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Holt JR, Cavichiolli de Oliveira N, Medina RF, Malacrinò A, Lindsey ARI. Insect-microbe interactions and their influence on organisms and ecosystems. Ecol Evol 2024; 14:e11699. [PMID: 39041011 PMCID: PMC11260886 DOI: 10.1002/ece3.11699] [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: 01/30/2024] [Revised: 06/14/2024] [Accepted: 06/21/2024] [Indexed: 07/24/2024] Open
Abstract
Microorganisms are important associates of insect and arthropod species. Insect-associated microbes, including bacteria, fungi, and viruses, can drastically impact host physiology, ecology, and fitness, while many microbes still have no known role. Over the past decade, we have increased our knowledge of the taxonomic composition and functional roles of insect-associated microbiomes and viromes. There has been a more recent shift toward examining the complexity of microbial communities, including how they vary in response to different factors (e.g., host genome, microbial strain, environment, and time), and the consequences of this variation for the host and the wider ecological community. We provide an overview of insect-microbe interactions, the variety of associated microbial functions, and the evolutionary ecology of these relationships. We explore the influence of the environment and the interactive effects of insects and their microbiomes across trophic levels. Additionally, we discuss the potential for subsequent synergistic and reciprocal impacts on the associated microbiomes, ecological interactions, and communities. Lastly, we discuss some potential avenues for the future of insect-microbe interactions that include the modification of existing microbial symbionts as well as the construction of synthetic microbial communities.
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Affiliation(s)
| | | | - Raul F. Medina
- Department of EntomologyTexas A&M University, Minnie Bell Heep CenterCollege StationTexasUSA
| | - Antonino Malacrinò
- Department of AgricultureUniversità Degli Studi Mediterranea di Reggio CalabriaReggio CalabriaItaly
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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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Zhu X, Li J, He A, Gurr GM, You M, You S. Developmental Shifts in the Microbiome of a Cosmopolitan Pest: Unraveling the Role of Wolbachia and Dominant Bacteria. INSECTS 2024; 15:132. [PMID: 38392551 PMCID: PMC10888865 DOI: 10.3390/insects15020132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
Wolbachia bacteria (phylum Proteobacteria) are ubiquitous intracellular parasites of diverse invertebrates. In insects, coevolution has forged mutualistic associations with Wolbachia species, influencing reproduction, immunity, development, pathogen resistance, and overall fitness. However, the impact of Wolbachia on other microbial associates within the insect microbiome, which are crucial for host fitness, remains less explored. The diamondback moth (Plutella xylostella), a major pest of cruciferous vegetables worldwide, harbors the dominant Wolbachia strain plutWB1, known to distort its sex ratio. This study investigated the bacterial community diversity and dynamics across different developmental life stages and Wolbachia infection states in P. xylostella using high-throughput 16S rDNA amplicon sequencing. Proteobacteria and Firmicutes dominated the P. xylostella microbiome regardless of life stage or Wolbachia infection. However, the relative abundance of dominant genera, including an unclassified genus of Enterobacteriaceae, Wolbachia, Carnobacterium, and Delftia tsuruhatensis, displayed significant stage-specific variations. While significant differences in bacterial diversity and composition were observed across life stages, Wolbachia infection had no substantial impact on overall diversity. Nonetheless, relative abundances of specific genera differed between infection states. Notably, Wolbachia exhibited a stable, high relative abundance across all stages and negatively correlated with an unclassified genus of Enterobacteriaceae, Delftia tsuruhatensis, and Carnobacterium. Our findings provide a foundational understanding of the complex interplay between the host, Wolbachia, and the associated microbiome in P. xylostella, paving the way for a deeper understanding of their complex interactions and potential implications for pest control strategies.
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Affiliation(s)
- Xiangyu Zhu
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jinyang Li
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ao He
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Geoff M Gurr
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Gulbali Institute, Charles Sturt University, Orange, NSW 2800, Australia
| | - Minsheng You
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shijun You
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
- Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou 350002, China
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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4
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Arai H, Legeai F, Kageyama D, Sugio A, Simon JC. Genomic insights into Spiroplasma endosymbionts that induce male-killing and protective phenotypes in the pea aphid. FEMS Microbiol Lett 2024; 371:fnae027. [PMID: 38632047 DOI: 10.1093/femsle/fnae027] [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: 01/12/2024] [Revised: 04/12/2024] [Accepted: 04/16/2024] [Indexed: 04/19/2024] Open
Abstract
The endosymbiotic bacteria Spiroplasma (Mollicutes) infect diverse plants and arthropods, and some of which induce male killing, where male hosts are killed during development. Male-killing Spiroplasma strains belong to either the phylogenetically distant Citri-Poulsonii or Ixodetis groups. In Drosophila flies, Spiroplasma poulsonii induces male killing via the Spaid toxin. While Spiroplasma ixodetis infects a wide range of insects and arachnids, little is known about the genetic basis of S. ixodetis-induced male killing. Here, we analyzed the genome of S. ixodetis strains in the pea aphid Acyrthosiphon pisum (Aphididae, Hemiptera). Genome sequencing constructed a complete genome of a male-killing strain, sAp269, consisting of a 1.5 Mb circular chromosome and an 80 Kb plasmid. sAp269 encoded putative virulence factors containing either ankyrin repeat, ovarian tumor-like deubiquitinase, or ribosome inactivating protein domains, but lacked the Spaid toxin. Further comparative genomics of Spiroplasma strains in A. pisum biotypes adapted to different host plants revealed their phylogenetic associations and the diversity of putative virulence factors. Although the mechanisms of S. ixodetis-induced male killing in pea aphids remain elusive, this study underlines the dynamic genome evolution of S. ixodetis and proposes independent acquisition events of male-killing mechanisms in insects.
