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Hernández-Pelegrín L, Huditz HI, García-Castillo P, de Ruijter NCA, van Oers MM, Herrero S, Ros VID. Covert RNA viruses in medflies differ in their mode of transmission and tissue tropism. J Virol 2024; 98:e0010824. [PMID: 38742874 PMCID: PMC11237731 DOI: 10.1128/jvi.00108-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/12/2024] [Indexed: 05/16/2024] Open
Abstract
Numerous studies have demonstrated the presence of covert viral infections in insects. These infections can be transmitted in insect populations via two main routes: vertical from parents to offspring, or horizontal between nonrelated individuals. Thirteen covert RNA viruses have been described in the Mediterranean fruit fly (medfly). Some of these viruses are established in different laboratory-reared and wild medfly populations, although variations in the viral repertoire and viral levels have been observed at different time points. To better understand these viral dynamics, we characterized the prevalence and levels of covert RNA viruses in two medfly strains, assessed the route of transmission of these viruses, and explored their distribution in medfly adult tissues. Altogether, our results indicated that the different RNA viruses found in medflies vary in their preferred route of transmission. Two iflaviruses and a narnavirus are predominantly transmitted through vertical transmission via the female, while a nodavirus and a nora virus exhibited a preference for horizontal transmission. Overall, our results give valuable insights into the viral tropism and transmission of RNA viruses in the medfly, contributing to the understanding of viral dynamics in insect populations. IMPORTANCE The presence of RNA viruses in insects has been extensively covered. However, the study of host-virus interaction has focused on viruses that cause detrimental effects to the host. In this manuscript, we uncovered which tissues are infected with covert RNA viruses in the agricultural pest Ceratitis capitata, and which is the preferred transmission route of these viruses. Our results showed that vertical and horizontal transmission can occur simultaneously, although each virus is transmitted more efficiently following one of these routes. Additionally, our results indicated an association between the tropism of the RNA virus and the preferred route of transmission. Overall, these results set the basis for understanding how viruses are established and maintained in medfly populations.
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Affiliation(s)
- Luis Hernández-Pelegrín
- Laboratory of Virology, Department of Plant Science, Wageningen University and Research, Wageningen, the Netherlands
- Department of Genetics and University Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
| | - Hannah-Isadora Huditz
- Laboratory of Virology, Department of Plant Science, Wageningen University and Research, Wageningen, the Netherlands
- Department of Genetics and University Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
- Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Vienna International Centre, Vienna, Austria
| | - Pablo García-Castillo
- Department of Genetics and University Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
| | - Norbert C A de Ruijter
- Laboratory of Cell and Developmental Biology, Department of Plant Science, Wageningen University and Research, Wageningen, the Netherlands
| | - Monique M van Oers
- Laboratory of Virology, Department of Plant Science, Wageningen University and Research, Wageningen, the Netherlands
| | - Salvador Herrero
- Department of Genetics and University Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
| | - Vera I D Ros
- Laboratory of Virology, Department of Plant Science, Wageningen University and Research, Wageningen, the Netherlands
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Somers DJ, Kushner DB, McKinnis AR, Mehmedovic D, Flame RS, Arnold TM. Epigenetic weapons in plant-herbivore interactions: Sulforaphane disrupts histone deacetylases, gene expression, and larval development in Spodoptera exigua while the specialist feeder Trichoplusia ni is largely resistant to these effects. PLoS One 2023; 18:e0293075. [PMID: 37856454 PMCID: PMC10586618 DOI: 10.1371/journal.pone.0293075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 10/03/2023] [Indexed: 10/21/2023] Open
Abstract
Cruciferous plants produce sulforaphane (SFN), an inhibitor of nuclear histone deacetylases (HDACs). In humans and other mammals, the consumption of SFN alters enzyme activities, DNA-histone binding, and gene expression within minutes. However, the ability of SFN to act as an HDAC inhibitor in nature, disrupting the epigenetic machinery of insects feeding on these plants, has not been explored. Here, we demonstrate that SFN consumed in the diet inhibits the activity of HDAC enzymes and slows the development of the generalist grazer Spodoptera exigua, in a dose-dependent fashion. After consuming SFN for seven days, the activities of HDAC enzymes in S. exigua were reduced by 50%. Similarly, larval mass was reduced by 50% and pupation was delayed by 2-5 days, with no additional mortality. Similar results were obtained when SFN was applied topically to eggs. RNA-seq analyses confirm that SFN altered the expression of thousands of genes in S. exigua. Genes associated with energy conversion pathways were significantly downregulated while those encoding for ribosomal proteins were dramatically upregulated in response to the consumption of SFN. In contrast, the co-evolved specialist feeder Trichoplusia ni was not negatively impacted by SFN, whether it was consumed in their diet at natural concentrations or applied topically to eggs. The activities of HDAC enzymes were not inhibited and development was not disrupted. In fact, SFN exposure sometimes accelerated T. ni development. RNA-seq analyses revealed that the consumption of SFN alters gene expression in T. ni in similar ways, but to a lesser degree, compared to S. exigua. This apparent resistance of T. ni can be overwhelmed by unnaturally high levels of SFN or by exposure to more powerful pharmaceutical HDAC inhibitors. These results demonstrate that dietary SFN interferes with the epigenetic machinery of insects, supporting the hypothesis that plant-derived HDAC inhibitors serve as "epigenetic weapons" against herbivores.
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Affiliation(s)
- Dana J. Somers
- Department of Biology, Program in Biochemistry and Molecular Biology, Dickinson College, Carlisle, PA United States of America
| | - David B. Kushner
- Department of Biology, Program in Biochemistry and Molecular Biology, Dickinson College, Carlisle, PA United States of America
| | - Alexandria R. McKinnis
- Department of Biology, Program in Biochemistry and Molecular Biology, Dickinson College, Carlisle, PA United States of America
| | - Dzejlana Mehmedovic
- Department of Biology, Program in Biochemistry and Molecular Biology, Dickinson College, Carlisle, PA United States of America
| | - Rachel S. Flame
- Department of Biology, Program in Biochemistry and Molecular Biology, Dickinson College, Carlisle, PA United States of America
| | - Thomas M. Arnold
- Department of Biology, Program in Biochemistry and Molecular Biology, Dickinson College, Carlisle, PA United States of America
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Buhlke EG, Hobbs AM, Rajput S, Rokusek B, Carlson DJ, Gillan C, Carlson KA. Characterization of Cross-Species Transmission of Drosophila melanogaster Nora Virus. Life (Basel) 2022; 12:1913. [PMID: 36431048 PMCID: PMC9697521 DOI: 10.3390/life12111913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
Drosophila melanogaster Nora virus (DmNV) is a novel picorna-like virus first characterized in 2006. Since then, Nora virus has been detected in several non-Drosophila species, including insects in the Orders Hymenoptera, Lepidoptera, Coleoptera, and Orthoptera. The objective of this study was to determine if DmNV could infect individuals of other species of invertebrates besides D. melanogaster. The presence of DmNV in native invertebrates and commercially available stocks was determined. Laboratory-reared D. yakuba, D. mercatorum, Gryllodes sigillatus, Tenebrio molitor, Galleria mellonella, and Musca domestica were intentionally infected with DmNV. In addition, native invertebrates were collected and D. melanogaster stocks were purchased and screened for DmNV presence using reverse transcription-polymerase chain reaction (RT-PCR) before being intentionally infected for study. All Drosophila species and other invertebrates, except M. domestica, that were intentionally infected with DmNV ended up scoring positive for the virus via RT-PCR. DmNV infection was also detected in three native invertebrates (Spilosoma virginica, Diplopoda, and Odontotaenius disjunctus) and all commercially available stocks tested. These findings suggest that DmNV readily infects individuals of other species of invertebrates, while also appearing to be an endemic virus in both wild and laboratory D. melanogaster populations. The detection of DmNV in commercially available stocks presents a cautionary message for scientists using these stocks in studies of virology and immunology.
