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Liberti J, Engel P, Cabirol A. Interplay between gut symbionts and behavioral variation in social insects. CURRENT OPINION IN INSECT SCIENCE 2024; 65:101233. [PMID: 39019113 DOI: 10.1016/j.cois.2024.101233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 05/27/2024] [Accepted: 07/09/2024] [Indexed: 07/19/2024]
Abstract
Social insects exhibit a high degree of intraspecific behavioral variation. Moreover, they often harbor specialized microbial communities in their gut. Recent studies suggest that these two characteristics of social insects are interlinked: insect behavioral phenotypes affect their gut microbiota composition, partly through exposure to different environments and diet, and in return, the gut microbiota has been shown to influence insect behavior. Here, we discuss the bidirectional relationship existing between intraspecific variation in gut microbiota composition and behavioral phenotypes in social insects.
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Affiliation(s)
- Joanito Liberti
- Department of Fundamental Microbiology, University of Lausanne, Switzerland; Department of Ecology and Evolution, University of Lausanne, Switzerland.
| | - Philipp Engel
- Department of Fundamental Microbiology, University of Lausanne, Switzerland
| | - Amélie Cabirol
- Department of Fundamental Microbiology, University of Lausanne, Switzerland.
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2
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Motta EVS, Moran NA. The honeybee microbiota and its impact on health and disease. Nat Rev Microbiol 2024; 22:122-137. [PMID: 38049554 PMCID: PMC10998682 DOI: 10.1038/s41579-023-00990-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/17/2023] [Indexed: 12/06/2023]
Abstract
Honeybees (Apis mellifera) are key pollinators that support global agriculture and are long-established models for developmental and behavioural research. Recently, they have emerged as models for studying gut microbial communities. Earlier research established that hindguts of adult worker bees harbour a conserved set of host-restricted bacterial species, each showing extensive strain variation. These bacteria can be cultured axenically and introduced to gnotobiotic hosts, and some have basic genetic tools available. In this Review, we explore the most recent research showing how the microbiota establishes itself in the gut and impacts bee biology and health. Microbiota members occupy specific niches within the gut where they interact with each other and the host. They engage in cross-feeding and antagonistic interactions, which likely contribute to the stability of the community and prevent pathogen invasion. An intact gut microbiota provides protection against diverse pathogens and parasites and contributes to the processing of refractory components of the pollen coat and dietary toxins. Absence or disruption of the microbiota results in altered expression of genes that underlie immunity, metabolism, behaviour and development. In the field, such disruption by agrochemicals may negatively impact bees. These findings demonstrate a key developmental and protective role of the microbiota, with broad implications for bee health.
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Affiliation(s)
- Erick V S Motta
- Department of Integrative Biology, University of Texas, Austin, TX, USA
| | - Nancy A Moran
- Department of Integrative Biology, University of Texas, Austin, TX, USA.
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Hotchkiss MZ, Forrest JRK, Poulain AJ. Exposure to a fungicide for a field-realistic duration does not alter bumble bee fecal microbiota structure. Appl Environ Microbiol 2024; 90:e0173923. [PMID: 38240563 PMCID: PMC10880609 DOI: 10.1128/aem.01739-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 12/25/2023] [Indexed: 02/22/2024] Open
Abstract
Social bees are frequently exposed to pesticides when foraging on nectar and pollen. Recent research has shown that pesticide exposure not only impacts social bee host health but can also alter the community structure of social bee gut microbiotas. However, most research on pesticide-bee gut microbiota interactions has been conducted in honey bees; bumble bees, native North American pollinators, have received less attention and, due to differences in their ecology, may be exposed to certain pesticides for shorter durations than honey bees. Here, we examine how exposure to the fungicide chlorothalonil for a short, field-realistic duration alters bumble bee fecal microbiotas (used as a proxy for gut microbiotas) and host performance. We expose small groups of Bombus impatiens workers (microcolonies) to field-realistic chlorothalonil concentrations for 5 days, track changes in fecal microbiotas during the exposure period and a recovery period, and compare microcolony offspring production between treatments at the end of the experiment. We also assess the use of fecal microbiotas as a gut microbiota proxy by comparing community structures of fecal and gut microbiotas. We find that chlorothalonil exposure for a short duration does not alter bumble bee fecal microbiota structure or affect microcolony production at any concentration but that fecal and gut microbiotas differ significantly in community structure. Our results show that, at least when exposure durations are brief and unaccompanied by other stressors, bumble bee microbiotas are resilient to fungicide exposure. Additionally, our work highlights the importance of sampling gut microbiotas directly, when possible.IMPORTANCEWith global pesticide use expected to increase in the coming decades, studies on how pesticides affect the health and performance of animals, including and perhaps especially pollinators, will be crucial to minimize negative environmental impacts of pesticides in agriculture. Here, we find no effect of exposure to chlorothalonil for a short, field-realistic period on bumble bee fecal microbiota community structure or microcolony production regardless of pesticide concentration. Our results can help inform pesticide use practices to minimize negative environmental impacts on the health and fitness of bumble bees, which are key native, commercial pollinators in North America. We also find that concurrently sampled bumble bee fecal and gut microbiotas contain similar microbes but differ from one another in community structure and consequently suggest that using fecal microbiotas as a proxy for gut microbiotas be done cautiously; this result contributes to our understanding of proxy use in gut microbiota research.
