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Tan Y, Aravind L, Zhang D. Genomic Underpinnings of Cytoplasmic Incompatibility: CIF Gene-Neighborhood Diversification Through Extensive Lateral Transfers and Recombination in Wolbachia. Genome Biol Evol 2024; 16:evae171. [PMID: 39106433 PMCID: PMC11342252 DOI: 10.1093/gbe/evae171] [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: 12/18/2023] [Revised: 07/30/2024] [Accepted: 07/31/2024] [Indexed: 08/09/2024] Open
Abstract
Cytoplasmic incompatibility (CI), a non-Mendelian genetic phenomenon, involves the manipulation of host reproduction by Wolbachia, a maternally transmitted alphaproteobacterium. The underlying mechanism is centered around the CI Factor (CIF) system governed by two genes, cifA and cifB, where cifB induces embryonic lethality, and cifA counteracts it. Recent investigations have unveiled intriguing facets of this system, including diverse cifB variants, prophage association in specific strains, copy number variation, and rapid component divergence, hinting at a complex evolutionary history. We utilized comparative genomics to systematically classify CIF systems, analyze their locus structure and domain architectures, and reconstruct their diversification and evolutionary trajectories. Our new classification identifies ten distinct CIF types, featuring not just versions present in Wolbachia, but also other intracellular bacteria, and eukaryotic hosts. Significantly, our analysis of CIF loci reveals remarkable variability in gene composition and organization, encompassing an array of diverse endonucleases, variable toxin domains, deubiquitinating peptidases (DUBs), prophages, and transposons. We present compelling evidence that the components within the loci have been diversifying their sequences and domain architectures through extensive, independent lateral transfers and interlocus recombination involving gene conversion. The association with diverse transposons and prophages, coupled with selective pressures from host immunity, likely underpins the emergence of CIF loci as recombination hotspots. Our investigation also posits the origin of CifB-REase domains from mobile elements akin to CR (Crinkler-RHS-type) effectors and Tribolium Medea1 factor, which is linked to another non-Mendelian genetic phenomenon. This comprehensive genomic analysis offers novel insights into the molecular evolution and genomic foundations of Wolbachia-mediated host reproductive control.
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Affiliation(s)
- Yongjun Tan
- Department of Biology, College of Arts and Sciences, Saint Louis University, St. Louis, MO 63103, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Dapeng Zhang
- Department of Biology, College of Arts and Sciences, Saint Louis University, St. Louis, MO 63103, USA
- Program of Bioinformatics and Computational Biology, College of Arts and Sciences, Saint Louis University, St. Louis, MO 63103, USA
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2
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Lehman SS, Verhoeve VI, Driscoll TP, Beckmann JF, Gillespie JJ. Metagenome diversity illuminates the origins of pathogen effectors. mBio 2024; 15:e0075923. [PMID: 38564675 PMCID: PMC11077975 DOI: 10.1128/mbio.00759-23] [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: 03/27/2023] [Accepted: 02/12/2024] [Indexed: 04/04/2024] Open
Abstract
Recent metagenome-assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. The discovery of basal lineages (novel families Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles exposed an evolutionary timepoint for the transition to host dependency, which seemingly occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for later-evolving rickettsial pathogens. MAG analysis also substantially increased diversity for the genus Rickettsia and delineated a sister lineage (the novel genus Tisiphia) that stands to inform on the emergence of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages illuminates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, indicating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role in shaping the rvh effector landscape, as evinced by the discovery of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can yield insight into pathogen effector origins, particularly how effector architectures might become tailored to the discrete host cell functions of different eukaryotic hosts.IMPORTANCEWhile rickettsioses are deadly vector-borne human diseases, factors distinguishing Rickettsia pathogens from the innumerable bevy of environmental rickettsial endosymbionts remain lacking. Recent metagenome-assembled genome (MAG) studies revealed evolutionary timepoints for rickettsial transitions to host dependency. The rvh type IV secretion system was likely repurposed from congener killing in basal extracellular species to parasitizing host cells in later-evolving pathogens. Our analysis of MAG diversity for over two dozen rvh effectors unearthed their presence in some non-pathogens. However, most effectors were found in multiple divergent forms with variable architectures, indicating gene duplication and recombination-fashioned effector repertoires of Rickettsia pathogens. Lateral gene transfer substantially shaped pathogen effector arsenals, evinced by the discovery of effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchanges between Rickettsia and Legionella species. Our study exemplifies how MAGs yield insight into pathogen effector origins and evolutionary processes tailoring effectors to eukaryotic host cell biology.
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Affiliation(s)
- Stephanie S. Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Victoria I. Verhoeve
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Timothy P. Driscoll
- Department of Biology, West Virginia University, Morgantown, West Virginia, USA
| | - John F. Beckmann
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, USA
| | - Joseph J. Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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3
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Penunuri G, Wang P, Corbett-Detig R, Russell SL. A Structural Proteome Screen Identifies Protein Mimicry in Host-Microbe Systems. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.10.588793. [PMID: 38645127 PMCID: PMC11030372 DOI: 10.1101/2024.04.10.588793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Host-microbe systems are evolutionary niches that produce coevolved biological interactions and are a key component of global health. However, these systems have historically been a difficult field of biological research due to their experimental intractability. Impactful advances in global health will be obtained by leveraging in silico screens to identify genes involved in mediating interspecific interactions. These predictions will progress our understanding of these systems and lay the groundwork for future in vitro and in vivo experiments and bioengineering projects. A driver of host-manipulation and intracellular survival utilized by host-associated microbes is molecular mimicry, a critical mechanism that can occur at any level from DNA to protein structures. We applied protein structure prediction and alignment tools to explore host-associated bacterial structural proteomes for examples of protein structure mimicry. By leveraging the Legionella pneumophila proteome and its many known structural mimics, we developed and validated a screen that can be applied to virtually any host-microbe system to uncover signals of protein mimicry. These mimics represent candidate proteins that mediate host interactions in microbial proteomes. We successfully applied this screen to other microbes with demonstrated effects on global health, Helicobacter pylori and Wolbachia , identifying protein mimic candidates in each proteome. We discuss the roles these candidates may play in important Wolbachia -induced phenotypes and show that Wobachia infection can partially rescue the loss of one of these factors. This work demonstrates how a genome-wide screen for candidates of host-manipulation and intracellular survival offers an opportunity to identify functionally important genes in host-microbe systems.
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Kaur R, McGarry A, Shropshire JD, Leigh BA, Bordenstein SR. Prophage proteins alter long noncoding RNA and DNA of developing sperm to induce a paternal-effect lethality. Science 2024; 383:1111-1117. [PMID: 38452081 PMCID: PMC11187695 DOI: 10.1126/science.adk9469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 01/30/2024] [Indexed: 03/09/2024]
Abstract
The extent to which prophage proteins interact with eukaryotic macromolecules is largely unknown. In this work, we show that cytoplasmic incompatibility factor A (CifA) and B (CifB) proteins, encoded by prophage WO of the endosymbiont Wolbachia, alter long noncoding RNA (lncRNA) and DNA during Drosophila sperm development to establish a paternal-effect embryonic lethality known as cytoplasmic incompatibility (CI). CifA is a ribonuclease (RNase) that depletes a spermatocyte lncRNA important for the histone-to-protamine transition of spermiogenesis. Both CifA and CifB are deoxyribonucleases (DNases) that elevate DNA damage in late spermiogenesis. lncRNA knockdown enhances CI, and mutagenesis links lncRNA depletion and subsequent sperm chromatin integrity changes to embryonic DNA damage and CI. Hence, prophage proteins interact with eukaryotic macromolecules during gametogenesis to create a symbiosis that is fundamental to insect evolution and vector control.
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Affiliation(s)
- Rupinder Kaur
- Pennsylvania State University, Departments of Biology and Entomology, University Park, PA 16802, USA
- One Health Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA
| | - Angelina McGarry
- Pennsylvania State University, Departments of Biology and Entomology, University Park, PA 16802, USA
- One Health Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - J. Dylan Shropshire
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| | - Brittany A. Leigh
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA
| | - Seth R. Bordenstein
- Pennsylvania State University, Departments of Biology and Entomology, University Park, PA 16802, USA
- One Health Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA
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5
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Aldridge RL, Gibson S, Linthicum KJ. Aedes aegypti Controls AE. Aegypti: SIT and IIT-An Overview. JOURNAL OF THE AMERICAN MOSQUITO CONTROL ASSOCIATION 2024; 40:32-49. [PMID: 38427588 DOI: 10.2987/23-7154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2024]
Abstract
The sterile insect technique (SIT) and the incompatible insect technique (IIT) are emerging and potentially revolutionary tools for controlling Aedes aegypti (L.), a prominent worldwide mosquito vector threat to humans that is notoriously difficult to reduce or eliminate in intervention areas using traditional integrated vector management (IVM) approaches. Here we provide an overview of the discovery, development, and application of SIT and IIT to Ae. aegypti control, and innovations and advances in technology, including transgenics, that could elevate these techniques to a worldwide sustainable solution to Ae. aegypti when combined with other IVM practices.
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6
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Pramono AK, Hidayanti AK, Tagami Y, Ando H. Bacterial community and genome analysis of cytoplasmic incompatibility-inducing Wolbachia in American serpentine leafminer, Liriomyza trifolii. Front Microbiol 2024; 15:1304401. [PMID: 38380092 PMCID: PMC10877061 DOI: 10.3389/fmicb.2024.1304401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 01/12/2024] [Indexed: 02/22/2024] Open
Abstract
Liriomyza trifolii, an agricultural pest, is occasionally infected by Wolbachia. A Wolbachia strain present in Liriomyza trifolii is associated with cytoplasmic incompatibility (CI) effects, leading to the death of embryos resulting from incompatible crosses between antibiotic-treated or naturally Wolbachia-free strain females and Wolbachia-infected males. In this study, high-throughput sequencing of hypervariable rRNA genes was employed to characterize the bacterial community in Wolbachia-infected L. trifolii without antibiotic treatment. The analysis revealed that Wolbachia dominates the bacterial community in L. trifolii, with minor presence of Acinetobacter, Pseudomonas, and Limnobacter. To elucidate the genetic basis of the CI phenotype, metagenomic sequencing was also conducted to assemble the genome of the Wolbachia strain. The draft-genome of the Wolbachia strain wLtri was 1.35 Mbp with 34% GC content and contained 1,487 predicted genes. Notably, within the wLtri genome, there are three distinct types of cytoplasmic incompatibility factor (cif) genes: Type I, Type III, and Type V cifA;B. These genes are likely responsible for inducing the strong cytoplasmic incompatibility observed in L. trifolii.
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Affiliation(s)
- Ajeng K. Pramono
- Laboratory of Phage Biologics, Graduate School of Medicine, Gifu University, Gifu, Japan
| | - Ardhiani K. Hidayanti
- School of Biological Environment, The United Graduate School of Agricultural Science, Gifu University, Gifu, Japan
- School of Life Sciences and Technology, Institut Teknologi Bandung (ITB), Bandung, Indonesia
| | - Yohsuke Tagami
- Laboratory of Applied Entomology, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan
| | - Hiroki Ando
- Laboratory of Phage Biologics, Graduate School of Medicine, Gifu University, Gifu, Japan
- Center for One Medicine Innovative Translational Research (COMIT), Gifu University, Gifu, Japan
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7
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Namias A, Ngaku A, Makoundou P, Unal S, Sicard M, Weill M. Intra-lineage microevolution of Wolbachia leads to the emergence of new cytoplasmic incompatibility patterns. PLoS Biol 2024; 22:e3002493. [PMID: 38315724 PMCID: PMC10868858 DOI: 10.1371/journal.pbio.3002493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 02/15/2024] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Mosquitoes of the Culex pipiens complex are worldwide vectors of arbovirus, filarial nematodes, and avian malaria agents. In these hosts, the endosymbiotic bacteria Wolbachia induce cytoplasmic incompatibility (CI), i.e., reduced embryo viability in so-called incompatible crosses. Wolbachia infecting Culex pipiens (wPip) cause CI patterns of unparalleled complexity, associated with the amplification and diversification of cidA and cidB genes, with up to 6 different gene copies described in a single wPip genome. In wPip, CI is thought to function as a toxin-antidote (TA) system where compatibility relies on having the right antidotes (CidA) in the female to bind and neutralize the male's toxins (CidB). By repeating crosses between Culex isofemale lines over a 17 years period, we documented the emergence of a new compatibility type in real time and linked it to a change in cid genes genotype. We showed that loss of specific cidA gene copies in some wPip genomes results in a loss of compatibility. More precisely, we found that this lost antidote had an original sequence at its binding interface, corresponding to the original sequence at the toxin's binding interface. We showed that these original cid variants are recombinant, supporting a role for recombination rather than point mutations in rapid CI evolution. These results strongly support the TA model in natura, adding to all previous data acquired with transgenes expression.