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Affiliation(s)
- Ella G. Buhlke
- Central City Senior High School, 1510 28th Street, Central City, NE 68826, USA
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Alexis M. Hobbs
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Sunanda Rajput
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Blase Rokusek
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Darby J. Carlson
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Chelle Gillan
- Central City Senior High School, 1510 28th Street, Central City, NE 68826, USA
| | - Kimberly A. Carlson
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
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Genetic characterisation of an Iflavirus associated with a vomiting disease in the Indian Tropical tasar silkworm, Antheraea mylitta. Virus Res 2022; 311:198703. [DOI: 10.1016/j.virusres.2022.198703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 08/28/2021] [Accepted: 01/28/2022] [Indexed: 11/22/2022]
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5
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Li T, Guan R, Wu Y, Chen S, Yuan G, Miao X, Li H. The Novel Agrotis ipsilon Nora Virus Confers Deleterious Effects to the Fitness of Spodoptera frugiperda (Lepidoptera: Noctuidae). Front Microbiol 2021; 12:727202. [PMID: 34867845 PMCID: PMC8634655 DOI: 10.3389/fmicb.2021.727202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/11/2021] [Indexed: 12/13/2022] Open
Abstract
In the present study, we identified a novel, positive-sense single-stranded RNA virus in the Chinese black cutworm, Agrotis ipsilon. It has a genome length of 11,312 nucleotides, excluding the poly(A) tails, and contains five open reading frames. The ORF2 encodes the conserved domains of RNA helicase and RNA-dependent RNA polymerase, while ORF4 and 5 encode three viral proteins. Herein, the A. ipsilon virus was clustered with a Helicoverpa armigera Nora virus and was thus provisionally named “Agrotis ipsilon Nora virus” (AINV). AINV was successfully transmitted into a novel host, Spodoptera frugiperda, through injection, causing a stable infection. This found the possibility of horizontal AINV transmission among moths belonging to the same taxonomic family. Nonetheless, AINV infection was deleterious to S. frugiperda and mainly mediated by antiviral and amino acid metabolism-related pathways. Furthermore, the infection significantly increased the S. frugiperda larval period but significantly reduced its moth eclosion rate. It suggests that AINV is probably to be a parasitic virus of S. frugiperda.
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Affiliation(s)
- Tong Li
- Institute of Plant Protection/Henan Key Laboratory of Crop Pest Control/Key Laboratory of Integrated Pest Management on Crops in Southern Region of North China, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Ruobing Guan
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Yuqing Wu
- Institute of Plant Protection/Henan Key Laboratory of Crop Pest Control/Key Laboratory of Integrated Pest Management on Crops in Southern Region of North China, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Su Chen
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Shanghai, China
| | - Guohui Yuan
- Institute of Plant Protection/Henan Key Laboratory of Crop Pest Control/Key Laboratory of Integrated Pest Management on Crops in Southern Region of North China, Henan Academy of Agricultural Sciences, Zhengzhou, China
| | - Xuexia Miao
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Shanghai, China
| | - Haichao Li
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, China.,Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Shanghai, China
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Roy MC, Ahmed S, Mollah MMI, Kim Y. Antiviral Treatment Reveals a Cooperative Pathogenicity of Baculovirus and Iflavirus in Spodoptera exigua, a Lepidopteran Insect. J Microbiol Biotechnol 2021; 31:529-539. [PMID: 33526755 PMCID: PMC9723280 DOI: 10.4014/jmb.2012.12045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/16/2021] [Accepted: 01/18/2021] [Indexed: 12/15/2022]
Abstract
NPVThe beet armyworm, Spodoptera exigua, is a serious insect pest infesting various vegetable crops. Two infectious insect viruses, baculovirus and iflavirus, are known to induce epizootics in S. exigua populations. Indeed, some laboratory colonies have appeared to be covertly infected by these viruses. Diagnostic PCR tests detected two different viruses: Spodoptera exigua multiple nucleopolyhedrosis virus (SeMNPV) and iflaviruses (SeIfV1 and SeIfV2). Viral extract from dead larvae of S. exigua could infect Sf9 cells and produce occlusion bodies (OBs). Feeding OBs to asymptomatic larvae of S. exigua caused significant viral disease. Interestingly, both SeIfV1 and SeIfV2 increased their titers at late larval stages. Sterilization of laid eggs with 1% sodium hypochloride significantly reduced SeMNPV titers and increased larval survival rate. Doublestranded RNA (dsRNA) specific to SeIfV1 or SeIfV2 significantly reduced viral titers and increased larval survival rate. To continuously feed dsRNA, a recombinant Escherichia coli HT115 expressing SeIfV1-dsRNA was constructed with an L4440 expression vector. Adding this recombinant E. coli to the artificial diet significantly reduced the SeIfV1 titer and increased larval survival. These results indicate that laboratory colony collapse of S. exigua is induced by multiple viral infections. In addition, either suppression of SeMNPV or SeIfV infection significantly increased larval survival, suggesting a cooperative pathogenicity between baculovirus and iflavirus against S. exigua.
