vitripennis with the plasmid pOM1‐gfp, re‐introduce this strain to N. vitripennis and then used this system to track symbiont life history in vivo. These data revealed transfer of the symbiont into the fly pupa by N. vitripennis during oviposition and N. vitripennis larvae developing infection over time through feeding. A strong tropism of A. nasoniae to the N. vitripennis ovipositor developed during wasp pupation, which aids onward transmission. The symbiont was also visualized in diapause larvae. Occasional necrotic diapause larvae were observed which displayed intense systemic infection alongside widespread melanotic nodules indicative of an active but failed immune response. Our results provide the foundation for the study of this symbiosis through in vivo tracking of the fate of symbionts through host development, which is rarely achieved in heritable microbe/insect interactions.
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Affiliation(s)
- Pol Nadal-Jimenez
- Institute for Integrative Biology, University of Liverpool, Liverpool, UK
| | - Joanne S Griffin
- Institute for Integrative Biology, University of Liverpool, Liverpool, UK
| | - Lianne Davies
- Institute for Integrative Biology, University of Liverpool, Liverpool, UK
| | - Crystal L Frost
- Institute for Integrative Biology, University of Liverpool, Liverpool, UK
| | - Marco Marcello
- Institute for Integrative Biology, University of Liverpool, Liverpool, UK
| | - Gregory D D Hurst
- Institute for Integrative Biology, University of Liverpool, Liverpool, UK
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30
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Merfa MV, Pérez-López E, Naranjo E, Jain M, Gabriel DW, De La Fuente L. Progress and Obstacles in Culturing ' Candidatus Liberibacter asiaticus', the Bacterium Associated with Huanglongbing. PHYTOPATHOLOGY 2019; 109:1092-1101. [PMID: 30998129 DOI: 10.1094/phyto-02-19-0051-rvw] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In recent decades, 'Candidatus Liberibacter spp.' have emerged as a versatile group of psyllid-vectored plant pathogens and endophytes capable of infecting a wide range of economically important plant hosts. The most notable example is 'Candidatus Liberibacter asiaticus' (CLas) associated with Huanglongbing (HLB) in several major citrus-producing areas of the world. CLas is a phloem-limited α-proteobacterium that is primarily vectored and transmitted among citrus species by the Asian citrus psyllid (ACP) Diaphorina citri. HLB was first detected in North America in Florida (USA) in 2005, following introduction of the ACP to the State in 1998. HLB rapidly spread to all citrus growing regions of Florida within three years, with severe economic consequences to growers and considerable expense to taxpayers of the state and nation. Inability to establish CLas in culture (except transiently) remains a significant scientific challenge toward effective HLB management. Lack of axenic cultures has restricted functional genomic analyses, transfer of CLas to either insect or plant hosts for fulfillment of Koch's postulates, characterization of host-pathogen interactions and effective screening of antibacterial compounds. In the last decade, substantial progress has been made toward CLas culturing: (i) three reports of transient CLas cultures were published, (ii) a new species of Liberibacter was identified and axenically cultured from diseased mountain papaya (Liberibacter crescens strain BT-1), (iii) psyllid hemolymph and citrus phloem sap were biochemically characterized, (iv) CLas phages were identified and lytic genes possibly affecting CLas growth were described, and (v) genomic sequences of 15 CLas strains were made available. In addition, development of L. crescens as a surrogate host for functional analyses of CLas genes, has provided valuable insights into CLas pathogenesis and its physiological dependence on the host cell. In this review we summarize the conclusions from these important studies.