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Affiliation(s)
- Alice Namias
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Annais Ngaku
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Patrick Makoundou
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Sandra Unal
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Mathieu Sicard
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
| | - Mylène Weill
- ISEM, Université de Montpellier, CNRS, IRD, EPHE, Montpellier, France
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8
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McNamara CJ, Ant TH, Harvey-Samuel T, White-Cooper H, Martinez J, Alphey L, Sinkins SP. Transgenic expression of cif genes from Wolbachia strain wAlbB recapitulates cytoplasmic incompatibility in Aedes aegypti. Nat Commun 2024; 15:869. [PMID: 38287029 PMCID: PMC10825118 DOI: 10.1038/s41467-024-45238-7] [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: 08/24/2023] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
The endosymbiotic bacteria Wolbachia can invade insect populations by modifying host reproduction through cytoplasmic incompatibility (CI), an effect that results in embryonic lethality when Wolbachia-carrying males mate with Wolbachia-free females. Here we describe a transgenic system for recreating CI in the major arbovirus vector Aedes aegypti using CI factor (cif) genes from wAlbB, a Wolbachia strain currently being deployed to reduce dengue transmission. CI-like sterility is induced when cifA and cifB are co-expressed in testes; this sterility is rescued by maternal cifA expression, thereby reproducing the pattern of Wolbachia-induced CI. Expression of cifB alone is associated with extensive DNA damage and disrupted spermatogenesis. The strength of rescue by maternal cifA expression is dependent on the comparative levels of cifA/cifB expression in males. These findings are consistent with CifB acting as a toxin and CifA as an antitoxin, with CifA attenuating CifB toxicity in both the male germline and in developing embryos. These findings provide important insights into the interactions between cif genes and their mechanism of activity and provide a foundation for the building of a cif gene-based drive system in Ae. aegypti.
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Affiliation(s)
- Cameron J McNamara
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow, G61 1QH, UK
| | - Thomas H Ant
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow, G61 1QH, UK
| | - Tim Harvey-Samuel
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
| | - Helen White-Cooper
- Molecular Biosciences Division, Cardiff University, Cardiff, CF10 3AX, UK
| | - Julien Martinez
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow, G61 1QH, UK
| | - Luke Alphey
- Arthropod Genetics, The Pirbright Institute, Ash Road, Pirbright, Surrey, GU24 0NF, UK
- The Department of Biology, University of York, Wentworth Way, York, YO10 5DD, UK
| | - Steven P Sinkins
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Road, Glasgow, G61 1QH, UK.
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Cortez CT, Murphy RO, Owens IM, Beckmann JF. Use of Drosophila Transgenics to Identify Functions for Symbiont Effectors. Methods Mol Biol 2024; 2739:301-320. [PMID: 38006559 DOI: 10.1007/978-1-0716-3553-7_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Wolbachia, one of the most successful and studied insect symbionts, and Drosophila, one of the most understood model insects, can be exploited as complementary tools to unravel mechanisms of insect symbiosis. Although Wolbachia itself cannot be grown axenically as clonal isolates or genetically manipulated by standard methods, its reproductive phenotypes, including cytoplasmic incompatibility (CI), have been elucidated using well-developed molecular tools and precise transgenic manipulations available for Drosophila melanogaster. Current research only scratches the surface of how Drosophila can provide a tool for understanding Wolbachia's evolutionary success and the molecular roles of its genetic elements. Here, we briefly outline basic methodologies inherent to transgenic Drosophila systems that have already contributed significant advances in understanding CI, but may be unfamiliar to those who lack experience in Drosophila genetics. In the future, these approaches will continue providing significant insights into Wolbachia that undoubtedly will be extended to other insect symbionts and their biological capabilities.
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Affiliation(s)
- Carai T Cortez
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Richard O Murphy
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Isabella M Owens
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - John F Beckmann
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA.
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Murphy RO, Beckmann JF. Using Baker's Yeast to Determine Functions of Novel Wolbachia (and Other Prokaryotic) Effectors. Methods Mol Biol 2024; 2739:321-336. [PMID: 38006560 DOI: 10.1007/978-1-0716-3553-7_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
Yeasts are single-celled eukaryotic organisms classified as fungi, mostly in the phylum Ascomycota. Of about 1500 named species, Saccharomyces cerevisiae, also known as baker's yeast, domesticated by humans in the context of cooking and brewing, is a profound genetic tool for exploring functions of novel effector proteins from Wolbachia and prokaryotes in general. Wolbachia is a Gram-negative alpha-proteobacterium that infects up to ~75% of all insects as an obligate intracellular microbe (Jeyaprakash A, Hoy MA, Insect Mol Biol 9:393-405, 2000). Wolbachia's lifestyle presents unique challenges for researchers. Wolbachia cannot be axenically cultured and has never been genetically manipulated. Furthermore, many Wolbachia genes have no known function or well-annotated orthologs in other genomes. Yet given the effects of Wolbachia on host phenotypes, which have considerable practical applications for pest control, they undoubtedly involve secreted effector proteins that interact with host gene products. Studying these effectors is challenging with Wolbachia's current genetic limitations. However, some of the constraints to working with Wolbachia can be overcome by expressing candidate proteins in S. cerevisiae. This approach capitalizes on yeast's small genome (~6500 genes), typical eukaryotic cellular organization, and the sophisticated suite of genetic tools available for its manipulation in culture. Thus, yeast can serve as a powerful mock eukaryotic host background to study Wolbachia effector function. Specifically, yeast is used for recombinant protein expression, drug discovery, protein localization studies, protein interaction mapping (yeast two-hybrid system), modeling chromosomal evolution, and examining interactions between proteins responsible for complex phenotypes in less tractable prokaryotic systems. As an example, the paired genes responsible for Wolbachia-mediated cytoplasmic incompatibility (CI) encode novel proteins with limited homology to other known proteins, and no obvious function. This article details how S. cerevisiae was used as an initial staging ground to explore the molecular basis of one of Wolbachia's trademark phenotypes (CI).
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Affiliation(s)
- Richard O Murphy
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - John F Beckmann
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, USA.
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11
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Chen J, Wang MK, Xie QX, Bing XL, Li TP, Hong XY. NDUFA8 potentially rescues Wolbachia-induced cytoplasmic incompatibility in Laodelphax striatellus. INSECT SCIENCE 2023; 30:1689-1700. [PMID: 36744754 DOI: 10.1111/1744-7917.13182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/11/2022] [Accepted: 01/25/2023] [Indexed: 06/18/2023]
Abstract
The endosymbiont Wolbachia manipulates host reproduction by several strategies, one of the most important of which is cytoplasmic incompatibility (CI). CI can be rescued when Wolbachia-infected males mate with females infected with the same Wolbachia strain. However, the potential rescue mechanism of CI in the small brown planthopper Laodelphax striatellus is unclear. In this study, comparative transcriptome analysis was applied to explore the effect of Wolbachia on L. striatellus eggs. A total of 1387 differentially expressed genes were identified. RNA interference of 7 Wolbachia-upregulated key planthopper genes reduced egg reproduction, suggesting that Wolbachia might improve fecundity in L. striatellus by affecting these 7 genes. Suppressing the expression of another upregulated gene, NDUFA8 (encoding NADH dehydrogenase [ubiquinone] 1 α subcomplex subunit 8-like) by RNA interference significantly increased the mortality of early embryos without affecting the number of deposited eggs. Wolbachia infection upregulated the mRNA level of NDUFA8, and dsNDUFA8 treatment of Wolbachia-infected females recreated CI-like symptoms, suggesting that NDUFA8 is associated with the rescue phenotype. Because all L. striatellus populations worldwide are infected with Wolbachia, NDUFA8 is a potential pest control target.
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Affiliation(s)
- Jie Chen
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Meng-Ke Wang
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Qi-Xian Xie
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Xiao-Li Bing
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Tong-Pu Li
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
| | - Xiao-Yue Hong
- Department of Entomology, Nanjing Agricultural University, Nanjing, China
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12
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Porter J, Sullivan W. The cellular lives of Wolbachia. Nat Rev Microbiol 2023; 21:750-766. [PMID: 37430172 DOI: 10.1038/s41579-023-00918-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2023] [Indexed: 07/12/2023]
Abstract
Wolbachia are successful Gram-negative bacterial endosymbionts, globally infecting a large fraction of arthropod species and filarial nematodes. Efficient vertical transmission, the capacity for horizontal transmission, manipulation of host reproduction and enhancement of host fitness can promote the spread both within and between species. Wolbachia are abundant and can occupy extraordinary diverse and evolutionary distant host species, suggesting that they have evolved to engage and manipulate highly conserved core cellular processes. Here, we review recent studies identifying Wolbachia-host interactions at the molecular and cellular levels. We explore how Wolbachia interact with a wide array of host cytoplasmic and nuclear components in order to thrive in a diversity of cell types and cellular environments. This endosymbiont has also evolved the ability to precisely target and manipulate specific phases of the host cell cycle. The remarkable diversity of cellular interactions distinguishes Wolbachia from other endosymbionts and is largely responsible for facilitating its global propagation through host populations. Finally, we describe how insights into Wolbachia-host cellular interactions have led to promising applications in controlling insect-borne and filarial nematode-based diseases.
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Affiliation(s)
- Jillian Porter
- Molecular, Cell and Developmental Biology, UC Santa Cruz, Santa Cruz, CA, USA
| | - William Sullivan
- Molecular, Cell and Developmental Biology, UC Santa Cruz, Santa Cruz, CA, USA.
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13
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Li J, Dong B, Zhong Y, Li Z. Transinfected Wolbachia strains induce a complex of cytoplasmic incompatibility phenotypes: Roles of CI factor genes. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:370-382. [PMID: 37194361 PMCID: PMC10472523 DOI: 10.1111/1758-2229.13169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 05/05/2023] [Indexed: 05/18/2023]
Abstract
Wolbachia can modulate the reproductive development of their hosts in multiple modes, and cytoplasmic incompatibility (CI) is the most well-studied phenotype. The whitefly Bemisia tabaci is highly receptive to different Wolbachia strains: wCcep strain from the rice moth Corcyra cephalonica and wMel strain from the fruit fly Drosophila melanogaster could successfully establish and induce CI in transinfected whiteflies. Nevertheless, it is unknown what will happen when these two exogenous Wolbachia strains are co-transinfected into a new host. Here, we artificially transinferred wCcep and wMel into the whitefly and established double- and singly-transinfected B. tabaci isofemale lines. Reciprocal crossing experiments showed that wCcep and wMel induced a complex of CI phenotypes in the recipient host, including unidirectional and bidirectional CI. We next sequenced the whole genome of wCcep and performed a comparative analysis of the CI factor genes between wCcep and wMel, indicating that their cif genes were phylogenetically and structurally divergent, which can explain the crossing results. The amino acid sequence identity and structural features of Cif proteins may be useful parameters for predicting their function. Structural comparisons between CifA and CifB provide valuable clues for explaining the induction or rescue of CI observed in crossing experiments between transinfected hosts.
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Affiliation(s)
- Jing Li
- Department of Entomology and Key Laboratory of Pest Monitoring and Green Management, MOA, College of Plant ProtectionChina Agricultural UniversityBeijingChina
| | - Bei Dong
- Jinan Academy of Agricultural SciencesJinanChina
| | - Yong Zhong
- Pingxiang Customs Comprehensive Technical Service CenterPingxiangChina
| | - Zheng‐Xi Li
- Department of Entomology and Key Laboratory of Pest Monitoring and Green Management, MOA, College of Plant ProtectionChina Agricultural UniversityBeijingChina
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14
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Hochstrasser M. Molecular Biology of Cytoplasmic Incompatibility Caused by Wolbachia Endosymbionts. Annu Rev Microbiol 2023; 77:299-316. [PMID: 37285552 DOI: 10.1146/annurev-micro-041020-024616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Among endosymbiotic bacteria living within eukaryotic cells, Wolbachia is exceptionally widespread, particularly in arthropods. Inherited through the female germline, it has evolved ways to increase the fraction of bacterially infected offspring by inducing parthenogenesis, feminization, male killing, or, most commonly, cytoplasmic incompatibility (CI). In CI, Wolbachia infection of males causes embryonic lethality unless they mate with similarly infected females, creating a relative reproductive advantage for infected females. A set of related Wolbachia bicistronic operons encodes the CI-inducing factors. The downstream gene encodes a deubiquitylase or nuclease and is responsible for CI induction by males, while the upstream product when expressed in females binds its sperm-introduced cognate partner and rescues viability. Both toxin-antidote and host-modification mechanisms have been proposed to explain CI. Interestingly, male killing by either Spiroplasma or Wolbachia endosymbionts involves deubiquitylases as well. Interference with the host ubiquitin system may therefore be a common theme among endosymbiont-mediated reproductive alterations.
