51
|
Pusceddu M, Floris I, Mura A, Theodorou P, Cirotto G, Piluzza G, Bullitta S, Angioni A, Satta A. The effects of raw propolis on Varroa-infested honey bee (Apis mellifera) workers. Parasitol Res 2018; 117:3527-3535. [DOI: 10.1007/s00436-018-6050-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 08/08/2018] [Indexed: 10/28/2022]
|
52
|
McMenamin AJ, Daughenbaugh KF, Parekh F, Pizzorno MC, Flenniken ML. Honey Bee and Bumble Bee Antiviral Defense. Viruses 2018; 10:E395. [PMID: 30060518 PMCID: PMC6115922 DOI: 10.3390/v10080395] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 12/12/2022] Open
Abstract
Bees are important plant pollinators in both natural and agricultural ecosystems. Managed and wild bees have experienced high average annual colony losses, population declines, and local extinctions in many geographic regions. Multiple factors, including virus infections, impact bee health and longevity. The majority of bee-infecting viruses are positive-sense single-stranded RNA viruses. Bee-infecting viruses often cause asymptomatic infections but may also cause paralysis, deformity or death. The severity of infection is governed by bee host immune responses and influenced by additional biotic and abiotic factors. Herein, we highlight studies that have contributed to the current understanding of antiviral defense in bees, including the Western honey bee (Apis mellifera), the Eastern honey bee (Apis cerana) and bumble bee species (Bombus spp.). Bee antiviral defense mechanisms include RNA interference (RNAi), endocytosis, melanization, encapsulation, autophagy and conserved immune pathways including Jak/STAT (Janus kinase/signal transducer and activator of transcription), JNK (c-Jun N-terminal kinase), MAPK (mitogen-activated protein kinases) and the NF-κB mediated Toll and Imd (immune deficiency) pathways. Studies in Dipteran insects, including the model organism Drosophila melanogaster and pathogen-transmitting mosquitos, provide the framework for understanding bee antiviral defense. However, there are notable differences such as the more prominent role of a non-sequence specific, dsRNA-triggered, virus limiting response in honey bees and bumble bees. This virus-limiting response in bees is akin to pathways in a range of organisms including other invertebrates (i.e., oysters, shrimp and sand flies), as well as the mammalian interferon response. Current and future research aimed at elucidating bee antiviral defense mechanisms may lead to development of strategies that mitigate bee losses, while expanding our understanding of insect antiviral defense and the potential evolutionary relationship between sociality and immune function.
Collapse
Affiliation(s)
- Alexander J McMenamin
- Department of Plant Sciences and Plant Pathology, Bozeman, MT 59717, USA.
- Department of Microbiology and Immunology, Bozeman, MT 59717, USA.
- Center for Pollinator Health, Montana State University, Bozeman, MT 59717, USA.
| | - Katie F Daughenbaugh
- Department of Plant Sciences and Plant Pathology, Bozeman, MT 59717, USA.
- Center for Pollinator Health, Montana State University, Bozeman, MT 59717, USA.
| | - Fenali Parekh
- Department of Plant Sciences and Plant Pathology, Bozeman, MT 59717, USA.
- Department of Microbiology and Immunology, Bozeman, MT 59717, USA.
- Center for Pollinator Health, Montana State University, Bozeman, MT 59717, USA.
| | - Marie C Pizzorno
- Biology Department, Bucknell University, Lewisburg, PA 17837, USA.
| | - Michelle L Flenniken
- Department of Plant Sciences and Plant Pathology, Bozeman, MT 59717, USA.
- Department of Microbiology and Immunology, Bozeman, MT 59717, USA.
- Center for Pollinator Health, Montana State University, Bozeman, MT 59717, USA.
