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Huang L, Chen TT, Dong ZQ, Zhang Y, Lin Y, Chen P, Pan MH, Lu C. BmHSP19.9 targeting P6.9 and VLF-1 to mediate the formation of defective progeny viruses in the silkworm antiviral variety 871C. Int J Biol Macromol 2024; 275:133300. [PMID: 38914396 DOI: 10.1016/j.ijbiomac.2024.133300] [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] [Received: 01/15/2024] [Revised: 05/20/2024] [Accepted: 05/29/2024] [Indexed: 06/26/2024]
Abstract
The 871C silkworm strain exhibits a high level of resistance to Bombyx mori nucleopolyhedrovirus (BmNPV), making it a valuable variety for the sericulture industry. Understanding the underlying mechanism of its resistance holds great biological significance and economic value in addressing viral disease risks in sericulture. Initially, we infected the resistant strain 871C and its control strain 871 with BmNPV and conducted secondary infection experiments using the progeny occlusion bodies (OBs). As a result, a significant decrease in pathogenicity was observed. Electron microscopy analysis revealed that 871C produces progeny virions with defective DNA packaging, reducing virulence following BmNPV infection. Blood proteomic identification of the silkworm variety 871C and control 871 after BmNPV infection demonstrated the crucial role of the viral proteins P6.9 and VLF-1 in the production of defective viruses by impeding the proper encapsulation of viral DNA. Additionally, we discovered that BmHSP19.9 interacts with P6.9 and VLF-1 and that its expression is significantly upregulated after BmNPV infection. BmHSP19.9 exhibits strong antiviral activity, in part by preventing the entry of the proteins P6.9 and VLF-1 into the nucleus, thereby hindering viral nucleocapsid and viral DNA assembly. Our findings indicate that the antiviral silkworm strain 871C inhibits BmNPV proliferation by upregulating Bmhsp19.9 and impeding the nuclear localization of the viral proteins P6.9 and VLF-1, leading to the production of defective viral particles. This study offers a comprehensive analysis of the antiviral mechanism in silkworms from a viral perspective, providing a crucial theoretical foundation for future antiviral research and the breeding of resistant silkworm strains.
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Affiliation(s)
- Liang Huang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Ting-Ting Chen
- Pathogen Biology and Immunology Laboratory, Lab Teaching & Management Center, Chongqing Medical University, Chongqing 400716, China
| | - Zhan-Qi Dong
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Ya Zhang
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Yu Lin
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Peng Chen
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China
| | - Min-Hui Pan
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
| | - Cheng Lu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Key Laboratory of Sericultural Biology and Genetic Breeding, Ministry of Agriculture, Southwest University, Chongqing 400716, China.
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Petersen JM, Burgess AL, van Oers MM, Herniou EA, Bojko J. Nudiviruses in free-living and parasitic arthropods: evolutionary taxonomy. Trends Parasitol 2024; 40:744-762. [PMID: 39019701 DOI: 10.1016/j.pt.2024.06.009] [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] [Received: 04/24/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 07/19/2024]
Abstract
The nudiviruses (family: Nudiviridae) are large double-stranded DNA (dsDNA) viruses that infect insects and crustaceans, and have most recently been identified from ectoparasitic members (fleas and lice). This virus family was created in 2014 and has since been expanded via the discovery of multiple novel viral candidates or accepted members, sparking the need for a new taxonomic and evolutionary overview. Using current information (including data from public databases), we construct a new comprehensive phylogeny, encompassing 49 different nudiviruses. We use this novel phylogeny to propose a new taxonomic structure of the Nudiviridae by suggesting two new viral genera (Zetanudivirus and Etanudivirus), from ectoparasitic lice. We detail novel emerging relationships between nudiviruses and their hosts, considering their evolutionary history and ecological role.
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Affiliation(s)
- Jirka Manuel Petersen
- Laboratory of Virology, Wageningen University and Research, 6708, PB, Wageningen, The Netherlands; Institut de Recherche sur la Biologie de l'Insecte, UMR7261 CNRS - Université de Tours, 37200 Tours, France.
| | - Amy L Burgess
- School of Health and Life Sciences, Teesside University, Middlesbrough, TS1 3BX, UK; National Horizons Centre, Teesside University, Darlington, DL1 1HG, UK
| | - Monique M van Oers
- Laboratory of Virology, Wageningen University and Research, 6708, PB, Wageningen, The Netherlands
| | - Elisabeth A Herniou
- Institut de Recherche sur la Biologie de l'Insecte, UMR7261 CNRS - Université de Tours, 37200 Tours, France
| | - Jamie Bojko
- School of Health and Life Sciences, Teesside University, Middlesbrough, TS1 3BX, UK; National Horizons Centre, Teesside University, Darlington, DL1 1HG, UK.
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Cornman RS. Data mining reveals tissue-specific expression and host lineage-associated forms of Apis mellifera filamentous virus. PeerJ 2023; 11:e16455. [PMID: 38025724 PMCID: PMC10655722 DOI: 10.7717/peerj.16455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Background Apis mellifera filamentous virus (AmFV) is a large double-stranded DNA virus of uncertain phylogenetic position that infects honey bees (Apis mellifera). Little is known about AmFV evolution or molecular aspects of infection. Accurate annotation of open-reading frames (ORFs) is challenged by weak homology to other known viruses. This study was undertaken to evaluate ORFs (including coding-frame conservation, codon bias, and purifying selection), quantify genetic variation within AmFV, identify host characteristics that covary with infection rate, and examine viral expression patterns in different tissues. Methods Short-read data were accessed from the Sequence Read Archive (SRA) of the National Center for Biotechnology Information (NCBI). Sequence reads were downloaded from accessions meeting search criteria and scanned for kmers representative of AmFV genomic sequence. Samples with kmer counts above specified thresholds were downloaded in full for mapping to reference sequences and de novo assembly. Results At least three distinct evolutionary lineages of AmFV exist. Clade 1 predominates in Europe but in the Americas and Africa it is replaced by the other clades as infection level increases in hosts. Only clade 3 was found at high relative abundance in hosts with African ancestry, whereas all clades achieved high relative abundance in bees of non-African ancestry. In Europe and Africa, clade 2 was generally detected only in low-level infections but was locally dominant in some North American samples. The geographic distribution of clade 3 was consistent with an introduction to the Americas with 'Africanized' honey bees in the 1950s. Localized genomic regions of very high nucleotide divergence in individual isolates suggest recombination with additional, as-yet unidentified AmFV lineages. A set of 155 high-confidence ORFs was annotated based on evolutionary conservation in six AmFV genome sequences representative of the three clades. Pairwise protein-level identity averaged 94.6% across ORFs (range 77.1-100%), which generally exhibited low evolutionary rates and moderate to strong codon bias. However, no robust example of positive diversifying selection on coding sequence was found in these alignments. Most of the genome was detected in RNA short-read alignments. Transcriptome assembly often yielded contigs in excess of 50 kb and containing ORFs in both orientations, and the termini of long transcripts were associated with tandem repeats. Lower levels of AmFV RNA were detected in brain tissue compared to abdominal tissue, and a distinct set of ORFs had minimal to no detectable expression in brain tissue. A scan of DNA accessions from the parasitic mite Varroa destructor was inconclusive with respect to replication in that species. Discussion Collectively, these results expand our understanding of this enigmatic virus, revealing transcriptional complexity and co-evolutionary associations with host lineage.
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Picciotti U, Araujo Dalbon V, Ciancio A, Colagiero M, Cozzi G, De Bellis L, Finetti-Sialer MM, Greco D, Ippolito A, Lahbib N, Logrieco AF, López-Llorca LV, Lopez-Moya F, Luvisi A, Mincuzzi A, Molina-Acevedo JP, Pazzani C, Scortichini M, Scrascia M, Valenzano D, Garganese F, Porcelli F. "Ectomosphere": Insects and Microorganism Interactions. Microorganisms 2023; 11:microorganisms11020440. [PMID: 36838405 PMCID: PMC9967823 DOI: 10.3390/microorganisms11020440] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/30/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
This study focuses on interacting with insects and their ectosymbiont (lato sensu) microorganisms for environmentally safe plant production and protection. Some cases help compare ectosymbiont microorganisms that are insect-borne, -driven, or -spread relevant to endosymbionts' behaviour. Ectosymbiotic bacteria can interact with insects by allowing them to improve the value of their pabula. In addition, some bacteria are essential for creating ecological niches that can host the development of pests. Insect-borne plant pathogens include bacteria, viruses, and fungi. These pathogens interact with their vectors to enhance reciprocal fitness. Knowing vector-phoront interaction could considerably increase chances for outbreak management, notably when sustained by quarantine vector ectosymbiont pathogens, such as the actual Xylella fastidiosa Mediterranean invasion episode. Insect pathogenic viruses have a close evolutionary relationship with their hosts, also being highly specific and obligate parasites. Sixteen virus families have been reported to infect insects and may be involved in the biological control of specific pests, including some economic weevils. Insects and fungi are among the most widespread organisms in nature and interact with each other, establishing symbiotic relationships ranging from mutualism to antagonism. The associations can influence the extent to which interacting organisms can exert their effects on plants and the proper management practices. Sustainable pest management also relies on entomopathogenic fungi; research on these species starts from their isolation from insect carcasses, followed by identification using conventional light or electron microscopy techniques. Thanks to the development of omics sciences, it is possible to identify entomopathogenic fungi with evolutionary histories that are less-shared with the target insect and can be proposed as pest antagonists. Many interesting omics can help detect the presence of entomopathogens in different natural matrices, such as soil or plants. The same techniques will help localize ectosymbionts, localization of recesses, or specialized morphological adaptation, greatly supporting the robust interpretation of the symbiont role. The manipulation and modulation of ectosymbionts could be a more promising way to counteract pests and borne pathogens, mitigating the impact of formulates and reducing food insecurity due to the lesser impact of direct damage and diseases. The promise has a preventive intent for more manageable and broader implications for pests, comparing what we can obtain using simpler, less-specific techniques and a less comprehensive approach to Integrated Pest Management (IPM).