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Affiliation(s)
- Mark Hochstrasser
- Department of Molecular Biophysics and Biochemistry and Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut, USA;
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15
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Arai H, Anbutsu H, Nishikawa Y, Kogawa M, Ishii K, Hosokawa M, Lin SR, Ueda M, Nakai M, Kunimi Y, Harumoto T, Kageyama D, Takeyama H, Inoue MN. Combined actions of bacteriophage-encoded genes in Wolbachia-induced male lethality. iScience 2023; 26:106842. [PMID: 37250803 PMCID: PMC10209535 DOI: 10.1016/j.isci.2023.106842] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/24/2023] [Accepted: 05/04/2023] [Indexed: 05/31/2023] Open
Abstract
Some Wolbachia endosymbionts induce male killing, whereby male offspring of infected females are killed during development; however, the origin and diversity of the underlying mechanisms remain unclear. In this study, we identified a 76 kbp prophage region specific to male-killing Wolbachia hosted by the moth Homona magnanima. The prophage encoded a homolog of the male-killing gene oscar in Ostrinia moths and the wmk gene that induces various toxicities in Drosophila melanogaster. Upon overexpressing these genes in D. melanogaster, wmk-1 and wmk-3 killed all males and most females, whereas Hm-oscar, wmk-2, and wmk-4 had no impact on insect survival. Strikingly, co-expression of tandemly arrayed wmk-3 and wmk-4 killed 90% of males and restored 70% of females, suggesting their conjugated functions for male-specific lethality. While the male-killing gene in the native host remains unknown, our findings highlight the role of bacteriophages in male-killing evolution and differences in male-killing mechanisms among insects.
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Affiliation(s)
- Hiroshi Arai
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan
- National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki 305-0851, Japan
| | - Hisashi Anbutsu
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Bioproduction Research Institute, AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
- Research Organization for Nano and Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan
| | - Yohei Nishikawa
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Research Organization for Nano and Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan
| | - Masato Kogawa
- Research Organization for Nano and Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan
| | - Kazuo Ishii
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan
| | - Masahito Hosokawa
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Research Organization for Nano and Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan
- Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Shiou-Ruei Lin
- Tea Research and Extension Station, 326011 Chung-Hsing RD, Yangmei, Taoyuan, Taiwan, R.O.C
| | - Masatoshi Ueda
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan
| | - Madoka Nakai
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan
| | - Yasuhisa Kunimi
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan
| | - Toshiyuki Harumoto
- Hakubi Center for Advanced Research, Kyoto University. Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501, Japan
- Graduate School of Biostudies, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Daisuke Kageyama
- National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki 305-0851, Japan
| | - Haruko Takeyama
- Computational Bio Big-Data Open Innovation Laboratory (CBBD-OIL), National Institute of Advanced Industrial Science and Technology (AIST), 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Research Organization for Nano and Life Innovation, Waseda University, 513 Wasedatsurumaki-cho, Shinjuku-ku, Tokyo 162-0041, Japan
- Institute for Advanced Research of Biosystem Dynamics, Waseda Research Institute for Science and Engineering, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan
- Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsucho, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Maki N. Inoue
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai, Fuchu, Tokyo 183-8509, Japan
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16
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Oladipupo SO, Carroll JD, Beckmann JF. Convergent Aedes and Drosophila CidB interactomes suggest cytoplasmic incompatibility targets are conserved. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 155:103931. [PMID: 36933571 DOI: 10.1016/j.ibmb.2023.103931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/09/2023] [Accepted: 03/09/2023] [Indexed: 05/10/2023]
Abstract
Wolbachia-mediated cytoplasmic incompatibility (CI) is a conditional embryonic lethality induced when Wolbachia-modified sperm fertilizes an uninfected egg. The Wolbachia proteins, CidA and CidB control CI. CidA is a rescue factor that reverses lethality. CidA binds to CidB. CidB contains a deubiquitinating enzyme and induces CI. Precisely how CidB induces CI and what it targets are unknown. Likewise, how CidA prevents sterilization by CidB is not clear. To identify CidB substrates in mosquitos we conducted pull-down assays using recombinant CidA and CidB mixed with Aedes aegypti lysates to identify the protein interactomes of CidB and the CidB/CidA protein complex. Our data allow us to cross compare CidB interactomes across taxa for Aedes and Drosophila. Our data replicate several convergent interactions, suggesting that CI targets conserved substrates across insects. Our data support a hypothesis that CidA rescues CI by tethering CidB away from its substrates. Specifically, we identify ten convergent candidate substrates including P32 (protamine-histone exchange factor), karyopherin alpha, ubiquitin-conjugating enzyme, and bicoid stabilizing factor. Future analysis on how these candidates contribute to CI will clarify mechanisms.
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Affiliation(s)
- Seun O Oladipupo
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL, 36849, USA; Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, 06520, USA.
| | - Jazmine D Carroll
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL, 36849, USA
| | - John F Beckmann
- Department of Entomology & Plant Pathology, Auburn University, Auburn, AL, 36849, USA.
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17
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Functional analysis of Wolbachia Cid effectors unravels cooperative interactions to target host chromatin during replication. PLoS Pathog 2023; 19:e1011211. [PMID: 36928089 PMCID: PMC10047532 DOI: 10.1371/journal.ppat.1011211] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 03/28/2023] [Accepted: 02/16/2023] [Indexed: 03/18/2023] Open
Abstract
Wolbachia are common bacteria among terrestrial arthropods. These endosymbionts transmitted through the female germline manipulate their host reproduction through several mechanisms whose most prevalent form called Cytoplasmic Incompatibility -CI- is a conditional sterility syndrome eventually favoring the infected progeny. Upon fertilization, the sperm derived from an infected male is only compatible with an egg harboring a compatible Wolbachia strain, this sperm leading otherwise to embryonic death. The Wolbachia Cif factors CidA and CidB responsible for CI and its neutralization function as a Toxin-Antitoxin system in the mosquito host Culex pipiens. However, the mechanism of CidB toxicity and its neutralization by the CidA antitoxin remain unexplored. Using transfected insect cell lines to perform a structure-function analysis of these effectors, we show that both CidA and CidB are chromatin interactors and CidA anchors CidB to the chromatin in a cell-cycle dependent-manner. In absence of CidA, the CidB toxin localizes to its own chromatin microenvironment and acts by preventing S-phase completion, independently of its deubiquitylase -DUB- domain. Experiments with transgenic Drosophila show that CidB DUB domain is required together with CidA during spermatogenesis to stabilize the CidA-CidB complex. Our study defines CidB functional regions and paves the way to elucidate the mechanism of its toxicity.
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18
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Verhoeve VI, Lehman SS, Driscoll TP, Beckmann JF, Gillespie JJ. Metagenome diversity illuminates origins of pathogen effectors. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.26.530123. [PMID: 36909625 PMCID: PMC10002696 DOI: 10.1101/2023.02.26.530123] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Recent metagenome assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. Discovery of basal lineages (Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles reveals an evolutionary timepoint for the transition to host dependency, which occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system (T4SS) and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for derived rickettsial pathogens. MAG analysis also substantially increased diversity for genus Rickettsia and delineated a basal lineage (Tisiphia) that stands to inform on the rise of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages indicates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, illuminating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role shaping the rvh effector landscape, as evinced by the discover of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can provide incredible insight on the origins of pathogen effectors and how their architectural modifications become tailored to eukaryotic host cell biology.
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Affiliation(s)
- Victoria I Verhoeve
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Stephanie S Lehman
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Timothy P Driscoll
- Department of Biology, West Virginia University, Morgantown, West Virginia, USA
| | - John F Beckmann
- Microbiology and Immunology, University of South Alabama, Mobile, AL, USA
| | - Joseph J Gillespie
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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19
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Dou W, Sun B, Miao Y, Huang D, Xiao J. Single-cell transcriptome sequencing reveals Wolbachia-mediated modification in early stages of Drosophila spermatogenesis. Proc Biol Sci 2023; 290:20221963. [PMID: 36629101 PMCID: PMC9832550 DOI: 10.1098/rspb.2022.1963] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/13/2022] [Indexed: 01/12/2023] Open
Abstract
Wolbachia are the most widely distributed intracellular bacteria, and their most common effect on host phenotype is cytoplasmic incompatibility (CI). A variety of models have been proposed to decipher the molecular mechanism of CI, among which the host modification (HM) model predicts that Wolbachia effectors play an important role in sperm modification. However, owing to the complexity of spermatogenesis and testicular cell-type heterogeneity, whether Wolbachia have different effects on cells at different stages of spermatogenesis or whether these effects are linked with CI remains unknown. Therefore, we used single-cell RNA sequencing to analyse gene expression profiles in adult male Drosophila testes that were infected or uninfected by Wolbachia. We found that Wolbachia significantly affected the proportion of different types of germ cells and affected multiple metabolic pathways in germ cells. Most importantly, Wolbachia had the greatest impact on germline stem cells, resulting in dysregulated expression of genes related to DNA compaction, and Wolbachia infection also influenced the histone-to-protamine transition in the late stage of sperm development. These results support the HM model and suggest that future studies on Wolbachia-induced CI should focus on cells in the early stages of spermatogenesis.
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Affiliation(s)
- Weihao Dou
- College of Life Sciences, Nankai University, Tianjin 300071, People's Republic of China
| | - Baofa Sun
- College of Life Sciences, Nankai University, Tianjin 300071, People's Republic of China
| | - Yunheng Miao
- College of Life Sciences, Nankai University, Tianjin 300071, People's Republic of China
| | - Dawei Huang
- College of Life Sciences, Nankai University, Tianjin 300071, People's Republic of China
| | - Jinhua Xiao
- College of Life Sciences, Nankai University, Tianjin 300071, People's Republic of China
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20
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Ritchie IT, Needles KT, Leigh BA, Kaur R, Bordenstein SR. Transgenic cytoplasmic incompatibility persists across age and temperature variation in Drosophila melanogaster. iScience 2022; 25:105327. [PMID: 36304111 PMCID: PMC9593245 DOI: 10.1016/j.isci.2022.105327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/28/2022] [Accepted: 10/07/2022] [Indexed: 12/03/2022] Open
Abstract
Environmental stressors can impact the basic biology and applications of host-microbe symbioses. For example, Wolbachia symbiont densities and cytoplasmic incompatibility (CI) levels can decline in response to extreme temperatures and host aging. To investigate whether transgenic expression of CI-causing cif genes overcomes the environmental sensitivity of CI, we exposed transgenic male flies to low and high temperatures as well as aging treatments. Our results indicate that transgenic cif expression induces nearly complete CI regardless of temperature and aging, despite severe weakening of Wolbachia-based wild-type CI. Strong CI levels correlate with higher levels of cif transgene expression in young males. Altogether, our results highlight that transgenic CI persists against common environmental pressures and may be relevant for future control applications involving the cifA and cifB transgenes. Symbiont adaptations are often weakened by life history and environmental parameters Cytoplasmic incompatibility (CI) declines with host age and temperature Transgenic CI is robust to age and temperature variation in Drosophila melanogaster Transgenic CI circumvents pressures that diminish wildtype CI
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Affiliation(s)
- Isabella T. Ritchie
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA,Vanderbilt University, Vanderbilt Microbiome Innovation Center, Nashville, TN 37235, USA,Corresponding author
| | - Kelly T. Needles
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA,Vanderbilt University, Vanderbilt Microbiome Innovation Center, Nashville, TN 37235, USA
| | - Brittany A. Leigh
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA,Vanderbilt University, Vanderbilt Microbiome Innovation Center, Nashville, TN 37235, USA
| | - Rupinder Kaur
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA,Vanderbilt University, Vanderbilt Microbiome Innovation Center, Nashville, TN 37235, USA,The Pennsylvania State University, Departments of Biology and Entomology, University Park, PA 16802, USA,The Pennsylvania State University, Microbiome Center, Huck Institutes of the Life Sciences, University Park, PA 16802, USA
| | - Seth R. Bordenstein
- Vanderbilt University, Department of Biological Sciences, Nashville, TN 37235, USA,Vanderbilt University, Vanderbilt Microbiome Innovation Center, Nashville, TN 37235, USA,The Pennsylvania State University, Departments of Biology and Entomology, University Park, PA 16802, USA,The Pennsylvania State University, Microbiome Center, Huck Institutes of the Life Sciences, University Park, PA 16802, USA,Corresponding author
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21
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Warecki B, Titen SWA, Alam MS, Vega G, Lemseffer N, Hug K, Minden JS, Sullivan W. Wolbachia action in the sperm produces developmentally deferred chromosome segregation defects during the Drosophila mid-blastula transition. eLife 2022; 11:81292. [PMID: 36149408 PMCID: PMC9507124 DOI: 10.7554/elife.81292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 09/09/2022] [Indexed: 11/29/2022] Open
Abstract
Wolbachia, a vertically transmitted endosymbiont infecting many insects, spreads rapidly through uninfected populations by a mechanism known as cytoplasmic incompatibility (CI). In CI, a paternally delivered modification of the sperm leads to chromatin defects and lethality during and after the first mitosis of embryonic development in multiple species. However, whether CI-induced defects in later stage embryos are a consequence of the first division errors or caused by independent defects remains unresolved. To address this question, we focused on ~1/3 of embryos from CI crosses in Drosophila simulans that develop apparently normally through the first and subsequent pre-blastoderm divisions before exhibiting mitotic errors during the mid-blastula transition and gastrulation. We performed single embryo PCR and whole genome sequencing to find a large percentage of these developed CI-derived embryos bypass the first division defect. Using fluorescence in situ hybridization, we find increased chromosome segregation errors in gastrulating CI-derived embryos that had avoided the first division defect. Thus, Wolbachia action in the sperm induces developmentally deferred defects that are not a consequence of the first division errors. Like the immediate defect, the delayed defect is rescued through crosses to infected females. These studies inform current models on the molecular and cellular basis of CI.