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Affiliation(s)
- Miltan Chandra Roy
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, Republic of Korea
| | - Shabbir Ahmed
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, Republic of Korea
| | - Md. Mahi Imam Mollah
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, Republic of Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong 36729, Republic of Korea,Corresponding author E-mail:
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7
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François S, Antoine-Lorquin A, Kulikowski M, Frayssinet M, Filloux D, Fernandez E, Roumagnac P, Froissart R, Ogliastro M. Characterisation of the Viral Community Associated with the Alfalfa Weevil ( Hypera postica) and Its Host Plant, Alfalfa ( Medicago sativa). Viruses 2021; 13:791. [PMID: 33925168 PMCID: PMC8145008 DOI: 10.3390/v13050791] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/26/2021] [Accepted: 04/26/2021] [Indexed: 12/22/2022] Open
Abstract
Advances in viral metagenomics have paved the way of virus discovery by making the exploration of viruses in any ecosystem possible. Applied to agroecosystems, such an approach opens new possibilities to explore how viruses circulate between insects and plants, which may help to optimise their management. It could also lead to identifying novel entomopathogenic viral resources potentially suitable for biocontrol strategies. We sampled the larvae of a natural population of alfalfa weevils (Hypera postica), a major herbivorous pest feeding on legumes, and its host plant alfalfa (Medicago sativa). Insect and plant samples were collected from a crop field and an adjacent meadow. We characterised the diversity and abundance of viruses associated with weevils and alfalfa, and described nine putative new virus species, including four associated with alfalfa and five with weevils. In addition, we found that trophic accumulation may result in a higher diversity of plant viruses in phytophagous pests compared to host plants.
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Affiliation(s)
- Sarah François
- Peter Medawar Building for Pathogen Research, Department of Zoology, University of Oxford, South Park Road, Oxford OX1 3SY, UK
- DGIMI Diversity, Genomes and Microorganisms–Insects Interactions, University of Montpellier, INRAE, 34095 Montpellier, France; (A.A.-L.); (M.K.); (M.F.)
| | - Aymeric Antoine-Lorquin
- DGIMI Diversity, Genomes and Microorganisms–Insects Interactions, University of Montpellier, INRAE, 34095 Montpellier, France; (A.A.-L.); (M.K.); (M.F.)
| | - Maximilien Kulikowski
- DGIMI Diversity, Genomes and Microorganisms–Insects Interactions, University of Montpellier, INRAE, 34095 Montpellier, France; (A.A.-L.); (M.K.); (M.F.)
| | - Marie Frayssinet
- DGIMI Diversity, Genomes and Microorganisms–Insects Interactions, University of Montpellier, INRAE, 34095 Montpellier, France; (A.A.-L.); (M.K.); (M.F.)
| | - Denis Filloux
- CIRAD, UMR PHIM, 34090 Montpellier, France; (D.F.); (E.F.); (P.R.)
- PHIM Plant Health Institute, University of Montpellier, CIRAD, INRAE, Institut Agro, IRD, 34090 Montpellier, France
| | - Emmanuel Fernandez
- CIRAD, UMR PHIM, 34090 Montpellier, France; (D.F.); (E.F.); (P.R.)
- PHIM Plant Health Institute, University of Montpellier, CIRAD, INRAE, Institut Agro, IRD, 34090 Montpellier, France
| | - Philippe Roumagnac
- CIRAD, UMR PHIM, 34090 Montpellier, France; (D.F.); (E.F.); (P.R.)
- PHIM Plant Health Institute, University of Montpellier, CIRAD, INRAE, Institut Agro, IRD, 34090 Montpellier, France
| | - Rémy Froissart
- MIVEGEC Infectious and Vector Diseases: Ecology, Genetics, Evolution and Control, University of Montpellier, CNRS, IRD, 34394 Montpellier, France;
| | - Mylène Ogliastro
- DGIMI Diversity, Genomes and Microorganisms–Insects Interactions, University of Montpellier, INRAE, 34095 Montpellier, France; (A.A.-L.); (M.K.); (M.F.)
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8
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Appearances are deceptive: Three RNA viruses co-infected with the nucleopolyhedrovirus in host Lymantria dispar. Virus Res 2021; 297:198371. [PMID: 33684420 DOI: 10.1016/j.virusres.2021.198371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 02/28/2021] [Accepted: 03/02/2021] [Indexed: 11/21/2022]
Abstract
The virus infection, which visually looks like typical monoinfection, in fact may hide a great complex of different species. Without detailed analysis, we may miss the important interaction between pathogens, including new species. In the current study, we found the new species inside the mix of cubic and polyhedral occlusion bodies (OBs) isolated from the gypsy moth, Lymantria dispar L. (Ld). Transmission electron microscopy (TEM) revealed that into the one cadaver were OBs which belonged to baculovirus and cypoviruses. The baculovirus produced polyhedral OBs, while cypoviruses produced polyhedral and cubic OBs. Genomic analysis detected the multiple Ld nucleopolyhedroviruses, and cypoviruses were Hubei lepidoptera virus 3 and Dendrolimus punctatus cypovirus 1. This represents the first isolation of the Hubei lepidoptera virus 3 from the gypsy moth, proposed as "Lymantria dispar cypovirus 3". The RNAseq analysis also revealed the presence of Lymantria dispar iflavirus 1. The insecticidal activity of the mixed infection was comparable to that of typical baculovirus monoinfection. Thus, we demonstrate that i) the shape of OBs identified by light microscopy cannot be a robust indicator of viral species infecting the host; ii) only specific analysis may reveal the true composition of viral infection.
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Jia W, Wang F, Li J, Chang X, Yang Y, Yao H, Bao Y, Song Q, Ye G. A Novel Iflavirus Was Discovered in Green Rice Leafhopper Nephotettix cincticeps and Its Proliferation Was Inhibited by Infection of Rice Dwarf Virus. Front Microbiol 2021; 11:621141. [PMID: 33488564 PMCID: PMC7820178 DOI: 10.3389/fmicb.2020.621141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 12/01/2020] [Indexed: 11/15/2022] Open
Abstract
The green rice leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), is a key insect vector transmitting rice dwarf virus (RDV) that causes rice dwarf disease. We discovered a novel iflavirus from the transcriptomes of N. cincticeps and named it as Nephotettix cincticeps positive-stranded RNA virus-1 (NcPSRV-1). The viral genome consists of 10,524 nucleotides excluding the poly(A) tail and contains one predicted open reading frame encoding a polyprotein of 3,192 amino acids, flanked by 5' and 3' untranslated regions. NcPSRV-1 has a typical iflavirus genome arrangement and is clustered with the members of the family Iflaviridae in the phylogenetic analysis. NcPSRV-1 was detected in all tested tissues and life stages of N. cincticeps and could be transmitted horizontally and vertically. Moreover, NcPSRV-1 had high prevalence in the laboratory populations and was widely spread in field populations of N. cincticeps. NcPSRV-1 could also infect the two-striped leafhopper, Nephotettix apicalis, at a 3.33% infection rate, but was absent in the zigzag leafhopper, Recilia dorsalis, and rice Oryza sativa variety TN1. The infection of RDV altered the viral load and infection rate of NcPSRV-1 in N. cincticeps, for which it seems that RDV has an antagonistic effect on NcPSRV-1 infection in the host.