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Martinet B, Przybyla K, Decroo C, Wattiez R, Aron S. Proteomic differences in seminal fluid of social insects whose sperm differ in heat tolerance. ROYAL SOCIETY OPEN SCIENCE 2023; 10:231389. [PMID: 38026028 PMCID: PMC10645120 DOI: 10.1098/rsos.231389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 10/17/2023] [Indexed: 12/01/2023]
Abstract
In the coming years, climate change is likely to increase the frequency and intensity of heatwaves. In many organisms, heat stress provokes physiological perturbations and can lead to decreased male fertility. Bumblebees are endo-heterothermic but display interspecific differences in thermotolerance that could have conservation implications. For the species of concern Bombus magnus, exposure to high temperatures can severely reduce sperm quality and, consequently, reproductive success. Such is not the case for B. terrestris, a ubiquitous species. To decipher the mechanisms at play, we characterized the seminal fluid proteomes of the two species. We quantified 1121 proteins, of which 522 were differentially expressed between B. terrestris and B. magnus. Several proteins with protective functions, such as proteases, antioxidant proteins and various heat-shock proteins, were present at higher levels in B. terrestris than in B. magnus under both control and heat-stress conditions. The same was true for proteins involved in cellular homeostasis, immunity, lipid/sugar metabolism and thermotolerance. Furthermore, proteins involved in the capture and elimination of reactive oxygen species also occurred at much high levels in B. terrestris. Overall, these results clearly indicate differences in the seminal proteome of the more thermotolerant B. terrestris versus B. magnus. The differences may contribute to explaining interspecific differences in sperm survival.
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Affiliation(s)
- Baptiste Martinet
- Evolutionary Biology & Ecology, Université Libre de Bruxelles, Avenue Paul Héger - CP 160/12, 1000 Bruxelles, Belgium
| | | | - Corentin Decroo
- Department of Proteomics and Microbiology, Université de Mons, 7000 Mons, Belgium
| | - Ruddy Wattiez
- Department of Proteomics and Microbiology, Université de Mons, 7000 Mons, Belgium
| | - Serge Aron
- Evolutionary Biology & Ecology, Université Libre de Bruxelles, Avenue Paul Héger - CP 160/12, 1000 Bruxelles, Belgium
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5
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Gekière A, Vanderplanck M, Michez D. Trace metals with heavy consequences on bees: A comprehensive review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 895:165084. [PMID: 37379929 DOI: 10.1016/j.scitotenv.2023.165084] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 06/30/2023]
Abstract
The pervasiveness of human imprint on Earth is alarming and most animal species, including bees (Hymenoptera: Apoidea: Anthophila), must cope with several stressors. Recently, exposure to trace metals and metalloids (TMM) has drawn attention and has been suggested as a threat for bee populations. In this review, we aimed at bringing together all the studies (n = 59), both in laboratories and in natura, that assessed the effects of TMM on bees. After a brief comment on semantics, we listed the potential routes of exposure to soluble and insoluble (i.e. nanoparticle) TMM, and the threat posed by metallophyte plants. Then, we reviewed the studies that addressed whether bees could detect and avoid TMM in their environment, as well as the ways bee detoxify these xenobiotics. Afterwards, we listed the impacts TMM have on bees at the community, individual, physiological, histological and microbial levels. We discussed around the interspecific variations among bees, as well as around the simultaneous exposure to TMM. Finally, we highlighted that bees are likely exposed to TMM in combination or with other stressors, such as pesticides and parasites. Overall, we showed that most studies focussed on the domesticated western honey bee and mainly addressed lethal effects. Because TMM are widespread in the environment and have been shown to result in detrimental consequences, evaluating their lethal and sublethal effects on bees, including non-Apis species, warrants further investigations.