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Affiliation(s)
- Brandt Warecki
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
| | - Simon William Abraham Titen
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States.,Department of Biology and Chemistry, California State University Monterey Bay, Seaside, United States
| | - Mohammad Shahriyar Alam
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
| | - Giovanni Vega
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
| | - Nassim Lemseffer
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
| | - Karen Hug
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
| | - Jonathan S Minden
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, United States
| | - William Sullivan
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, United States
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22
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Wang W, Cui W, Yang H. Toward an accurate mechanistic understanding of Wolbachia-induced cytoplasmic incompatibility. Environ Microbiol 2022; 24:4519-4532. [PMID: 35859330 DOI: 10.1111/1462-2920.16125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/28/2022] [Accepted: 07/02/2022] [Indexed: 11/27/2022]
Abstract
Wolbachia are the most successful intracellular bacteria in arthropods. They can manipulate host reproduction to favour infected females, which transmit Wolbachia to their progeny and increase the presence of Wolbachia in the population. The reproductive alterations caused by Wolbachia include feminization, parthenogenesis, male killing and cytoplasmic incompatibility (CI), among which CI is the most common. CI leads to embryonic lethality when Wolbachia-infected males mate with uninfected females or those infected with an incompatible strain. This lethality can be rescued if females are infected with a compatible strain. Although CI was described in the 1960s and its connection to Wolbachia was made in the 1970s, the genes responsible for CI, called CI factors, were not identified until recently. Since then, significant progress has been made in understanding the molecular mechanism of CI using a combination of genetic, phylogenetic, biochemical and structural approaches. The detailed molecular mechanisms behind this fascinating endosymbiotic bacteria-induced phenotype have begun to emerge. Here, we summarize recent progress in understanding the molecular mechanism of CI, especially focusing on the recently solved CI factor structures and discussing what these new structures brought in terms of CI mechanism.
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Affiliation(s)
- Wei Wang
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Wen Cui
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Haitao Yang
- Shanghai Institute for Advanced Immunochemical Studies and School of Life Science and Technology, ShanghaiTech University, Shanghai, China.,Tianjin International Joint Academy of Biotechnology and Medicine, Tianjin, China
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23
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Zhou JC, Shang D, Qian Q, Zhang C, Zhang LS, Dong H. Penetrance during Wolbachia-mediated parthenogenesis of Trichogramma wasps is reduced by continuous oviposition, associated with exhaustion of Wolbachia titers in ovary and offspring eggs. PEST MANAGEMENT SCIENCE 2022; 78:3080-3089. [PMID: 35437949 DOI: 10.1002/ps.6934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/11/2022] [Accepted: 04/18/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Thelytokous Wolbachia-infected Trichogramma wasps are superior to bisexual uninfected wasps regarding biological control programs. However, continuous oviposition weakens the parthenogenesis-inducing (PI) strength of Wolbachia. Whether this reduced PI strength relates to decreases in the titer of Wolbachia in the ovary and offspring eggs of Trichogramma remains unclear. Here, using fluorescence in situ hybridization (FISH) and reverse transcription quantitative polymerase chain reaction (RT-qPCR) methods, we investigated how the penetrance of Wolbachia-mediated parthenogenesis, Wolbachia density, and distributions of two Wolbachia-infected Trichogramma species, T. pretiosum (TP) and T. dendrolimi (TD), were influenced by different host access treatments [newly-emerged virgin females (NE), 7-day-old females without access to host eggs (NAH), and 7-day-old virgin females with access to host eggs (AH)]. RESULTS Continuous oviposition decreased Wolbachia PI strength and titers in TP and TD. Continuous oviposition in AH decreased Wolbachia titers in abdomen and offspring eggs of TP and TD females, compared with NAH and NE; NAH had a lower thorax Wolbachia titer than NE. The numbers of parasitized host eggs and offspring wasps, and emergence rates of offspring deposited by AH were lower than those of NE and NAH, for either species. CONCLUSION Weakened PI strength, driven by continuous oviposition in Trichogramma wasps, is associated with Wolbachia titer exhaustion in ovary and offspring eggs. Wolbachia density is dependent on PI strength in Trichogramma wasps, highlighting the side effects of continuous oviposition regarding thelytokous Wolbachia-infected Trichogramma in biological control programs. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Jin-Cheng Zhou
- College of Plant Protection, Shenyang Agricultural University, Shenyang, P. R. China
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Dan Shang
- College of Plant Protection, Shenyang Agricultural University, Shenyang, P. R. China
| | - Qian Qian
- College of Plant Protection, Shenyang Agricultural University, Shenyang, P. R. China
| | - Chen Zhang
- College of Plant Protection, Shenyang Agricultural University, Shenyang, P. R. China
| | - Li-Sheng Zhang
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Hui Dong
- College of Plant Protection, Shenyang Agricultural University, Shenyang, P. R. China
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Shropshire JD, Hamant E, Conner WR, Cooper BS. cifB-transcript levels largely explain cytoplasmic incompatibility variation across divergent Wolbachia. PNAS NEXUS 2022; 1:pgac099. [PMID: 35967981 PMCID: PMC9364212 DOI: 10.1093/pnasnexus/pgac099] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 06/23/2022] [Indexed: 02/05/2023]
Abstract
Divergent hosts often associate with intracellular microbes that influence their fitness. Maternally transmitted Wolbachia bacteria are the most common of these endosymbionts, due largely to cytoplasmic incompatibility (CI) that kills uninfected embryos fertilized by Wolbachia-infected males. Closely related infections in females rescue CI, providing a relative fitness advantage that drives Wolbachia to high frequencies. One prophage-associated gene (cifA) governs rescue, and two contribute to CI (cifA and cifB), but CI strength ranges from very strong to very weak for unknown reasons. Here, we investigate CI-strength variation and its mechanistic underpinnings in a phylogenetic context across 20 million years (MY) of Wolbachia evolution in Drosophila hosts diverged up to 50 MY. These Wolbachia encode diverse Cif proteins (100% to 7.4% pairwise similarity), and AlphaFold structural analyses suggest that CifB sequence similarities do not predict structural similarities. We demonstrate that cifB-transcript levels in testes explain CI strength across all but two focal systems. Despite phylogenetic discordance among cifs and the bulk of the Wolbachia genome, closely related Wolbachia tend to cause similar CI strengths and transcribe cifB at similar levels. This indicates that other non-cif regions of the Wolbachia genome modulate cif-transcript levels. CI strength also increases with the length of the host's larval life stage, presumably due to prolonged cif action. Our findings reveal that cifB-transcript levels largely explain CI strength, while highlighting other covariates. Elucidating CI's mechanism contributes to our understanding of Wolbachia spread in natural systems and to improving the efficacy of CI-based biocontrol of arboviruses and agricultural pests globally.
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Affiliation(s)
| | - Emily Hamant
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - William R Conner
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Brandon S Cooper
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
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Infection Dynamics of Cotransmitted Reproductive Symbionts Are Mediated by Sex, Tissue, and Development. Appl Environ Microbiol 2022; 88:e0052922. [PMID: 35730939 PMCID: PMC9275221 DOI: 10.1128/aem.00529-22] [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: 12/25/2022] Open
Abstract
One of the most prevalent intracellular infections on earth is with Wolbachia, a bacterium in the Rickettsiales that infects a range of insects, crustaceans, chelicerates, and nematodes. Wolbachia is maternally transmitted to offspring and has profound effects on the reproduction and physiology of its hosts, which can result in reproductive isolation, altered vectorial capacity, mitochondrial sweeps, and even host speciation. Some populations stably harbor multiple Wolbachia strains, which can further contribute to reproductive isolation and altered host physiology. However, almost nothing is known about the requirements for multiple intracellular microbes to be stably maintained across generations while they likely compete for space and resources. Here, we use a coinfection of two Wolbachia strains (“wHa” and “wNo”) in Drosophila simulans to define the infection and transmission dynamics of an evolutionarily stable double infection. We find that a combination of sex, tissue, and host development contributes to the infection dynamics of the two microbes and that these infections exhibit a degree of niche partitioning across host tissues. wHa is present at a significantly higher titer than wNo in most tissues and developmental stages, but wNo is uniquely dominant in ovaries. Unexpectedly, the ratio of wHa to wNo in embryos does not reflect those observed in the ovaries, indicative of strain-specific transmission dynamics. Understanding how Wolbachia strains interact to establish and maintain stable infections has important implications for the development and effective implementation of Wolbachia-based vector biocontrol strategies, as well as more broadly defining how cooperation and conflict shape intracellular communities. IMPORTANCEWolbachia is a maternally transmitted intracellular bacterium that manipulates the reproduction and physiology of arthropods, resulting in drastic effects on the fitness, evolution, and even speciation of its hosts. Some hosts naturally harbor multiple strains of Wolbachia that are stably transmitted across generations, but almost nothing is known about the factors that limit or promote these coinfections, which can have profound effects on the host’s biology and evolution and are under consideration as an insect-management tool. Here, we define the infection dynamics of a known stably transmitted double infection in Drosophila simulans with an eye toward understanding the patterns of infection that might facilitate compatibility between the two microbes. We find that a combination of sex, tissue, and development all contributes to infection dynamics of the coinfection.
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Bordenstein SR, Bordenstein SR. Widespread phages of endosymbionts: Phage WO genomics and the proposed taxonomic classification of Symbioviridae. PLoS Genet 2022; 18:e1010227. [PMID: 35666732 PMCID: PMC9203015 DOI: 10.1371/journal.pgen.1010227] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 06/16/2022] [Accepted: 04/29/2022] [Indexed: 11/19/2022] Open
Abstract
Wolbachia are the most common obligate, intracellular bacteria in animals. They exist worldwide in arthropod and nematode hosts in which they commonly act as reproductive parasites or mutualists, respectively. Bacteriophage WO, the largest of Wolbachia’s mobile elements, includes reproductive parasitism genes, serves as a hotspot for genetic divergence and genomic rearrangement of the bacterial chromosome, and uniquely encodes a Eukaryotic Association Module with eukaryotic-like genes and an ensemble of putative host interaction genes. Despite WO’s relevance to genome evolution, selfish genetics, and symbiotic applications, relatively little is known about its origin, host range, diversification, and taxonomic classification. Here we analyze the most comprehensive set of 150 Wolbachia and phage WO assemblies to provide a framework for discretely organizing and naming integrated phage WO genomes. We demonstrate that WO is principally in arthropod Wolbachia with relatives in diverse endosymbionts and metagenomes, organized into four variants related by gene synteny, often oriented opposite the putative origin of replication in the Wolbachia chromosome, and the large serine recombinase is an ideal typing tool to distinguish the four variants. We identify a novel, putative lytic cassette and WO’s association with a conserved eleven gene island, termed Undecim Cluster, that is enriched with virulence-like genes. Finally, we evaluate WO-like Islands in the Wolbachia genome and discuss a new model in which Octomom, a notable WO-like Island, arose from a split with WO. Together, these findings establish the first comprehensive Linnaean taxonomic classification of endosymbiont phages, including non-Wolbachia phages from aquatic environments, that includes a new family and two new genera to capture the collective relatedness of these viruses.
