scholarly journals Transcriptomic Responses of the Honey Bee Brain to Infection with Deformed Wing Virus

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 287
Author(s):  
Marie C. Pizzorno ◽  
Kenneth Field ◽  
Amanda L. Kobokovich ◽  
Phillip L. Martin ◽  
Riju A. Gupta ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Behavioral Changes ◽  
Rna Seq ◽  
Transcriptomic Response ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
And Function ◽  
G Protein Coupled ◽  
The Brain

Managed colonies of European honey bees (Apis mellifera) are under threat from Varroa destructor mite infestation and infection with viruses vectored by mites. In particular, deformed wing virus (DWV) is a common viral pathogen infecting honey bees worldwide that has been shown to induce behavioral changes including precocious foraging and reduced associative learning. We investigated how DWV infection of bees affects the transcriptomic response of the brain. The transcriptomes of individual brains were analyzed using RNA-Seq after experimental infection of newly emerged adult bees with DWV. Two analytical methods were used to identify differentially expressed genes from the ~15,000 genes in the Apis mellifera genome. The 269 genes that had increased expression in DWV infected brains included genes involved in innate immunity such as antimicrobial peptides (AMPs), Ago2, and Dicer. Single bee brain NMR metabolomics methodology was developed for this work and indicates that proline is strongly elevated in DWV infected brains, consistent with the increased presence of the AMPs abaecin and apidaecin. The 1361 genes with reduced expression levels includes genes involved in cellular communication including G-protein coupled, tyrosine kinase, and ion-channel regulated signaling pathways. The number and function of the downregulated genes suggest that DWV has a major impact on neuron signaling that could explain DWV related behavioral changes.

scholarly journals Feral and managed honey bees, Apis mellifera (Hymenoptera: Apidae), in southern California have similar levels of viral pathogens

2021 ◽  
Author(s):  
Amy C Geffre ◽  
Dillon Travis ◽  
Joshua Kohn ◽  
James Nieh
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Southern California ◽  
Multiple Stressors ◽  
Pollination Services ◽  
Viral Pathogens ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Native Bee ◽  
Queen Cell

Bees provide critical pollination services but are threatened by multiple stressors, including viral pathogens. Most studies of pollinator health focus on managed honey bees (Apis mellifera Linnaeus) (MHB) or native bee species, but a third player, the feral honey bee (FHB), requires further study. Spillover and spillback of viral pathogens between these managed, feral, and native bees is generating increasing interest. In this case study, we provide evidence suggesting that FHB colonies play an important role in viral pathogen dynamics of southern California pollinator communities because they act as reservoirs, of viral pathogens such as acute bee paralysis virus (ABPV), black queen cell virus (BQCV), and deformed wing virus (DWV). Surprisingly, even though FHB are not treated for diseases or parasites, they harbor similar pathogen loads to MHB, which are usually highly treated, suggesting the need for future studies to determine if FHB resist or are more resilient to viruses.

scholarly journals Efficacy of an Eco-Friendly Bloom Thinning Formulation on Mango Trees and Its Olfactory Effect on an Insect Pollinator, Apis mellifera

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 62
Author(s):  
Tae-Kwon Son ◽  
Md Munir Mostafiz ◽  
Hwal-Su Hwang ◽  
Nguyen Truong Thạnh ◽  
Kyeong-Yeoll Lee
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Fruit Size ◽  
Fruit Trees ◽  
Fruit Weight ◽  
Behavioral Changes ◽  
Control Treatment ◽  
Environmental Concerns ◽  
Olfactory Behavior ◽  
Insect Pollinator

In various orchard fruit trees, thinning of blossoms and fruits is important to increase fruit size and quality and to promote a new bloom in the following season. Several chemical thinning agents are currently commercially available, but they are inconsistent and produce side effects in crop plants and insect pollinators. Because of environmental concerns, developing alternative eco-friendly bloom thinning agents is necessary. We developed an eco-friendly bloom thinning formulation (BTF) using minerals and extracts of various medicinal plants. Our BTF spray (0.1%, <i>w/v</i>) decreased the number of fruits per tree (46.5%) and fruit yield per tree (81.5%) but increased the fruit weight (196.8%) compared with the control treatment; the spray induced a small number of larger mango fruits in the treated trees. We also investigated the effect of BTF on the olfactory behavior of <i>Apis mellifera</i> L. (Hymenoptera, Apidae), a major insect pollinator. We analyzed the behavioral changes of adult workers at two different concentrations (0.1% and 1%) of nine different BTF spray components using a Y-tube olfactometer. The behavioral responses of honey bees to nine BTF components showed significant differences. However, honey bees showed no clear attraction or repellent behavior towards the tested BTF components. Our results suggest that the newly developed eco-friendly BTF is practically applicable in mango orchards without interrupting honey bee behavior.