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Affiliation(s)
- Hiroshi Arai
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki 305-0851, Japan
| | - Fabrice Legeai
- IGEPP, INRAE, Institut Agro, Univ Rennes, 35653, Le Rheu, France
| | - Daisuke Kageyama
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), 1-2 Owashi, Tsukuba, Ibaraki 305-0851, Japan
| | - Akiko Sugio
- IGEPP, INRAE, Institut Agro, Univ Rennes, 35653, Le Rheu, France
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5
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Wierz JC, Dirksen P, Kirsch R, Krüsemer R, Weiss B, Pauchet Y, Engl T, Kaltenpoth M. Intracellular symbiont Symbiodolus is vertically transmitted and widespread across insect orders. THE ISME JOURNAL 2024; 18:wrae099. [PMID: 38874172 PMCID: PMC11322605 DOI: 10.1093/ismejo/wrae099] [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: 02/06/2024] [Revised: 04/05/2024] [Accepted: 06/05/2024] [Indexed: 06/15/2024]
Abstract
Insects engage in manifold interactions with bacteria that can shift along the parasitism-mutualism continuum. However, only a small number of bacterial taxa managed to successfully colonize a wide diversity of insects, by evolving mechanisms for host-cell entry, immune evasion, germline tropism, reproductive manipulation, and/or by providing benefits to the host that stabilize the symbiotic association. Here, we report on the discovery of an Enterobacterales endosymbiont (Symbiodolus, type species Symbiodolus clandestinus) that is widespread across at least six insect orders and occurs at high prevalence within host populations. Fluorescence in situ hybridization in several Coleopteran and one Dipteran species revealed Symbiodolus' intracellular presence in all host life stages and across tissues, with a high abundance in female ovaries, indicating transovarial vertical transmission. Symbiont genome sequencing across 16 host taxa revealed a high degree of functional conservation in the eroding and transposon-rich genomes. All sequenced Symbiodolus genomes encode for multiple secretion systems, alongside effectors and toxin-antitoxin systems, which likely facilitate host-cell entry and interactions with the host. However, Symbiodolus-infected insects show no obvious signs of disease, and biosynthetic pathways for several amino acids and cofactors encoded by the bacterial genomes suggest that the symbionts may also be able to provide benefits to the hosts. A lack of host-symbiont cospeciation provides evidence for occasional horizontal transmission, so Symbiodolus' success is likely based on a mixed transmission mode. Our findings uncover a hitherto undescribed and widespread insect endosymbiont that may present valuable opportunities to unravel the molecular underpinnings of symbiosis establishment and maintenance.
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Affiliation(s)
- Jürgen C Wierz
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Philipp Dirksen
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, 55128 Mainz, Germany
| | - Roy Kirsch
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Ronja Krüsemer
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Benjamin Weiss
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Yannick Pauchet
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Tobias Engl
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Martin Kaltenpoth
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
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6
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Su S, Hong M, Cui MY, Gui Z, Ma SF, Wu L, Xing LL, Mu L, Yu JF, Fu SY, Gao RJ, Qi DD. Microbial diversity of ticks and a novel typhus group Rickettsia species (Rickettsiales bacterium Ac37b) in Inner Mongolia, China. Parasite 2023; 30:58. [PMID: 38084939 PMCID: PMC10714680 DOI: 10.1051/parasite/2023057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
Ticks can carry multiple pathogens, and Inner Mongolia's animal husbandry provides excellent environmental conditions for ticks. This study characterized the microbiome of ticks from different geographical locations in Inner Mongolia; 905 Dermacentor nuttalli and 36 Ixodes persulcatus were collected from sheep in three main pasture areas and from bushes within the forested area. Mixed DNA samples were prepared from three specimens from each region and tick species. Microbial diversity was analyzed by 16S rRNA sequencing, and α and β diversity were determined. The predominant bacterial genera were Rickettsia (54.60%), including Rickettsiales bacterium Ac37b (19.33%) and other Rickettsia (35.27%), Arsenophonus (11.21%), Candidatus Lariskella (10.84%), and Acinetobacter (7.17%). Rickettsia bellii was identified in I. persulcatus, while Rickettsiales bacterium Ac37b was found in D. nuttalli from Ordos and Chifeng. Potential Rickettsia and Anaplasma coinfections were observed in the Ordos region. Tick microbial diversity analysis in Inner Mongolia suggests that sheep at the sampling sites were exposed to multiple pathogens.