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Affiliation(s)
- Antoine Gekière
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 20 Place du Parc, 7000 Mons, Belgium.
| | - Maryse Vanderplanck
- CEFE, Univ Montpellier, CNRS, EPHE, IRD, 1919 Route de Mende, 34090 Montpellier, France.
| | - Denis Michez
- Laboratory of Zoology, Research Institute for Biosciences, University of Mons, 20 Place du Parc, 7000 Mons, Belgium.
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So J, Choe DH, Rust MK, Trumble JT, Lee CY. The impact of selenium on insects. JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:1041-1062. [PMID: 37289432 DOI: 10.1093/jee/toad084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 04/11/2023] [Accepted: 04/25/2023] [Indexed: 06/09/2023]
Abstract
Selenium, a naturally occurring metalloid, is an essential trace element for many higher organisms, including humans. Humans primarily become exposed to selenium by ingesting food products containing trace amounts of selenium compounds. Although essential in these small amounts, selenium exhibits toxic effects at higher doses. Previous studies investigating the effects on insects of order Blattodea, Coleoptera, Diptera, Ephemeroptera, Hemiptera, Hymenoptera, Lepidoptera, Odonata, and Orthoptera revealed impacts on mortality, growth, development, and behavior. Nearly every study examining selenium toxicity has shown that insects are negatively affected by exposure to selenium in their food. However, there were no clear patterns of toxicity between insect orders or similarities between insect species within families. At this time, the potential for control will need to be determined on a species-by-species basis. We suspect that the multiple modes of action, including mutation-inducing modification of important amino acids as well as impacts on microbiome composition, influence this variability. There are relatively few studies that have examined the potential effects of selenium on beneficial insects, and the results have ranged from increased predation (a strong positive effect) to toxicity resulting in reduced population growth or even the effective elimination of the natural enemies (more common negative effects). As a result, in those pest systems where selenium use is contemplated, additional research may be necessary to ascertain if selenium use is compatible with key biological control agents. This review explores selenium as a potential insecticide and possible future directions for research.
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Affiliation(s)
- John So
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - Dong-Hwan Choe
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - Michael K Rust
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - John T Trumble
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - Chow-Yang Lee
- Department of Entomology, University of California, Riverside, CA 92521, USA
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Seidenath D, Weig AR, Mittereder A, Hillenbrand T, Brüggemann D, Opel T, Langhof N, Riedl M, Feldhaar H, Otti O. Diesel exhaust particles alter gut microbiome and gene expression in the bumblebee Bombus terrestris. Ecol Evol 2023; 13:e10180. [PMID: 37351478 PMCID: PMC10283033 DOI: 10.1002/ece3.10180] [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: 12/21/2022] [Revised: 04/13/2023] [Accepted: 05/29/2023] [Indexed: 06/24/2023] Open
Abstract
Insect decline is a major threat to ecosystems around the world as they provide many important functions, such as pollination or pest control. Pollution is one of the main reasons for the decline, alongside changes in land use, global warming, and invasive species. While negative impacts of pesticides are well-studied, there is still a lack of knowledge about the effects of other anthropogenic pollutants, such as airborne particulate matter, on insects. To address this, we exposed workers of the bumblebee Bombus terrestris to sublethal doses of diesel exhaust particles (DEPs) and brake dust, orally or via air. After 7 days, we looked at the composition of the gut microbiome and tracked changes in gene expression. While there were no changes in the other treatments, oral DEP exposure significantly altered the structure of the gut microbiome. In particular, the core bacterium Snodgrassella had a decreased abundance in the DEP treatment. Similarly, transcriptome analysis revealed changes in gene expression after oral DEP exposure, but not in the other treatments. The changes are related to metabolism and signal transduction, which indicates a general stress response. Taken together, our results suggest potential health effects of DEP exposure on insects, here shown in bumblebees, as gut dysbiosis may increase the susceptibility of bumblebees to pathogens, while a general stress response may lower available energy resources. Those effects may exacerbate under natural conditions where insects face a multiple-stressor environment.