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Affiliation(s)
- Wenxi Jia
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Fei Wang
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Jingjing Li
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China.,Division of Plant Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, MO, United States
| | - Xuefei Chang
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yi Yang
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Hongwei Yao
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Yanyuan Bao
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
| | - Qisheng Song
- Division of Plant Sciences, College of Agriculture, Food and Natural Resources, University of Missouri, Columbia, MO, United States
| | - Gongyin Ye
- State Key Laboratory of Rice Biology, Ministry of Agriculture and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou, China
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10
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Carballo A, Williams T, Murillo R, Caballero P. Iflavirus Covert Infection Increases Susceptibility to Nucleopolyhedrovirus Disease in Spodoptera exigua. Viruses 2020; 12:E509. [PMID: 32380682 PMCID: PMC7290388 DOI: 10.3390/v12050509] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 04/30/2020] [Accepted: 05/01/2020] [Indexed: 01/04/2023] Open
Abstract
Naturally occurring covert infections in lepidopteran populations can involve multiple viruses with potentially different transmission strategies. In this study, we characterized covert infection by two RNA viruses, Spodoptera exigua iflavirus 1 (SeIV-1) and Spodoptera exigua iflavirus 2 (SeIV-2) (family Iflaviridae) that naturally infect populations of Spodoptera exigua, and examined their influence on susceptibility to patent disease by the nucleopolyhedrovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) (family Baculoviridae). The abundance of SeIV-1 genomes increased up to ten-thousand-fold across insect developmental stages after surface contamination of host eggs with a mixture of SeIV-1 and SeIV-2 particles, whereas the abundance of SeIV-2 remained constant across all developmental stages. Low levels of SeIV-2 infection were detected in all groups of insects, including those that hatched from surface-decontaminated egg masses. SeIV-1 infection resulted in reduced larval weight gain, and an unbalanced sex ratio, whereas larval developmental time, pupal weight, and adult emergence and fecundity were not significantly affected in infected adults. The inoculation of S. exigua egg masses with iflavirus, followed by a subsequent infection with SeMNPV, resulted in an additive effect on larval mortality. The 50% lethal concentration (LC50) of SeMNPV was reduced nearly 4-fold and the mean time to death was faster by 12 h in iflavirus-treated insects. These results suggest that inapparent iflavirus infections may be able to modulate the host response to a new pathogen, a finding that has particular relevance to the use of SeMNPV as the basis for biological pest control products.
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Affiliation(s)
- Arkaitz Carballo
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, 31006 Pamplona, Spain; (A.C.); (P.C.)
- Departamento de Biotecnología, Agronomía y Alimentos, Universidad Pública de Navarra, 31006 Pamplona, Spain
| | | | - Rosa Murillo
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, 31006 Pamplona, Spain; (A.C.); (P.C.)
- Departamento de Biotecnología, Agronomía y Alimentos, Universidad Pública de Navarra, 31006 Pamplona, Spain
| | - Primitivo Caballero
- Institute for Multidisciplinary Research in Applied Biology, Universidad Pública de Navarra, 31006 Pamplona, Spain; (A.C.); (P.C.)
- Departamento de Biotecnología, Agronomía y Alimentos, Universidad Pública de Navarra, 31006 Pamplona, Spain
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11
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Parry R, Naccache F, Ndiaye EH, Fall G, Castelli I, Lühken R, Medlock J, Cull B, Hesson JC, Montarsi F, Failloux AB, Kohl A, Schnettler E, Diallo M, Asgari S, Dietrich I, Becker SC. Identification and RNAi Profile of a Novel Iflavirus Infecting Senegalese Aedes vexans arabiensis Mosquitoes. Viruses 2020; 12:E440. [PMID: 32295109 PMCID: PMC7232509 DOI: 10.3390/v12040440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/10/2020] [Accepted: 04/11/2020] [Indexed: 01/16/2023] Open
Abstract
The inland floodwater mosquito Aedes vexans (Meigen, 1830) is a competent vector of numerous arthropod-borne viruses such as Rift Valley fever virus (Phenuiviridae) and Zika virus (Flaviviridae). Aedes vexans spp. have widespread Afrotropical distribution and are common European cosmopolitan mosquitoes. We examined the virome of Ae. vexans arabiensis samples from Barkédji village, Senegal, with small RNA sequencing, bioinformatic analysis, and RT-PCR screening. We identified a novel 9494 nt iflavirus (Picornaviridae) designated here as Aedes vexans iflavirus (AvIFV). Annotation of the AvIFV genome reveals a 2782 amino acid polyprotein with iflavirus protein domain architecture and typical iflavirus 5' internal ribosomal entry site and 3' poly-A tail. Aedes vexans iflavirus is most closely related to a partial virus sequence from Venturia canescens (a parasitoid wasp) with 56.77% pairwise amino acid identity. Analysis of AvIFV-derived small RNAs suggests that AvIFV is targeted by the exogenous RNA interference pathway but not the PIWI-interacting RNA response, as ~60% of AvIFV reads corresponded to 21 nt Dicer-2 virus-derived small RNAs and the 24-29 nt AvIFV read population did not exhibit a "ping-pong" signature. The RT-PCR screens of archival and current (circa 2011-2020) Ae. vexans arabiensis laboratory samples and wild-caught mosquitoes from Barkédji suggest that AvIFV is ubiquitous in these mosquitoes. Further, we screened wild-caught European Ae. vexans samples from Germany, the United Kingdom, Italy, and Sweden, all of which tested negative for AvIFV RNA. This report provides insight into the diversity of commensal Aedes viruses and the host RNAi response towards iflaviruses.
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Affiliation(s)
- Rhys Parry
- Australian Infectious Diseases Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (R.P.); (S.A.)
| | - Fanny Naccache
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - El Hadji Ndiaye
- Pole de Zoologie Médicale, Institut Pasteur de Dakar, Dakar BP 220, Senegal; (E.H.N.); (M.D.)
| | - Gamou Fall
- Pole de Virologie, Unité des Arbovirus et Virus de Fièvres Hémorragiques, Institut Pasteur de Dakar, Dakar BP 220, Senegal;
| | - Ilaria Castelli
- Arboviruses and Insect Vectors, Department of Virology, Institut Pasteur, 75724 Paris, France; (I.C.); (A.-B.F.)
| | - Renke Lühken
- Faculty of Mathematics, Informatics and Natural Sciences, Universiät Hamburg, 20148 Hamburg, Germany; (R.L.); (E.S.)