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Affiliation(s)
- Si Su
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Graduate School, Inner Mongolia Medical University Hohhot 010059 Inner Mongolia China
| | - Mei Hong
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School of Basic Medicine, Inner Mongolia Medical University Hohhot 010110 Inner Mongolia China
| | - Meng-Yu Cui
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Graduate School, Inner Mongolia Medical University Hohhot 010059 Inner Mongolia China
| | - Zheng Gui
- First Hospital of Jilin University Changchun 130021 China
| | - Shi-Fa Ma
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Hulunbuir Mental Health Center Hulunbuir 022150 Inner Mongolia China
| | - Lin Wu
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Beijing Guoke Biotechnology Co., Ltd 102200 Beijing China
| | - Li-Li Xing
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Department of Infection Control, Second Affiliated Hospital of Inner Mongolia Medical University Hohhot Inner Mongolia Autonomous Region 010000 China
| | - Lan Mu
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School of Basic Medicine, Inner Mongolia Medical University Hohhot 010110 Inner Mongolia China
| | - Jing-Feng Yu
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School of Basic Medicine, Inner Mongolia Medical University Hohhot 010110 Inner Mongolia China
| | - Shao-Yin Fu
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Inner Mongolia Academy of Agricultural & Animal Husbandry Science Hohhot 010031 Inner Mongolia China
| | - Rui-Juan Gao
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School of Basic Medicine, Inner Mongolia Medical University Hohhot 010110 Inner Mongolia China
| | - Dong-Dong Qi
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Hulunbuir Mental Health Center Hulunbuir 022150 Inner Mongolia China
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7
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Hitchcock TJ, Gardner A. Sexual antagonism in sequential hermaphrodites. Proc Biol Sci 2023; 290:20232222. [PMID: 37989243 PMCID: PMC10688264 DOI: 10.1098/rspb.2023.2222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 10/30/2023] [Indexed: 11/23/2023] Open
Abstract
Females and males may have distinct phenotypic optima, but share essentially the same complement of genes, potentially leading to trade-offs between attaining high fitness through female versus male reproductive success. Such sexual antagonism may be particularly acute in hermaphrodites, where both reproductive strategies are housed within a single individual. While previous models have focused on simultaneous hermaphroditism, we lack theory for how sexual antagonism may play out under sequential hermaphroditism, which has the additional complexities of age-structure. Here, we develop a formal theory of sexual antagonism in sequential hermaphrodites. First, we construct a general theoretical overview of the problem, then consider different types of sexually antagonistic and life-history trade-offs, under different modes of genetic inheritance (autosomal or cytoplasmic), and different forms of sequential hermaphroditism (protogynous, protoandrous or bidirectional). Finally, we provide a concrete illustration of these general patterns by developing a two-stage two-sex model, which yields conditions for both invasion of sexually antagonistic alleles and maintenance of sexually antagonistic polymorphisms.
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Affiliation(s)
- Thomas J. Hitchcock
- RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN, Wako, Saitama 351-0198, Japan
- School of Biology, University of St Andrews, St Andrews, Fife KY16 9TH, UK
| | - Andy Gardner
- School of Biology, University of St Andrews, St Andrews, Fife KY16 9TH, UK
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8
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Harumoto T. Self-stabilization mechanism encoded by a bacterial toxin facilitates reproductive parasitism. Curr Biol 2023; 33:4021-4029.e6. [PMID: 37673069 DOI: 10.1016/j.cub.2023.08.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/30/2023] [Accepted: 08/10/2023] [Indexed: 09/08/2023]
Abstract
A wide variety of maternally transmitted endosymbionts in insects are associated with reproductive parasitism, whereby they interfere with host reproduction to increase the ratio of infected females and spread within populations.1,2 Recent successes in identifying bacterial factors responsible for reproductive parasitism3,4,5,6,7 as well as further omics approaches8,9,10,11,12 have highlighted the common appearance of deubiquitinase domains, although their biological roles-in particular, how they link to distinct manipulative phenotypes-remain poorly defined. Spiroplasma poulsonii is a helical and motile bacterial endosymbiont of Drosophila,13,14 which selectively kills male progeny with a male-killing toxin Spaid (S. poulsonii androcidin), which encodes an ovarian tumor (OTU) deubiquitinase domain.6 Artificial expression of Spaid in flies reproduces male-killing-associated pathologies that include abnormal apoptosis and neural defects during embryogenesis6,15,16,17,18,19; moreover, it highly accumulates on the dosage-compensated male X chromosome,20 congruent with cellular defects such as the DNA damage/chromatin bridge breakage specifically induced upon that chromosome.6,21,22,23 Here, I show that without the function of OTU, Spaid is polyubiquitinated and degraded through the host ubiquitin-proteasome pathway, leading to the attenuation of male-killing activity as shown previously.6 Furthermore, I find that Spaid utilizes its OTU domain to deubiquitinate itself in an intermolecular manner. Collectively, the deubiquitinase domain of Spaid serves as a self-stabilization mechanism to facilitate male killing in flies, optimizing a molecular strategy of endosymbionts that enables the efficient manipulation of the host at a low energetic cost.
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Affiliation(s)
- 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.