| |
Collapse
|
53
|
Galbraith DA, Fuller ZL, Ray AM, Brockmann A, Frazier M, Gikungu MW, Martinez JFI, Kapheim KM, Kerby JT, Kocher SD, Losyev O, Muli E, Patch HM, Rosa C, Sakamoto JM, Stanley S, Vaudo AD, Grozinger CM. Investigating the viral ecology of global bee communities with high-throughput metagenomics. Sci Rep 2018; 8:8879. [PMID: 29891995 PMCID: PMC5995813 DOI: 10.1038/s41598-018-27164-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 05/29/2018] [Indexed: 01/25/2023] Open
Abstract
Bee viral ecology is a fascinating emerging area of research: viruses exert a range of effects on their hosts, exacerbate impacts of other environmental stressors, and, importantly, are readily shared across multiple bee species in a community. However, our understanding of bee viral communities is limited, as it is primarily derived from studies of North American and European Apis mellifera populations. Here, we examined viruses in populations of A. mellifera and 11 other bee species from 9 countries, across 4 continents and Oceania. We developed a novel pipeline to rapidly and inexpensively screen for bee viruses. This pipeline includes purification of encapsulated RNA/DNA viruses, sequence-independent amplification, high throughput sequencing, integrated assembly of contigs, and filtering to identify contigs specifically corresponding to viral sequences. We identified sequences for (+)ssRNA, (−)ssRNA, dsRNA, and ssDNA viruses. Overall, we found 127 contigs corresponding to novel viruses (i.e. previously not observed in bees), with 27 represented by >0.1% of the reads in a given sample, and 7 contained an RdRp or replicase sequence which could be used for robust phylogenetic analysis. This study provides a sequence-independent pipeline for viral metagenomics analysis, and greatly expands our understanding of the diversity of viruses found in bee communities.
Collapse
Affiliation(s)
- David A Galbraith
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA.
| | - Zachary L Fuller
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA.,Department of Biology, Pennsylvania State University, University Park, PA, USA.,Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Allyson M Ray
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA
| | - Axel Brockmann
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, India
| | - Maryann Frazier
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA
| | - Mary W Gikungu
- Department of Zoology, National Museums of Kenya, Nairobi, Kenya
| | | | - Karen M Kapheim
- Department of Biology, Utah State University, Logan, UT, USA.,Smithsonian Tropical Research Institute, Panama City, Panama
| | - Jeffrey T Kerby
- Neukom Institute for Computational Science, Dartmouth College, Hanover, NH, USA
| | - Sarah D Kocher
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Oleksiy Losyev
- Department of Beekeeping, The National University of Life and Environmental Sciences of Ukraine, Kyiv, Ukraine
| | - Elliud Muli
- The International Center of Insect Physiology and Ecology, Nairobi, Kenya
| | - Harland M Patch
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA
| | - Cristina Rosa
- Department of Plant Pathology, Pennsylvania State University, University Park, PA, USA
| | - Joyce M Sakamoto
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA
| | - Scott Stanley
- Division of Pediatric Hematology and Oncology, Pennsylvania State University Children's Hospital, Hershey, PA, USA
| | - Anthony D Vaudo
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA
| | - Christina M Grozinger
- Department of Entomology, Center for Pollinator Research, Huck Institutes of the Life Sciences Pennsylvania State University, University Park, PA, USA
| |
Collapse
|
54
|
McMenamin AJ, Flenniken ML. Recently identified bee viruses and their impact on bee pollinators. CURRENT OPINION IN INSECT SCIENCE 2018; 26:120-129. [PMID: 29764651 DOI: 10.1016/j.cois.2018.02.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 12/22/2017] [Accepted: 02/02/2018] [Indexed: 06/08/2023]
Abstract
Bees are agriculturally and ecologically important plant pollinators. Recent high annual losses of honey bee colonies, and reduced populations of native and wild bees in some geographic locations, may impact the availability of affordable food crops and the diversity and abundance of native and wild plant species. Multiple factors including viral infections affect pollinator health. The majority of well-characterized bee viruses are picorna-like RNA viruses, which may be maintained as covert infections or cause symptomatic infections or death. Next generation sequencing technologies have been utilized to identify additional bee-infecting viruses including the Lake Sinai viruses and Rhabdoviruses. In addition, sequence data is instrumental for defining specific viral strains and characterizing associated pathogenicity, such as the recent characterization of Deformed wing virus master variants (DWV-A, DWV-B, and DWV-C) and their impact on bee health.