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Affiliation(s)
- Sarah R. Bordenstein
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Microbiome Innovation Center, Vanderbilt University, Nashville, Tennessee, United States of America
- * E-mail:
| | - Seth R. Bordenstein
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Microbiome Innovation Center, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, Tennessee, United States of America
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Gao S, Ren YS, Su CY, Zhu DH. High Levels of Multiple Phage WO Infections and Its Evolutionary Dynamics Associated With Wolbachia-Infected Butterflies. Front Microbiol 2022; 13:865227. [PMID: 35531293 PMCID: PMC9070984 DOI: 10.3389/fmicb.2022.865227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Wolbachia is a maternally inherited bacterium that is widely distributed among arthropods, in which it manipulates the reproduction of its hosts. Phage WO is the only bacteriophage known to infect Wolbachia, and may provide benefit to its host or arthropods. We screened for the presence of phage WO in Wolbachia-infected butterfly species for the first time, to investigate their diversity and evolutionary dynamics. All Wolbachia-infected butterfly species, including members of the families Hesperiidae, Lycaenidae, Nymphalidae, Papilionidae, and Pieridae, were found to harbor phage WO. Interestingly, 84% of 19 butterfly species, which were infected with a single Wolbachia strain harbored high levels of multiple phage types (ranging from 3 to 17 types), another three species harbored one or two phage types. For Wolbachia strains (ST-41, ST-19, ST-125 and ST-374) shared among various butterfly species, their host insects all harbored multiple phage types, while two Wolbachia strains (ST-297 and ST-wPcau) were found to infect one butterfly species, whose insect hosts harbored a single phage type, suggesting that horizontal transfer of Wolbachia between insects increased the likelihood of exposure to phages, resulting in increased phage genetic diversity. Twelve horizontal transmission events of phage WO were found, which shared common phage WO types among different Wolbachia strains associated with butterflies. Most horizontal transfer events involved different Wolbachia supergroups (A and B). Horizontal acquisition of phage WO might also occur between eukaryotes without Wolbachia transfer. Furthermore, 22 putative recombination events were identified in 13 of 16 butterfly species which harbored multiple phage types. These results showed that horizontal transfer of Wolbachia caused it to be exposed to the phage gene pool, and that horizontal transmission of phage WO, as well as intragenic recombination were important dynamics for phage WO genome evolution, which effectively promoted the high level of phage WO diversity associated with butterflies.
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Hochstrasser M. Cytoplasmic incompatibility: A Wolbachia toxin-antidote mechanism comes into view. Curr Biol 2022; 32:R287-R289. [PMID: 35349818 DOI: 10.1016/j.cub.2022.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The Wolbachia cidA and cidB genes promote bacterial endosymbiont inheritance through the host female germline. CidB is now shown to load into maturing sperm nuclei. Following fertilization, it disrupts paternal chromosome condensation, triggering embryonic arrest if not countered by CidA in Wolbachia-infected eggs.
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Affiliation(s)
- Mark Hochstrasser
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
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Crystal Structures of Wolbachia CidA and CidB Reveal Determinants of Bacteria-induced Cytoplasmic Incompatibility and Rescue. Nat Commun 2022; 13:1608. [PMID: 35338130 PMCID: PMC8956670 DOI: 10.1038/s41467-022-29273-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 03/03/2022] [Indexed: 02/05/2023] Open
Abstract
Cytoplasmic incompatibility (CI) results when Wolbachia bacteria-infected male insects mate with uninfected females, leading to embryonic lethality. “Rescue” of viability occurs if the female harbors the same Wolbachia strain. CI is caused by linked pairs of Wolbachia genes called CI factors (CifA and CifB). The co-evolution of CifA-CifB pairs may account in part for the incompatibility patterns documented in insects infected with different Wolbachia strains, but the molecular mechanisms remain elusive. Here, we use X-ray crystallography and AlphaFold to analyze the CI factors from Wolbachia strain wMel called CidAwMel and CidBwMel. Substituting CidAwMel interface residues with those from CidAwPip (from strain wPip) enables the mutant protein to bind CidBwPip and rescue CidBwPip-induced yeast growth defects, supporting the importance of CifA-CifB interaction in CI rescue. Sequence divergence in CidAwPip and CidBwPip proteins affects their pairwise interactions, which may help explain the complex incompatibility patterns of mosquitoes infected with different wPip strains. Wolbachia induced cytoplasmic incompatibility (CI) is caused by linked pairs of genes named cifA and cifB. Here, authors show that the residues at interfaces of the CidA-CidB complex is crucial for their binding and contribute to the diversity of CI.
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The CinB Nuclease from wNo Wolbachia Is Sufficient for Induction of Cytoplasmic Incompatibility in Drosophila. mBio 2022; 13:e0317721. [PMID: 35073749 PMCID: PMC8787490 DOI: 10.1128/mbio.03177-21] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Wolbachia is an obligate intracellular bacterium that can alter reproduction of its arthropod hosts, often through a mechanism called cytoplasmic incompatibility (CI). In CI, uninfected females fertilized by infected males yield few offspring, but if both are similarly infected, normal embryo viability results (called "rescue"). CI factors (Cifs) responsible for CI are pairs of proteins encoded by linked genes. The downstream gene in each pair encodes either a deubiquitylase (CidB) or a nuclease (CinB). The upstream gene products, CidA and CinA, bind their cognate enzymes with high specificity. Expression of CidB or CinB in yeast inhibits growth, but growth is rescued by expression of the cognate CifA protein. By contrast, transgenic Drosophila male germ line expression of both cifA and cifB was reported to be necessary to induce CI-like embryonic arrest; cifA expression alone in females is sufficient for rescue. This pattern, seen with genes from several Wolbachia strains, has been called the "2-by-1" model. Here, we show that male germ line expression of the cinB gene alone, from a distinct clade of cif genes from wNo Wolbachia, is sufficient to induce nearly complete loss of embryo viability. This male sterility is fully rescued by cognate cinAwNo expression in the female germ line. The proteins behave similarly in yeast. CinBwNo toxicity depends on its nuclease active site. These results demonstrate that highly divergent CinB nucleases can induce CI, that rescue by cognate CifA factors is a general feature of Wolbachia CI systems, and that CifA is not strictly required in males for CI induction. IMPORTANCE Wolbachia bacteria live within the cells of many insects. Like mitochondria, they are only inherited from females. Wolbachia often increases the number of infected females to promote spread of infection using a type of male sterility called cytoplasmic incompatibility (CI): when uninfected females mate with infected males, most embryos die; if both are similarly infected, embryos develop normally, giving infected females an advantage in producing offspring. CI is being used against disease-carrying mosquitoes and agricultural pests. Wolbachia proteins called CifA and CifB, which bind one another, cause CI, but how they work has been unclear. Here, we show that a CifB protein singly produced in fruit fly males causes sterility in crosses to normal females, but this is rescued if the females produce the CifA partner. These findings clarify a broad range of observations on CI and will allow more rational approaches to using it for insect control.
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31
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Namias A, Sicard M, Weill M, Charlat S. From Wolbachia genomics to phenotype: molecular models of cytoplasmic incompatibility must account for the multiplicity of compatibility types. CURRENT OPINION IN INSECT SCIENCE 2022; 49:78-84. [PMID: 34954414 DOI: 10.1016/j.cois.2021.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/22/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Wolbachia endosymbionts commonly induce cytoplasmic incompatibility, making infected males' sperm lethal to the embryos unless these are rescued by the same bacterium, inherited from their mother. Causal genes were recently identified but two families of mechanistic models are still opposed. In the toxin-antidote model, interaction between the toxin and the antidote is required for rescuing the embryos. In host modification models, a host factor is misregulated in sperm and rescue occurs through compensation or withdrawal of this modification. While these models have been thoroughly discussed, the multiplicity of compatibility types, that is, the existence of many mutually incompatible strains, as seen in Culex mosquitoes, has not received sufficient attention. To explain such a fact, host modification models must posit that the same embryonic defects can be induced and rescued through a large variety of host targets. Conversely, the toxin-antidote model simply accommodates this pattern in a lock-key fashion, through variations in the toxin-antidote interaction sites.
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Affiliation(s)
- Alice Namias
- ISEM, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Mathieu Sicard
- ISEM, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Mylène Weill
- ISEM, Université de Montpellier, CNRS, IRD, Montpellier, France
| | - Sylvain Charlat
- Laboratoire de Biométrie et Biologie Evolutive, Université de Lyon, Université Lyon 1, CNRS, UMR 5558, 43 boulevard du 11 novembre 1918, Villeurbanne, F-69622, France.
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Dedukh D, Krasikova A. Delete and survive: strategies of programmed genetic material elimination in eukaryotes. Biol Rev Camb Philos Soc 2022; 97:195-216. [PMID: 34542224 PMCID: PMC9292451 DOI: 10.1111/brv.12796] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 02/06/2023]
Abstract
Genome stability is a crucial feature of eukaryotic organisms because its alteration drastically affects the normal development and survival of cells and the organism as a whole. Nevertheless, some organisms can selectively eliminate part of their genomes from certain cell types during specific stages of ontogenesis. This review aims to describe the phenomenon of programmed DNA elimination, which includes chromatin diminution (together with programmed genome rearrangement or DNA rearrangements), B and sex chromosome elimination, paternal genome elimination, parasitically induced genome elimination, and genome elimination in animal and plant hybrids. During programmed DNA elimination, individual chromosomal fragments, whole chromosomes, and even entire parental genomes can be selectively removed. Programmed DNA elimination occurs independently in different organisms, ranging from ciliate protozoa to mammals. Depending on the sequences destined for exclusion, programmed DNA elimination may serve as a radical mechanism of dosage compensation and inactivation of unnecessary or dangerous genetic entities. In hybrids, genome elimination results from competition between parental genomes. Despite the different consequences of DNA elimination, all genetic material destined for elimination must be first recognised, epigenetically marked, separated, and then removed and degraded.
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Affiliation(s)
- Dmitrij Dedukh
- Saint‐Petersburg State University7/9 Universitetskaya EmbankmentSaint‐Petersburg199034Russia
| | - Alla Krasikova
- Saint‐Petersburg State University7/9 Universitetskaya EmbankmentSaint‐Petersburg199034Russia
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Male Age and Wolbachia Dynamics: Investigating How Fast and Why Bacterial Densities and Cytoplasmic Incompatibility Strengths Vary. mBio 2021; 12:e0299821. [PMID: 34903056 PMCID: PMC8686834 DOI: 10.1128/mbio.02998-21] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Endosymbionts can influence host reproduction and fitness to favor their maternal transmission. For example, endosymbiotic Wolbachia bacteria often cause cytoplasmic incompatibility (CI) that kills uninfected embryos fertilized by Wolbachia-modified sperm. Infected females can rescue CI, providing them a relative fitness advantage. Wolbachia-induced CI strength varies widely and tends to decrease as host males age. Since strong CI drives Wolbachia to high equilibrium frequencies, understanding how fast and why CI strength declines with male age is crucial to explaining age-dependent CI’s influence on Wolbachia prevalence. Here, we investigate if Wolbachia densities and/or CI gene (cif) expression covary with CI-strength variation and explore covariates of age-dependent Wolbachia-density variation in two classic CI systems. wRi CI strength decreases slowly with Drosophila simulans male age (6%/day), but wMel CI strength decreases very rapidly (19%/day), yielding statistically insignificant CI after only 3 days of Drosophila melanogaster adult emergence. Wolbachia densities and cif expression in testes decrease as wRi-infected males age, but both surprisingly increase as wMel-infected males age, and CI strength declines. We then tested if phage lysis, Octomom copy number (which impacts wMel density), or host immune expression covary with age-dependent wMel densities. Only host immune expression correlated with density. Together, our results identify how fast CI strength declines with male age in two model systems and reveal unique relationships between male age, Wolbachia densities, cif expression, and host immunity. We discuss new hypotheses about the basis of age-dependent CI strength and its contributions to Wolbachia prevalence.