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Affiliation(s)
- Marcus V Merfa
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
| | - Edel Pérez-López
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
| | - Eber Naranjo
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
| | - Mukesh Jain
- 2 Department of Plant Pathology, University of Florida, Gainesville, FL 32611, U.S.A
| | - Dean W Gabriel
- 2 Department of Plant Pathology, University of Florida, Gainesville, FL 32611, U.S.A
| | - Leonardo De La Fuente
- 1 Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, U.S.A
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van Oppen MJH, Blackall LL. Coral microbiome dynamics, functions and design in a changing world. Nat Rev Microbiol 2019; 17:557-567. [DOI: 10.1038/s41579-019-0223-4] [Citation(s) in RCA: 137] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2019] [Indexed: 12/20/2022]
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Mateos M, Silva NO, Ramirez P, Higareda-Alvear VM, Aramayo R, Erickson JW. Effect of heritable symbionts on maternally-derived embryo transcripts. Sci Rep 2019; 9:8847. [PMID: 31222094 PMCID: PMC6586653 DOI: 10.1038/s41598-019-45371-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 05/28/2019] [Indexed: 11/09/2022] Open
Abstract
Maternally-transmitted endosymbiotic bacteria are ubiquitous in insects. Among other influential phenotypes, many heritable symbionts of arthropods are notorious for manipulating host reproduction through one of four reproductive syndromes, which are generally exerted during early developmental stages of the host: male feminization; parthenogenesis induction; male killing; and cytoplasmic incompatibility (CI). Major advances have been achieved in understanding mechanisms and identifying symbiont factors involved in reproductive manipulation, particularly male killing and cytoplasmic incompatibility. Nonetheless, whether cytoplasmically-transmitted bacteria influence the maternally-loaded components of the egg or early embryo has not been examined. In the present study, we investigated whether heritable endosymbionts that cause different reproductive phenotypes in Drosophila melanogaster influence the mRNA transcriptome of early embryos. We used mRNA-seq to evaluate differential expression in Drosophila embryos lacking endosymbionts (control) to those harbouring the male-killing Spiroplasma poulsonii strain MSRO-Br, the CI-inducing Wolbachia strain wMel, or Spiroplasma poulsonii strain Hyd1; a strain that lacks a reproductive phenotype and is naturally associated with Drosophila hydei. We found no consistent evidence of influence of symbiont on mRNA composition of early embryos, suggesting that the reproductive manipulation mechanism does not involve alteration of maternally-loaded transcripts. In addition, we capitalized on several available mRNA-seq datasets derived from Spiroplasma-infected Drosophila melanogaster embryos, to search for signals of depurination of rRNA, consistent with the activity of Ribosome Inactivating Proteins (RIPs) encoded by Spiroplasma poulsonii. We found small but statistically significant signals of depurination of Drosophila rRNA in the Spiroplasma treatments (both strains), but not in the symbiont-free control or Wolbachia treatment, consistent with the action of RIPs. The depurination signal was slightly stronger in the treatment with the male-killing strain. This result supports a recent report that RIP-induced damage contributes to male embryo death.
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Affiliation(s)
- Mariana Mateos
- Department Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA.
| | - Nadisha O Silva
- Department Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA.,Department Biology, Texas A&M University, College Station, TX, USA
| | - Paulino Ramirez
- Department Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA
| | - Victor M Higareda-Alvear
- Centro de Ciencias Genómicas (CCG), Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, Mexico
| | - Rodolfo Aramayo
- Department Biology, Texas A&M University, College Station, TX, USA
| | - James W Erickson
- Department Biology, Texas A&M University, College Station, TX, USA
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Ballinger MJ, Perlman SJ. The defensive Spiroplasma. CURRENT OPINION IN INSECT SCIENCE 2019; 32:36-41. [PMID: 31113629 DOI: 10.1016/j.cois.2018.10.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/11/2018] [Accepted: 10/15/2018] [Indexed: 05/06/2023]
Abstract
Defensive microbes are of great interest for their roles in arthropod health, disease transmission, and biocontrol efforts. Obligate bacterial passengers of arthropods, such as Spiroplasma, confer protection against the natural enemies of their hosts to improve their own fitness. Although known for less than a decade, Spiroplasma's defensive reach extends to diverse parasites, both microbial and multicellular. We provide an overview of known defensive phenotypes against nematodes, parasitoid wasps, and fungi, and highlight recent studies supporting the role of Spiroplasma-encoded ribosome-inactivating proteins in protection. With cellular features well-suited for life in the hemolymph, broad distribution among invertebrate hosts, and the capacity to repeatedly evolve vertical transmission, Spiroplasma may be uniquely equipped to form intimate, defensive associations to combat extracellular parasites. Along with insights into defensive mechanisms, recent significant advances have been made in male-killing - a phenotype with interesting evolutionary ties to defense. Finally, we look forward to an exciting decade using the genetic tools of Drosophila, and the rapidly-advancing tractability of Spiroplasma itself, to better understand mechanisms and evolution in defensive symbiosis.