Collapse
Affiliation(s)
- Alexander J McMenamin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA; Pollinator Health Center, Montana State University, Bozeman, MT, USA; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Michelle L Flenniken
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA; Pollinator Health Center, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
55
|
Amiri E, Kryger P, Meixner MD, Strand MK, Tarpy DR, Rueppell O. Quantitative patterns of vertical transmission of deformed wing virus in honey bees. PLoS One 2018; 13:e0195283. [PMID: 29596509 PMCID: PMC5875871 DOI: 10.1371/journal.pone.0195283] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/19/2018] [Indexed: 12/24/2022] Open
Abstract
Deformed wing virus (DWV) is an important pathogen in a broad range of insects, including honey bees. Concordant with the spread of Varroa, DWV is present in the majority of honey bee colonies and can result in either low-level infections with asymptomatic bees that nonetheless exhibit increased colony loss under stress, or high-level infections with acute effects on bee health and viability. DWV can be transmitted vertically or horizontally and evidence suggests that horizontal transmission via Varroa is associated with acute symptomatic infections. Vertical transmission also occurs and is presumably important for the maintenance of DWV in honey bee populations. To further our understanding the vertical transmission of DWV through queens, we performed three experiments: we studied the quantitative effectiveness of vertical transmission, surveyed the prevalence of successful egg infection under commercial conditions, and distinguished among three possible mechanisms of transmission. We find that queen-infection level predicts the DWV titers in their eggs, although the transmission is not very efficient. Our quantitative assessment of DWV demonstrates that eggs in 1/3 of the colonies are infected with DWV and highly infected eggs are rare in newly-installed spring colonies. Additionally, our results indicate that DWV transmission occurs predominantly by virus adhering to the surface of eggs (transovum) rather than intracellularly. Our combined results suggest that the queens' DWV vectoring capacity in practice is not as high as its theoretical potential. Thus, DWV transmission by honey bee queens is part of the DWV epidemic with relevant practical implications, which should be further studied.
Collapse
Affiliation(s)
- Esmaeil Amiri
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, United States of America
- Department of Agroecology, Aarhus University, Slagelse, Denmark
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, United States of America
| | - Per Kryger
- Department of Agroecology, Aarhus University, Slagelse, Denmark
| | - Marina D. Meixner
- Bieneninstitut Kirchhain, Landesbetrieb Landwirtschaft Hessen, Kirchhain, Germany
| | - Micheline K. Strand
- Life Sciences Division, U.S. Army Research Office, Research Triangle Park, NC, United States of America
| | - David R. Tarpy
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC, United States of America
| | - Olav Rueppell
- Department of Biology, University of North Carolina at Greensboro, Greensboro, NC, United States of America
| |
Collapse
|
56
|
Evidence of Varroa-mediated deformed wing virus spillover in Hawaii. J Invertebr Pathol 2018; 151:126-130. [DOI: 10.1016/j.jip.2017.11.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/04/2017] [Accepted: 11/15/2017] [Indexed: 11/19/2022]
|
57
|
A real-time PCR method for quantification of the total and major variant strains of the deformed wing virus. PLoS One 2017; 12:e0190017. [PMID: 29261772 PMCID: PMC5736226 DOI: 10.1371/journal.pone.0190017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 12/06/2017] [Indexed: 11/19/2022] Open
Abstract
European honey bees (Apis mellifera) are critically important to global food production by virtue of their pollination services but are severely threatened by deformed wing virus (DWV) especially in the presence of the external parasite Varroa destructor. DWV exists as many viral strains with the two major variants (DWV-A and DWV-B) varying in virulence. A single plasmid standard was constructed containing three sections for the specific determination of DWV-A (VP2 capsid region), DWV-B (IRES) and a conserved region suitable for total DWV (helicase region). The assays were confirmed as specific and discriminatory with limits of detections of 25, 25 and 50 genome equivalents for DWV-A, DWV-B and total-DWV, respectively. The methods were successfully tested on Apis mellifera and V. destructor samples with varying DWV profiles. The new method determined a more accurate total DWV titre in samples with substantial DWV-B than the method currently described in the COLOSS Beebook. The proposed assays could be utilized for the screening of large quantities of bee material for both a total DWV load overview along with more detailed investigations into DWV-A and DWV-B profiles.