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9
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Moore LD, Ballinger MJ. The toxins of vertically transmitted Spiroplasma. Front Microbiol 2023; 14:1148263. [PMID: 37275155 PMCID: PMC10232968 DOI: 10.3389/fmicb.2023.1148263] [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: 01/19/2023] [Accepted: 04/19/2023] [Indexed: 06/07/2023] Open
Abstract
Vertically transmitted (VT) microbial symbionts play a vital role in the evolution of their insect hosts. A longstanding question in symbiont research is what genes help promote long-term stability of vertically transmitted lifestyles. Symbiont success in insect hosts is due in part to expression of beneficial or manipulative phenotypes that favor symbiont persistence in host populations. In Spiroplasma, these phenotypes have been linked to toxin and virulence domains among a few related strains. However, these domains also appear frequently in phylogenetically distant Spiroplasma, and little is known about their distribution across the Spiroplasma genus. In this study, we present the complete genome sequence of the Spiroplasma symbiont of Drosophila atripex, a non-manipulating member of the Ixodetis clade of Spiroplasma, for which genomic data are still limited. We perform a genus-wide comparative analysis of toxin domains implicated in defensive and reproductive phenotypes. From 12 VT and 31 non-VT Spiroplasma genomes, ribosome-inactivating proteins (RIPs), OTU-like cysteine proteases (OTUs), ankyrins, and ETX/MTX2 domains show high propensity for VT Spiroplasma compared to non-VT Spiroplasma. Specifically, OTU and ankyrin domains can be found only in VT-Spiroplasma, and RIP domains are found in all VT Spiroplasma and three non-VT Spiroplasma. These domains are frequently associated with Spiroplasma plasmids, suggesting a possible mechanism for dispersal and maintenance among heritable strains. Searching insect genome assemblies available on public databases uncovered uncharacterized Spiroplasma genomes from which we identified several spaid-like genes encoding RIP, OTU, and ankyrin domains, suggesting functional interactions among those domain types. Our results suggest a conserved core of symbiont domains play an important role in the evolution and persistence of VT Spiroplasma in insects.
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Affiliation(s)
- Logan D. Moore
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, United States
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10
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Oliver KM. Flies co-opt bacterial toxins for use in defense against parasitoids. Proc Natl Acad Sci U S A 2023; 120:e2304493120. [PMID: 37126694 PMCID: PMC10175828 DOI: 10.1073/pnas.2304493120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Affiliation(s)
- Kerry M. Oliver
- Department of Entomology, University of Georgia, Athens, GA30602
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11
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Verster KI, Cinege G, Lipinszki Z, Magyar LB, Kurucz É, Tarnopol RL, Ábrahám E, Darula Z, Karageorgi M, Tamsil JA, Akalu SM, Andó I, Whiteman NK. Evolution of insect innate immunity through domestication of bacterial toxins. Proc Natl Acad Sci U S A 2023; 120:e2218334120. [PMID: 37036995 PMCID: PMC10120054 DOI: 10.1073/pnas.2218334120] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 03/01/2023] [Indexed: 04/12/2023] Open
Abstract
Toxin cargo genes are often horizontally transferred by phages between bacterial species and are known to play an important role in the evolution of bacterial pathogenesis. Here, we show how these same genes have been horizontally transferred from phage or bacteria to animals and have resulted in novel adaptations. We discovered that two widespread bacterial genes encoding toxins of animal cells, cytolethal distending toxin subunit B (cdtB) and apoptosis-inducing protein of 56 kDa (aip56), were captured by insect genomes through horizontal gene transfer from bacteria or phages. To study the function of these genes in insects, we focused on Drosophila ananassae as a model. In the D. ananassae subgroup species, cdtB and aip56 are present as singular (cdtB) or fused copies (cdtB::aip56) on the second chromosome. We found that cdtB and aip56 genes and encoded proteins were expressed by immune cells, some proteins were localized to the wasp embryo's serosa, and their expression increased following parasitoid wasp infection. Species of the ananassae subgroup are highly resistant to parasitoid wasps, and we observed that D. ananassae lines carrying null mutations in cdtB and aip56 toxin genes were more susceptible to parasitoids than the wild type. We conclude that toxin cargo genes were captured by these insects millions of years ago and integrated as novel modules into their innate immune system. These modules now represent components of a heretofore undescribed defense response and are important for resistance to parasitoid wasps. Phage or bacterially derived eukaryotic toxin genes serve as macromutations that can spur the instantaneous evolution of novelty in animals.