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Affiliation(s)
- Ugo Picciotti
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
- Department of Marine Science and Applied Biology, University of Alicante, 03690 Alicante, Spain
| | | | - Aurelio Ciancio
- Institute for Sustainable Plant Protection, National Research Council (CNR), Via G. Amendola 122/D, 70126 Bari, Italy
| | - Mariantonietta Colagiero
- Institute for Sustainable Plant Protection, National Research Council (CNR), Via G. Amendola 122/D, 70126 Bari, Italy
| | - Giuseppe Cozzi
- Institute of Food Production Sciences, National Research Council (CNR), Via G. Amendola 122/O, 70126 Bari, Italy
| | - Luigi De Bellis
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | | | - Davide Greco
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Antonio Ippolito
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
| | - Nada Lahbib
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
- Faculty of Sciences of Tunis, University of Tunis El-Manar, Tunis 1002, Tunisia
| | - Antonio Francesco Logrieco
- Institute of Food Production Sciences, National Research Council (CNR), Via G. Amendola 122/O, 70126 Bari, Italy
| | | | - Federico Lopez-Moya
- Department of Marine Science and Applied Biology, University of Alicante, 03690 Alicante, Spain
| | - Andrea Luvisi
- Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy
| | - Annamaria Mincuzzi
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
| | - Juan Pablo Molina-Acevedo
- Colombian Corporation for Agricultural Research Agrosavia C. I. Turipana-AGROSAVIA, Km. 13, Vía Montería-Cereté 230558, Colombia
| | - Carlo Pazzani
- Dipartimento di Bioscienze, Biotecnologie e Ambiente (DBBA), University of Bari Aldo Moro, 70126 Bari, Italy
| | - Marco Scortichini
- Research Centre for Olive, Fruit and Citrus Crops, Council for Agricultural Research and Economics (CREA), 00134 Roma, Italy
| | - Maria Scrascia
- Dipartimento di Bioscienze, Biotecnologie e Ambiente (DBBA), University of Bari Aldo Moro, 70126 Bari, Italy
| | - Domenico Valenzano
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
| | - Francesca Garganese
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
- Correspondence:
| | - Francesco Porcelli
- Dipartimento di Scienze del Suolo, della Pianta e degli Alimenti, University of Bari Aldo Moro, 70126 Bari, Italy
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Cerqueira de Araujo A, Leobold M, Bézier A, Musset K, Uzbekov R, Volkoff AN, Drezen JM, Huguet E, Josse T. Conserved Viral Transcription Plays a Key Role in Virus-Like Particle Production of the Parasitoid Wasp Venturia canescens. J Virol 2022; 96:e0052422. [PMID: 35678601 PMCID: PMC9278141 DOI: 10.1128/jvi.00524-22] [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: 04/01/2022] [Accepted: 05/04/2022] [Indexed: 11/20/2022] Open
Abstract
Nudiviruses are large double-stranded DNA viruses related to baculoviruses known to be endogenized in the genomes of certain parasitic wasp species. These wasp-virus associations allow the production of viral particles or virus-like particles that ensure wasp parasitism success within lepidopteran hosts. Venturia canescens is an ichneumonid wasp belonging to the Campopleginae subfamily that has endogenized nudivirus genes belonging to the Alphanudivirus genus to produce "virus-like particles" (Venturia canescens virus-like particles [VcVLPs]), which package proteic virulence factors. The main aim of this study was to determine whether alphanudivirus gene functions have been conserved following endogenization. The expression dynamics of alphanudivirus genes was monitored by a high throughput transcriptional approach, and the functional role of lef-4 and lef-8 genes predicted to encode viral RNA polymerase components was investigated by RNA interference. As described for baculovirus infections and for endogenized nudivirus genes in braconid wasp species producing bracoviruses, a transcriptional cascade involving early and late expressed alphanudivirus genes could be observed. The expression of lef-4 and lef-8 was also shown to be required for the expression of alphanudivirus late genes allowing correct particle formation. Together with previous literature, the results show that endogenization of nudiviruses in parasitoid wasps has repeatedly led to the conservation of the viral RNA polymerase function, allowing the production of viruses or viral-like particles that differ in composition but enable wasp parasitic success. IMPORTANCE This study shows that endogenization of a nudivirus genome in a Campopleginae parasitoid wasp has led to the conservation, as for endogenized nudiviruses in braconid parasitoid wasps, of the viral RNA polymerase function, required for the transcription of genes encoding viral particles involved in wasp parasitism success. We also showed for the first time that RNA interference (RNAi) can be successfully used to downregulate gene expression in this species, a model in behavioral ecology. This opens the opportunity to investigate the function of genes involved in other traits important for parasitism success, such as reproductive strategies and host choice. Fundamental data acquired on gene function in Venturia canescens are likely to be transferable to other parasitoid wasp species used in biological control programs. This study also renders possible the investigation of other nudivirus gene functions, for which little data are available.
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Affiliation(s)
| | - Matthieu Leobold
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, Tours, France
| | - Annie Bézier
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, Tours, France
| | - Karine Musset
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, Tours, France
| | - Rustem Uzbekov
- Université de Tours, Département des Microscopies, Tours, France
- Faculty of Bioengineering and Bioinformatics, Moscow State University, Moscow, Russia
| | - Anne-Nathalie Volkoff
- Diversité, Génomes & Interactions Microorganismes - Insectes (DGIMI), UMR 1333, Université de Montpellier - INRAE, Montpellier, France
| | - Jean-Michel Drezen
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, Tours, France
| | - Elisabeth Huguet
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, Tours, France
| | - Thibaut Josse
- Institut de Recherche sur la Biologie de l'Insecte (IRBI), UMR 7261, CNRS - Université de Tours, Tours, France
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Petersen JM, Bézier A, Drezen JM, van Oers MM. The naked truth: An updated review on nudiviruses and their relationship to bracoviruses and baculoviruses. J Invertebr Pathol 2022; 189:107718. [DOI: 10.1016/j.jip.2022.107718] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 10/19/2022]
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The Membrane-Anchoring Region of the AcMNPV P74 Protein Is Expendable or Interchangeable with Homologs from Other Species. Viruses 2021; 13:v13122416. [PMID: 34960685 PMCID: PMC8704774 DOI: 10.3390/v13122416] [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: 11/05/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 11/24/2022] Open
Abstract
Baculoviruses are insect pathogens that are characterized by assembling the viral dsDNA into two different enveloped virions during an infective cycle: occluded virions (ODVs; immersed in a protein matrix known as occlusion body) and budded virions (BVs). ODVs are responsible for the primary infection in midgut cells of susceptible larvae thanks to the per os infectivity factor (PIF) complex, composed of at least nine essential viral proteins. Among them, P74 is a crucial factor whose activity has been identified as virus-specific. In this work, the p74 gene from AcMNPV was pseudogenized using CRISPR/Cas9 technology and then complemented with wild-type alleles from SeMNPV and HearSNPV species, as well as chimeras combining the P74 amino and carboxyl domains. The results on Spodoptera exigua and Rachiplusia nu larvae showed that an amino terminal sector of P74 (lacking two potential transmembrane regions but possessing a putative nuclear export signal) is sufficient to restore the virus infectivity whether alone or fused to the P74 transmembrane regions of the other evaluated viral species. These results provide novel information about the functional role of P74 and delimit the region on which mutagenesis could be applied to enhance viral activity and, thus, produce better biopesticides.
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Duffield KR, Hunt J, Sadd BM, Sakaluk SK, Oppert B, Rosario K, Behle RW, Ramirez JL. Active and Covert Infections of Cricket Iridovirus and Acheta domesticus Densovirus in Reared Gryllodes sigillatus Crickets. Front Microbiol 2021; 12:780796. [PMID: 34917059 PMCID: PMC8670987 DOI: 10.3389/fmicb.2021.780796] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/01/2021] [Indexed: 11/21/2022] Open
Abstract
Interest in developing food, feed, and other useful products from farmed insects has gained remarkable momentum in the past decade. Crickets are an especially popular group of farmed insects due to their nutritional quality, ease of rearing, and utility. However, production of crickets as an emerging commodity has been severely impacted by entomopathogenic infections, about which we know little. Here, we identified and characterized an unknown entomopathogen causing mass mortality in a lab-reared population of Gryllodes sigillatus crickets, a species used as an alternative to the popular Acheta domesticus due to its claimed tolerance to prevalent entomopathogenic viruses. Microdissection of sick and healthy crickets coupled with metagenomics-based identification and real-time qPCR viral quantification indicated high levels of cricket iridovirus (CrIV) in a symptomatic population, and evidence of covert CrIV infections in a healthy population. Our study also identified covert infections of Acheta domesticus densovirus (AdDNV) in both populations of G. sigillatus. These results add to the foundational research needed to better understand the pathology of mass-reared insects and ultimately develop the prevention, mitigation, and intervention strategies needed for economical production of insects as a commodity.
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Affiliation(s)
- Kristin R. Duffield
- Crop BioProtection Research Unit, Agricultural Research Service, United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL, United States
- *Correspondence: Kristin R. Duffield,
| | - John Hunt
- School of Science, Western Sydney University, Richmond, NSW, Australia
| | - Ben M. Sadd
- School of Biological Sciences, Illinois State University, Normal, IL, United States
| | - Scott K. Sakaluk
- School of Biological Sciences, Illinois State University, Normal, IL, United States
| | - Brenda Oppert
- Stored Product Insect and Engineering Research Unit, Agricultural Research Service, United States Department of Agriculture, Center for Grain and Animal Health Research, Manhattan, KS, United States
| | - Karyna Rosario
- Marine Genomics Laboratory, University of South Florida, St. Petersburg, FL, United States
| | - Robert W. Behle
- Crop BioProtection Research Unit, Agricultural Research Service, United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL, United States
| | - José L. Ramirez
- Crop BioProtection Research Unit, Agricultural Research Service, United States Department of Agriculture, National Center for Agricultural Utilization Research, Peoria, IL, United States
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Bertola M, Mutinelli F. A Systematic Review on Viruses in Mass-Reared Edible Insect Species. Viruses 2021; 13:2280. [PMID: 34835086 PMCID: PMC8619331 DOI: 10.3390/v13112280] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 01/22/2023] Open
Abstract
Edible insects are expected to become an important nutrient source for animals and humans in the Western world in the near future. Only a few studies on viruses in edible insects with potential for industrial rearing have been published and concern only some edible insect species. Viral pathogens that can infect insects could be non-pathogenic, or pathogenic to the insects themselves, or to humans and animals. The objective of this systematic review is to provide an overview of the viruses detected in edible insects currently considered for use in food and/or feed in the European Union or appropriate for mass rearing, and to collect information on clinical symptoms in insects and on the vector role of insects themselves. Many different virus species have been detected in edible insect species showing promise for mass production systems. These viruses could be a risk for mass insect rearing systems causing acute high mortality, a drastic decline in growth in juvenile stages and in the reproductive performance of adults. Furthermore, some viruses could pose a risk to human and animal health where insects are used for food and feed.
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Affiliation(s)
- Michela Bertola
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, PD, Italy
| | - Franco Mutinelli
- National Rereference Laboratory for Honey Bee Health, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, PD, Italy;
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de Miranda JR, Granberg F, Low M, Onorati P, Semberg E, Jansson A, Berggren Å. Virus Diversity and Loads in Crickets Reared for Feed: Implications for Husbandry. Front Vet Sci 2021; 8:642085. [PMID: 34095270 PMCID: PMC8173086 DOI: 10.3389/fvets.2021.642085] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/22/2021] [Indexed: 11/17/2022] Open
Abstract
Insects generally have high reproductive rates leading to rapid population growth and high local densities; ideal conditions for disease epidemics. The parasites and diseases that naturally regulate wild insect populations can also impact when these insects are produced commercially, on farms. While insects produced for human or animal consumption are often reared under high density conditions, very little is known about the microbes associated with these insects, particularly those with pathogenic potential. In this study we used both target-free and targeted screening approaches to explore the virome of two cricket species commonly reared for feed and food, Acheta domesticus and Gryllus bimaculatus. The target-free screening of DNA and RNA from a single A. domesticus frass sample revealed that only 1% of the nucleic acid reads belonged to viruses, including known cricket, insect, bacterial and plant pathogens, as well as a diverse selection of novel viruses. The targeted screening revealed relatively high levels of Acheta domesticus densovirus, invertebrate iridovirus 6 and a novel iflavirus, as well as low levels of Acheta domesticus volvovirus, in insect and frass samples from several retailers. Our findings highlight the value of multiple screening approaches for a comprehensive and robust cricket disease monitoring and management strategy. This will become particularly relevant as-and-when cricket rearing facilities scale up and transform from producing insects for animal feed to producing insects for human consumption.