Collapse
|
58
|
Bigot D, Dalmon A, Roy B, Hou C, Germain M, Romary M, Deng S, Diao Q, Weinert LA, Cook JM, Herniou EA, Gayral P. The discovery of Halictivirus resolves the Sinaivirus phylogeny. J Gen Virol 2017; 98:2864-2875. [DOI: 10.1099/jgv.0.000957] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Diane Bigot
- Institut de Recherche sur la Biologie de l’Insecte, UMR 7261, CNRS, Université de Tours, 37200 Tours, France
| | - Anne Dalmon
- INRA UR 406 Abeilles et environnement, Centre de recherche Provence-Alpes-Côte d'Azur, Site Agroparc, Domaine St Paul 228, Route de l'aérodrome CS40509 84914 Avignon, France
| | - Bronwen Roy
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
| | - Chunsheng Hou
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, PR China
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Beijing 100093, PR China
| | - Michèle Germain
- Institut de Recherche sur la Biologie de l’Insecte, UMR 7261, CNRS, Université de Tours, 37200 Tours, France
| | - Manon Romary
- Institut de Recherche sur la Biologie de l’Insecte, UMR 7261, CNRS, Université de Tours, 37200 Tours, France
| | - Shuai Deng
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, PR China
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Beijing 100093, PR China
| | - Qingyun Diao
- Institute of Apicultural Research, Chinese Academy of Agricultural Sciences, Beijing 100093, PR China
- Key Laboratory of Pollinating Insect Biology, Ministry of Agriculture, Beijing 100093, PR China
| | - Lucy A. Weinert
- Institut des Sciences de l'Evolution UMR5554, Université Montpellier–CNRS–IRD–EPHE, Montpellier, France
- Present address: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK
| | - James M. Cook
- Hawkesbury Institute for the Environment, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
| | - Elisabeth A. Herniou
- Institut de Recherche sur la Biologie de l’Insecte, UMR 7261, CNRS, Université de Tours, 37200 Tours, France
| | - Philippe Gayral
- Institut de Recherche sur la Biologie de l’Insecte, UMR 7261, CNRS, Université de Tours, 37200 Tours, France
| |
Collapse
|
59
|
Complete Genome Sequence of Deformed Wing Virus Isolated from Vespa crabro in Italy. GENOME ANNOUNCEMENTS 2017; 5:5/40/e00961-17. [PMID: 28982990 PMCID: PMC5629047 DOI: 10.1128/genomea.00961-17] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this article, we document the first isolation of a replication-competent deformed wing virus from Vespa crabro in Italy. Although the virus has never been isolated from this insect, the sequence of this virus shows a strong sequence homology with isolates obtained from Apis mellifera, which is considered its natural host.
Collapse
|
60
|
Gisder S, Genersch E. Viruses of commercialized insect pollinators. J Invertebr Pathol 2017; 147:51-59. [DOI: 10.1016/j.jip.2016.07.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/18/2016] [Accepted: 07/20/2016] [Indexed: 02/05/2023]
|
61
|
Radzevičiūtė R, Theodorou P, Husemann M, Japoshvili G, Kirkitadze G, Zhusupbaeva A, Paxton RJ. Replication of honey bee-associated RNA viruses across multiple bee species in apple orchards of Georgia, Germany and Kyrgyzstan. J Invertebr Pathol 2017; 146:14-23. [PMID: 28392285 DOI: 10.1016/j.jip.2017.04.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/16/2017] [Accepted: 04/04/2017] [Indexed: 11/25/2022]
Abstract
The essential ecosystem service of pollination is provided largely by insects, which are considered threatened by diverse biotic and abiotic global change pressures. RNA viruses are one such pressure, and have risen in prominence as a major threat for honey bees (Apis mellifera) and global apiculture, as well as a risk factor for other bee species through pathogen spill-over between managed honey bees and sympatric wild pollinator communities. Yet despite their potential role in global bee decline, the prevalence of honey bee-associated RNA viruses in wild bees is poorly known from both geographic and taxonomic perspectives. We screened members of pollinator communities (honey bees, bumble bees and other wild bees belonging to four families) collected from apple orchards in Georgia, Germany and Kyrgyzstan for six common honey bee-associated RNA virus complexes encompassing nine virus targets. The Deformed wing virus complex (DWV genotypes A and B) had the highest prevalence across all localities and host species and was the only virus complex found in wild bee species belonging to all four studied families. Based on amplification of negative-strand viral RNA, we found evidence for viral replication in wild bee species of DWV-A/DWV-B (hosts: Andrena haemorrhoa and several Bombus spp.) and Black queen cell virus (hosts: Anthophora plumipes, several Bombus spp., Osmia bicornis and Xylocopa spp.). Viral amplicon sequences revealed that DWV-A and DWV-B are regionally distinct but identical in two or more bee species at any one site, suggesting virus is shared amongst sympatric bee taxa. This study demonstrates that honey bee associated RNA viruses are geographically and taxonomically widespread, likely infective in wild bee species, and shared across bee taxa.