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany
| | - Jolyon Medlock
- Health Protection Research Unit in Emerging and Zoonotic Infection, Public Health England, Porton Down, Salisbury SP4 0JG, UK;
- Medical Entomology & Zoonoses Ecology, Emergency Response Department Science & Technology, Public Health England, Porton Down, Salisbury SP4 0JG, UK; or
| | - Benjamin Cull
- Medical Entomology & Zoonoses Ecology, Emergency Response Department Science & Technology, Public Health England, Porton Down, Salisbury SP4 0JG, UK; or
| | - Jenny C. Hesson
- Department of Medical Biochemistry and Microbiology/Zoonosis Science Center, Uppsala University, 75237 Uppsala, Sweden;
| | - Fabrizio Montarsi
- Laboratory of Parasitology, Istituto Zooprofilattico Sperimentale delle Venezie, 35020 Legnaro (Padua), Italy;
| | - Anna-Bella Failloux
- Arboviruses and Insect Vectors, Department of Virology, Institut Pasteur, 75724 Paris, France; (I.C.); (A.-B.F.)
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK;
| | - Esther Schnettler
- Faculty of Mathematics, Informatics and Natural Sciences, Universiät Hamburg, 20148 Hamburg, Germany; (R.L.); (E.S.)
- Bernhard-Nocht-Institute for Tropical Medicine, 20359 Hamburg, Germany
- German Centre for Infection Research, partner site Hamburg-Lübeck-Borstel-Riems, 20359 Hamburg, Germany
| | - Mawlouth Diallo
- Pole de Zoologie Médicale, Institut Pasteur de Dakar, Dakar BP 220, Senegal; (E.H.N.); (M.D.)
| | - Sassan Asgari
- Australian Infectious Diseases Research Centre, School of Biological Sciences, The University of Queensland, Brisbane, QLD 4072, Australia; (R.P.); (S.A.)
| | | | - Stefanie C. Becker
- Institute for Parasitology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
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12
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Yang X, Xu P, Yuan H, Graham RI, Wilson K, Wu K. Discovery and characterization of a novel picorna-like RNA virus in the cotton bollworm Helicoverpa armigera. J Invertebr Pathol 2019; 160:1-7. [DOI: 10.1016/j.jip.2018.11.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 11/02/2018] [Accepted: 11/14/2018] [Indexed: 11/26/2022]
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13
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Maciel-Vergara G, Jensen AB, Eilenberg J. Cannibalism as a Possible Entry Route for Opportunistic Pathogenic Bacteria to Insect Hosts, Exemplified by Pseudomonas aeruginosa, a Pathogen of the Giant Mealworm Zophobas morio. INSECTS 2018; 9:insects9030088. [PMID: 30042293 PMCID: PMC6163536 DOI: 10.3390/insects9030088] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/10/2018] [Accepted: 07/14/2018] [Indexed: 01/01/2023]
Abstract
Opportunistic bacteria are often ubiquitous and do not trigger disease in insects unless the conditions are specifically favorable for bacterial development in a suitable host. In this paper, we isolated and identified a bacterium, Pseudomonas aeruginosa, from the larvae of the giant mealworm Zophobas morio and we studied the possible entry routes by challenging larvae with per os injection and subdermal injection. We also evaluated the effect of exposing groups of larvae to P. aeruginosa inoculated in their feed and the effect of exposing wounded larvae to P. aeruginosa. We concluded that the mortality rate of Z. morio larvae is higher when P. aeruginosa gets in direct contact with the hemolymph via intracoelomic injection compared to a situation where the bacterium is force-fed. Larvae with an open wound exposed to P. aeruginosa presented higher mortality rate compared to larvae with a wound that was not exposed to the bacterium. We documented too, that cannibalism and scavenging were more prevalent among larvae in a group, when P. aeruginosa is present compared to when it is absent. We discuss hereby different aspects related with the pathogen’s entry routes to insects the complexity of pathogen´s transmission in high population densities and different ways to prevent and/or control P. aeruginosa in mass rearing systems.
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Affiliation(s)
- Gabriela Maciel-Vergara
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 3rd floor, 1871 Frederiksberg C, Denmark.
- Laboratory of Entomology, Wageningen University, Radix Building 107, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
- Laboratory of Virology, Wageningen University, Radix Building 107, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
| | - Annette Bruun Jensen
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 3rd floor, 1871 Frederiksberg C, Denmark.
| | - Jørgen Eilenberg
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 3rd floor, 1871 Frederiksberg C, Denmark.
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14
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Carballo A, Murillo R, Jakubowska A, Herrero S, Williams T, Caballero P. Co-infection with iflaviruses influences the insecticidal properties of Spodoptera exigua multiple nucleopolyhedrovirus occlusion bodies: Implications for the production and biosecurity of baculovirus insecticides. PLoS One 2017; 12:e0177301. [PMID: 28475633 PMCID: PMC5419652 DOI: 10.1371/journal.pone.0177301] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 04/25/2017] [Indexed: 11/18/2022] Open
Abstract
Biological insecticides based on Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) can efficiently control S. exigua larvae on field and greenhouse crops in many parts of the world. Spanish wild populations and laboratory colonies of S. exigua are infected by two iflaviruses (SeIV-1 and SeIV-2). Here we evaluated the effect of iflavirus co-infection on the insecticidal characteristics of SeMNPV occlusion bodies (OBs). Overall, iflavirus co-inoculation consistently reduced median lethal concentrations (LC50) for SeMNPV OBs compared to larvae infected with SeMNPV alone. However, the speed of kill of SeMNPV was similar in the presence or absence of the iflaviruses. A reduction of the weight gain (27%) associated with iflavirus infection resulted in a 30% reduction in total OB production per larva. Adult survivors of SeMNPV OB inoculation were examined for covert infection. SeMNPV DNA was found to be present at a high prevalence in all SeIV-1 and SeIV-2 co-infection treatments. Interestingly, co-inoculation of SeMNPV with SeIV-2 alone or in mixtures with SeIV-1 resulted in a significant increase in the SeMNPV load of sublethally infected adults, suggesting a role for SeIV-2 in vertical transmission or reactivation of sublethal SeMNPV infections. In conclusion, iflaviruses are not desirable in insect colonies used for large scale baculovirus production, as they may result in diminished larval growth, reduced OB production and, depending on their host-range, potential risks to non-target Lepidoptera.