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Affiliation(s)
- Joachim R de Miranda
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Fredrik Granberg
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Matthew Low
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Piero Onorati
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Emilia Semberg
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Anna Jansson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Åsa Berggren
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Arvin MJ, Lorenzi A, Burke GR, Strand MR. MdBVe46 is an envelope protein that is required for virion formation by Microplitis demolitor bracovirus. J Gen Virol 2021; 102:001565. [PMID: 33591247 PMCID: PMC8515855 DOI: 10.1099/jgv.0.001565] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/18/2021] [Indexed: 11/18/2022] Open
Abstract
Bracoviruses (BVs) are endogenized nudiviruses that braconid parasitoid wasps have coopted for functions in parasitizing hosts. Microplitis demolitor is a braconid wasp that produces Microplitis demolitor bracovirus (MdBV) and parasitizes the larval stage of the moth Chrysodeixis includens. Some BV core genes are homologs of genes also present in baculoviruses while others are only known from nudiviruses or other BVs. In this study, we had two main goals. The first was to separate MdBV virions into envelope and nucleocapsid fractions before proteomic analysis to identify core gene products that were preferentially associated with one fraction or the other. Results indicated that nearly all MdBV baculovirus-like gene products that were detected by our proteomic analysis had similar distributions to homologs in the occlusion-derived form of baculoviruses. Several core gene products unknown from baculoviruses were also identified as envelope or nucleocapsid components. Our second goal was to functionally characterize a core gene unknown from baculoviruses that was originally named HzNVorf64-like. Immunoblotting assays supported our proteomic data that identified HzNVorf64-like as an envelope protein. We thus renamed HzNVorf64-like as MdBVe46, which we further hypothesized was important for infection of C. includens. Knockdown of MdBVe46 by RNA interference (RNAi) greatly reduced transcript and protein abundance. Knockdown of MdBVe46 also altered virion morphogenesis, near-fully inhibited infection of C. includens, and significantly reduced the proportion of hosts that were successfully parasitized by M. demolitor.
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Affiliation(s)
- Michael J. Arvin
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| | - Ange Lorenzi
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| | - Gaelen R. Burke
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
| | - Michael R. Strand
- Department of Entomology, University of Georgia, Athens, GA 30602, USA
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12
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Liu S, Sappington TW, Coates BS, Bonning BC. Nudivirus Sequences Identified from the Southern and Western Corn Rootworms (Coleoptera: Chrysomelidae). Viruses 2021; 13:v13020269. [PMID: 33572446 PMCID: PMC7916170 DOI: 10.3390/v13020269] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 01/08/2023] Open
Abstract
Analysis of pooled genomic short read sequence data revealed the presence of nudivirus-derived sequences from U.S. populations of both southern corn rootworm (SCR, Diabrotica undecimpunctata howardi Barber) and western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte). A near complete nudivirus genome sequence was assembled from sequence data for an SCR population with relatively high viral titers. A total of 147,179 bp was assembled from five contigs that collectively encode 109 putative open reading frames (ORFs) including 20 nudivirus core genes. In contrast, genome sequence recovery was incomplete for a second nudivirus from WCR, although sequences derived from this virus were present in three geographically dispersed populations. Only 48,989 bp were assembled with 48 putative ORFs including 13 core genes, representing about 20% of a typical nudivirus genome. Phylogenetic analysis indicated that both corn rootworm nudiviruses grouped with the third known nudivirus of beetles, Oryctes rhinoceros nudivirus in the genus Alphanudivirus. On the basis of phylogenetic and additional analyses, we propose further taxonomic separation of nudiviruses within Alphanudivirus and Betanudivirus into two subfamilies and five genera. Identification of nudivirus-derived sequences from two species of corn rootworm highlights the diversity of viruses associated with these agricultural insect pests.
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Affiliation(s)
- Sijun Liu
- Department of Entomology, Iowa State University, Ames, IA 50011, USA;
| | - Thomas W. Sappington
- Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA 50011, USA; (T.W.S.); (B.S.C.)
| | - Brad S. Coates
- Corn Insects and Crop Genetics Research Unit, USDA-ARS, Ames, IA 50011, USA; (T.W.S.); (B.S.C.)
| | - Bryony C. Bonning
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA
- Correspondence:
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13
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Hill T, Unckless RL. Recurrent evolution of high virulence in isolated populations of a DNA virus. eLife 2020; 9:e58931. [PMID: 33112738 PMCID: PMC7685711 DOI: 10.7554/elife.58931] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 10/28/2020] [Indexed: 12/30/2022] Open
Abstract
Hosts and viruses are constantly evolving in response to each other: as a host attempts to suppress a virus, the virus attempts to evade and suppress the host's immune system. Here, we describe the recurrent evolution of a virulent strain of a DNA virus, which infects multiple Drosophila species. Specifically, we identified two distinct viral types that differ 100-fold in viral titer in infected individuals, with similar differences observed in multiple species. Our analysis suggests that one of the viral types recurrently evolved at least four times in the past ~30,000 years, three times in Arizona and once in another geographically distinct species. This recurrent evolution may be facilitated by an effective mutation rate which increases as each prior mutation increases viral titer and effective population size. The higher titer viral type suppresses the host-immune system and an increased virulence compared to the low viral titer type.
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Affiliation(s)
- Tom Hill
- The Department of Molecular Biosciences, University of KansasLawrenceUnited States
| | - Robert L Unckless
- The Department of Molecular Biosciences, University of KansasLawrenceUnited States
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14
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The first clawed lobster virus Homarus gammarus nudivirus (HgNV n. sp.) expands the diversity of the Nudiviridae. Sci Rep 2019; 9:10086. [PMID: 31300678 PMCID: PMC6626001 DOI: 10.1038/s41598-019-46008-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 06/20/2019] [Indexed: 12/20/2022] Open
Abstract
Viral diseases of crustaceans are increasingly recognised as challenges to shellfish farms and fisheries. Here we describe the first naturally-occurring virus reported in any clawed lobster species. Hypertrophied nuclei with emarginated chromatin, characteristic histopathological lesions of DNA virus infection, were observed within the hepatopancreatic epithelial cells of juvenile European lobsters (Homarus gammarus). Transmission electron microscopy revealed infection with a bacilliform virus containing a rod shaped nucleocapsid enveloped in an elliptical membrane. Assembly of PCR-free shotgun metagenomic sequencing produced a circular genome of 107,063 bp containing 97 open reading frames, the majority of which share sequence similarity with a virus infecting the black tiger shrimp: Penaeus monodon nudivirus (PmNV). Multiple phylogenetic analyses confirm the new virus to be a novel member of the Nudiviridae: Homarus gammarus nudivirus (HgNV). Evidence of occlusion body formation, characteristic of PmNV and its closest relatives, was not observed, questioning the horizontal transmission strategy of HgNV outside of the host. We discuss the potential impacts of HgNV on juvenile lobster growth and mortality and present HgNV-specific primers to serve as a diagnostic tool for monitoring the virus in wild and farmed lobster stocks.
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15
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The cysteine-rich region of a baculovirus VP91 protein contributes to the morphogenesis of occlusion bodies. Virology 2019; 535:144-153. [PMID: 31302508 DOI: 10.1016/j.virol.2019.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 06/26/2019] [Indexed: 11/21/2022]
Abstract
The baculovirus core gene vp91 has been reported to be essential for nucleocapsid assembly and oral infection. Here, we studied the function of vp91 by analyzing its homologue, ha76, in Helicoverpa armigera nucleopolyhedrovirus (HearNPV). HA76 was expressed at the late stage of HearNPV infection; deletion of ha76 showed that the gene is required for budded virus production. A series of recombinants with truncated ha76 was constructed and analyzed in vitro and in vivo. The results showed that the region encoding the C-terminus of HA76 was essential for nucleocapsid assembly, whereas the N-terminal cysteine-rich region was responsible for oral infection. Electron microscope analyses further showed that the cysteine-rich region contributed to morphogenesis of occlusion bodies (OBs), with amino acids 136-223 of HA76 being critical for this function. The results revealed a novel function of VP91 and suggested that the impact on OB morphogenesis is partially related to oral infectivity.
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16
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Induction and Suppression of NF-κB Signalling by a DNA Virus of Drosophila. J Virol 2019; 93:JVI.01443-18. [PMID: 30404807 DOI: 10.1128/jvi.01443-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/29/2018] [Indexed: 12/12/2022] Open
Abstract
Interactions between the insect immune system and RNA viruses have been extensively studied in Drosophila, in which RNA interference, NF-κB, and JAK-STAT pathways underlie antiviral immunity. In response to RNA interference, insect viruses have convergently evolved suppressors of this pathway that act by diverse mechanisms to permit viral replication. However, interactions between the insect immune system and DNA viruses have received less attention, primarily because few Drosophila-infecting DNA virus isolates are available. In this study, we used a recently isolated DNA virus of Drosophila melanogaster, Kallithea virus (KV; family Nudiviridae), to probe known antiviral immune responses and virus evasion tactics in the context of DNA virus infection. We found that fly mutants for RNA interference and immune deficiency (Imd), but not Toll, pathways are more susceptible to Kallithea virus infection. We identified the Kallithea virus-encoded protein gp83 as a potent inhibitor of Toll signalling, suggesting that Toll mediates antiviral defense against Kallithea virus infection but that it is suppressed by the virus. We found that Kallithea virus gp83 inhibits Toll signalling through the regulation of NF-κB transcription factors. Furthermore, we found that gp83 of the closely related Drosophila innubila nudivirus (DiNV) suppresses D. melanogaster Toll signalling, suggesting an evolutionarily conserved function of Toll in defense against DNA viruses. Together, these results provide a broad description of known antiviral pathways in the context of DNA virus infection and identify the first Toll pathway inhibitor in a Drosophila virus, extending the known diversity of insect virus-encoded immune inhibitors.IMPORTANCE Coevolution of multicellular organisms and their natural viruses may lead to an intricate relationship in which host survival requires effective immunity and virus survival depends on evasion of such responses. Insect antiviral immunity and reciprocal virus immunosuppression tactics have been well studied in Drosophila melanogaster, primarily during RNA, but not DNA, virus infection. Therefore, we describe interactions between a recently isolated Drosophila DNA virus (Kallithea virus [KV]) and immune processes known to control RNA viruses, such as RNA interference (RNAi) and Imd pathways. We found that KV suppresses the Toll pathway and identified gp83 as a KV-encoded protein that underlies this suppression. This immunosuppressive ability is conserved in another nudivirus, suggesting that the Toll pathway has conserved antiviral activity against DNA nudiviruses, which have evolved suppressors in response. Together, these results indicate that DNA viruses induce and suppress NF-κB responses, and they advance the application of KV as a model to study insect immunity.