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Affiliation(s)
- Dimitri Seidenath
- Animal Ecology I, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
| | - Alfons R. Weig
- Keylab Genomics and Bioinformatics, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
| | - Andreas Mittereder
- Department of Engineering Thermodynamics and Transport ProcessesUniversity of BayreuthBayreuthGermany
| | - Thomas Hillenbrand
- Department of Engineering Thermodynamics and Transport ProcessesUniversity of BayreuthBayreuthGermany
| | - Dieter Brüggemann
- Department of Engineering Thermodynamics and Transport ProcessesUniversity of BayreuthBayreuthGermany
| | - Thorsten Opel
- Department of Ceramic Materials EngineeringUniversity of BayreuthBayreuthGermany
| | - Nico Langhof
- Department of Ceramic Materials EngineeringUniversity of BayreuthBayreuthGermany
| | - Marcel Riedl
- Animal Ecology I, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
| | - Heike Feldhaar
- Animal Ecology I, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
| | - Oliver Otti
- Animal Ecology I, Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
- Applied ZoologyTU DresdenDresdenGermany
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8
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Motta EVS, Moran NA. The effects of glyphosate, pure or in herbicide formulation, on bumble bees and their gut microbial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 872:162102. [PMID: 36764553 PMCID: PMC11050743 DOI: 10.1016/j.scitotenv.2023.162102] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 01/29/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
The widespread use of glyphosate-based formulations to eliminate unwanted vegetation has increased concerns regarding their effects on non-target organisms, such as honey bees and their gut microbial communities. These effects have been associated with both glyphosate and co-formulants, but it is still unknown whether they translate to other bee species. In this study, we tested whether glyphosate, pure or in herbicide formulation, can affect the gut microbiota and survival rates of the eastern bumble bee, Bombus impatiens. We performed mark-recapture experiments with bumble bee workers from four different commercial colonies, which were exposed to field relevant concentrations of glyphosate or a glyphosate-based formulation (0.01 mM to 1 mM). After a 5-day period of exposure, we returned the bees to their original colonies, and they were sampled at days 0, 3 and 7 post-exposure to investigate changes in microbial community and microbiota resilience by 16S rRNA amplicon sequencing and quantitative PCR. We found that exposure to glyphosate, pure or in herbicide formulation, reduced the relative abundance of a beneficial bee gut bacterium, Snodgrassella, in bees from two of four colonies when compared to control bees at day 0 post-exposure, but this reduction became non-significant at days 3 and 7 post-exposure, suggesting microbiota resilience. We did not find significant changes in total bacteria between control and exposed bees. Moreover, we observed an overall trend in decreased survival rates in bumble bees exposed to 1 mM herbicide formulation during the 7-day post-exposure period, suggesting a potential negative effect of this formulation on bumble bees.
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Affiliation(s)
- Erick V S Motta
- Department of Integrative Biology, University of Texas at Austin, TX, USA.
| | - Nancy A Moran
- Department of Integrative Biology, University of Texas at Austin, TX, USA.
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9
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Hammer TJ, Easton-Calabria A, Moran NA. Microbiome assembly and maintenance across the lifespan of bumble bee workers. Mol Ecol 2023; 32:724-740. [PMID: 36333950 PMCID: PMC9871002 DOI: 10.1111/mec.16769] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/13/2022] [Accepted: 09/21/2022] [Indexed: 11/06/2022]
Abstract
How a host's microbiome changes over its lifespan can influence development and ageing. As these temporal patterns have only been described in detail for a handful of hosts, an important next step is to compare microbiome succession more broadly and investigate why it varies. Here we characterize the temporal dynamics and stability of the bumble bee worker gut microbiome. Bumble bees have simple and host-specific gut microbiomes, and their microbial dynamics may influence health and pollination services. We used 16S rRNA gene sequencing, quantitative PCR and metagenomics to characterize gut microbiomes over the lifespan of Bombus impatiens workers. We also sequenced gut transcriptomes to examine host factors that may control the microbiome. At the community level, microbiome assembly is highly predictable and similar to patterns of primary succession observed in the human gut. However, at the strain level, partitioning of bacterial variants among colonies suggests stochastic colonization events similar to those observed in flies and nematodes. We also find strong differences in temporal dynamics among symbiont species, suggesting ecological differences among microbiome members in colonization and persistence. Finally, we show that both the gut microbiome and host transcriptome-including expression of key immunity genes-stabilize, as opposed to senesce, with age. We suggest that in highly social groups such as bumble bees, maintenance of both microbiomes and immunity contribute to inclusive fitness, and thus remain under selection even in old age. Our findings provide a foundation for exploring the mechanisms and functional outcomes of bee microbiome succession.