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Affiliation(s)
- Arkaitz Carballo
- Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Navarra, Spain
- Departamento de Producción Agraria, Universidad Pública de Navarra, Navarra, Spain
| | - Rosa Murillo
- Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Navarra, Spain
- Departamento de Producción Agraria, Universidad Pública de Navarra, Navarra, Spain
| | - Agata Jakubowska
- Departamento de Genética, Universitat de Valencia, Valencia, Spain
| | - Salvador Herrero
- Departamento de Genética, Universitat de Valencia, Valencia, Spain
| | | | - Primitivo Caballero
- Instituto de Agrobiotecnología, CSIC-Gobierno de Navarra, Navarra, Spain
- Departamento de Producción Agraria, Universidad Pública de Navarra, Navarra, Spain
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15
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Yang X, Xu P, Graham RI, Yuan H, Wu K. Protocols for Investigating the Host-tissue Distribution, Transmission-mode, and Effect on the Host Fitness of a Densovirus in the Cotton Bollworm. J Vis Exp 2017:55534. [PMID: 28448051 PMCID: PMC5564690 DOI: 10.3791/55534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Many novel viruses have been discovered in animal hosts using next-generation sequencing technologies. Previously, we reported a mutualistic virus, Helicoverpa armigera densovirus (HaDV2), in a lepidopteran species, the cotton bollworm, Helicoverpa armigera (Hubner). Here, we describe the protocols that are currently used to study the effect of HaDV2 on its host. First, we establish a HaDV2-free cotton bollworm colony from a single breeding pair. Then, we orally inoculate some neonate larval offspring with HaDV2-containing filtered liquid to produce two colonies with the same genetic background: one HaDV2-infected, the other uninfected. A protocol to compare life table parameters (e.g., larval, pupal, and adult periods and fecundity) between the HaDV2-infected and -uninfected individuals is also presented, as are the protocols for determining the host-tissue distribution and transmission efficiency of HaDV2. These protocols would also be suitable for investigating the effects of other orally transmitted viruses on their insect hosts, lepidopteran hosts in particular.
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Affiliation(s)
- Xianming Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences
| | - Pengjun Xu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences
| | | | - He Yuan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences;
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16
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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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17
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Llopis-Giménez A, Maria González R, Millán-Leiva A, Catalá M, Llacer E, Urbaneja A, Herrero S. Novel RNA viruses producing simultaneous covert infections in Ceratitis capitata. Correlations between viral titers and host fitness, and implications for SIT programs. J Invertebr Pathol 2016; 143:50-60. [PMID: 27914927 DOI: 10.1016/j.jip.2016.11.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 11/28/2016] [Accepted: 11/29/2016] [Indexed: 12/25/2022]
Abstract
The Mediterranean fruit fly (medfly), Ceratitis capitata is a highly polyphagous pest, which infests multiple species of fruits and vegetables worldwide. In addition to the traditional control with chemical insecticides, sterile insect technique (SIT) has been implemented in integrated programs worldwide, and has become an essential measure for the control of this pest. A key issue for SIT is to release sterile males that are sufficiently competitive with males from the wild population. Using sequence information available in public databases, three novel picornaviruses infecting medflies were discovered and named as C. capitata iflavirus 1 and 2 (CcaIV1 and CcaIV2), and C. capitata noravirus (CcaNV). Additional analyses have revealed the presence of CcaIV2 and CcaNV covertly infecting most of the medfly strains used in the different SIT programs around the world, as well as in field captures in the east of Spain. High viral titers of CcaNV were associated with a reduction in the lifespan of males released to the field for the control of this pest, suggesting the possibility that CcaNV may impair the fitness of sterile flies produced by SIT programs.
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Affiliation(s)
- Angel Llopis-Giménez
- Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain; Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI-BIOTECMED), Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain
| | - Rosa Maria González
- Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain; Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI-BIOTECMED), Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain
| | - Anabel Millán-Leiva
- Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain; Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI-BIOTECMED), Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain
| | - Marta Catalá
- Instituto Valenciano de Investigaciones Agrarias, Unidad Asociada de Entomología IVIA-UJI, Centro de Protección Vegetal y Biotecnología, 46113 Moncada, Spain
| | - Elena Llacer
- Instituto Valenciano de Investigaciones Agrarias, Unidad Asociada de Entomología IVIA-UJI, Centro de Protección Vegetal y Biotecnología, 46113 Moncada, Spain
| | - Alberto Urbaneja
- Instituto Valenciano de Investigaciones Agrarias, Unidad Asociada de Entomología IVIA-UJI, Centro de Protección Vegetal y Biotecnología, 46113 Moncada, Spain
| | - Salvador Herrero
- Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain; Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI-BIOTECMED), Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain.
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18
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Abbà S, Galetto L, Vallino M, Rossi M, Turina M, Sicard A, Marzachì C. Genome sequence, prevalence and quantification of the first iflavirus identified in a phytoplasma insect vector. Arch Virol 2016; 162:799-809. [PMID: 27888410 DOI: 10.1007/s00705-016-3158-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 10/18/2016] [Indexed: 01/29/2023]
Abstract
The leafhopper Euscelidius variegatus is a natural vector of chrysanthemum yellows phytoplasma (CY) and an efficient vector of flavescence dorée phytoplasma (FD) under laboratory conditions. During a transcriptome sequencing (RNA-seq) project aimed at investigating the interactions between the insect and the two phytoplasmas, a 10,616-nucleotide-long contig with high sequence similarity to known picorna-like viruses was identified among the assembled insect transcripts. The discovery came totally unexpected, because insects from the laboratory colony did not show any evident symptom that could be related to the presence of a virus. The amino acid sequence, the shape and size of viral particles, and the results of phylogenetic analysis suggest that this virus, named Euscelidius variegatus virus 1 (EVV-1), can be considered a new member of a new species in the genus Iflavirus. EVV-1 was detected in all of the tested insects from the laboratory colony used for RNA-seq, both in phytoplasma-exposed and in non-exposed insects, but the viral load measured in FD-exposed samples was significantly lower than that in non-exposed insects. This result suggests the possible existence of an intriguing cross-talk among insects, endogenous bacteria, and viruses. The identification of two other E. variegatus laboratory colonies that were free of EVV-1 could represent the key to addressing some basic virological issues, e.g., viral replication and transmission mechanisms, and offer the opportunity to use infectious clones to express heterologous genes in the leafhopper and manipulate the expression of endogenous genes by promoting virus-induced gene silencing.