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17
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MicroRNAs derived from the insect virus HzNV-1 promote lytic infection by suppressing histone methylation. Sci Rep 2018; 8:17817. [PMID: 30546025 PMCID: PMC6292938 DOI: 10.1038/s41598-018-35782-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/06/2018] [Indexed: 12/19/2022] Open
Abstract
Heliothis zea nudivirus-1 (HzNV-1) is an insect virus that can induce both lytic and latent infections in various insect cell lines. During latent infection, several microRNAs (miRNAs) are produced from persistency-associated gene 1 (pag1) as the only detectable HzNV-1 transcript. Previous studies have shown that the pag1 gene suppresses the immediate-early gene hhi1 and promotes host switching into a latent infection via miRNAs derived from pag1. Although other functions of the miRNAs derived from pag1 have not yet been elucidated, several studies have suggested that miRNAs encoded from latency-associated genes can regulate histone-associated enzymes. Because pag1 is a noncoding transcript, it potentially regulates host chromatin structure through miRNAs upon infection. Nevertheless, the exact mechanism by which pag1 alters viral infections remains unknown. In this study, we found that the pag1-encoded miRNA miR-420 suppresses expression of the histone modification-associated enzyme su(var)3-9. Therefore, this miRNA causes histone modification to promote HzNV-1 infection. These results suggest that HzNV-1 may directly influence epigenetic regulation in host cells through interactions with pag1 miRNAs to promote lytic infection. This study provides us with a better understanding of both the HzNV-1 infection pathway and the relationship between viral miRNAs and epigenetic regulation.
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18
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Leobold M, Bézier A, Pichon A, Herniou EA, Volkoff AN, Drezen JM. The Domestication of a Large DNA Virus by the Wasp Venturia canescens Involves Targeted Genome Reduction through Pseudogenization. Genome Biol Evol 2018; 10:1745-1764. [PMID: 29931159 PMCID: PMC6054256 DOI: 10.1093/gbe/evy127] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2018] [Indexed: 12/13/2022] Open
Abstract
Polydnaviruses (PDVs) are compelling examples of viral domestication, in which wasps express a large set of genes originating from a chromosomally integrated virus to produce particles necessary for their reproductive success. Parasitoid wasps generally use PDVs as a virulence gene delivery system allowing the protection of their progeny in the body of parasitized host. However, in the wasp Venturia canescens an independent viral domestication process led to an alternative strategy as the wasp incorporates virulence proteins in viral liposomes named virus-like particles (VLPs), instead of DNA molecules. Proteomic analysis of purified VLPs and transcriptome sequencing revealed the loss of some viral functions. In particular, the genes coding for capsid components are no longer expressed, which explains why VLPs do not incorporate DNA. Here a thorough examination of V. canescens genome revealed the presence of the pseudogenes corresponding to most of the genes involved in lost functions. This strongly suggests that an accumulation of mutations that leads to gene specific pseudogenization precedes the loss of viral genes observed during virus domestication. No evidence was found for block loss of collinear genes, although extensive gene order reshuffling of the viral genome was identified from comparisons between endogenous and exogenous viruses. These results provide the first insights on the early stages of large DNA virus domestication implicating massive genome reduction through gene-specific pseudogenization, a process which differs from the large deletions described for bacterial endosymbionts.
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Affiliation(s)
- Matthieu Leobold
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS - Université de Tours, UFR des Sciences et Techniques, Parc de Grandmont, Tours, France
| | - Annie Bézier
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS - Université de Tours, UFR des Sciences et Techniques, Parc de Grandmont, Tours, France
| | - Apolline Pichon
- Diversity, Genomes and Interactions Microorganisms-Insect, UMR INRA 1333, Université de Montpellier 2, Montpellier, France
| | - Elisabeth A Herniou
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS - Université de Tours, UFR des Sciences et Techniques, Parc de Grandmont, Tours, France
| | - Anne-Nathalie Volkoff
- Diversity, Genomes and Interactions Microorganisms-Insect, UMR INRA 1333, Université de Montpellier 2, Montpellier, France
| | - Jean-Michel Drezen
- Institut de Recherche sur la Biologie de l'Insecte, UMR 7261, CNRS - Université de Tours, UFR des Sciences et Techniques, Parc de Grandmont, Tours, France
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19
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Burke GR, Simmonds TJ, Sharanowski BJ, Geib SM. Rapid Viral Symbiogenesis via Changes in Parasitoid Wasp Genome Architecture. Mol Biol Evol 2018; 35:2463-2474. [DOI: 10.1093/molbev/msy148] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- Gaelen R Burke
- Department of Entomology, University of Georgia, Athens, GA
| | | | | | - Scott M Geib
- Tropical Crop and Commodity Protection Research Unit, USDA-ARS Daniel K Inouye U.S. Pacific Basin Agricultural Research Center, USDA-ARS, Hilo, HI
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20
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The 38K-Mediated Specific Dephosphorylation of the Viral Core Protein P6.9 Plays an Important Role in the Nucleocapsid Assembly of Autographa californica Multiple Nucleopolyhedrovirus. J Virol 2018; 92:JVI.01989-17. [PMID: 29444944 PMCID: PMC5899202 DOI: 10.1128/jvi.01989-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/07/2018] [Indexed: 02/02/2023] Open
Abstract
Encapsidation of the viral genomes, leading to the assembly of the nucleocapsids to form infectious progeny virions, is a key step in many virus life cycles. Baculovirus nucleocapsid assembly is a complex process that involves many proteins. Our previous studies showed that the deletion of the core gene 38K (ac98) interrupted the nucleocapsid assembly by producing capsid sheaths devoid of viral genomes by an unknown mechanism. All homologs of 38K contain conserved motifs of the haloacid dehalogenase superfamily, which are involved in phosphoryl transfer. The requirements of these motifs for nucleocapsid assembly, confirmed in the present study, suggest that 38K may be a functioning haloacid dehalogenase. P6.9 is also encoded by a core gene (ac100) and is required for viral genome encapsidation. It has been reported that multiple phosphorylated species of P6.9 are present in virus-infected cells, while only an unphosphorylated species is detected in the budded virus. Therefore, whether 38K mediates the dephosphorylation of P6.9 was investigated. An additional phosphorylated species of P6.9 in 38K-deleted or -mutated virus-transfected cells was detected, and the dephosphorylated sites mediated by 38K were determined by mass spectrometry. To assess the effects of dephosphorylation of P6.9 mediated by 38K on virus replication, these sites were mutated to glutamic acids (phosphorylation-mimic mutant) or to alanines (phosphorylation-deficient mutant). Studies showed that the nucleocapsid assembly was interrupted in phosphorylation-mimic mutant virus-transfected cells. Taken together, our findings demonstrate that 38K mediates the dephosphorylation of specific sites at the C terminus of P6.9, which is essential for viral genome encapsidation.IMPORTANCE Genome packaging is a fundamental process in the virus life cycle, and viruses have different strategies to perform this step. For several double-stranded DNA (dsDNA) viruses, the procapsid is formed before genome encapsidation, which may require basic proteins that help to neutralize the nucleic acid charge repulsion to facilitate the compaction of the genome within the confined capsid space. Baculovirus encodes a small basic protein, P6.9, which is required for a variety of processes in the virus infection cycle. The phosphorylation of P6.9 is thought to result in nucleocapsid uncoating, while the dephosphorylation of P6.9 is involved in viral DNA encapsidation during nucleocapsid assembly. Here, we demonstrate that a haloacid dehalogenase homolog encoded by baculovirus core gene 38K is involved in nucleocapsid assembly by mediating the dephosphorylation of 5 specific sites at the C terminus of P6.9. This finding contributes to the understanding of the mechanisms of virus nucleocapsid assembly.
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21
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Hill T, Unckless RL. The dynamic evolution of Drosophila innubila Nudivirus. INFECTION GENETICS AND EVOLUTION 2017; 57:151-157. [PMID: 29155284 DOI: 10.1016/j.meegid.2017.11.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 11/06/2017] [Accepted: 11/11/2017] [Indexed: 12/30/2022]
Abstract
Viruses coevolve with their hosts to overcome host resistance and gain the upper hand in the evolutionary arms race. Drosophila innubila nudivirus (DiNV) is a double stranded DNA virus, closely related to Oryctes rhinoceros nudivirus (OrNV) and Kallithea virus. DiNV is the first DNA virus found to naturally infect Drosophila and therefore has the potential to be developed as a model for DNA virus immune defense and host/virus coevolution within its well-studied host system. Here we sequence and annotate the genome of DiNV and identify signatures of adaptation, revealing clues for genes involved in host-parasite coevolution. The circular genome is 155,555bp and contains 107 coding open reading frames (ORFs) and a wealth of AT-rich simple sequence repeats. While synteny is highly conserved between DiNV and Kallithea virus, it drops off rapidly as sequences become more divergent, consistent with rampant rearrangements across nudiviruses. Overall, we show that evolution of DiNV is likely due to adaptation of a very few genes coupled with high gene turnover.
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Affiliation(s)
- Tom Hill
- 4055 Haworth Hall, 1200 Sunnyside Avenue, Lawrence, KS 66045, USA.
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22
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Diversity of large DNA viruses of invertebrates. J Invertebr Pathol 2017; 147:4-22. [DOI: 10.1016/j.jip.2016.08.001] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/03/2016] [Accepted: 08/04/2016] [Indexed: 11/17/2022]
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23
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Abstract
Several lineages of endoparasitoid wasps, which develop inside the body of other insects, have domesticated viruses, used as delivery tools of essential virulence factors for the successful development of their progeny. Virus domestications are major evolutionary transitions in highly diverse parasitoid wasps. Much progress has recently been made to characterize the nature of these ancestrally captured endogenous viruses that have evolved within the wasp genomes. Virus domestication from different viral families occurred at least three times in parasitoid wasps. This evolutionary convergence led to different strategies. Polydnaviruses (PDVs) are viral gene transfer agents and virus-like particles of the wasp Venturia canescens deliver proteins. Here, we take the standpoint of parasitoid wasps to review current knowledge on virus domestications by different parasitoid lineages. Then, based on genomic data from parasitoid wasps, PDVs and exogenous viruses, we discuss the different evolutionary steps required to transform viruses into vehicles for the delivery of the virulence molecules that we observe today. Finally, we discuss how endoparasitoid wasps manipulate host physiology and ensure parasitism success, to highlight the possible advantages of viral domestication as compared with other virulence strategies.