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34
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Structural and mechanistic insights into the complexes formed by Wolbachia cytoplasmic incompatibility factors. Proc Natl Acad Sci U S A 2021; 118:2107699118. [PMID: 34620712 DOI: 10.1073/pnas.2107699118] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/19/2021] [Indexed: 11/18/2022] Open
Abstract
Wolbachia bacteria, inherited through the female germ line, infect a large fraction of arthropod species. Many Wolbachia strains manipulate host reproduction, most commonly through cytoplasmic incompatibility (CI). CI, a conditional male sterility, results when Wolbachia-infected male insects mate with uninfected females; viability is restored if the female is similarly infected (called "rescue"). CI is used to help control mosquito-borne viruses such as dengue and Zika, but its mechanisms remain unknown. The coexpressed CI factors CifA and CifB form stable complexes in vitro, but the timing and function of this interaction in the insect are unresolved. CifA expression in the female germ line is sufficient for rescue. We report high-resolution structures of a CI-factor complex, CinA-CinB, which utilizes a unique binding mode between the CinA rescue factor and the CinB nuclease; the structures were validated by biochemical and yeast growth analyses. Importantly, transgenic expression in Drosophila of a nonbinding CinA mutant, designed based on the CinA-CinB structure, suggests CinA expressed in females must bind CinB imported by sperm in order to rescue embryonic viability. Binding between cognate factors is conserved in an enzymatically distinct CI system, CidA-CidB, suggesting universal features in Wolbachia CI induction and rescue.
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Beckmann JF, Van Vaerenberghe K, Akwa DE, Cooper BS. A single mutation weakens symbiont-induced reproductive manipulation through reductions in deubiquitylation efficiency. Proc Natl Acad Sci U S A 2021; 118:e2113271118. [PMID: 34548405 PMCID: PMC8488622 DOI: 10.1073/pnas.2113271118] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 11/18/2022] Open
Abstract
Animals interact with microbes that affect their performance and fitness, including endosymbionts that reside inside their cells. Maternally transmitted Wolbachia bacteria are the most common known endosymbionts, in large part because of their manipulation of host reproduction. For example, many Wolbachia cause cytoplasmic incompatibility (CI) that reduces host embryonic viability when Wolbachia-modified sperm fertilize uninfected eggs. Operons termed cifs control CI, and a single factor (cifA) rescues it, providing Wolbachia-infected females a fitness advantage. Despite CI's prevalence in nature, theory indicates that natural selection does not act to maintain CI, which varies widely in strength. Here, we investigate the genetic and functional basis of CI-strength variation observed among sister Wolbachia that infect Drosophila melanogaster subgroup hosts. We cloned, Sanger sequenced, and expressed cif repertoires from weak CI-causing wYak in Drosophila yakuba, revealing mutations suspected to weaken CI relative to model wMel in D. melanogaster A single valine-to-leucine mutation within the deubiquitylating (DUB) domain of the wYak cifB homolog (cidB) ablates a CI-like phenotype in yeast. The same mutation reduces both DUB efficiency in vitro and transgenic CI strength in the fly, each by about twofold. Our results map hypomorphic transgenic CI to reduced DUB activity and indicate that deubiquitylation is central to CI induction in cid systems. We also characterize effects of other genetic variation distinguishing wMel-like cifs Importantly, CI strength determines Wolbachia prevalence in natural systems and directly influences the efficacy of Wolbachia biocontrol strategies in transinfected mosquito systems. These approaches rely on strong CI to reduce human disease.
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Affiliation(s)
- John F Beckmann
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849;
| | | | - Daniel E Akwa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849
| | - Brandon S Cooper
- Division of Biological Sciences, University of Montana, Missoula, MT 59801
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Morrow JL, Riegler M. Genome analyses of four Wolbachia strains and associated mitochondria of Rhagoletis cerasi expose cumulative modularity of cytoplasmic incompatibility factors and cytoplasmic hitchhiking across host populations. BMC Genomics 2021; 22:616. [PMID: 34388986 PMCID: PMC8361831 DOI: 10.1186/s12864-021-07906-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022] Open
Abstract
Background The endosymbiont Wolbachia can manipulate arthropod reproduction and invade host populations by inducing cytoplasmic incompatibility (CI). Some host species are coinfected with multiple Wolbachia strains which may have sequentially invaded host populations by expressing different types of modular CI factor (cif) genes. The tephritid fruit fly Rhagoletis cerasi is a model for CI and Wolbachia population dynamics. It is associated with at least four Wolbachia strains in various combinations, with demonstrated (wCer2, wCer4), predicted (wCer1) or unknown (wCer5) CI phenotypes. Results We sequenced and assembled the draft genomes of the Wolbachia strains wCer1, wCer4 and wCer5, and compared these with the previously sequenced genome of wCer2 which currently invades R. cerasi populations. We found complete cif gene pairs in all strains: four pairs in wCer2 (three Type I; one Type V), two pairs in wCer1 (both Type I) and wCer4 (one Type I; one Type V), and one pair in wCer5 (Type IV). Wolbachia genome variant analyses across geographically and genetically distant host populations revealed the largest diversity of single nucleotide polymorphisms (SNPs) in wCer5, followed by wCer1 and then wCer2, indicative of their different lengths of host associations. Furthermore, mitogenome analyses of the Wolbachia genome-sequenced individuals in combination with SNP data from six European countries revealed polymorphic mitogenome sites that displayed reduced diversity in individuals infected with wCer2 compared to those without. Conclusions Coinfections with Wolbachia are common in arthropods and affect options for Wolbachia-based management strategies of pest and vector species already infected by Wolbachia. Our analyses of Wolbachia genomes of a host naturally coinfected by several strains unravelled signatures of the evolutionary dynamics in both Wolbachia and host mitochondrial genomes as a consequence of repeated invasions. Invasion of already infected populations by new Wolbachia strains requires new sets of functionally different cif genes and thereby may select for a cumulative modularity of cif gene diversity in invading strains. Furthermore, we demonstrated at the mitogenomic scale that repeated CI-driven Wolbachia invasions of hosts result in reduced mitochondrial diversity and hitchhiking effects. Already resident Wolbachia strains may experience similar cytoplasmic hitchhiking effects caused by the invading Wolbachia strain. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07906-6.
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Affiliation(s)
- Jennifer L Morrow
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia
| | - Markus Riegler
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
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37
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Shropshire JD, Rosenberg R, Bordenstein SR. The impacts of cytoplasmic incompatibility factor (cifA and cifB) genetic variation on phenotypes. Genetics 2021; 217:1-13. [PMID: 33683351 PMCID: PMC8218869 DOI: 10.1093/genetics/iyaa007] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/13/2020] [Indexed: 11/13/2022] Open
Abstract
Wolbachia are maternally transmitted, intracellular bacteria that can
often selfishly spread through arthropod populations via cytoplasmic incompatibility (CI).
CI manifests as embryonic death when males expressing prophage WO genes
cifA and cifB mate with uninfected females or females
harboring an incompatible Wolbachia strain. Females with a compatible
cifA-expressing strain rescue CI. Thus, cif-mediated
CI confers a relative fitness advantage to females transmitting
Wolbachia. However, whether cif sequence variation
underpins incompatibilities between Wolbachia strains and variation in CI
penetrance remains unknown. Here, we engineer Drosophila melanogaster to
transgenically express cognate and non-cognate cif homologs and assess
their CI and rescue capability. Cognate expression revealed that cifA;B
native to D. melanogaster causes strong CI, and cognate
cifA;B homologs from two other Drosophila-associated
Wolbachia cause weak transgenic CI, including the first demonstration
of phylogenetic type 2 cifA;B CI. Intriguingly, non-cognate expression of
cifA and cifB alleles from different strains revealed
that cifA homologs generally contribute to strong transgenic CI and
interchangeable rescue despite their evolutionary divergence, and cifB
genetic divergence contributes to weak or no transgenic CI. Finally, we find that a type 1
cifA can rescue CI caused by a genetically divergent type 2
cifA;B in a manner consistent with unidirectional incompatibility. By
genetically dissecting individual CI functions for type 1 and 2 cifA and
cifB, this work illuminates new relationships between
cif genotype and CI phenotype. We discuss the relevance of these
findings to CI’s genetic basis, phenotypic variation patterns, and mechanism.
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Affiliation(s)
- J Dylan Shropshire
- Department of Biological Sciences, Vanderbilt University, VU Station B, Box 35-1634, Nashville, TN 37235, USA.,Vanderbilt Microbiome Initiative, Vanderbilt University, VU Station B, Box 35-1634, Nashville, TN 37235, USA.,Division of Biological Sciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
| | - Rachel Rosenberg
- Department of Biological Sciences, Vanderbilt University, VU Station B, Box 35-1634, Nashville, TN 37235, USA.,Vanderbilt Microbiome Initiative, Vanderbilt University, VU Station B, Box 35-1634, Nashville, TN 37235, USA
| | - Seth R Bordenstein
- Department of Biological Sciences, Vanderbilt University, VU Station B, Box 35-1634, Nashville, TN 37235, USA.,Vanderbilt Microbiome Initiative, Vanderbilt University, VU Station B, Box 35-1634, Nashville, TN 37235, USA.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN 37235, USA.,Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37235, USA
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Takano SI, Gotoh Y, Hayashi T. "Candidatus Mesenet longicola": Novel Endosymbionts of Brontispa longissima that Induce Cytoplasmic Incompatibility. MICROBIAL ECOLOGY 2021; 82:512-522. [PMID: 33454808 DOI: 10.1007/s00248-021-01686-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
Intracellular bacteria that are mainly transmitted maternally affect their arthropod hosts' biology in various ways. One such effect is known as cytoplasmic incompatibility (CI), and three bacterial species are known to induce CI: Wolbachia, Cardinium hertigii, and a recently found alphaproteobacterial symbiont. To clarify the taxonomic status and provide the foundation for future studies to reveal CI mechanisms and other phenotypes, we investigated genetic and morphological properties of the third CI inducer that we have previously reported inducing CI in the coconut beetle Brontispa longissima. The draft genome of the bacteria was obtained from the oocytes of two isofemale lines of B. longissima infected with the bacteria: one from Japan (GL2) and the other from Vietnam (L5). Genome features of the symbionts (sGL2 and sL5) were highly similar, showing 1.3 Mb in size, 32.1% GC content, and 99.83% average nucleotide sequence. A phylogenetic study based on 43 universal and single-copy phylogenetic marker genes indicates that they formed a distinct clade in the family Anaplasmataceae. 16S rRNA gene sequences indicate that they are different from the closest known relatives, at least at the genus level. Therefore, we propose a new genus and species, "Candidatus Mesenet longicola", for the symbionts of B. longissima. Morphological analyses showed that Ca. M. longicola is an intracellular bacterium that is ellipsoidal to rod-shaped and 0.94 ± 0.26 μm (mean ± SD) in length, and accumulated in the anterior part of the oocyte. Candidates for the Ca. M. longicola genes responsible for CI induction are also described.