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Affiliation(s)
- Simona Abbà
- Institute for Sustainable Plant Protection, National Research Council of Italy, IPSP-CNR, Strada delle Cacce 73, 10135, Turin, Italy.
| | - Luciana Galetto
- Institute for Sustainable Plant Protection, National Research Council of Italy, IPSP-CNR, Strada delle Cacce 73, 10135, Turin, Italy
| | - Marta Vallino
- Institute for Sustainable Plant Protection, National Research Council of Italy, IPSP-CNR, Strada delle Cacce 73, 10135, Turin, Italy
| | - Marika Rossi
- Institute for Sustainable Plant Protection, National Research Council of Italy, IPSP-CNR, Strada delle Cacce 73, 10135, Turin, Italy
| | - Massimo Turina
- Institute for Sustainable Plant Protection, National Research Council of Italy, IPSP-CNR, Strada delle Cacce 73, 10135, Turin, Italy
| | - Anne Sicard
- Department of Environmental Science, Policy and Management, University of California, 130 Mulford Hall, Berkeley, CA, 94720, USA
| | - Cristina Marzachì
- Institute for Sustainable Plant Protection, National Research Council of Italy, IPSP-CNR, Strada delle Cacce 73, 10135, Turin, Italy
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19
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Yang YT, Nai YS, Lee SJ, Lee MR, Kim S, Kim JS. A novel picorna-like virus, Riptortus pedestris virus-1 (RiPV-1), found in the bean bug, R. pedestris, after fungal infection. J Invertebr Pathol 2016; 141:57-65. [PMID: 27840139 DOI: 10.1016/j.jip.2016.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 11/07/2016] [Accepted: 11/09/2016] [Indexed: 10/20/2022]
Abstract
A viral genome was assembled de novo from next-generation sequencing (NGS) data from bean bugs, Riptortus pedestris, infected with an entomopathogenic fungus, Beauveria bassiana (Bb), and was further confirmed via the RACE method. This is a novel insect positive-sense single-stranded RNA virus, which we named Riptortus pedestris virus-1 (RiPV-1) (GenBank accession no. KU958718). The genome of RiPV-1 consists of 10,554 nucleotides (nt), excluding the poly(A) tail, which contains a single large open reading frame (ORF) of 10,371 nt encoding a polyprotein (3456 aa) and flanked by 71 and 112 nt at the 5' and 3' untranslated regions (UTR), respectively. RiPV-1 genome organization from the 5' end contains a consensus organization of picorna-like RNA virus helicase, cysteine protease, and RNA-dependent RNA polymerase (RdRp), in addition to two putative structural proteins located at the 3' region and a poly(A) tail at the 3' end. The viral particles were approximately 30nm in diameter with some dispersal distinctive surface projections. Based on the phylogenetic analysis of the RdRp sequences, RiPV-1 was clustered in the unassigned insect RNA viruses with two other viruses, APV and KFV. These three viruses were suggested to constitute a new group of insect RNA viruses. RiPV-1 could be found in all stages of lab-reared bean bugs and was detected abundantly in the thorax, abdomen, midgut and fat body, but not in the reproductive organs and muscle. Interestingly, RiPV-1 replication was increased dramatically in bean bugs 2-6days after fungal infection. In conclusion, a novel insect RNA virus was found by NGS data assembly. This virus can provide further insight into the interaction between virus, fungus and the host.
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Affiliation(s)
- Yi-Ting Yang
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, Republic of Korea
| | - Yu-Shin Nai
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, Republic of Korea; Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan
| | - Se Jin Lee
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, Republic of Korea
| | - Mi Rong Lee
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, Republic of Korea
| | - Sihyeon Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, Republic of Korea
| | - Jae Su Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, Republic of Korea.
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20
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Sadanandan SA, Ekström JO, Jonna VR, Hofer A, Hultmark D. VP3 is crucial for the stability of Nora virus virions. Virus Res 2016; 223:20-7. [PMID: 27329665 DOI: 10.1016/j.virusres.2016.06.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/15/2016] [Accepted: 06/17/2016] [Indexed: 10/21/2022]
Abstract
Nora virus is an enteric virus that causes persistent, non-pathological infection in Drosophila melanogaster. It replicates in the fly gut and is transmitted via the fecal-oral route. Nora virus has a single-stranded positive-sense RNA genome, which is translated in four open reading frames. Reading frame three encodes the VP3 protein, the structure and function of which we have investigated in this work. We have shown that VP3 is a trimer that has an α-helical secondary structure, with a functionally important coiled-coil domain. In order to identify the role of VP3 in the Nora virus life cycle, we constructed VP3-mutants using the cDNA clone of the virus. Our results show that VP3 does not have a role in the actual assembly of the virus particles, but virions that lack VP3 or harbor VP3 with a disrupted coiled coil domain are incapable of transmission via the fecal-oral route. Removing the region downstream of the putative coiled coil appears to have an effect on the fitness of the virus but does not hamper its replication or transmission. We also found that the VP3 protein and particularly the coiled coil domain are crucial for the stability of Nora virus virions when exposed to heat or proteases. Hence, we propose that VP3 is imperative to Nora virus virions as it confers stability to the viral capsid.
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Affiliation(s)
| | - Jens-Ola Ekström
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden; Institute of Biomedical Technology, University of Tampere, FI-33520 Tampere, Finland
| | - Venkateswara Rao Jonna
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden
| | - Dan Hultmark
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden; Institute of Biomedical Technology, University of Tampere, FI-33520 Tampere, Finland.
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21
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Jakubowska AK, Murillo R, Carballo A, Williams T, van Lent JWM, Caballero P, Herrero S. Iflavirus increases its infectivity and physical stability in association with baculovirus. PeerJ 2016; 4:e1687. [PMID: 26966651 PMCID: PMC4782719 DOI: 10.7717/peerj.1687] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 01/22/2016] [Indexed: 11/20/2022] Open
Abstract
Virus transmission and the prevalence of infection depend on multiple factors, including the interaction with other viral pathogens infecting the same host. In this study, active replication of an iflavirus, Spodoptera exigua iflavirus 1 (order Picornavirales) was observed in the offspring of insects that survived following inoculation with a pathogenic baculovirus, Spodoptera exigua multiple nucleopolyhedrovirus. Tracking the origin of the iflavirus suggested the association of this virus with the occlusion bodies of the baculovirus. Here we investigated the effect of this association on the stability and infectivity of both viruses. A reduction in baculovirus pathogenicity, without affecting its infectivity and productivity, was observed when associated with the iflavirus. In contrast, viral association increased the infectivity of the iflavirus and its resistance to ultraviolet radiation and high temperature, two of the main factors affecting virus stability in the field. In addition, electron microscopy analysis revealed the presence of particles resembling iflavirus virions inside the occlusion bodies of the baculovirus, suggesting the possible co-occlusion of both viruses. Results reported here are indicative of facultative phoresis of a virus and suggest that virus–virus interactions may be more common than currently recognized, and may be influential in the ecology of baculovirus and host populations and in consequence in the use of baculoviruses as biological insecticides.