scholarly journals Pupal cannibalism by worker honey bees contributes to the spread of deformed wing virus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco Posada-Florez ◽  
Zachary S. Lamas ◽  
David J. Hawthorne ◽  
Yanping Chen ◽  
Jay D. Evans ◽  
...  
Keyword(s):  
Honey Bees ◽  
Control Strategies ◽  
Virus Transmission ◽  
Experimental Conditions ◽  
Colony Losses ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Hygienic Behaviour ◽  
Pathogen Virulence ◽  
Comprehensive Knowledge

AbstractTransmission routes impact pathogen virulence and genetics, therefore comprehensive knowledge of these routes and their contribution to pathogen circulation is essential for understanding host–pathogen interactions and designing control strategies. Deformed wing virus (DWV), a principal viral pathogen of honey bees associated with increased honey bee mortality and colony losses, became highly virulent with the spread of its vector, the ectoparasitic mite Varroa destructor. Reproduction of Varroa mites occurs in capped brood cells and mite-infested pupae from these cells usually have high levels of DWV. The removal of mite-infested pupae by worker bees, Varroa Sensitive Hygiene (VSH), leads to cannibalization of pupae with high DWV loads, thereby offering an alternative route for virus transmission. We used genetically tagged DWV to investigate virus transmission to and between worker bees following pupal cannibalisation under experimental conditions. We demonstrated that cannibalization of DWV-infected pupae resulted in high levels of this virus in worker bees and that the acquired virus was then transmitted between bees via trophallaxis, allowing circulation of Varroa-vectored DWV variants without the mites. Despite the known benefits of hygienic behaviour, it is possible that higher levels of VSH activity may result in increased transmission of DWV via cannibalism and trophallaxis.

scholarly journals Deformed Wing Virus Infection in Honey Bees (Apis mellifera L.)

2019 ◽  
Vol 56 (4) ◽  
pp. 636-641 ◽  
Author(s):  
Roman V. Koziy ◽  
Sarah C. Wood ◽  
Ivanna V. Kozii ◽  
Claire Janse van Rensburg ◽  
Igor Moshynskyy ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Honey Bees ◽  
Rna Virus ◽  
Mandibular Glands ◽  
Deformed Wing Virus ◽  
Clinically Normal ◽  
Bee Health ◽  
Honey Bee Health ◽  
Honey Bee Workers

Deformed wing virus (DWV) is a single-stranded RNA virus of honey bees ( Apis mellifera L.) transmitted by the parasitic mite Varroa destructor. Although DWV represents a major threat to honey bee health worldwide, the pathological basis of DWV infection is not well documented. The objective of this study was to investigate clinicopathological and histological aspects of natural DWV infection in honey bee workers. Emergence of worker honey bees was observed in 5 colonies that were clinically affected with DWV and the newly emerged bees were collected for histopathology. DWV-affected bees were 2 times slower to emerge and had 30% higher mortality compared to clinically normal bees. Hypopharyngeal glands in bees with DWV were hypoplastic, with fewer intracytoplasmic secretory vesicles; cells affected by apoptosis were observed more frequently. Mandibular glands were hypoplastic and were lined by cuboidal epithelium in severely affected bees compared to tall columnar epithelium in nonaffected bees. The DWV load was on average 1.7 × 106 times higher ( P < .001) in the severely affected workers compared to aged-matched sister honey bee workers that were not affected by deformed wing disease based on gross examination. Thus, DWV infection is associated with prolonged emergence, increased mortality during emergence, and hypoplasia of hypopharyngeal and mandibular glands in newly emerged worker honey bees in addition to previously reported deformed wing abnormalities.

scholarly journals Novel Insight Into the Development and Function of Hypopharyngeal Glands in Honey Bees

2021 ◽  
Vol 11 ◽  
Author(s):  
Saboor Ahmad ◽  
Shahmshad Ahmed Khan ◽  
Khalid Ali Khan ◽  
Jianke Li
Keyword(s):  
Honey Bees ◽  
Future Research ◽  
Factors Affecting ◽  
Hypopharyngeal Glands ◽  
And Function ◽  
First Time ◽  
The Brain ◽  
Insight Into ◽  
Made In