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Affiliation(s)
- Shun-Ichiro Takano
- Faculty of Agriculture, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan.
| | - Yasuhiro Gotoh
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
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Dutra HLC, Ford SA, Allen SL, Bordenstein SR, Chenoweth SF, Bordenstein SR, McGraw EA. The impact of artificial selection for Wolbachia-mediated dengue virus blocking on phage WO. PLoS Negl Trop Dis 2021; 15:e0009637. [PMID: 34314434 PMCID: PMC8345842 DOI: 10.1371/journal.pntd.0009637] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 08/06/2021] [Accepted: 07/08/2021] [Indexed: 11/18/2022] Open
Abstract
Wolbachia is currently at the forefront of global efforts to control arbovirus transmission from the vector Aedes aegypti. The use of Wolbachia relies on two phenotypes—cytoplasmic incompatibility (CI), conferred by cifA and cifB genes in prophage WO, and Wolbachia-mediated pathogen blocking (WMPB). These traits allow for local, self-sustaining reductions in transmission of dengue (DENV) following release of Wolbachia-infected A. aegypti. Here, aided by previous artificial selection experiment that generated Low and High pathogen blocking lines, we examined the potential link between WMPB and phage WO. We found no evidence that Wolbachia or phage WO relative densities predict DENV blocking strength across selected lines. However, selection resulted in reduced phage WO relative density for the Low WMPB line. The Low blocking line was previously shown to have reduced fitness as a result of selection. Through subsequent genomic analyses, we demonstrate that SNP variation underpinning selection for low blocking led to elevated frequency of potential deleterious SNPs on chromosome 1. The key region on chromosome 1 contains genes relating to cell cycle regulation, oxidative stress, transcriptional pausing, among others, that may have cascading effects on Wolbachia intracellular environment. We hypothesize that reduction in phage WO may be driven by changes in the loci directly under selection for blocking, or by the accumulation of predicted deleterious alleles in linkage disequilibrium with blocking loci resulting from hitchhiking. For the Low line with fewer phage WO, we also detected reduced expression of cifA and cifB CI genes, with patterns of expression varying between somatic and reproductive tissues. In conclusion, we propose that artificial selection for WMPB trait had corresponding impacts on phage WO densities, and also the transcription of CI-causing genes. Future studies may include a more detailed analysis of the regions the A. aegypti chromosome 1’s ability to affect WMPB and other Wolbachia-associated intrinsic factors such as phage WO. Wolbachia are widespread endosymbiotic bacteria of insects that cause Wolbachia-mediated pathogen blocking (WMPB) and cytoplasmic incompatibility (CI). The latter mediated by cif genes localized in the prophage WO region. Because of that, Wolbachia-infected mosquitoes are currently being used in field to fight the transmission of vector-borne viruses such as Dengue (DENV) to human populations. Aided by a previous artificial selection experiment that generated lines with variable (High and Low) DENV blocking strength, we tested for a potential link between WMPB and phage WO. There was no evidence that Wolbachia nor phage WO densities predict DENV blocking strength. However, we found that the Low blocking line had reduced phage WO density, and lower expression of the cif genes in a tissue-specific manner. We demonstrate that in addition to previous report of reduced fitness, the Low blocking line also exhibited increased frequency of potential deleterious SNPs on chromosome 1. Our hypotheses are that reduction in phage WO may have resulted from changes in the loci directly under selection for blocking, or by linkage disequilibrium events linked to the accumulation of mosquito predicted deleterious alleles. Our results highlight the importance of chromosome 1 for WMPB and its potential impact for other Wolbachia-associated factors like phage WO.
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Affiliation(s)
- Heverton L. C. Dutra
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, University Park, Pennsylvania, United States of America
| | - Suzanne A. Ford
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, University Park, Pennsylvania, United States of America
| | - Scott L. Allen
- School of Biological Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Sarah R. Bordenstein
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Microbiome Initiative, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Stephen F. Chenoweth
- School of Biological Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Seth R. Bordenstein
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Microbiome Initiative, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee, United States of America
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, Tennessee, United States of America
| | - Elizabeth A. McGraw
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania, United States of America
- Center for Infectious Disease Dynamics, Huck Institutes of the Life Sciences, University Park, Pennsylvania, United States of America
- * E-mail:
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40
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Caragata EP, Dutra HLC, Sucupira PHF, Ferreira AGA, Moreira LA. Wolbachia as translational science: controlling mosquito-borne pathogens. Trends Parasitol 2021; 37:1050-1067. [PMID: 34303627 DOI: 10.1016/j.pt.2021.06.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/21/2021] [Accepted: 06/29/2021] [Indexed: 01/23/2023]
Abstract
In this review we examine how exploiting the Wolbachia-mosquito relationship has become an increasingly popular strategy for controlling arbovirus transmission. Field deployments of Wolbachia-infected mosquitoes have led to significant decreases in dengue virus incidence via high levels of mosquito population suppression and replacement, emphasizing the success of Wolbachia approaches. Here, we examine how improved knowledge of Wolbachia-host interactions has provided key insight into the mechanisms of the essential phenotypes of pathogen blocking and cytoplasmic incompatibility. And we discuss recent studies demonstrating that extrinsic factors, such as ambient temperature, can modulate Wolbachia density and maternal transmission. Finally, we assess the prospects of using Wolbachia to control other vectors and agricultural pest species.
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Affiliation(s)
- Eric P Caragata
- Florida Medical Entomology Laboratory, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences, University of Florida, Vero Beach, FL, USA.
| | - Heverton L C Dutra
- Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Pedro H F Sucupira
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Instituto René Rachou - Fiocruz, Belo Horizonte, MG, Brazil
| | - Alvaro G A Ferreira
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Instituto René Rachou - Fiocruz, Belo Horizonte, MG, Brazil
| | - Luciano A Moreira
- Mosquitos Vetores: Endossimbiontes e Interação Patógeno-Vetor, Instituto René Rachou - Fiocruz, Belo Horizonte, MG, Brazil.
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41
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Morrow JL, Schneider DI, Klasson L, Janitz C, Miller WJ, Riegler M. Parallel Sequencing of Wolbachia wCer2 from Donor and Novel Hosts Reveals Multiple Incompatibility Factors and Genome Stability after Host Transfers. Genome Biol Evol 2021; 12:720-735. [PMID: 32163151 PMCID: PMC7259677 DOI: 10.1093/gbe/evaa050] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2020] [Indexed: 12/11/2022] Open
Abstract
The application of Wolbachia in insect pest and vector control requires the establishment of genotypically stable host associations. The cytoplasmic incompatibility (CI) inducing Wolbachia strain wCer2 naturally occurs in the cherry fruit fly Rhagoletis cerasi as co-infection with other strains and was transferred to other fruit fly species by embryonic microinjections. We obtained wCer2 genome data from its native and three novel hosts, Drosophila simulans, Drosophila melanogaster, and Ceratitis capitata and assessed its genome stability, characteristics, and CI factor (cif) genes. De novo assembly was successful from Wolbachia cell-enriched singly infected D. simulans embryos, with minimal host and other bacterial genome traces. The low yield of Wolbachia sequence reads from total genomic extracts of one multiply infected R. cerasi pupa and one singly infected C. capitata adult limited de novo assemblies but was sufficient for comparative analyses. Across hosts wCer2 was stable in genome synteny and content. Polymorphic nucleotide sites were found in wCer2 of each host; however, only one nucleotide was different between R. cerasi and C. capitata, and none between replicated D. simulans lines. The wCer2 genome is highly similar to wAu (D. simulans), wMel (D. melanogaster), and wRec (Drosophila recens). In contrast to wMel and wRec (each with one cif gene pair) and wAu (without any cif genes), wCer2 has three pairs of Type I cif genes, and one Type V cifB gene without a cifA complement. This may explain previously reported CI patterns of wCer2, including incomplete rescue of its own CI modification in three novel host species.
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Affiliation(s)
- Jennifer L Morrow
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Daniela I Schneider
- Division of Cell & Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria.,Department of Epidemiology of Microbial Diseases, Yale University, New Haven, Connecticut
| | - Lisa Klasson
- Molecular Evolution, Department of Cell and Molecular Biology, Uppsala University, Sweden
| | - Caroline Janitz
- Next Generation Sequencing Facility, Western Sydney University, Penrith, NSW, Australia
| | - Wolfgang J Miller
- Division of Cell & Developmental Biology, Center for Anatomy and Cell Biology, Medical University of Vienna, Austria
| | - Markus Riegler
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
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42
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Ün Ç, Schultner E, Manzano-Marín A, Flórez LV, Seifert B, Heinze J, Oettler J. Cytoplasmic incompatibility between Old and New World populations of a tramp ant. Evolution 2021; 75:1775-1791. [PMID: 34047357 DOI: 10.1111/evo.14261] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 12/21/2022]
Abstract
Reproductive manipulation by endosymbiotic Wolbachia can cause unequal inheritance, allowing the manipulator to spread and potentially impacting evolutionary dynamics in infected hosts. Tramp and invasive species are excellent models to study the dynamics of host-Wolbachia associations because introduced populations often diverge in their microbiomes after colonizing new habitats, resulting in infection polymorphisms between native and introduced populations. Ants are the most abundant group of insects on earth, and numerous ant species are classified as highly invasive. However, little is known about the role of Wolbachia in these ecologically dominant insects. Here, we provide the first description of reproductive manipulation by Wolbachia in an ant. We show that Old and New World populations of the cosmotropic tramp ant Cardiocondyla obscurior harbor distinct Wolbachia strains, and that only the Old World strain manipulates host reproduction by causing cytoplasmic incompatibility (CI) in hybrid crosses. By uncovering a symbiont-induced mechanism of reproductive isolation in a social insect, our study provides a novel perspective on the biology of tramp ants and introduces a new system for studying the evolutionary consequences of CI.
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Affiliation(s)
- Çiğdem Ün
- Zoology/Evolutionary Biology, University of Regensburg, Regensburg, 93053, Germany
| | - Eva Schultner
- Zoology/Evolutionary Biology, University of Regensburg, Regensburg, 93053, Germany
| | - Alejandro Manzano-Marín
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, 1090, Austria
| | - Laura V Flórez
- Institute of Organismic and Molecular Evolution, Evolutionary Ecology Department, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Bernhard Seifert
- Senckenberg Museum of Natural History Görlitz, Görlitz, 02826, Germany
| | - Jürgen Heinze
- Zoology/Evolutionary Biology, University of Regensburg, Regensburg, 93053, Germany
| | - Jan Oettler
- Zoology/Evolutionary Biology, University of Regensburg, Regensburg, 93053, Germany
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43
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Baião GC, Janice J, Galinou M, Klasson L. Comparative Genomics Reveals Factors Associated with Phenotypic Expression of Wolbachia. Genome Biol Evol 2021; 13:6277727. [PMID: 34003269 DOI: 10.1093/gbe/evab111] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/05/2021] [Accepted: 05/17/2021] [Indexed: 12/18/2022] Open
Abstract
Wolbachia is a widespread, vertically transmitted bacterial endosymbiont known for manipulating arthropod reproduction. Its most common form of reproductive manipulation is cytoplasmic incompatibility (CI), observed when a modification in the male sperm leads to embryonic lethality unless a compatible rescue factor is present in the female egg. CI attracts scientific attention due to its implications for host speciation and in the use of Wolbachia for controlling vector-borne diseases. However, our understanding of CI is complicated by the complexity of the phenotype, whose expression depends on both symbiont and host factors. In the present study, we perform a comparative analysis of nine complete Wolbachia genomes with known CI properties in the same genetic host background, Drosophila simulans STC. We describe genetic differences between closely related strains and uncover evidence that phages and other mobile elements contribute to the rapid evolution of both genomes and phenotypes of Wolbachia. Additionally, we identify both known and novel genes associated with the modification and rescue functions of CI. We combine our observations with published phenotypic information and discuss how variability in cif genes, novel CI-associated genes, and Wolbachia titer might contribute to poorly understood aspects of CI such as strength and bidirectional incompatibility. We speculate that high titer CI strains could be better at invading new hosts already infected with a CI Wolbachia, due to a higher rescue potential, and suggest that titer might thus be a relevant parameter to consider for future strategies using CI Wolbachia in biological control.
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Affiliation(s)
- Guilherme Costa Baião
- Molecular Evolution, Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Jessin Janice
- Molecular Evolution, Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Maria Galinou
- Molecular Evolution, Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Lisa Klasson
- Molecular Evolution, Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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44
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Dalla Benetta E, Akbari OS, Ferree PM. Mechanistically comparing reproductive manipulations caused by selfish chromosomes and bacterial symbionts. Heredity (Edinb) 2021; 126:707-716. [PMID: 33649572 PMCID: PMC8102561 DOI: 10.1038/s41437-021-00410-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 01/18/2021] [Accepted: 01/18/2021] [Indexed: 01/30/2023] Open
Abstract
Insects naturally harbor a broad range of selfish agents that can manipulate their reproduction and development, often leading to host sex ratio distortion. Such effects directly benefit the spread of the selfish agents. These agents include two broad groups: bacterial symbionts and selfish chromosomes. Recent studies have made steady progress in uncovering the cellular targets of these agents and their effector genes. Here we highlight what is known about the targeted developmental processes, developmental timing, and effector genes expressed by several selfish agents. It is now becoming apparent that: (1) the genetic toolkits used by these agents to induce a given reproductive manipulation are simple, (2) these agents target sex-specific cellular processes very early in development, and (3) in some cases, similar processes are targeted. Knowledge of the molecular underpinnings of these systems will help to solve long-standing puzzles and provide new tools for controlling insect pests.