Collapse
Affiliation(s)
- Rita Radzevičiūtė
- Molecular Evolution and Animal Systematics, Institute of Biology, University of Leipzig, Talstraβe 33, 04103 Leipzig, Germany; General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany; Life Sciences Center, Vilnius University, Saulėtekio al. 7, 10223 Vilnius, Lithuania.
| | - Panagiotis Theodorou
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Martin Husemann
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany; Department of Entomology, Centrum für Naturkunde (CeNak), University of Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
| | - George Japoshvili
- Institute of Entomology, Agricultural University of Georgia, 240 Agmashenebeli Alley, Tbilisi 0159, Georgia; Invertebrate Research Center, 26 Agladze str., Tbilisi 0119, Georgia
| | - Giorgi Kirkitadze
- Institute of Entomology, Agricultural University of Georgia, 240 Agmashenebeli Alley, Tbilisi 0159, Georgia
| | - Aigul Zhusupbaeva
- Academy of Public Administration Under the President of the Kyrgyz Republic, 237 Panfilova str., Bishkek, Kyrgyzstan
| | - Robert J Paxton
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
| |
Collapse
|
62
|
Honey Bee Deformed Wing Virus Structures Reveal that Conformational Changes Accompany Genome Release. J Virol 2017; 91:JVI.01795-16. [PMID: 27852845 DOI: 10.1128/jvi.01795-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 11/02/2016] [Indexed: 11/20/2022] Open
Abstract
The picornavirus-like deformed wing virus (DWV) has been directly linked to colony collapse; however, little is known about the mechanisms of host attachment or entry for DWV or its molecular and structural details. Here we report the three-dimensional (3-D) structures of DWV capsids isolated from infected honey bees, including the immature procapsid, the genome-filled virion, the putative entry intermediate (A-particle), and the empty capsid that remains after genome release. The capsids are decorated by large spikes around the 5-fold vertices. The 5-fold spikes had an open flower-like conformation for the procapsid and genome-filled capsids, whereas the putative A-particle and empty capsids that had released the genome had a closed tube-like spike conformation. Between the two conformations, the spikes undergo a significant hinge-like movement that we predicted using a Robetta model of the structure comprising the spike. We conclude that the spike structures likely serve a function during host entry, changing conformation to release the genome, and that the genome may escape from a 5-fold vertex to initiate infection. Finally, the structures illustrate that, similarly to picornaviruses, DWV forms alternate particle conformations implicated in assembly, host attachment, and RNA release. IMPORTANCE Honey bees are critical for global agriculture, but dramatic losses of entire hives have been reported in numerous countries since 2006. Deformed wing virus (DWV) and infestation with the ectoparasitic mite Varroa destructor have been linked to colony collapse disorder. DWV was purified from infected adult worker bees to pursue biochemical and structural studies that allowed the first glimpse into the conformational changes that may be required during transmission and genome release for DWV.
Collapse
|
63
|
Mazzei M, Fronte B, Sagona S, Carrozza ML, Forzan M, Pizzurro F, Bibbiani C, Miragliotta V, Abramo F, Millanta F, Bagliacca M, Poli A, Felicioli A. Effect of 1,3-1,6 β-Glucan on Natural and Experimental Deformed Wing Virus Infection in Newly Emerged Honeybees (Apis mellifera ligustica). PLoS One 2016; 11:e0166297. [PMID: 27829027 PMCID: PMC5102454 DOI: 10.1371/journal.pone.0166297] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 10/26/2016] [Indexed: 01/26/2023] Open
Abstract
The Western Honeybee is a key pollinator for natural as well as agricultural ecosystems. In the last decade massive honeybee colony losses have been observed worldwide, the result of a complex syndrome triggered by multiple stress factors, with the RNA virus Deformed Wing Virus (DWV) and the mite Varroa destructor playing crucial roles. The mite supports replication of DWV to high titers, which exert an immunosuppressive action and correlate with the onset of the disease. The aim of this study was to investigate the effect of 1,3-1,6 β-glucan, a natural innate immune system modulator, on honeybee response to low-titer natural and high-titer experimental DWV infection. As the effects exerted by ß-glucans can be remarkably different, depending on the target organism and the dose administered, two parallel experiments were performed, where 1,3-1,6 ß-glucan at a concentration of 0.5% and 2% respectively, was added to the diet of three cohorts of newly emerged honeybees, which were sampled from a Varroa-free apiary and harboured a low endogenous DWV viral titer. Each cohort was subjected to one of the following experimental treatments: no injection, injection of a high-copy number DWV suspension into the haemocel (experimental DWV infection) or injection of PBS into the haemocoel (physical injury). Control bees fed a ß-glucan-free diet were subjected to the same treatments. Viral load, survival rate, haemocyte populations and phenoloxidase activity of each experimental group were measured and compared. The results indicated that oral administration of 0.5% ß-glucan to naturally infected honeybees was associated with a significantly decrease of the number of infected bees and viral load they carried, and with a significant increase of the survival rate, suggesting that this natural immune modulator molecule might contribute to increase honeybee resistance to viral infection.