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Affiliation(s)
- Kirsten I. Verster
- Department of Integrative Biology, University of California, Berkeley, CA94720
| | - Gyöngyi Cinege
- Innate Immunity Group, Institute of Genetics, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
| | - Zoltán Lipinszki
- MTA SZBK Lendület Laboratory of Cell Cycle Regulation, Institute of Biochemistry, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
| | - Lilla B. Magyar
- Innate Immunity Group, Institute of Genetics, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
- Doctoral School of Biology, University of Szeged, Szeged6720, Hungary
| | - Éva Kurucz
- Innate Immunity Group, Institute of Genetics, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
| | - Rebecca L. Tarnopol
- Department of Plant and Microbial Biology, University of California, Berkeley, CA94720
| | - Edit Ábrahám
- MTA SZBK Lendület Laboratory of Cell Cycle Regulation, Institute of Biochemistry, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
| | - Zsuzsanna Darula
- Single Cell Omics Advanced Core Facility, Hungarian Centre of Excellence for Molecular Medicine, Szeged6728, Hungary
- Laboratory of Proteomics Research, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
| | | | - Josephine A. Tamsil
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Saron M. Akalu
- Department of Integrative Biology, University of California, Berkeley, CA94720
| | - István Andó
- Innate Immunity Group, Institute of Genetics, Biological Research Centre, Eötvös Loránd Research Network, Szeged6726, Hungary
| | - Noah K. Whiteman
- Department of Integrative Biology, University of California, Berkeley, CA94720
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA94720
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12
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Kageyama D, Harumoto T, Nagamine K, Fujiwara A, Sugimoto TN, Jouraku A, Tamura M, Katoh TK, Watada M. A male-killing gene encoded by a symbiotic virus of Drosophila. Nat Commun 2023; 14:1357. [PMID: 36914655 PMCID: PMC10011393 DOI: 10.1038/s41467-023-37145-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 03/03/2023] [Indexed: 03/16/2023] Open
Abstract
In most eukaryotes, biparentally inherited nuclear genomes and maternally inherited cytoplasmic genomes have different evolutionary interests. Strongly female-biased sex ratios that are repeatedly observed in various arthropods often result from the male-specific lethality (male-killing) induced by maternally inherited symbiotic bacteria such as Spiroplasma and Wolbachia. However, despite some plausible case reports wherein viruses are raised as male-killers, it is not well understood how viruses, having much smaller genomes than bacteria, are capable of inducing male-killing. Here we show that a maternally inherited double-stranded RNA (dsRNA) virus belonging to the family Partitiviridae (designated DbMKPV1) induces male-killing in Drosophila. DbMKPV1 localizes in the cytoplasm and possesses only four genes, i.e., one gene in each of the four genomic segments (dsRNA1-dsRNA4), in contrast to ca. 1000 or more genes possessed by Spiroplasma or Wolbachia. We also show that a protein (designated PVMKp1; 330 amino acids in size), encoded by a gene on the dsRNA4 segment, is necessary and sufficient for inducing male-killing. Our results imply that male-killing genes can be easily acquired by symbiotic viruses through reassortment and that symbiotic viruses are hidden players in arthropod evolution. We anticipate that host-manipulating genes possessed by symbiotic viruses can be utilized for controlling arthropods.
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Affiliation(s)
- Daisuke Kageyama
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-0851, 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
| | - Keisuke Nagamine
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-0851, Japan
| | - Akiko Fujiwara
- Center for Food Science and Wellness, Gunma University, 4-2 Aramaki, Maebashi, Gunma, 371-8510, Japan
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama, 351-0198, Japan
| | - Takafumi N Sugimoto
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-0851, Japan
| | - Akiya Jouraku
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, 1-2 Owashi, Tsukuba, Ibaraki, 305-0851, Japan
| | - Masaru Tamura
- Division of Food Safety Information, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa, 210-9501, Japan
| | - Takehiro K Katoh
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime, 780-8857, Japan
- Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, Tokyo, 192-0397, Japan
| | - Masayoshi Watada
- Graduate School of Science and Engineering, Ehime University, Matsuyama, Ehime, 780-8857, Japan.
- Department of Biological Sciences, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachioji, Tokyo, 192-0397, Japan.
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13
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Abstract
Insects are highly successful in colonizing a wide spectrum of ecological niches and in feeding on a wide diversity of diets. This is notably linked to their capacity to get from their microbiota any essential component lacking in the diet such as vitamins and amino acids. Over a century of research based on dietary analysis, antimicrobial treatment, gnotobiotic rearing, and culture-independent microbe detection progressively generated a wealth of information about the role of the microbiota in specific aspects of insect fitness. Thanks to the recent increase in sequencing capacities, whole-genome sequencing of a number of symbionts has facilitated tracing of biosynthesis pathways, validation of experimental data and evolutionary analyses. This field of research has generated a considerable set of data in a diversity of hosts harboring specific symbionts or nonspecific microbiota members. Here, we review the current knowledge on the involvement of the microbiota in insect and tick nutrition, with a particular focus on B vitamin provision. We specifically question if there is any specificity of B vitamin provision by symbionts compared to the redundant yet essential contribution of nonspecific microbes. We successively highlight the known aspects of microbial vitamin provision during three main life stages of invertebrates: postembryonic development, adulthood, and reproduction.
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14
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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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15
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Halter T, Köstlbacher S, Rattei T, Hendrickx F, Manzano-Marín A, Horn M. One to host them all: genomics of the diverse bacterial endosymbionts of the spider Oedothorax gibbosus. Microb Genom 2023; 9:mgen000943. [PMID: 36757767 PMCID: PMC9997750 DOI: 10.1099/mgen.0.000943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
Bacterial endosymbionts of the groups Wolbachia, Cardinium and Rickettsiaceae are well known for their diverse effects on their arthropod hosts, ranging from mutualistic relationships to reproductive phenotypes. Here, we analysed a unique system in which the dwarf spider Oedothorax gibbosus is co-infected with up to five different endosymbionts affiliated with Wolbachia, 'Candidatus Tisiphia' (formerly Torix group Rickettsia), Cardinium and Rhabdochlamydia. Using short-read genome sequencing data, we show that the endosymbionts are heterogeneously distributed among O. gibbosus populations and are frequently found co-infecting spider individuals. To study this intricate host-endosymbiont system on a genome-resolved level, we used long-read sequencing to reconstruct closed genomes of the Wolbachia, 'Ca. Tisiphia' and Cardinium endosymbionts. We provide insights into the ecology and evolution of the endosymbionts and shed light on the interactions with their spider host. We detected high quantities of transposable elements in all endosymbiont genomes and provide evidence that ancestors of the Cardinium, 'Ca. Tisiphia' and Wolbachia endosymbionts have co-infected the same hosts in the past. Our findings contribute to broadening our knowledge about endosymbionts infecting one of the largest animal phyla on Earth and show the usefulness of transposable elements as an evolutionary 'contact-tracing' tool.