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24
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Kariithi HM, Yao X, Yu F, Teal PE, Verhoeven CP, Boucias DG. Responses of the Housefly, Musca domestica, to the Hytrosavirus Replication: Impacts on Host's Vitellogenesis and Immunity. Front Microbiol 2017; 8:583. [PMID: 28424677 PMCID: PMC5380684 DOI: 10.3389/fmicb.2017.00583] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 03/21/2017] [Indexed: 12/15/2022] Open
Abstract
Hytrosaviridae family members replicate in the salivary glands (SGs) of their adult dipteran hosts and are transmitted to uninfected hosts via saliva during feeding. Despite inducing similar gross symptoms (SG hypertrophy; SGH), hytrosaviruses (SGHVs) have distinct pathobiologies, including sex-ratio distortions in tsetse flies and refusal of infected housefly females to copulate. Via unknown mechanism(s), SGHV replication in other tissues results in reduced fecundity in tsetse flies and total shutdown of vitellogenesis and sterility in housefly females. We hypothesized that vitellogenesis shutdown was caused by virus-induced modulation of hormonal titers. Here, we used RNA-Seq to investigate virus-induced modulation of host genes/pathways in healthy and virus-infected houseflies, and we validated expression of modulated genes (n = 23) by RT-qPCR. We also evaluated the levels and activities of hemolymph AMPs, levels of endogenous sesquiterpenoids, and impacts of exogenous hormones on ovarian development in viremic females. Of the 973 housefly unigenes that were significantly modulated (padj ≤ 0.01, log2FC ≤ -2.0 or ≥ 2.0), 446 and 527 genes were downregulated and upregulated, respectively. While the most downregulated genes were related to reproduction (embryogenesis/oogenesis), the repertoire of upregulated genes was overrepresented by genes related to non-self recognition, ubiquitin-protease system, cytoskeletal traffic, cellular proliferation, development and movement, and snRNA processing. Overall, the virus, Musca domestica salivary gland hytrosavirus (MdSGHV), induced the upregulation of various components of the siRNA, innate antimicrobial immune, and autophagy pathways. We show that MdSGHV undergo limited morphogenesis in the corpora allata/corpora cardiaca (CA/CC) complex of M. domestica. MdSGHV replication in CA/CC potentially explains the significant reduction of hemolymph sesquiterpenoids levels, the refusal to mate, and the complete shutdown of egg development in viremic females. Notably, hormonal rescue of vitellogenesis did not result in egg production. The mechanism underlying MdSGHV-induced sterility has yet to be resolved.
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Affiliation(s)
- Henry M Kariithi
- Biotechnology Research Institute, Kenya Agricultural and Livestock Research OrganizationNairobi, Kenya.,Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and AgricultureVienna, Austria
| | - Xu Yao
- Entomology and Nematology Department, University of FloridaGainesville, FL, USA
| | - Fahong Yu
- Interdisciplinary Centre for Biotechnology Research, University of FloridaGainesville, FL, USA
| | - Peter E Teal
- Center for Medical, Agricultural and Veterinary Entomology, USDA, ARSGainesville, FL, USA
| | - Chelsea P Verhoeven
- Entomology and Nematology Department, University of FloridaGainesville, FL, USA
| | - Drion G Boucias
- Entomology and Nematology Department, University of FloridaGainesville, FL, USA
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25
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Maciel-Vergara G, Ros VID. Viruses of insects reared for food and feed. J Invertebr Pathol 2017; 147:60-75. [PMID: 28189501 DOI: 10.1016/j.jip.2017.01.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 02/07/2023]
Abstract
The use of insects as food for humans or as feed for animals is an alternative for the increasing high demand for meat and has various environmental and social advantages over the traditional intensive production of livestock. Mass rearing of insects, under insect farming conditions or even in industrial settings, can be the key for a change in the way natural resources are utilized in order to produce meat, animal protein and a list of other valuable animal products. However, because insect mass rearing technology is relatively new, little is known about the different factors that determine the quality and yield of the production process. Obtaining such knowledge is crucial for the success of insect-based product development. One of the issues that is likely to compromise the success of insect rearing is the outbreak of insect diseases. In particular, viral diseases can be devastating for the productivity and the quality of mass rearing systems. Prevention and management of viral diseases imply the understanding of the different factors that interact in insect mass rearing. This publication provides an overview of the known viruses in insects most commonly reared for food and feed. Nowadays with large-scale sequencing techniques, new viruses are rapidly being discovered. We discuss factors affecting the emergence of viruses in mass rearing systems, along with virus transmission routes. Finally we provide an overview of the wide range of measures available to prevent and manage virus outbreaks in mass rearing systems, ranging from simple sanitation methods to highly sophisticated methods including RNAi and transgenics.
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Affiliation(s)
- Gabriela Maciel-Vergara
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
| | - Vera I D Ros
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
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26
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Shrimp AHPND-causing plasmids encoding the PirAB toxins as mediated by pirAB-Tn903 are prevalent in various Vibrio species. Sci Rep 2017; 7:42177. [PMID: 28169338 PMCID: PMC5294582 DOI: 10.1038/srep42177] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 01/06/2017] [Indexed: 11/08/2022] Open
Abstract
Acute hepatopancreatic necrosis disease (AHPND) is a newly emerging shrimp disease caused by pirAB toxins encoded by a plasmid found in Vibrio parahaemolyticus. The pirAB toxins are the homologs of the Photorhabdus insect-related (Pir) toxins. Here, we report the complete sequences of the AHPND-causing plasmid isolated from V. owensii, as well as those of its 11 siblings (pVH family). In addition, we also included 13 related plasmids (pVH-r family) without the pirAB genes isolated from a variety of species within the Vibrio Harveyi clade. Furthermore, the pirAB-Tn903 composite transposon was identified in pVH, and both ends of the transposon appeared to have inserted simultaneously into the ancestor plasmid at different sites. The homologue counterparts of pirAB were also detected in a non-pVH plasmid in V. campbellii. Taken together, our results provide novel insights into the acquisition and evolution of pirAB as well as related plasmids in the Vibrio Harveyi clade.
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Bézier A, Harichaux G, Musset K, Labas V, Herniou EA. Qualitative proteomic analysis of Tipula oleracea nudivirus occlusion bodies. J Gen Virol 2017; 98:284-295. [DOI: 10.1099/jgv.0.000661] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Annie Bézier
- Institut de Recherche sur la Biologie de l’Insecte (IRBI), UMR 7261 CNRS Université François-Rabelais, Tours 37200, France
| | - Grégoire Harichaux
- INRA, PRC UMR85-CNRS 7247-UFR-IFCE, Laboratoire de Spectrométrie de masse, Plateforme d’Analyse Intégrative des Biomolécules et de Phénomique des Animaux d’Intérêt Bio-agronomique (PAIB2), Nouzilly 37380, France
| | - Karine Musset
- Institut de Recherche sur la Biologie de l’Insecte (IRBI), UMR 7261 CNRS Université François-Rabelais, Tours 37200, France
| | - Valérie Labas
- INRA, PRC UMR85-CNRS 7247-UFR-IFCE, Laboratoire de Spectrométrie de masse, Plateforme d’Analyse Intégrative des Biomolécules et de Phénomique des Animaux d’Intérêt Bio-agronomique (PAIB2), Nouzilly 37380, France
| | - Elisabeth A Herniou
- Institut de Recherche sur la Biologie de l’Insecte (IRBI), UMR 7261 CNRS Université François-Rabelais, Tours 37200, France
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Abd-Alla AMM, Kariithi HM, Cousserans F, Parker NJ, İnce İA, Scully ED, Boeren S, Geib SM, Mekonnen S, Vlak JM, Parker AG, Vreysen MJB, Bergoin M. Comprehensive annotation of Glossina pallidipes salivary gland hypertrophy virus from Ethiopian tsetse flies: a proteogenomics approach. J Gen Virol 2016; 97:1010-1031. [PMID: 26801744 DOI: 10.1099/jgv.0.000409] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Glossina pallidipes salivary gland hypertrophy virus (GpSGHV; family Hytrosaviridae) can establish asymptomatic and symptomatic infection in its tsetse fly host. Here, we present a comprehensive annotation of the genome of an Ethiopian GpSGHV isolate (GpSGHV-Eth) compared with the reference Ugandan GpSGHV isolate (GpSGHV-Uga; GenBank accession number EF568108). GpSGHV-Eth has higher salivary gland hypertrophy syndrome prevalence than GpSGHV-Uga. We show that the GpSGHV-Eth genome has 190 291 nt, a low G+C content (27.9 %) and encodes 174 putative ORFs. Using proteogenomic and transcriptome mapping, 141 and 86 ORFs were mapped by transcripts and peptides, respectively. Furthermore, of the 174 ORFs, 132 had putative transcriptional signals [TATA-like box and poly(A) signals]. Sixty ORFs had both TATA-like box promoter and poly(A) signals, and mapped by both transcripts and peptides, implying that these ORFs encode functional proteins. Of the 60 ORFs, 10 ORFs are homologues to baculovirus and nudivirus core genes, including three per os infectivity factors and four RNA polymerase subunits (LEF4, 5, 8 and 9). Whereas GpSGHV-Eth and GpSGHV-Uga are 98.1 % similar at the nucleotide level, 37 ORFs in the GpSGHV-Eth genome had nucleotide insertions (n = 17) and deletions (n = 20) compared with their homologues in GpSGHV-Uga. Furthermore, compared with the GpSGHV-Uga genome, 11 and 24 GpSGHV ORFs were deleted and novel, respectively. Further, 13 GpSGHV-Eth ORFs were non-canonical; they had either CTG or TTG start codons instead of ATG. Taken together, these data suggest that GpSGHV-Eth and GpSGHV-Uga represent two different lineages of the same virus. Genetic differences combined with host and environmental factors possibly explain the differential GpSGHV pathogenesis observed in different G. pallidipes colonies.
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Affiliation(s)
- Adly M M Abd-Alla
- Insect Pest Control Laboratories, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | - Henry M Kariithi
- Insect Pest Control Laboratories, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria.,Biotechnology Research Institute, Kenya Agricultural and Livestock Research Organization, PO Box 57811, Loresho, Nairobi, Kenya.,Laboratory of Virology, Wageningen University, 6708 PB, Wageningen, The Netherlands
| | - François Cousserans
- Laboratoire de Pathologie Comparée, Faculté des Sciences, Université de Montpellier, 34095 Montpellier, France
| | | | - İkbal Agah İnce
- Department of Medical Microbiology, School of Medicine, Acibadem University, 34752 Atas¸ehir, Istanbul, Turkey
| | - Erin D Scully
- Grain, Forage and Bioenergy Research Unit, USDA-ARS, University of Nebraska East Campus, Lincoln, NE 68583, USA
| | - Sjef Boeren
- Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands
| | - Scott M Geib
- Tropical Crop and Commodity Protection Research Unit, USDA-ARS Daniel K. Inouye US Pacific Basin Agricultural Research Centre, Hilo, HI 96720, USA
| | - Solomon Mekonnen
- National Institute for Control and Eradication of Tsetse and Trypanosomosis (NICETT), Addis Ababa, Ethiopia
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, 6708 PB, Wageningen, The Netherlands
| | - Andrew G Parker
- Insect Pest Control Laboratories, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | - Marc J B Vreysen
- Insect Pest Control Laboratories, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna, Austria
| | - Max Bergoin
- Laboratoire de Pathologie Comparée, Faculté des Sciences, Université de Montpellier, 34095 Montpellier, France
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Volkman LE. Baculoviruses and nucleosome management. Virology 2015; 476:257-263. [PMID: 25569454 DOI: 10.1016/j.virol.2014.12.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Revised: 12/09/2014] [Accepted: 12/10/2014] [Indexed: 11/30/2022]
Abstract
Negatively-supercoiled-ds DNA molecules, including the genomes of baculoviruses, spontaneously wrap around cores of histones to form nucleosomes when present within eukaryotic nuclei. Hence, nucleosome management should be essential for baculovirus genome replication and temporal regulation of transcription, but this has not been documented. Nucleosome mobilization is the dominion of ATP-dependent chromatin-remodeling complexes. SWI/SNF and INO80, two of the best-studied complexes, as well as chromatin modifier TIP60, all contain actin as a subunit. Retrospective analysis of results of AcMNPV time course experiments wherein actin polymerization was blocked by cytochalasin D drug treatment implicate actin-containing chromatin modifying complexes in decatenating baculovirus genomes, shutting down host transcription, and regulating late and very late phases of viral transcription. Moreover, virus-mediated nuclear localization of actin early during infection may contribute to nucleosome management.