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Affiliation(s)
- Tobin J. Hammer
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697,Department of Integrative Biology, University of Texas at Austin, Austin, TX 78703,Corresponding author:
| | | | - Nancy A. Moran
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78703
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10
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Motta EVS, Gage A, Smith TE, Blake KJ, Kwong WK, Riddington IM, Moran N. Host-microbiome metabolism of a plant toxin in bees. eLife 2022; 11:82595. [PMID: 36472498 PMCID: PMC9897726 DOI: 10.7554/elife.82595] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
While foraging for nectar and pollen, bees are exposed to a myriad of xenobiotics, including plant metabolites, which may exert a wide range of effects on their health. Although the bee genome encodes enzymes that help in the metabolism of xenobiotics, it has lower detoxification gene diversity than the genomes of other insects. Therefore, bees may rely on other components that shape their physiology, such as the microbiota, to degrade potentially toxic molecules. In this study, we show that amygdalin, a cyanogenic glycoside found in honey bee-pollinated almond trees, can be metabolized by both bees and members of the gut microbiota. In microbiota-deprived bees, amygdalin is degraded into prunasin, leading to prunasin accumulation in the midgut and hindgut. In microbiota-colonized bees, on the other hand, amygdalin is degraded even further, and prunasin does not accumulate in the gut, suggesting that the microbiota contribute to the full degradation of amygdalin into hydrogen cyanide. In vitro experiments demonstrated that amygdalin degradation by bee gut bacteria is strain-specific and not characteristic of a particular genus or species. We found strains of Bifidobacterium, Bombilactobacillus, and Gilliamella that can degrade amygdalin. The degradation mechanism appears to vary since only some strains produce prunasin as an intermediate. Finally, we investigated the basis of degradation in Bifidobacterium wkB204, a strain that fully degrades amygdalin. We found overexpression and secretion of several carbohydrate-degrading enzymes, including one in glycoside hydrolase family 3 (GH3). We expressed this GH3 in Escherichia coli and detected prunasin as a byproduct when cell lysates were cultured with amygdalin, supporting its contribution to amygdalin degradation. These findings demonstrate that both host and microbiota can act together to metabolize dietary plant metabolites.
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Affiliation(s)
- Erick VS Motta
- Department of Integrative Biology, The University of Texas at AustinAustinUnited States
| | - Alejandra Gage
- Department of Integrative Biology, The University of Texas at AustinAustinUnited States
| | - Thomas E Smith
- Department of Integrative Biology, The University of Texas at AustinAustinUnited States
| | - Kristin J Blake
- Mass Spectrometry Facility, Department of Chemistry, The University of Texas at AustinAustinUnited States
| | | | - Ian M Riddington
- Mass Spectrometry Facility, Department of Chemistry, The University of Texas at AustinAustinUnited States
| | - Nancy Moran
- Department of Integrative Biology, The University of Texas at AustinAustinUnited States
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Nguyen PN, Rehan SM. The effects of urban land use gradients on wild bee microbiomes. Front Microbiol 2022; 13:992660. [PMID: 36466654 PMCID: PMC9714450 DOI: 10.3389/fmicb.2022.992660] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 11/01/2022] [Indexed: 12/23/2023] Open
Abstract
Bees and their microbes interact in complex networks in which bees form symbiotic relationships with their bacteria and fungi. Microbial composition and abundance affect bee health through nutrition, immunity, and fitness. In ever-expanding urban landscapes, land use development changes bee habitats and floral resource availability, thus altering the sources of microbes that wild bees need to establish their microbiome. Here, we implement metabarcoding of the bacterial 16S and fungal ITS regions to characterize the diversity and composition of the microbiome in 58 small carpenter bees, Ceratina calcarata, across urban land use gradients (study area 6,425 km2). By categorizing land use development, green space, precipitation, and temperature variables as indicators of habitat across the city, we found that land use variables can predict microbial diversity. Microbial composition was also found to vary across urban land use gradients, with certain microbes such as Acinetobacter and Apilactobacillus overrepresented in less urban locations and Penicillium more abundant in developed areas. Environmental features may also lead to differences in microbe interactions, as co-occurrences between bacteria and fungi varied across percent land use development, exemplified by the correlation between Methylobacterium and Sphingomonas being more prevalent in areas of higher urban development. Surrounding landscapes change the microbial landscape in wild bees and alter the relationships they have with their microbiome. As such, urban centres should consider the impact of growing cities on their pollinators' health and protect wild bees from the effects of anthropogenic activities.