Hypopharyngeal glands (HGs) are the most important organ of hymenopterans which play critical roles for the insect physiology. In honey bees, HGs are paired structures located bilaterally in the head, in front of the brain between compound eyes. Each gland is composed of thousands of secretory units connecting to secretory duct in worker bees. To better understand the recent progress made in understanding the structure and function of these glands, we here review the ontogeny of HGs, and the factors affecting the morphology, physiology, and molecular basis of the functionality of the glands. We also review the morphogenesis of HGs in the pupal and adult stages, and the secretory role of the glands across the ages for the first time. Furthermore, recent transcriptome, proteome, and phosphoproteome analyses have elucidated the potential mechanisms driving the HGs development and functionality. This adds a comprehensive novel knowledge of the development and physiology of HGs in honey bees over time, which may be helpful for future research investigations.

scholarly journals DWV 3C protease uncovers the diverse catalytic triad in insect RNA viruses

2022 ◽  
Author(s):  
Xuye Yuan ◽  
Tatsuhiko Kadowaki
Keyword(s):  
Honey Bees ◽  
Rna Viruses ◽  
Catalytic Triad ◽  
Enzymatic Properties ◽  
Host Cells ◽  
Deformed Wing Virus ◽  
Mutant Proteins ◽  
3C Protease ◽  
Infected Cells ◽  
And Function

Deformed wing virus (DWV) is the most prevalent Iflavirus that is infecting honey bees worldwide. However, the mechanisms of its infection and replication in host cells are poorly understood. In this study, we analyzed the structure and function of DWV 3C protease (3Cpro), which is necessary for the cleavage of the polyprotein to synthesize mature viral proteins. We found that the 3Cpros of DWV and picornaviruses share common enzymatic properties, including sensitivity to the same inhibitors, such as rupintrivir. The predicted structure of DWV 3Cpro by AlphaFold2, the predicted rupintrivir binding domain, and the protease activities of mutant proteins revealed that it has a Cys-His-Asn catalytic triad. Moreover, 3Cpros of other Iflaviruses and Dicistrovirus appear to contain Asn, Ser, Asp, or Glu as the third residue of the catalytic triad, suggesting diversity in insect RNA viruses. Both precursor 3Cpro with RNA-dependent RNA polymerase and mature 3Cpro are present in DWV-infected cells, suggesting that they may have different enzymatic properties and functions. DWV 3Cpro is the first 3Cpro characterized among insect RNA viruses, and our study uncovered both the common and unique characteristics among 3Cpros of Picornavirales. Furthermore, the specific inhibitors of DWV 3Cpro could be used to control DWV infection in honey bees.

scholarly journals Tolerance of Honey Bees to Varroa Mite in the Absence of Deformed Wing Virus

Viruses ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 575 ◽  
Author(s):  
John M. K. Roberts ◽  
Nelson Simbiken ◽  
Chris Dale ◽  
Joel Armstrong ◽  
Denis L. Anderson
Keyword(s):  
Honey Bee ◽  
Honey Bees ◽  
High Throughput Sequencing ◽  
Solomon Islands ◽  
Host Shift ◽  
Colony Losses ◽  
Viral Pathogen ◽  
Deformed Wing Virus ◽  
Bee Health ◽  
Queen Cell

The global spread of the parasitic mite Varroa destructor has emphasized the significance of viruses as pathogens of honey bee (Apis mellifera) populations. In particular, the association of deformed wing virus (DWV) with V. destructor and its devastating effect on honey bee colonies has led to that virus now becoming one of the most well-studied insect viruses. However, there has been no opportunity to examine the effects of Varroa mites without the influence of DWV. In Papua New Guinea (PNG), the sister species, V. jacobsoni, has emerged through a host-shift to reproduce on the local A. mellifera population. After initial colony losses, beekeepers have maintained colonies without chemicals for more than a decade, suggesting that this bee population has an unknown mite tolerance mechanism. Using high throughput sequencing (HTS) and target PCR detection, we investigated whether the viral landscape of the PNG honey bee population is the underlying factor responsible for mite tolerance. We found A. mellifera and A. cerana from PNG and nearby Solomon Islands were predominantly infected by sacbrood virus (SBV), black queen cell virus (BQCV) and Lake Sinai viruses (LSV), with no evidence for any DWV strains. V. jacobsoni was infected by several viral homologs to recently discovered V. destructor viruses, but Varroa jacobsoni rhabdovirus-1 (ARV-1 homolog) was the only virus detected in both mites and honey bees. We conclude from these findings that A. mellifera in PNG may tolerate V. jacobsoni because the damage from parasitism is significantly reduced without DWV. This study also provides further evidence that DWV does not exist as a covert infection in all honey bee populations, and remaining free of this serious viral pathogen can have important implications for bee health outcomes in the face of Varroa.

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