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Affiliation(s)
- Loy E Volkman
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
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The genome of the nucleopolyhedrosis-causing virus from Tipula oleracea sheds new light on the Nudiviridae family. J Virol 2014; 89:3008-25. [PMID: 25540386 DOI: 10.1128/jvi.02884-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED A large double-stranded DNA (dsDNA) virus that produces occlusion bodies, typical of baculoviruses, has been described to infect crane fly larvae of the genus Tipula (Diptera, Tipulidae). Because of a lack of genomic data, this virus has remained unclassified. Electron microscopy of an archival virus isolated from Tipula oleracea, T. oleracea nudivirus (ToNV), showed irregularly shaped occlusion bodies measuring from 2 to 5 μm in length and 2 μm in middiameter, filled with rod-shape virions containing single nucleocapsids within a bilayer envelope. Whole-genome amplification and Roche 454 sequencing revealed a complete circular genome sequence of 145.7 kb, containing five direct repeat regions. We predicted 131 open reading frames, including a homolog of the polyhedrin gene encoding the major occlusion body protein of T. paludosa nucleopolyhedrovirus (NPV). BLAST searches demonstrated that ToNV had 21 of the 37 baculovirus core genes but shared 52 genes with nudiviruses (NVs). Phylogenomic analyses indicated that ToNV clearly belongs to the Nudiviridae family but should probably be assigned to a new genus. Among nudiviruses, ToNV was most closely related to the Penaeus monodon NV and Heliothis zea NV clade but distantly related to Drosophila innubia NV, the other nudivirus infecting a Diptera. Lastly, ToNV was found to be most closely related to the nuvidirus ancestor of bracoviruses. This was also reflected in terms of gene content, as ToNV was the only known exogenous virus harboring homologs of the Cc50C22.6 and 27b (Cc50C22.7) genes found in the nudiviral genomic cluster involved in bracovirus particle production. IMPORTANCE The Nudiviridae is a family of arthropod dsDNA viruses from which striking cases of endogenization have been reported (i.e., symbiotic bracoviruses deriving from a nudivirus and the endogenous nudivirus of the brown planthopper). Although related to baculoviruses, relatively little is known about the genomic diversity of exogenous nudiviruses. Here, we characterized, morphologically and genetically, an archival sample of the Tipula oleracea nudivirus (ToNV), which has the particularity of forming occlusion bodies. Comparative genomic and phylogenomic analyses showed ToNV to be to date the closest known relative of the exogenous ancestor of bracoviruses and that ToNV should be assigned to a new genus. Moreover, we revised the homology relationships of nudiviral genes and identified a new set of 32 core genes for the Nudiviridae, of which 21 were also baculovirus core genes. These findings provide important insights into the evolutionary history of large arthropod dsDNA viruses.
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Yang YT, Lee DY, Wang Y, Hu JM, Li WH, Leu JH, Chang GD, Ke HM, Kang ST, Lin SS, Kou GH, Lo CF. The genome and occlusion bodies of marine Penaeus monodon nudivirus (PmNV, also known as MBV and PemoNPV) suggest that it should be assigned to a new nudivirus genus that is distinct from the terrestrial nudiviruses. BMC Genomics 2014; 15:628. [PMID: 25063321 PMCID: PMC4132918 DOI: 10.1186/1471-2164-15-628] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 07/03/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Penaeus monodon nudivirus (PmNV) is the causative agent of spherical baculovirosis in shrimp (Penaeus monodon). This disease causes significant mortalities at the larval stage and early postlarval (PL) stage and may suppress growth and reduce survival and production in aquaculture. The nomenclature and classification status of PmNV has been changed several times due to morphological observation and phylogenetic analysis of its partial genome sequence. In this study, we therefore completed the genome sequence and constructed phylogenetic trees to clarify PmNV's taxonomic position. To better understand the characteristics of the occlusion bodies formed by this marine occluded virus, we also compared the chemical properties of the polyhedrin produced by PmNV and the baculovirus AcMNPV (Autographa californica nucleopolyhedrovirus). RESULTS We used next generation sequencing and traditional PCR methods to obtain the complete PmNV genome sequence of 119,638 bp encoding 115 putative ORFs. Phylogenetic tree analysis showed that several PmNV genes and sequences clustered with the non-occluded nudiviruses and not with the baculoviruses. We also investigated the characteristics of PmNV polyhedrin, which is a functionally important protein and the major component of the viral OBs (occlusion bodies). We found that both recombinant PmNV polyhedrin and wild-type PmNV OBs were sensitive to acid conditions, but unlike the baculoviral OBs, they were not susceptible to alkali treatment. CONCLUSIONS From the viral genome features and phylogenetic analysis we conclude that PmNV is not a baculovirus, and that it should be assigned to the proposed Nudiviridae family with the other nudiviruses, but into a distinct new genus (Gammanudivirus).
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Guang-Hsiung Kou
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.
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Abstract
UNLABELLED The brown planthopper (BPH), Nilaparvata lugens (Hemiptera:Delphacidae), is one of the most destructive insect pests of rice crops in Asia. Nudivirus-like sequences were identified during the whole-genome sequencing of BPH. PCR examination showed that the virus sequences were present in all of the 22 BPH populations collected from East, Southeast, and South Asia. Thirty-two of the 33 nudivirus core genes were identified, including 20 homologues of baculovirus core genes. In addition, several gene clusters that were arranged collinearly with those of other nudiviruses were found in the partial virus genome. In a phylogenetic tree constructed using the supermatrix method, the original virus was grouped with other nudiviruses and was closely related to polydnavirus. Taken together, these data indicated that the virus sequences belong to a new member of the family Nudiviridae. More specifically, the virus sequences were integrated into the chromosome of its insect host during coevolution. This study is the first report of a large double-stranded circular DNA virus genome in a sap-sucking hemipteran insect. IMPORTANCE This is the first report of a large double-stranded DNA virus integrated genome in the planthopper, a plant sap-sucking hemipteran insect. It is an exciting addition to the evolutionary story of bracoviruses (polydnaviruses), nudiviruses, and baculoviruses. The results on the virus sequences integrated in the chromosomes of its insect host also represent a story of successful coevolution of an invertebrate virus and a plant sap-sucking insect.
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Kariithi HM, van Oers MM, Vlak JM, Vreysen MJB, Parker AG, Abd-Alla AMM. Virology, Epidemiology and Pathology of Glossina Hytrosavirus, and Its Control Prospects in Laboratory Colonies of the Tsetse Fly, Glossina pallidipes (Diptera; Glossinidae). INSECTS 2013; 4:287-319. [PMID: 26462422 PMCID: PMC4553466 DOI: 10.3390/insects4030287] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/13/2013] [Accepted: 06/13/2013] [Indexed: 01/03/2023]
Abstract
The Glossina hytrosavirus (family Hytrosaviridae) is a double-stranded DNA virus with rod-shaped, enveloped virions. Its 190 kbp genome encodes 160 putative open reading frames. The virus replicates in the nucleus, and acquires a fragile envelope in the cell cytoplasm. Glossina hytrosavirus was first isolated from hypertrophied salivary glands of the tsetse fly, Glossina pallidipes Austen (Diptera; Glossinidae) collected in Kenya in 1986. A certain proportion of laboratory G. pallidipes flies infected by Glossina hytrosavirus develop hypertrophied salivary glands and midgut epithelial cells, gonadal anomalies and distorted sex-ratios associated with reduced insemination rates, fecundity and lifespan. These symptoms are rare in wild tsetse populations. In East Africa, G. pallidipes is one of the most important vectors of African trypanosomosis, a debilitating zoonotic disease that afflicts 37 sub-Saharan African countries. There is a large arsenal of control tactics available to manage tsetse flies and the disease they transmit. The sterile insect technique (SIT) is a robust control tactic that has shown to be effective in eradicating tsetse populations when integrated with other control tactics in an area-wide integrated approach. The SIT requires production of sterile male flies in large production facilities. To supply sufficient numbers of sterile males for the SIT component against G. pallidipes, strategies have to be developed that enable the management of the Glossina hytrosavirus in the colonies. This review provides a historic chronology of the emergence and biogeography of Glossina hytrosavirus, and includes researches on the infectomics (defined here as the functional and structural genomics and proteomics) and pathobiology of the virus. Standard operation procedures for viral management in tsetse mass-rearing facilities are proposed and a future outlook is sketched.
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Affiliation(s)
- Henry M Kariithi
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
- Biotechnology Centre, Kenya Agricultural Research Institute, Waiyaki Way, P.O. Box 14733-00100, Nairobi, Kenya.
| | - Monique M van Oers
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, Wageningen 6708 PB, The Netherlands.
| | - Marc J B Vreysen
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
| | - Andrew G Parker
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
| | - Adly M M Abd-Alla
- Insect Pest Control Laboratories, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagrammer Strasse 5, P.O. Box 100, 1400 Vienna, Austria.
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The bracovirus genome of the parasitoid wasp Cotesia congregata is amplified within 13 replication units, including sequences not packaged in the particles. J Virol 2013; 87:9649-60. [PMID: 23804644 DOI: 10.1128/jvi.00886-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The relationship between parasitoid wasps and polydnaviruses constitutes one of the few known mutualisms between viruses and eukaryotes. Viral particles are injected with the wasp eggs into parasitized larvae, and the viral genes thus introduced are used to manipulate lepidopteran host physiology. The genome packaged in the particles is composed of 35 double-stranded DNA (dsDNA) circles produced in wasp ovaries by amplification of viral sequences from proviral segments integrated in tandem arrays in the wasp genome. These segments and their flanking regions within the genome of the wasp Cotesia congregata were recently isolated, allowing extensive mapping of amplified sequences. The bracovirus DNAs packaged in the particles were found to be amplified within more than 12 replication units. Strikingly, the nudiviral cluster, the genes of which encode particle structural components, was also amplified, although not encapsidated. Amplification of bracoviral sequences was shown to involve successive head-to-head and tail-to-tail concatemers, which was not expected given the nudiviral origin of bracoviruses.