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Affiliation(s)
- Matthew J Ballinger
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, 39762, USA.
| | - Steve J Perlman
- Department of Biology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
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Gil R, Latorre A. Unity Makes Strength: A Review on Mutualistic Symbiosis in Representative Insect Clades. Life (Basel) 2019; 9:E21. [PMID: 30823538 PMCID: PMC6463088 DOI: 10.3390/life9010021] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/11/2019] [Accepted: 02/19/2019] [Indexed: 12/14/2022] Open
Abstract
Settled on the foundations laid by zoologists and embryologists more than a century ago, the study of symbiosis between prokaryotes and eukaryotes is an expanding field. In this review, we present several models of insect⁻bacteria symbioses that allow for the detangling of most known features of this distinctive way of living, using a combination of very diverse screening approaches, including molecular, microscopic, and genomic techniques. With the increasing the amount of endosymbiotic bacteria genomes available, it has been possible to develop evolutionary models explaining the changes undergone by these bacteria in their adaptation to the intracellular host environment. The establishment of a given symbiotic system can be a root cause of substantial changes in the partners' way of life. Furthermore, symbiont replacement and/or the establishment of bacterial consortia are two ways in which the host can exploit its interaction with environmental bacteria for endosymbiotic reinvigoration. The detailed study of diverse and complex symbiotic systems has revealed a great variety of possible final genomic products, frequently below the limit considered compatible with cellular life, and sometimes with unanticipated genomic and population characteristics, raising new questions that need to be addressed in the near future through a wider exploration of new models and empirical observations.
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Affiliation(s)
- Rosario Gil
- Institute for Integrative Systems Biology (I2SysBio), Universitat de València/CSIC. Calle Catedrático Agustín Escardino, 9, 46980 Paterna (Valencia), Spain.
- Departament de Genètica, Universitat de València. Calle Dr. Moliner, 50, 46100 Burjassot (València), Spain.
- Área de Genómica y Salud, Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO). Avenida de Cataluña 21, 46020 València, Spain.
| | - Amparo Latorre
- Institute for Integrative Systems Biology (I2SysBio), Universitat de València/CSIC. Calle Catedrático Agustín Escardino, 9, 46980 Paterna (Valencia), Spain.
- Departament de Genètica, Universitat de València. Calle Dr. Moliner, 50, 46100 Burjassot (València), Spain.
- Área de Genómica y Salud, Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO). Avenida de Cataluña 21, 46020 València, Spain.
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Garcia-Arraez MG, Masson F, Escobar JCP, Lemaitre B. Functional analysis of RIP toxins from the Drosophila endosymbiont Spiroplasma poulsonii. BMC Microbiol 2019; 19:46. [PMID: 30786854 PMCID: PMC6383259 DOI: 10.1186/s12866-019-1410-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 01/31/2019] [Indexed: 01/09/2023] Open
Abstract
Background Insects frequently live in close relationship with symbiotic bacteria that carry out beneficial functions for their host, like protection against parasites and viruses. However, in some cases, the mutualistic nature of such associations is put into question because of detrimental phenotypes caused by the symbiont. One example is the association between the vertically transmitted facultative endosymbiont Spiroplasma poulsonii and its natural host Drosophila melanogaster. Whereas S. poulsonii protects its host against parasitoid wasps and nematodes by the action of toxins from the family of Ribosome Inactivating Proteins (RIPs), the presence of S. poulsonii has been reported to reduce host’s life span and to kill male embryos by a toxin called Spaid. In this work, we investigate the harmful effects of Spiroplasma RIPs on Drosophila in the absence of parasite infection. Results We show that only two Spiroplasma RIPs (SpRIP1 and SpRIP2) among the five RIP genes encoded in the S. poulsonii genome are significantly expressed during the whole Drosophila life cycle. Heterologous expression of SpRIP1 and 2 in uninfected flies confirms their toxicity, as indicated by a reduction of Drosophila lifespan and hemocyte number. We also show that RIPs can cause the death of some embryos, including females. Conclusion Our results indicate that RIPs released by S. poulsonii contribute to the reduction of host lifespan and embryo mortality. This suggests that SpRIPs may impact the insect-symbiont homeostasis beyond their protective function against parasites. Electronic supplementary material The online version of this article (10.1186/s12866-019-1410-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mario Gonzalo Garcia-Arraez