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Affiliation(s)
- Elena Dalla Benetta
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA 91711 USA ,grid.266100.30000 0001 2107 4242Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, CA 92093 USA
| | - Omar S. Akbari
- grid.266100.30000 0001 2107 4242Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, 9500 Gilman Drive, CA 92093 USA
| | - Patrick M. Ferree
- W. M. Keck Science Department, Claremont McKenna, Pitzer, and Scripps Colleges, Claremont, CA 91711 USA
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45
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Cytoplasmic Incompatibility Variations in Relation with Wolbachia cid Genes Divergence in Culex pipiens. mBio 2021; 12:mBio.02797-20. [PMID: 33563818 PMCID: PMC7885119 DOI: 10.1128/mbio.02797-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Culex pipiens mosquitoes are infected with wPip. These endosymbionts induce a conditional sterility called CI resulting from embryonic deaths, which constitutes a cornerstone for Wolbachia antivectorial methods. In arthropods, Wolbachia endosymbionts induce conditional sterility, called cytoplasmic incompatibility (CI), resulting from embryonic lethality. CI penetrance (i.e., embryonic death rate) varies depending on host species and Wolbachia strains involved. All Culex pipiens mosquitoes are infected by the endosymbiotic alphaproteobacteria Wolbachia wPip. CI in Culex, characterized as a binary “compatible/incompatible” phenomenon, revealed an unparalleled diversity of patterns linked to the amplification-diversification of cidA and cidB genes. Here, we accurately studied CI penetrance variations in the light of cid genes divergence by generating a C. pipiens compatibility matrix between 11 lines hosting different phylogenetic wPip groups and exhibiting distinct cid gene repertoires. We showed, as expected, that crosses involving wPip from the same group were mostly compatible. In contrast, only 22% of the crosses involving different wPip groups were compatible, while 54% were fully incompatible. For the remaining 24% of the crosses, “intermediate” compatibilities were reported, and a cytological observation of the first zygotic division confirmed the occurrence of “canonical” CI phenotypes in a fraction of the eggs. Backcross experiments demonstrated that intermediate compatibilities were not linked to host genetic background but to the Wolbachia strains involved. This previously unstudied intermediate penetrance CI was more severe and frequent in crosses involving wPip-IV strains exhibiting cid variants markedly divergent from other wPip groups. Our data demonstrate that CI is not always a binary compatible/incompatible phenomenon in C. pipiens but that intermediate compatibilities putatively resulting from partial mismatch due to Cid proteins divergence exist in this species complex.
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46
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Intracellular Density of Wolbachia Is Mediated by Host Autophagy and the Bacterial Cytoplasmic Incompatibility Gene cifB in a Cell Type-Dependent Manner in Drosophila melanogaster. mBio 2021; 12:mBio.02205-20. [PMID: 33436431 PMCID: PMC7844536 DOI: 10.1128/mbio.02205-20] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Autophagy is an intracellular degradation pathway involved in innate immunity. Pathogenic bacteria have evolved several mechanisms to escape degradation or exploit autophagy to acquire host nutrients. In the case of endosymbionts, which often have commensal or mutualistic interactions with the host, autophagy is not well characterized. We utilized tissue-specific autophagy mutants to determine if Wolbachia, a vertically transmitted obligate endosymbiont of Drosophila melanogaster, is regulated by autophagy in somatic and germ line cell types. Our analysis revealed core autophagy proteins Atg1 and Atg8 and a selective autophagy-specific protein Ref(2)p negatively regulate Wolbachia in the hub, a male gonad somatic cell type. Furthermore, we determined that the Wolbachia effector protein, CifB, modulates autophagy-Wolbachia interactions, identifying a new host-related pathway which these bacterial proteins interact with. In the female germ line, the cell type necessary for inheritance of Wolbachia through vertical transmission, we discovered that bulk autophagy mediated by Atg1 and Atg8 positively regulates Wolbachia density, whereas Ref(2)p had no effect. Global metabolomics of fly ovaries deficient in germ line autophagy revealed reduced lipid and carbon metabolism, implicating metabolites from these pathways as positive regulators of Wolbachia Our work provides further understanding of how autophagy affects bacteria in a cell type-dependent manner.IMPORTANCE Autophagy is a eukaryotic intracellular degradation pathway which can act as an innate immune response to eliminate pathogens. Conversely, pathogens can evolve proteins which modulate the autophagy pathway to subvert degradation and establish an infection. Wolbachia, a vertically transmitted obligate endosymbiont which infects up to 40% of insect species, is negatively regulated by autophagy in whole animals, but the specific molecular mechanism and tissue which govern this interaction remain unknown. Our studies use cell type-specific autophagy mutants to reveal that Wolbachia is negatively regulated by selective autophagy in the soma, while nonselective autophagy positively regulates Wolbachia in the female germ line. These data provide evidence that cell type can drive different basal autophagy programs which modulate intracellular microbes differently. Additionally, we identified that the Wolbachia effector CifB acts in the selective autophagy pathway to aid in intracellular bacterial survival, providing a new function for CifB beyond its previously identified role in reproductive manipulation.
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47
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Martinez J, Klasson L, Welch JJ, Jiggins FM. Life and Death of Selfish Genes: Comparative Genomics Reveals the Dynamic Evolution of Cytoplasmic Incompatibility. Mol Biol Evol 2021; 38:2-15. [PMID: 32797213 PMCID: PMC7783169 DOI: 10.1093/molbev/msaa209] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cytoplasmic incompatibility is a selfish reproductive manipulation induced by the endosymbiont Wolbachia in arthropods. In males Wolbachia modifies sperm, leading to embryonic mortality in crosses with Wolbachia-free females. In females, Wolbachia rescues the cross and allows development to proceed normally. This provides a reproductive advantage to infected females, allowing the maternally transmitted symbiont to spread rapidly through host populations. We identified homologs of the genes underlying this phenotype, cifA and cifB, in 52 of 71 new and published Wolbachia genome sequences. They are strongly associated with cytoplasmic incompatibility. There are up to seven copies of the genes in each genome, and phylogenetic analysis shows that Wolbachia frequently acquires new copies due to pervasive horizontal transfer between strains. In many cases, the genes have subsequently acquired loss-of-function mutations to become pseudogenes. As predicted by theory, this tends to occur first in cifB, whose sole function is to modify sperm, and then in cifA, which is required to rescue the cross in females. Although cif genes recombine, recombination is largely restricted to closely related homologs. This is predicted under a model of coevolution between sperm modification and embryonic rescue, where recombination between distantly related pairs of genes would create a self-incompatible strain. Together, these patterns of gene gain, loss, and recombination support evolutionary models of cytoplasmic incompatibility.
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Affiliation(s)
- Julien Martinez
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, United Kingdom
| | - Lisa Klasson
- Molecular Evolution, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - John J Welch
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Francis M Jiggins
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
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48
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Adams KL, Abernathy DG, Willett BC, Selland EK, Itoe MA, Catteruccia F. Wolbachia cifB induces cytoplasmic incompatibility in the malaria mosquito vector. Nat Microbiol 2021; 6:1575-1582. [PMID: 34819638 PMCID: PMC8612931 DOI: 10.1038/s41564-021-00998-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 10/18/2021] [Indexed: 12/04/2022]
Abstract
Wolbachia, a maternally inherited intracellular bacterial species, can manipulate host insect reproduction by cytoplasmic incompatibility (CI), which results in embryo lethality in crosses between infected males and uninfected females. CI is encoded by two prophage genes, cifA and cifB. Wolbachia, coupled with the sterile insect technique, has been used in field trials to control populations of the dengue vector Aedes albopictus, but CI-inducing strains are not known to infect the malaria vector Anopheles gambiae. Here we show that cifA and cifB can induce conditional sterility in the malaria vector An. gambiae. We used transgenic expression of these Wolbachia-derived genes in the An. gambiae germline to show that cifB is sufficient to cause embryonic lethality and that cifB-induced sterility is rescued by cifA expression in females. When we co-expressed cifA and cifB in male mosquitoes, the CI phenotype was attenuated. In female mosquitoes, cifB impaired fertility, which was overcome by co-expression of cifA. Our findings pave the way towards using CI to control malaria mosquito vectors.
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Affiliation(s)
- Kelsey L. Adams
- grid.38142.3c000000041936754XDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Daniel G. Abernathy
- grid.38142.3c000000041936754XDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Bailey C. Willett
- grid.38142.3c000000041936754XDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Emily K. Selland
- grid.38142.3c000000041936754XDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Maurice A. Itoe
- grid.38142.3c000000041936754XDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA USA
| | - Flaminia Catteruccia
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
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49
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Driscoll TP, Verhoeve VI, Brockway C, Shrewsberry DL, Plumer M, Sevdalis SE, Beckmann JF, Krueger LM, Macaluso KR, Azad AF, Gillespie JJ. Evolution of Wolbachia mutualism and reproductive parasitism: insight from two novel strains that co-infect cat fleas. PeerJ 2020; 8:e10646. [PMID: 33362982 PMCID: PMC7750005 DOI: 10.7717/peerj.10646] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/03/2020] [Indexed: 12/26/2022] Open
Abstract
Wolbachiae are obligate intracellular bacteria that infect arthropods and certain nematodes. Usually maternally inherited, they may provision nutrients to (mutualism) or alter sexual biology of (reproductive parasitism) their invertebrate hosts. We report the assembly of closed genomes for two novel wolbachiae, wCfeT and wCfeJ, found co-infecting cat fleas (Ctenocephalides felis) of the Elward Laboratory colony (Soquel, CA, USA). wCfeT is basal to nearly all described Wolbachia supergroups, while wCfeJ is related to supergroups C, D and F. Both genomes contain laterally transferred genes that inform on the evolution of Wolbachia host associations. wCfeT carries the Biotin synthesis Operon of Obligate intracellular Microbes (BOOM); our analyses reveal five independent acquisitions of BOOM across the Wolbachia tree, indicating parallel evolution towards mutualism. Alternately, wCfeJ harbors a toxin-antidote operon analogous to the wPip cinAB operon recently characterized as an inducer of cytoplasmic incompatibility (CI) in flies. wCfeJ cinB and three adjacent genes are collectively similar to large modular toxins encoded in CI-like operons of certain Wolbachia strains and Rickettsia species, signifying that CI toxins streamline by fission of large modular toxins. Remarkably, the C. felis genome itself contains two CI-like antidote genes, divergent from wCfeJ cinA, revealing episodic reproductive parasitism in cat fleas and evidencing mobility of CI loci independent of WO-phage. Additional screening revealed predominant co-infection (wCfeT/wCfeJ) amongst C. felis colonies, though fleas in wild populations mostly harbor wCfeT alone. Collectively, genomes of wCfeT, wCfeJ, and their cat flea host supply instances of lateral gene transfers that could drive transitions between parasitism and mutualism.
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Affiliation(s)
| | - Victoria I Verhoeve
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | | | | | - Mariah Plumer
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Spiridon E Sevdalis
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | - John F Beckmann
- Entomology and Plant Pathology, Auburn University, Auburn, AL, USA
| | - Laura M Krueger
- Orange County Mosquito and Vector Control District, Garden Grove, CA, USA
| | - Kevin R Macaluso
- Microbiology and Immunology, University of South Alabama, Mobile, AL, USA
| | - Abdu F Azad
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
| | - Joseph J Gillespie
- Microbiology and Immunology, University of Maryland at Baltimore, Baltimore, MD, USA
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50
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Abstract
In life's constant battle for survival, it takes one to kill but two to conquer. Toxin-antitoxin or toxin-antidote (TA) elements are genetic dyads that cheat the laws of inheritance to guarantee their transmission to the next generation. This seemingly simple genetic arrangement—a toxin linked to its antidote—is capable of quickly spreading and persisting in natural populations. TA elements were first discovered in bacterial plasmids in the 1980s and have recently been characterized in fungi, plants, and animals, where they underlie genetic incompatibilities and sterility in crosses between wild isolates. In this review, we provide a unified view of TA elements in both prokaryotic and eukaryotic organisms and highlight their similarities and differences at the evolutionary, genetic, and molecular levels. Finally, we propose several scenarios that could explain the paradox of the evolutionary origin of TA elements and argue that these elements may be key evolutionary players and that the full scope of their roles is only beginning to be uncovered.
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Affiliation(s)
- Alejandro Burga
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Eyal Ben-David
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los Angeles, California 90095, USA
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University School of Medicine, Jerusalem 91120, Israel
| | - Leonid Kruglyak
- Department of Human Genetics, Department of Biological Chemistry, and Howard Hughes Medical Institute, University of California, Los Angeles, California 90095, USA
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