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Affiliation(s)
- Tamara Halter
- Centre for Microbiology and Environmental Systems Science, University of Vienna. Djerassiplatz 1, 1030 Vienna, Austria.,Doctoral School in Microbiology and Environmental Science, University of Vienna. Universitätsring 1, 1010 Vienna, Austria
| | - Stephan Köstlbacher
- Centre for Microbiology and Environmental Systems Science, University of Vienna. Djerassiplatz 1, 1030 Vienna, Austria.,Doctoral School in Microbiology and Environmental Science, University of Vienna. Universitätsring 1, 1010 Vienna, Austria.,Current address: Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6700 EH Wageningen, The Netherlands
| | - Thomas Rattei
- Centre for Microbiology and Environmental Systems Science, University of Vienna. Djerassiplatz 1, 1030 Vienna, Austria
| | - Frederik Hendrickx
- OD Taxonomy and Phylogeny, Royal Belgian Institute of Natural Sciences. Rue Vautier/Vautierstraat 29,, 1000 Brussels, Belgium
| | - Alejandro Manzano-Marín
- Centre for Microbiology and Environmental Systems Science, University of Vienna. Djerassiplatz 1, 1030 Vienna, Austria
| | - Matthias Horn
- Centre for Microbiology and Environmental Systems Science, University of Vienna. Djerassiplatz 1, 1030 Vienna, Austria
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16
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Phylogenomic analysis of Wolbachia genomes from the Darwin Tree of Life biodiversity genomics project. PLoS Biol 2023; 21:e3001972. [PMID: 36689552 PMCID: PMC9894559 DOI: 10.1371/journal.pbio.3001972] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 02/02/2023] [Accepted: 12/19/2022] [Indexed: 01/24/2023] Open
Abstract
The Darwin Tree of Life (DToL) project aims to sequence all described terrestrial and aquatic eukaryotic species found in Britain and Ireland. Reference genome sequences are generated from single individuals for each target species. In addition to the target genome, sequenced samples often contain genetic material from microbiomes, endosymbionts, parasites, and other cobionts. Wolbachia endosymbiotic bacteria are found in a diversity of terrestrial arthropods and nematodes, with supergroups A and B the most common in insects. We identified and assembled 110 complete Wolbachia genomes from 93 host species spanning 92 families by filtering data from 368 insect species generated by the DToL project. From 15 infected species, we assembled more than one Wolbachia genome, including cases where individuals carried simultaneous supergroup A and B infections. Different insect orders had distinct patterns of infection, with Lepidopteran hosts mostly infected with supergroup B, while infections in Diptera and Hymenoptera were dominated by A-type Wolbachia. Other than these large-scale order-level associations, host and Wolbachia phylogenies revealed no (or very limited) cophylogeny. This points to the occurrence of frequent host switching events, including between insect orders, in the evolutionary history of the Wolbachia pandemic. While supergroup A and B genomes had distinct GC% and GC skew, and B genomes had a larger core gene set and tended to be longer, it was the abundance of copies of bacteriophage WO who was a strong determinant of Wolbachia genome size. Mining raw genome data generated for reference genome assemblies is a robust way of identifying and analysing cobiont genomes and giving greater ecological context for their hosts.
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17
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Ramirez P, Leavitt JC, Gill JJ, Mateos M. Preliminary Characterization of Phage-Like Particles from the Male-Killing Mollicute Spiroplasma poulsonii (an Endosymbiont of Drosophila). Curr Microbiol 2022; 80:6. [PMID: 36445499 DOI: 10.1007/s00284-022-03099-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 10/24/2022] [Indexed: 11/30/2022]
Abstract
Bacteriophages are vastly abundant, diverse, and influential, but with few exceptions (e.g. the Proteobacteria genera Wolbachia and Hamiltonella), the role of phages in heritable bacteria-arthropod interactions, which are ubiquitous and diverse, remains largely unexplored. Despite prior studies documenting phage-like particles in the mollicute Spiroplasma associated with Drosophila flies, genomic sequences of such phage are lacking, and their effects on the Spiroplasma-Drosophila interaction have not been comprehensively characterized. We used a density step gradient to isolate phage-like particles from the male-killing bacterium Spiroplasma poulsonii (strains NSRO and MSRO-Br) harbored by Drosophila melanogaster. Isolated particles were subjected to DNA sequencing, assembly, and annotation. Several lines of evidence suggest that we recovered phage-like particles of similar features (shape, size, DNA content) to those previously reported in Drosophila-associated Spiroplasma strains. We recovered three ~ 19 kb phage-like contigs (two in NSRO and one in MSRO-Br) containing 21-24 open reading frames, a read-alignment pattern consistent with circular permutation, and terminal redundancy (at least in NSRO). Although our results do not allow us to distinguish whether these phage-like contigs represent infective phage-like particles capable of transmitting their DNA to new hosts, their encoding of several typical phage genes suggests that they are at least remnants of functional phage. We also recovered two smaller non-phage-like contigs encoding a known Spiroplasma toxin (Ribosome Inactivating Protein; RIP), and an insertion element, suggesting that they are packaged into particles. Substantial homology of our particle-derived contigs was found in the genome assemblies of members of the Spiroplasma poulsonii clade.