Collapse
Affiliation(s)
- Maurizio Mazzei
- Department of Veterinary Science, University of Pisa, Pisa, Italy
- * E-mail:
| | | | - Simona Sagona
- Department of Veterinary Science, University of Pisa, Pisa, Italy
| | | | - Mario Forzan
- Department of Veterinary Science, University of Pisa, Pisa, Italy
| | | | - Carlo Bibbiani
- Department of Veterinary Science, University of Pisa, Pisa, Italy
| | | | - Francesca Abramo
- Department of Veterinary Science, University of Pisa, Pisa, Italy
| | | | - Marco Bagliacca
- Department of Veterinary Science, University of Pisa, Pisa, Italy
| | - Alessandro Poli
- Department of Veterinary Science, University of Pisa, Pisa, Italy
| | | |
Collapse
|
64
|
Amiri E, Meixner MD, Kryger P. Deformed wing virus can be transmitted during natural mating in honey bees and infect the queens. Sci Rep 2016; 6:33065. [PMID: 27608961 PMCID: PMC5016801 DOI: 10.1038/srep33065] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 08/19/2016] [Indexed: 11/18/2022] Open
Abstract
Deformed wing virus is an important contributor to honey bee colony losses. Frequently queen failure is reported as a cause for colony loss. Here we examine whether sexual transmission during multiple matings of queens is a possible way of virus infection in queens. In an environment with high prevalence of deformed wing virus, queens (n = 30) were trapped upon their return from natural mating flights. The last drone's endophallus (n = 29), if present, was removed from the mated queens for deformed wing virus quantification, leading to the detection of high-level infection in 3 endophalli. After oviposition, viral quantification revealed that seven of the 30 queens had high-level deformed wing virus infections, in all tissues, including the semen stored in the spermathecae. Two groups of either unmated queens (n = 8) with induced egg laying, or queens (n = 12) mated in isolation with drones showing comparatively low deformed wing virus infections served as control. None of the control queens exhibited high-level viral infections. Our results demonstrate that deformed wing virus infected drones are competitive to mate and able to transmit the virus along with semen, which occasionally leads to queen infections. Virus transmission to queens during mating may be common and can contribute noticeably to queen failure.
Collapse
Affiliation(s)
- Esmaeil Amiri
- Department of Agroecology, Aarhus University, Slagelse, 4200, Denmark
- Department of Biology, University of North Carolina, Greensboro, NC, 27403, USA
| | | | - Per Kryger
- Department of Agroecology, Aarhus University, Slagelse, 4200, Denmark
| |
Collapse
|
65
|
Tehel A, Brown MJF, Paxton RJ. Impact of managed honey bee viruses on wild bees. Curr Opin Virol 2016; 19:16-22. [DOI: 10.1016/j.coviro.2016.06.006] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 06/10/2016] [Accepted: 06/13/2016] [Indexed: 11/25/2022]
|
66
|
McMenamin AJ, Brutscher LM, Glenny W, Flenniken ML. Abiotic and biotic factors affecting the replication and pathogenicity of bee viruses. CURRENT OPINION IN INSECT SCIENCE 2016; 16:14-21. [PMID: 27720045 PMCID: PMC5113721 DOI: 10.1016/j.cois.2016.04.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/14/2016] [Accepted: 04/14/2016] [Indexed: 05/20/2023]
Abstract
Bees are important pollinators of plants in both agricultural and non-agricultural landscapes. Recent losses of both managed and wild bee species have negative impacts on crop production and ecosystem diversity. Therefore, in order to mitigate bee losses, it is important to identify the factors most responsible. Multiple factors including pathogens, agrochemical exposure, lack of quality forage, and reduced habitat affect bee health. Pathogen prevalence is one factor that has been associated with colony losses. Numerous pathogens infect bees including fungi, protists, bacteria, and viruses, the majority of which are RNA viruses including several that infect multiple bee species. RNA viruses readily infect bees, yet there is limited understanding of their impacts on bee health, particularly in the context of other stressors. Herein we review the influence environmental factors have on the replication and pathogenicity of bee viruses and identify research areas that require further investigation.