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Affiliation(s)
- Agata K Jakubowska
- Department of Genetics, Universitat de València, Burjassot, Valencia, Spain; Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI-BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
| | - Rosa Murillo
- Instituto de Agrobiotecnología, Universidad Pública de Navarra, Pamplona, Spain; Departamento de Producción Agraria, Universidad Pública de Navarra, Pamplona, Navarra, Spain
| | - Arkaitz Carballo
- Instituto de Agrobiotecnología, Universidad Pública de Navarra, Pamplona, Spain; Departamento de Producción Agraria, Universidad Pública de Navarra, Pamplona, Navarra, Spain
| | | | - Jan W M van Lent
- Laboratory of Virology, Dept. of Plant Sciences, Wageningen Agricultural University , Wageningen , Netherlands
| | - Primitivo Caballero
- Instituto de Agrobiotecnología, Universidad Pública de Navarra, Pamplona, Spain; Departamento de Producción Agraria, Universidad Pública de Navarra, Pamplona, Navarra, Spain
| | - Salvador Herrero
- Department of Genetics, Universitat de València, Burjassot, Valencia, Spain; Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI-BIOTECMED), Universitat de València, Burjassot, Valencia, Spain
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22
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Graham RI, Tummala Y, Rhodes G, Cory JS, Shirras A, Grzywacz D, Wilson K. Development of a Real-Time qPCR Assay for Quantification of Covert Baculovirus Infections in a Major African Crop Pest. INSECTS 2015; 6:746-59. [PMID: 26463414 PMCID: PMC4598664 DOI: 10.3390/insects6030746] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 08/14/2015] [Accepted: 08/19/2015] [Indexed: 12/24/2022]
Abstract
Many pathogens and parasites are present in host individuals and populations without any obvious signs of disease. This is particularly true for baculoviruses infecting lepidopteran hosts, where studies have shown that covert persistent viral infections are almost ubiquitous in many species. To date, the infection intensity of covert viruses has rarely been quantified. In this study, we investigated the dynamics of a covert baculovirus infection within the lepidopteran crop pest Spodoptera exempta. A real-time quantitative polymerase chain reaction (qPCR) procedure using a 5' nuclease hydrolysis (TaqMan) probe was developed for specific detection and quantification of Spodoptera exempta nucleopolyhedrovirus (SpexNPV). The qPCR assay indicated that covert baculovirus dynamics varied considerably over the course of the host life-cycle, with infection load peaking in early larval instars and being lowest in adults and final-instar larvae. Adult dissections indicated that, contrary to expectation, viral load aggregation was highest in the head, wings and legs, and lowest in the thorax and abdomen. The data presented here have broad implications relating to our understanding of transmission patterns of baculoviruses and the role of covert infections in host-pathogen dynamics.
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Affiliation(s)
- Robert I Graham
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
| | - Yamini Tummala
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
| | - Glenn Rhodes
- Lake Ecosystems Group, Centre for Ecology and Hydrology, Bailrigg, Lancaster LA1 4AP, UK.
| | - Jenny S Cory
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.
| | - Alan Shirras
- Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK.
| | - David Grzywacz
- Natural Resources Institute, University of Greenwich, Chatham Maritime, Kent ME4 4TB, UK.
| | - Kenneth Wilson
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
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23
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Carrillo-Tripp J, Bonning BC, Miller WA. Challenges associated with research on RNA viruses of insects. CURRENT OPINION IN INSECT SCIENCE 2015; 8:62-68. [PMID: 32846681 DOI: 10.1016/j.cois.2014.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 11/14/2014] [Indexed: 06/11/2023]
Abstract
Dicistroviridae and Iflaviridae (part of the group formerly identified as picorna-like viruses) are rapidly growing families within the order Picornavirales. Work on these emerging groups of arthropod viruses offers a unique and exciting opportunity for virologist, but this task comes with particular challenges. The lack of cell culture systems and infectious clones has imposed limitations on the advancement of study of these viruses. Here we discuss the goals and challenges regarding the establishment of controlled systems as well as some issues associated with insect RNA virology at the organismal level. These concerns apply to RNA viruses affecting other organisms for which basic research tools are limited. A list of pitfalls associated with RNA virus research along with recommendations is provided.
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Affiliation(s)
- Jimena Carrillo-Tripp
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011, United States.
| | - Bryony C Bonning
- Department of Entomology, Iowa State University, Ames, IA 50011, United States
| | - W Allen Miller
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA 50011, United States
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24
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Cory JS. Insect virus transmission: different routes to persistence. CURRENT OPINION IN INSECT SCIENCE 2015; 8:130-135. [PMID: 32846660 DOI: 10.1016/j.cois.2015.01.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 01/15/2015] [Accepted: 01/15/2015] [Indexed: 05/05/2023]
Abstract
Transmission is a fundamental process in disease ecology; however, the factors that modulate transmission and the dynamical and evolutionary consequences of these factors in host populations are difficult to study in natural settings. Much of our current knowledge comes from a limited number of virus groups and few ecological studies. Alternatively, progress has been made in the detection of new viruses and in probing the molecular basis of behavioural manipulation of hosts that might influence virus transmission. An expanding theoretical framework provides guidelines on the conditions under which particular transmission strategies might evolve, and their dynamical consequences, but empirical tests are lacking.
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Affiliation(s)
- Jenny S Cory
- Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6.
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25
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In search of pathogens: transcriptome-based identification of viral sequences from the pine processionary moth (Thaumetopoea pityocampa). Viruses 2015; 7:456-79. [PMID: 25626148 PMCID: PMC4353898 DOI: 10.3390/v7020456] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 12/29/2014] [Accepted: 01/13/2015] [Indexed: 01/06/2023] Open
Abstract
Thaumetopoea pityocampa (pine processionary moth) is one of the most important pine pests in the forests of Mediterranean countries, Central Europe, the Middle East and North Africa. Apart from causing significant damage to pinewoods, T. pityocampa occurrence is also an issue for public and animal health, as it is responsible for dermatological reactions in humans and animals by contact with its irritating hairs. High throughput sequencing technologies have allowed the fast and cost-effective generation of genetic information of interest to understand different biological aspects of non-model organisms as well as the identification of potential pathogens. Using these technologies, we have obtained and characterized the transcriptome of T. pityocampa larvae collected in 12 different geographical locations in Turkey. cDNA libraries for Illumina sequencing were prepared from four larval tissues, head, gut, fat body and integument. By pooling the sequences from Illumina platform with those previously published using the Roche 454-FLX and Sanger methods we generated the largest reference transcriptome of T. pityocampa. In addition, this study has also allowed identification of possible viral pathogens with potential application in future biocontrol strategies.
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26
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Virto C, Navarro D, Tellez MM, Herrero S, Williams T, Murillo R, Caballero P. Natural populations of Spodoptera exigua are infected by multiple viruses that are transmitted to their offspring. J Invertebr Pathol 2014; 122:22-7. [DOI: 10.1016/j.jip.2014.07.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/28/2014] [Accepted: 07/29/2014] [Indexed: 02/06/2023]
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