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Affiliation(s)
- Paulino Ramirez
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA.,Department of Cell Systems and Anatomy, University of Texas Health San Antonio, San Antonio, TX, USA
| | - Justin C Leavitt
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Jason J Gill
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Mariana Mateos
- Department of Wildlife and Fisheries Sciences, Texas A&M University, College Station, TX, USA. .,Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, USA.
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18
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Arai H, Inoue MN, Kageyama D. Male-killing mechanisms vary between Spiroplasma species. Front Microbiol 2022; 13:1075199. [PMID: 36519169 PMCID: PMC9742256 DOI: 10.3389/fmicb.2022.1075199] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 11/08/2022] [Indexed: 03/11/2024] Open
Abstract
Male-killing, a male-specific death of arthropod hosts during development, is induced by Spiroplasma (Mollicutes) endosymbionts of the Citri-Poulsonii and the Ixodetis groups, which are phylogenetically distant groups. Spiroplasma poulsonii induces male-killing in Drosophila melanogaster (Diptera) using the Spaid toxin that harbors ankyrin repeats, whereas little is known about the origin and mechanisms of male-killing induced by Spiroplasma ixodetis. Here, we analyzed the genome and the biological characteristics of a male-killing S. ixodetis strain sHm in the moth Homona magnanima (Tortricidae, Lepidoptera). Strain sHm harbored a 2.1 Mb chromosome and two potential plasmids encoding Type IV effectors, putatively involved in virulence and host-symbiont interactions. Moreover, sHm did not harbor the spaid gene but harbored 10 ankyrin genes that were homologous to those in other S. ixodetis strains. In contrast to the predominant existence of S. poulsonii in hemolymph, our quantitative PCR assays revealed a systemic distribution of strain sHm in H. magnanima, with particularly high titers in Malpighian tubules but low titers in hemolymph. Furthermore, transinfection assays confirmed that strain sHm can infect cultured cells derived from distantly related insects, namely Aedes albopictus (Diptera) and Bombyx mori (Lepidoptera). These results suggest different origins and characteristics of S. ixodetis- and S. poulsonii-induced male-killing.
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Affiliation(s)
- Hiroshi Arai
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
| | - Maki N. Inoue
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Japan
| | - Daisuke Kageyama
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization (NARO), Tsukuba, Japan
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19
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Pollmann M, Moore LD, Krimmer E, D'Alvise P, Hasselmann M, Perlman SJ, Ballinger MJ, Steidle JL, Gottlieb Y. Highly transmissible cytoplasmic incompatibility by the extracellular insect symbiont Spiroplasma. iScience 2022; 25:104335. [PMID: 35602967 PMCID: PMC9118660 DOI: 10.1016/j.isci.2022.104335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 04/06/2022] [Accepted: 04/26/2022] [Indexed: 11/19/2022] Open
Abstract
Cytoplasmic incompatibility (CI) is a form of reproductive manipulation caused by maternally inherited endosymbionts infecting arthropods, like Wolbachia, whereby matings between infected males and uninfected females produce few or no offspring. We report the discovery of a new CI symbiont, a strain of Spiroplasma causing CI in the parasitoid wasp Lariophagus distinguendus. Its extracellular occurrence enabled us to establish CI in uninfected adult insects by transferring Spiroplasma-infected hemolymph. We sequenced the CI-Spiroplasma genome and did not find any homologues of any of the cif genes discovered to cause CI in Wolbachia, suggesting independent evolution of CI. Instead, the genome contains other potential CI-causing candidate genes, such as homologues of high-mobility group (HMG) box proteins that are crucial in eukaryotic development but rare in bacterial genomes. Spiroplasma's extracellular nature and broad host range encompassing medically and agriculturally important arthropods make it a promising tool to study CI and its applications.