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Florent Masson
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | | | - Bruno Lemaitre
- Global Health Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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Ballinger MJ, Gawryluk RMR, Perlman SJ. Toxin and Genome Evolution in a Drosophila Defensive Symbiosis. Genome Biol Evol 2019; 11:253-262. [PMID: 30576446 PMCID: PMC6349354 DOI: 10.1093/gbe/evy272] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2018] [Indexed: 12/25/2022] Open
Abstract
Defenses conferred by microbial symbionts play a vital role in the health and fitness of their animal hosts. An important outstanding question in the study of defensive symbiosis is what determines long term stability and effectiveness against diverse natural enemies. In this study, we combine genome and transcriptome sequencing, symbiont transfection and parasite protection experiments, and toxin activity assays to examine the evolution of the defensive symbiosis between Drosophila flies and their vertically transmitted Spiroplasma bacterial symbionts, focusing in particular on ribosome-inactivating proteins (RIPs), symbiont-encoded toxins that have been implicated in protection against both parasitic wasps and nematodes. Although many strains of Spiroplasma, including the male-killing symbiont (sMel) of Drosophila melanogaster, protect against parasitic wasps, only the strain (sNeo) that infects the mycophagous fly Drosophila neotestacea appears to protect against parasitic nematodes. We find that RIP repertoire is a major differentiating factor between strains that do and do not offer nematode protection, and that sMel RIPs do not show activity against nematode ribosomes in vivo. We also discovered a strain of Spiroplasma infecting a mycophagous phorid fly, Megaselia nigra. Although both the host and its Spiroplasma are distantly related to D. neotestacea and its symbiont, genome sequencing revealed that the M. nigra symbiont encodes abundant and diverse RIPs, including plasmid-encoded toxins that are closely related to the RIPs in sNeo. Our results suggest that distantly related Spiroplasma RIP toxins may perform specialized functions with regard to parasite specificity and suggest an important role for horizontal gene transfer in the emergence of novel defensive phenotypes.
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Affiliation(s)
- Matthew J Ballinger
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS
| | - Ryan M R Gawryluk
- Department of Biology, University of Victoria, British Columbia, Canada
| | - Steve J Perlman
- Department of Biology, University of Victoria, British Columbia, Canada
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Gillespie JJ, Driscoll TP, Verhoeve VI, Rahman MS, Macaluso KR, Azad AF. A Tangled Web: Origins of Reproductive Parasitism. Genome Biol Evol 2018; 10:2292-2309. [PMID: 30060072 PMCID: PMC6133264 DOI: 10.1093/gbe/evy159] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2018] [Indexed: 12/13/2022] Open
Abstract
While typically a flea parasite and opportunistic human pathogen, the presence of Rickettsia felis (strain LSU-Lb) in the non-blood-feeding, parthenogenetically reproducing booklouse, Liposcelis bostrychophila, provides a system to ascertain factors governing not only host transitions but also obligate reproductive parasitism (RP). Analysis of plasmid pLbAR, unique to R. felis str. LSU-Lb, revealed a toxin–antitoxin module with similar features to prophage-encoded toxin–antitoxin modules utilized by parasitic Wolbachia strains to induce another form of RP, cytoplasmic incompatibility, in their arthropod hosts. Curiously, multiple deubiquitinase and nuclease domains of the large (3,841 aa) pLbAR toxin, as well the entire antitoxin, facilitated the detection of an assortment of related proteins from diverse intracellular bacteria, including other reproductive parasites. Our description of these remarkable components of the intracellular mobilome, including their presence in certain arthropod genomes, lends insight on the evolution of RP, while invigorating research on parasite-mediated biocontrol of arthropod-borne viral and bacterial pathogens.
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Affiliation(s)
- Joseph J Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine
| | | | | | | | - Kevin R Macaluso
- Vector-borne Disease Laboratories, Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University
| | - Abdu F Azad
- Department of Microbiology and Immunology, University of Maryland School of Medicine
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