Collapse
Affiliation(s)
- Alexander J McMenamin
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Laura M Brutscher
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - William Glenny
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA; Department of Ecology, Montana State University, Bozeman, MT, USA
| | - Michelle L Flenniken
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA; Institute on Ecosystems, Montana State University, Bozeman, MT, USA; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA.
| |
Collapse
|
67
|
Brutscher LM, Daughenbaugh KF, Flenniken ML. Antiviral Defense Mechanisms in Honey Bees. CURRENT OPINION IN INSECT SCIENCE 2015; 10:71-82. [PMID: 26273564 PMCID: PMC4530548 DOI: 10.1016/j.cois.2015.04.016] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Honey bees are significant pollinators of agricultural crops and other important plant species. High annual losses of honey bee colonies in North America and in some parts of Europe have profound ecological and economic implications. Colony losses have been attributed to multiple factors including RNA viruses, thus understanding bee antiviral defense mechanisms may result in the development of strategies that mitigate colony losses. Honey bee antiviral defense mechanisms include RNA-interference, pathogen-associated molecular pattern (PAMP) triggered signal transduction cascades, and reactive oxygen species generation. However, the relative importance of these and other pathways is largely uncharacterized. Herein we review the current understanding of honey bee antiviral defense mechanisms and suggest important avenues for future investigation.
Collapse
Affiliation(s)
- Laura M Brutscher
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA ; Institute on Ecosystems, Montana State University, Bozeman, MT, USA ; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Katie F Daughenbaugh
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA
| | - Michelle L Flenniken
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman, MT, USA ; Institute on Ecosystems, Montana State University, Bozeman, MT, USA ; Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| |
Collapse
|
68
|
Ravoet J, De Smet L, Wenseleers T, de Graaf DC. Genome sequence heterogeneity of Lake Sinai Virus found in honey bees and Orf1/RdRP-based polymorphisms in a single host. Virus Res 2015; 201:67-72. [PMID: 25725149 DOI: 10.1016/j.virusres.2015.02.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 02/08/2023]
Abstract
Honey bees (Apis mellifera) are susceptible to a wide range of pathogens, including a broad set of viruses. Recently, next-generation sequencing has expanded the list of viruses with, for instance, two strains of Lake Sinai Virus. Soon after its discovery in the USA, LSV was also discovered in other countries and in other hosts. In the present study, we assemble four almost complete LSV genomes, and show that there is remarkable sequence heterogeneity based on the Orf1, RNA-dependent RNA polymerase and capsid protein sequences in comparison to the previously identified LSV 1 and 2 strains. Phylogenetic analyses of LSV sequences obtained from single honey bee specimens further revealed that up to three distinctive clades could be present in a single bee. Such superinfections have not previously been identified for other honey bee viruses. In a search for the putative routes of LSV transmission, we were able to demonstrate the presence of LSV in pollen pellets and in Varroa destructor mites. However, negative-strand analyses demonstrated that the virus only actively replicates in honey bees and mason bees (Osmia cornuta) and not in Varroa mites.
Collapse
Affiliation(s)
- Jorgen Ravoet
- Laboratory of Molecular Entomology and Bee Pathology, Ghent University, Ghent B-9000, Belgium.
| | - Lina De Smet
- Laboratory of Molecular Entomology and Bee Pathology, Ghent University, Ghent B-9000, Belgium
| | - Tom Wenseleers
- Laboratory of Socioecology and Social Evolution, K.U. Leuven, Leuven B-3000, Belgium
| | - Dirk C de Graaf
- Laboratory of Molecular Entomology and Bee Pathology, Ghent University, Ghent B-9000, Belgium
| |
Collapse
|