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Affiliation(s)
- Marie Pollmann
- Department of Chemical Ecology 190t, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Logan D. Moore
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Elena Krimmer
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany
| | - Paul D'Alvise
- Institute of Medical Microbiology and Hygiene, University Hospital of Tuebingen, 72016 Tuebingen, Germany
| | - Martin Hasselmann
- Department of Livestock Population Genomics 460h, Institute of Animal Science, University of Hohenheim, 70599 Stuttgart, Germany
| | - Steve J. Perlman
- Department of Biology, University of Victoria, Victoria, BC V8W 3N5, Canada
| | - Matthew J. Ballinger
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Johannes L.M. Steidle
- Department of Chemical Ecology 190t, Institute of Biology, University of Hohenheim, 70599 Stuttgart, Germany
- KomBioTa - Center of Biodiversity and Integrative Taxonomy, University of Hohenheim, 70599 Stuttgart, Germany
| | - Yuval Gottlieb
- Koret School of Veterinary Medicine, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, POB 12, Rehovot 76100, Israel
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20
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Hill T, Unckless RL, Perlmutter JI. Positive Selection and Horizontal Gene Transfer in the Genome of a Male-Killing Wolbachia. Mol Biol Evol 2022; 39:msab303. [PMID: 34662426 PMCID: PMC8763111 DOI: 10.1093/molbev/msab303] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Wolbachia are a genus of widespread bacterial endosymbionts in which some strains can hijack or manipulate arthropod host reproduction. Male killing is one such manipulation in which these maternally transmitted bacteria benefit surviving daughters in part by removing competition with the sons for scarce resources. Despite previous findings of interesting genome features of microbial sex ratio distorters, the population genomics of male-killers remain largely uncharacterized. Here, we uncover several unique features of the genome and population genomics of four Arizonan populations of a male-killing Wolbachia strain, wInn, that infects mushroom-feeding Drosophila innubila. We first compared the wInn genome with other closely related Wolbachia genomes of Drosophila hosts in terms of genome content and confirm that the wInn genome is largely similar in overall gene content to the wMel strain infecting D. melanogaster. However, it also contains many unique genes and repetitive genetic elements that indicate lateral gene transfers between wInn and non-Drosophila eukaryotes. We also find that, in line with literature precedent, genes in the Wolbachia prophage and Octomom regions are under positive selection. Of all the genes under positive selection, many also show evidence of recent horizontal transfer among Wolbachia symbiont genomes. These dynamics of selection and horizontal gene transfer across the genomes of several Wolbachia strains and diverse host species may be important underlying factors in Wolbachia's success as a male-killer of divergent host species.
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Affiliation(s)
- Tom Hill
- NIAID Collaborative Bioinformatics Resource, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
- Advanced Biomedical Computational Science, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Robert L Unckless
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, USA
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21
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Hurst MRH, Beattie A, Laugraud A, Townsend R, Sitter L, van Koten C, Harper L. Identification of Diverse Toxin Complex Clusters and an eCIS Variant in Serratia proteamaculans Pathovars of the New Zealand Grass Grub ( Costelytra Giveni) and Manuka Beetle ( Pyronota Spp.) Larvae. Microbiol Spectr 2021; 9:e0112321. [PMID: 34668742 PMCID: PMC8528098 DOI: 10.1128/spectrum.01123-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 09/08/2021] [Indexed: 12/01/2022] Open
Abstract
The grass grub endemic to New Zealand, Costelytra giveni (Coleoptera: Scarabaeidae), and the manuka beetle, Pyronota festiva and P. setosa (Coleoptera: Scarabaeidae), are prevalent pest species. Through assessment of bacterial strains isolated from diseased cadavers of these insect species, 19 insect-active Serratia proteamaculans variants and a single Serratia entomophila strain were isolated. When independently bioassayed, these isolates differed in host range, the rate of disease progression, and 12-day mortality rates, which ranged from 60 to 100% of the challenged larvae. A Pyronota spp.-derived S. proteamaculans isolate caused a transient disease phenotype in challenged C. giveni larvae, whereby larvae appeared diseased before recovering to a healthy state. Genome sequence analysis revealed that all but two of the sequenced isolates contained a variant of the S. entomophila amber-disease-associated plasmid, pADAP. Each isolate also encoded one of seven distinct members of the toxin complex (Tc) family of insect-active toxins, five of which are newly described, or a member of the extracellular contractile injection (eCIS) machine family, with a new AfpX variant designated SpF. Targeted mutagenesis of each of the predicted Tc- or eCIS-encoding regions abolished or attenuated pathogenicity. Host-range testing showed that several of the S. proteamaculans Tc-encoding isolates affected both Pyronota and C. giveni species, with other isolates specific for either Pyronota spp. or C. giveni. The isolation of several distinct host-specific pathotypes of Serratia spp. may reflect pathogen-host speciation. IMPORTANCE New pathotypes of the insect pathogen Serratia, each with differing virulence attributes and host specificity toward larvae of the New Zealand manuka beetle and grass grub, have been identified. All of the Serratia proteamaculans isolates contained one of seven different insect-active toxin clusters or one of three eCIS variants. The diversity of these Serratia-encoded virulence clusters, resulting in differences in larval disease progression and host specificity in endemic scarab larvae, suggests speciation of these pathogens with their insect hosts. The differing virulence properties of these Serratia species may affect their potential infectivity and distribution among the insect populations. Based on their differing geographic isolation and pathotypes, several of these Serratia isolates, including the manuka beetle-active isolates, are likely to be more effective biopesticides in specific environments or could be used in combination for greater effect.
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Affiliation(s)
- Mark R. H. Hurst
- Resilient Agriculture, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
- Bio-Protection Research Centre, Lincoln University, Christchurch, New Zealand
| | - Amy Beattie
- Resilient Agriculture, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Aurelie Laugraud
- Knowledge & Analytics, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Richard Townsend
- Resilient Agriculture, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Lesley Sitter
- Resilient Agriculture, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
- Bio-Protection Research Centre, Lincoln University, Christchurch, New Zealand
| | - Chikako van Koten
- Knowledge & Analytics, AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Lincoln Harper
- Curtin University, Centre for Crop and Disease Management, School of Molecular and Life, Bentley, Western Australia, Australia
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