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Xiang X, Shen Y, Yang R, Chen L, Hu X, Wu X. Bombyx mori nucleopolyhedrovirus BmP95 plays an essential role in budded virus production and nucleocapsid assembly. J Gen Virol 2013; 94:1669-1679. [PMID: 23535571 DOI: 10.1099/vir.0.050583-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) BmP95 is a highly conserved gene that is found in all of the baculovirus genomes sequenced to date and is also found in nudiviruses. To investigate the role of BmP95 in virus infection in vitro, a BmP95 deletion virus (vBmP95-De) was generated by homologous recombination in Escherichia coli. Fluorescence and light microscopy and titration analysis indicated that the BmP95 deletion bacmid led to a defect in production of infectious budded virus (BV). However, deletion of BmP95 did not affect viral DNA replication. Electron microscopy showed that masses of aberrant tubular structures were present in cells transfected with the BmP95 deletion bacmid, indicating that deletion of BmP95 affected assembly of the nucleocapsid. This defect could be rescued by insertion of full-length BmP95 into the polyhedrin locus of the BmP95-knockout bacmid but not the N-terminal domain of BmP95. Together, these results showed that full-length BmP95 is essential for BV production and is required for nucleocapsid assembly.
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Affiliation(s)
- Xingwei Xiang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Yunwang Shen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Rui Yang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Lin Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Xiaolong Hu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
| | - Xiaofeng Wu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China
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Abstract
Virophages, e.g., Sputnik, Mavirus, and Organic Lake virophage (OLV), are unusual parasites of giant double-stranded DNA (dsDNA) viruses, yet little is known about their diversity. Here, we describe the global distribution, abundance, and genetic diversity of virophages based on analyzing and mapping comprehensive metagenomic databases. The results reveal a distinct abundance and worldwide distribution of virophages, involving almost all geographical zones and a variety of unique environments. These environments ranged from deep ocean to inland, iced to hydrothermal lakes, and human gut- to animal-associated habitats. Four complete virophage genomic sequences (Yellowstone Lake virophages [YSLVs]) were obtained, as was one nearly complete sequence (Ace Lake Mavirus [ALM]). The genomes obtained were 27,849 bp long with 26 predicted open reading frames (ORFs) (YSLV1), 23,184 bp with 21 ORFs (YSLV2), 27,050 bp with 23 ORFs (YSLV3), 28,306 bp with 34 ORFs (YSLV4), and 17,767 bp with 22 ORFs (ALM). The homologous counterparts of five genes, including putative FtsK-HerA family DNA packaging ATPase and genes encoding DNA helicase/primase, cysteine protease, major capsid protein (MCP), and minor capsid protein (mCP), were present in all virophages studied thus far. They also shared a conserved gene cluster comprising the two core genes of MCP and mCP. Comparative genomic and phylogenetic analyses showed that YSLVs, having a closer relationship to each other than to the other virophages, were more closely related to OLV than to Sputnik but distantly related to Mavirus and ALM. These findings indicate that virophages appear to be widespread and genetically diverse, with at least 3 major lineages.
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Lin F, Huang H, Ke W, Hou L, Li F, Yang F. Characterization of white spot syndrome virus immediate-early gene promoters. J Gen Virol 2013; 94:387-392. [DOI: 10.1099/vir.0.047274-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Twenty-one immediate-early (IE) genes of white spot syndrome virus (WSSV) have been identified so far. However, the transcriptional regulation of WSSV IE genes remains largely unknown. In this report, the 5′ flanking regions of 18 WSSV IE genes were cloned and eight functional promoter regions were identified. WSSV IE gene promoters normally contained a TATA box approximately 30 bp upstream of the transcriptional initiation site. Also, the cyclic AMP response element (CRE; TGACGTCA) was frequently found within the WSSV IE promoter regions. Mutations of the CREs of WSSV IE promoters P403 and P465 reduced their activity significantly, suggesting that these elements have a role in WSSV IE gene transcription. Our findings provide a more global view of WSSV IE gene promoters and will facilitate the in-depth investigation of viral gene transcriptional regulation.
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Affiliation(s)
- Fanyu Lin
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen 361005, PR China
- School of Life Science, Xiamen University, Xiamen 361005, PR China
| | - He Huang
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen 361005, PR China
- School of Life Science, Xiamen University, Xiamen 361005, PR China
| | - Wei Ke
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen 361005, PR China
- School of Life Science, Xiamen University, Xiamen 361005, PR China
| | - Luhong Hou
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen 361005, PR China
| | - Fang Li
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen 361005, PR China
| | - Feng Yang
- Key Laboratory of Marine Biogenetic Resources, Third Institute of Oceanography, State Oceanic Administration (SOA), Xiamen 361005, PR China
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Rajendran KV, Makesh M, Karunasagar I. Monodon baculovirus of shrimp. INDIAN JOURNAL OF VIROLOGY : AN OFFICIAL ORGAN OF INDIAN VIROLOGICAL SOCIETY 2012; 23:149-60. [PMID: 23997439 DOI: 10.1007/s13337-012-0086-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2011] [Accepted: 06/29/2012] [Indexed: 11/28/2022]
Abstract
Among the viruses infecting penaeid shrimp, monodon-type baculovirus (MBV) otherwise known as Penaeus monodon singly enveloped nuclear polyhedrosis virus (PmSNPV), is one of the widely reported and well described viruses. It is a rod-shaped, enveloped, double-stranded DNA virus, and considered till recently, as the type A baculovirus. Besides MBV, two strains of SNPV are reported-plebejus baculovirus and bennettae baculovirus. MBV was reported to be originated from Taiwan and has wide geographic distribution and is reported to be enzootic in wild penaeids of the Indo-pacific coasts of Asia. The virus also has diverse host-range including a variety of cultured and captured shrimp species and freshwater prawn, Macrobrachium rosenbergii. MBV has been reported in all life stages of P. monodon with late larval, postlarval and young juvenile as the most susceptible stages/ages. However, MBV has not been documented in early larval stages. Although MBV has been reported to be tolerated well by shrimp, the infection has been attributed to decreased productivity. The target organs or tissues of MBV are the hepatopancreatic tubules and duct epithelium of postlarvae, juveniles and adults, and the anterior midgut epithelium of very young postlarvae. The prominent clinical sign of infection is the presence of multiple spherical inclusion bodies in the hepatopancreas and midgut epithelial cells. The major mode of transmission of the virus is horizontal through oral exposure to occlusion bodies, contaminated tissues or fomites. Minor morphometric variation of the virus has been reported among different isolates. The rod-shaped enveloped virus particles range from 265-324 nm in length and 42-77 nm in diameter. Although complete genome sequence of MBV is not available, nucleic acid of MBV is circular, double-stranded DNA with a genome size ranging from 80 to 160 kbp. The virus codes for a 53 kDa major polyhedrin polypeptide and two minor 47 and 49 kDa polypeptides. A variety of diagnostic tools have been reported for this virus including real-time PCR and LAMP-based detection. Taxonomic position is still uncertain and International Committee on Taxonomy of Viruses lists MBV as a tentative species named PemoNPV in the genus Nucleopolyhedrovirus. However, according to the latest genomic information on the virus, it has been suggested to create a new group of non-occluded bacilliform viruses called nudiviruses with MBV as one of the members. The aim of the current work is to describe the knowledge on the status, distribution and host-range, pathology, transmission, virus structure and morphogenesis, genomic characteristics, diagnosis and the latest taxonomic position of MBV.
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Affiliation(s)
- K V Rajendran
- Central Institute of Fisheries Education (CIFE), Mumbai, India
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39
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Phylogeny and evolution of Hytrosaviridae. J Invertebr Pathol 2012; 112 Suppl:S62-7. [PMID: 22841640 DOI: 10.1016/j.jip.2012.07.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/21/2012] [Accepted: 05/22/2012] [Indexed: 11/21/2022]
Abstract
The Hytrosaviridae comprises a family of dsDNA viruses with a circular genome of 120-190 kb p. They are exclusively associated with Diptera, such as the tsetse fly, the house fly and the Narcissus bulb fly. Hytrosaviruses cause a very unique pathology including hypertrophy of salivary glands as well as testicular and ovarian malformation. On the other hand these viruses share a significant number of gene homologues with other dsDNA viruses, esp. baculoviruses and nudiviruses. These gene homologues include twelve so-called baculovirus core genes involved in transcription, DNA replication and the infection process. Most strikingly, the Musca domestica salivary gland hypertrophy virus (MdSGHV) encodes a homologue of a polyhedrin/granulin gene of Alpha-, Beta-, Gammabaculoviruses. Hence, it is proposed that hytrosaviruses are phylogenetically related to baculoviruses but evolved in a very close association with their dipteran hosts.
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Burand JP, Kim W, Afonso CL, Tulman ER, Kutish GF, Lu Z, Rock DL. Analysis of the genome of the sexually transmitted insect virus Helicoverpa zea nudivirus 2. Viruses 2012; 4:28-61. [PMID: 22355451 PMCID: PMC3280521 DOI: 10.3390/v4010028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 12/30/2011] [Accepted: 12/31/2011] [Indexed: 01/10/2023] Open
Abstract
The sexually transmitted insect virus Helicoverpa zea nudivirus 2 (HzNV-2) was determined to have a circular double-stranded DNA genome of 231,621 bp coding for an estimated 113 open reading frames (ORFs). HzNV-2 is most closely related to the nudiviruses, a sister group of the insect baculoviruses. Several putative ORFs that share homology with the baculovirus core genes were identified in the viral genome. However, HzNV-2 lacks several key genetic features of baculoviruses including the late transcriptional regulation factor, LEF-1 and the palindromic hrs, which serve as origins of replication. The HzNV-2 genome was found to code for three ORFs that had significant sequence homology to cellular genes which are not generally found in viral genomes. These included a presumed juvenile hormone esterase gene, a gene coding for a putative zinc-dependent matrix metalloprotease, and a major facilitator superfamily protein gene; all of which are believed to play a role in the cellular proliferation and the tissue hypertrophy observed in the malformation of reproductive organs observed in HzNV-2 infected corn earworm moths, Helicoverpa zea.
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Affiliation(s)
- John P. Burand
- Department of Plant, Soil and Insect Sciences, University of Massachusetts Amherst, Amherst, MA 01003, USA;
| | - Woojin Kim
- Department of Plant, Soil and Insect Sciences, University of Massachusetts Amherst, Amherst, MA 01003, USA;
| | - Claudio L. Afonso
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA; (C.L.A.); (E.R.T.); (G.F.K.); (Z.L.); (D.L.R.)
| | - Edan R. Tulman
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA; (C.L.A.); (E.R.T.); (G.F.K.); (Z.L.); (D.L.R.)
| | - Gerald F. Kutish
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA; (C.L.A.); (E.R.T.); (G.F.K.); (Z.L.); (D.L.R.)
| | - Zhiqiang Lu
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA; (C.L.A.); (E.R.T.); (G.F.K.); (Z.L.); (D.L.R.)
| | - Daniel L. Rock
- Plum Island Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Greenport, NY 11944, USA; (C.L.A.); (E.R.T.); (G.F.K.); (Z.L.); (D.L.R.)
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Abstract
Little is known about the viruses infecting most species. Even in groups as well-studied as Drosophila, only a handful of viruses have been well-characterized. A viral metagenomic approach was used to explore viral diversity in 83 wild-caught Drosophila innubila, a mushroom feeding member of the quinaria group. A single fly that was injected with, and died from, Drosophila C Virus (DCV) was added to the sample as a control. Two-thirds of reads in the infected sample had DCV as the best BLAST hit, suggesting that the protocol developed is highly sensitive. In addition to the DCV hits, several sequences had Oryctes rhinoceros Nudivirus, a double-stranded DNA virus, as a best BLAST hit. The virus associated with these sequences was termed Drosophila innubila Nudivirus (DiNV). PCR screens of natural populations showed that DiNV was both common and widespread taxonomically and geographically. Electron microscopy confirms the presence of virions in fly fecal material similar in structure to other described Nudiviruses. In 2 species, D. innubila and D. falleni, the virus is associated with a severe (∼80-90%) loss of fecundity and significantly decreased lifespan.
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Affiliation(s)
- Robert L Unckless
- Department of Biology, University of Rochester, Rochester, New York, United States of America.
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42
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Abstract
To understand how extant viruses interact with their hosts, we need a historical framework of their evolutionary association. Akin to retrovirus or hepadnavirus viral fossils present in eukaryotic genomes, bracoviruses are integrated in braconid wasp genomes and are transmitted by Mendelian inheritance. However, unlike viral genomic fossils, they have retained functional machineries homologous to those of large dsDNA viruses pathogenic to arthropods. Using a phylogenomic approach, we resolved the relationships between bracoviruses and their closest free relatives: baculoviruses and nudiviruses. The phylogeny showed that bracoviruses are nested within the nudivirus clade. Bracoviruses establish a bridge between the virus and animal worlds. Their inclusion in a virus phylogeny allowed us to relate free viruses to fossils. The ages of the wasps were used to calibrate the virus phylogeny. Bayesian analyses revealed that insect dsDNA viruses first evolved at ∼310 Mya in the Paleozoic Era during the Carboniferous Period with the first insects. Furthermore the virus diversification time frame during the Mesozoic Era appears linked to the diversification of insect orders; baculoviruses that infect larvae evolved at the same period as holometabolous insects. These results imply ancient coevolution by resource tracking between several insect dsDNA virus families and their hosts, dating back to 310 Mya.
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Wu YL, Wu CP, Liu CYY, Hsu PWC, Wu EC, Chao YC. A non-coding RNA of insect HzNV-1 virus establishes latent viral infection through microRNA. Sci Rep 2011; 1:60. [PMID: 22355579 PMCID: PMC3216547 DOI: 10.1038/srep00060] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Accepted: 07/22/2011] [Indexed: 11/17/2022] Open
Abstract
Heliothis zea nudivirus-1 (HzNV-1) is an insect virus previously known as Hz-1 baculovirus. One of its major early genes, hhi1, is responsible for the establishment of productive viral infection; another gene, pag1, which expresses a non-coding RNA, is the only viral transcript detectable during viral latency. Here we showed that this non-coding RNA was further processed into at least two distinct miRNAs, which targeted and degraded hhi1 transcript. This is a result strikingly similar to a recent report that herpes simplex virus produces tightly-regulated latent specific miRNAs to silence its own key early transcripts. Nevertheless, proof for the establishment of viral latency by miRNA is still lacking. We further showed that HzNV-1 latency could be directly induced by pag1-derived miRNAs in cells infected with a pag1-deleted, latency-deficient virus. This result suggests the existence of a novel mechanism, where miRNAs can be functional for the establishment of viral latency.
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Affiliation(s)
- Yueh-Lung Wu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei 105; Taiwan
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Castro MEB, Paula DP, Almeida GF, Ribeiro ZMA, Souza ML, Inglis PW, Ribeiro BM. Identification and sequence analysis of the Condylorrhiza vestigialis MNPV p74 gene. Virus Genes 2011; 43:471-5. [PMID: 21720731 DOI: 10.1007/s11262-011-0640-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 06/20/2011] [Indexed: 10/18/2022]
Abstract
The baculovirus Condylorrhiza vestigialis multiple nucleopolyhedrovirus (CoveMNPV), isolated from C. vestigialis infected larvae in Paraná (Brazil), was identified in our laboratory. A full-length clone was obtained from the CoveMNPV genome, of the gene that encodes the homolog to baculoviral p74, essential for oral infectivity which was then sequenced and characterized. The CoveMNPV p74 gene (GenBank accession number EU919397) contains an ORF of 1935 bp that encodes a deduced protein of 73.61 kDa. The phylogenetic affiliations of the CoveMNPV gene were determined by a heuristic search of 40 aligned baculovirus p74 nucleotide sequences using maximum parsimony (PAUP 4.0b4a). The phylogenetic analysis placed CoveMNPV within lepidopteran nucleopolyhedrovirus (NPV) Group I, Clade A, as being the closest to Choristoneura fumiferana defective NPV.
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Affiliation(s)
- Maria Elita B Castro
- Embrapa Recursos Genéticos e Biotecnologia, Parque Estação Biológica W5 Norte Final, Brasília, Brazil.
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Heliothis zea nudivirus 1 gene hhi1 induces apoptosis which is blocked by the Hz-iap2 gene and a noncoding gene, pag1. J Virol 2011; 85:6856-66. [PMID: 21543471 DOI: 10.1128/jvi.01843-10] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Heliothis zea nudivirus 1 (HzNV-1 or Hz-1 virus), previously regarded as a nonoccluded baculovirus, recently has been placed in the Nudivirus genus. This virus generates HzNV-1 HindIII-I 1 (hhi1) and many other transcripts during productive viral infection; during latent viral infection, however, persistency-associated gene 1 (pag1) is the only gene expressed. In this report, we used transient expression assays to show that hhi1 can trigger strong apoptosis in transfected cells, which can be blocked, at least partially, by the inhibitor of apoptosis genes Autographa californica iap2 (Ac-iap2) and H. zea iap2 (Hz-iap2). In addition to these two genes, unexpectedly, pag1, which encodes a noncoding RNA with no detectable protein product, was found to efficiently suppress hhi1-induced apoptosis. The assay of pro-Sf-caspase-1 processing by hhi1 transfection did not detect the small P12 subunit at any of the time intervals tested, suggesting that hhi1 of HzNV-1 induces apoptosis through alternative caspase pathways.
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Wang Y, Bininda-Emonds ORP, van Oers MM, Vlak JM, Jehle JA. The genome of Oryctes rhinoceros nudivirus provides novel insight into the evolution of nuclear arthropod-specific large circular double-stranded DNA viruses. Virus Genes 2011; 42:444-56. [DOI: 10.1007/s11262-011-0589-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Accepted: 02/21/2011] [Indexed: 11/29/2022]
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47
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Wetterwald C, Roth T, Kaeslin M, Annaheim M, Wespi G, Heller M, Maser P, Roditi I, Pfister-Wilhelm R, Bezier A, Gyapay G, Drezen JM, Lanzrein B. Identification of bracovirus particle proteins and analysis of their transcript levels at the stage of virion formation. J Gen Virol 2010; 91:2610-9. [DOI: 10.1099/vir.0.022699-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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48
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Specificity of baculovirus P6.9 basic DNA-binding proteins and critical role of the C terminus in virion formation. J Virol 2010; 84:8821-8. [PMID: 20519380 DOI: 10.1128/jvi.00072-10] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The majority of double-stranded DNA (dsDNA) viruses infecting eukaryotic organisms use host- or virus-expressed histones or protamine-like proteins to condense their genomes. In contrast, members of the Baculoviridae family use a protamine-like protein named P6.9. The dephosphorylated form of P6.9 binds to DNA in a non-sequence-specific manner. By using a p6.9-null mutant of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), we demonstrate that P6.9 is not required for viral DNA replication but is essential for the production of infectious virus. Virion production was rescued by P6.9 homologs from a number of Alphabaculovirus species and one Gammabaculovirus species but not from the genus Betabaculovirus, comprising the granuloviruses, or by the P6.9 homolog VP15 from the unrelated white spot syndrome virus of shrimp. Mutational analyses demonstrated that AcMNPV P6.9 with a conserved 11-residue deletion of the C terminus was not capable of rescuing p6.9-null AcMNPV, while a chimeric Betabaculovirus P6.9 containing the P6.9 C-terminal region of an Alphabaculovirus strain was able to do so. This implies that the C terminus of baculovirus P6.9 contains sequence elements essential for virion formation. Such elements may possibly interact with species- or genus-specific domains of other nucleocapsid proteins during virus assembly.
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The early gene hhi1 reactivates Heliothis zea nudivirus 1 in latently infected cells. J Virol 2009; 84:1057-65. [PMID: 19889784 DOI: 10.1128/jvi.01548-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Heliothis zea nudivirus 1 (HzNV-1), previously known as Hz-1 virus, is an insect virus able to establish both productive and latent infections in several lepidopteran insect cells. Here, we have cloned and characterized one of the HzNV-1 early genes, hhi1, which maps to the HindIII-I fragment of the viral genome. During the productive viral infection, a 6.2-kb hhi1 transcript was detectable as early as 0.5 h postinfection (hpi). The level of transcript reached a maximum at 2 hpi and gradually decreased after 4 hpi. The transcript was not detectable during the latent phase of viral infection. Upon cycloheximide treatment, much higher levels of hhi1 transcript were detected throughout the productive viral infection cycle, suggesting that newly synthesized proteins are not needed for the expression of hhi1. Nevertheless, viral coinfection can further stimulate the expression of transfected hhi1 promoter in a plasmid. Transient hhi1 expression in latently infected cells resulted in a significant increase in virus titer and viral DNA propagation, suggesting that hhi1 plays a critical role in viral reactivation. Additional experiments showed that six early genes, which possibly function in transcription or DNA replication, were activated in the latent cells upon hhi1 transfection. Among these six genes, orf90 and orf121 expression could be induced by hhi1 alone without the need for other viral genes. Our discovery should be useful for future mechanistic study of the switches of latent/productive HzNV-1 viral infections.
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Whole-proteome phylogeny of large dsDNA virus families by an alignment-free method. Proc Natl Acad Sci U S A 2009; 106:12826-31. [PMID: 19553209 DOI: 10.1073/pnas.0905115106] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The vast sequence divergence among different virus groups has presented a great challenge to alignment-based sequence comparison among different virus families. Using an alignment-free comparison method, we construct the whole-proteome phylogeny for a population of viruses from 11 viral families comprising 142 large dsDNA eukaryote viruses. The method is based on the feature frequency profiles (FFP), where the length of the feature (l-mer) is selected to be optimal for phylogenomic inference. We observe that (i) the FFP phylogeny segregates the population into clades, the membership of each has remarkable agreement with current classification by the International Committee on the Taxonomy of Viruses, with one exception that the mimivirus joins the phycodnavirus family; (ii) the FFP tree detects potential evolutionary relationships among some viral families; (iii) the relative position of the 3 herpesvirus subfamilies in the FFP tree differs from gene alignment-based analysis; (iv) the FFP tree suggests the taxonomic positions of certain "unclassified" viruses; and (v) the FFP method identifies candidates for horizontal gene transfer between virus families.
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