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12
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Early Queen Development in Honey Bees: Social Context and Queen Breeder Source Affect Gut Microbiota and Associated Metabolism. Microbiol Spectr 2022; 10:e0038322. [PMID: 35867384 PMCID: PMC9430896 DOI: 10.1128/spectrum.00383-22] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The highly social honey bee has dense populations but a significantly reduced repertoire of immune genes relative to solitary species, suggesting a greater reliance on social immunity. Here we investigate immune gene expression and gut microbial succession in queens during colony introduction. Recently mated queens were placed into an active colony or a storage hive for multiple queens: a queen-bank. Feeding intensity, social context, and metabolic demand differ greatly between the two environments. After 3 weeks, we examined gene expression associated with oxidative stress and immunity and performed high-throughput sequencing of the queen gut microbiome across four alimentary tract niches. Microbiota and gene expression in the queen hindgut differed by time, queen breeder source, and metabolic environment. In the ileum, upregulation of most immune and oxidative stress genes occurred regardless of treatment conditions, suggesting postmating effects on gut gene expression. Counterintuitively, queens exposed to the more social colony environment contained significantly less bacterial diversity indicative of social immune factors shaping the queens microbiome. Queen bank queens resembled much older queens with decreased Alpha 2.1, greater abundance of Lactobacillus firm5 and Bifidobacterium in the hindgut, and significantly larger ileum microbiotas, dominated by blooms of Snodgrassella alvi. Combined with earlier findings, we conclude that the queen gut microbiota experiences an extended period of microbial succession associated with queen breeder source, postmating development, and colony assimilation. IMPORTANCE In modern agriculture, honey bee queen failure is repeatedly cited as one of the major reasons for yearly colony loss. Here we discovered that the honey bee queen gut microbiota alters according to early social environment and is strongly tied to the identity of the queen breeder. Like human examples, this early life variation appears to set the trajectory for ecological succession associated with social assimilation and queen productivity. The high metabolic demand of natural colony assimilation is associated with less bacterial diversity, a smaller hindgut microbiome, and a downregulation of genes that control pathogens and oxidative stress. Queens placed in less social environments with low metabolic demand (queen banks) developed a gut microbiota that resembled much older queens that produce fewer eggs. The queens key reproductive role in the colony may rely in part on a gut microbiome shaped by social immunity and the early queen rearing environment.
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13
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Martin VN, Schaeffer RN, Fukami T. Potential effects of nectar microbes on pollinator health. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210155. [PMID: 35491594 DOI: 10.1098/rstb.2021.0155] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Floral nectar is prone to colonization by nectar-adapted yeasts and bacteria via air-, rain-, and animal-mediated dispersal. Upon colonization, microbes can modify nectar chemical constituents that are plant-provisioned or impart their own through secretion of metabolic by-products or antibiotics into the nectar environment. Such modifications can have consequences for pollinator perception of nectar quality, as microbial metabolism can leave a distinct imprint on olfactory and gustatory cues that inform foraging decisions. Furthermore, direct interactions between pollinators and nectar microbes, as well as consumption of modified nectar, have the potential to affect pollinator health both positively and negatively. Here, we discuss and integrate recent findings from research on plant-microbe-pollinator interactions and their consequences for pollinator health. We then explore future avenues of research that could shed light on the myriad ways in which nectar microbes can affect pollinator health, including the taxonomic diversity of vertebrate and invertebrate pollinators that rely on this reward. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
| | | | - Tadashi Fukami
- Department of Biology, Stanford University, Stanford, CA, USA
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14
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Giambò F, Costa C, Teodoro M, Fenga C. Role-Playing Between Environmental Pollutants and Human Gut Microbiota: A Complex Bidirectional Interaction. Front Med (Lausanne) 2022; 9:810397. [PMID: 35252248 PMCID: PMC8888443 DOI: 10.3389/fmed.2022.810397] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 01/18/2022] [Indexed: 12/12/2022] Open
Abstract
There is a growing interest in the characterization of the involvement of toxicant and pollutant exposures in the development and the progression of several diseases such as obesity, diabetes, cancer, as well as in the disruption of the immune and reproductive homeostasis. The gut microbiota is considered a pivotal player against the toxic properties of chemicals with the establishment of a dynamic bidirectional relationship, underlining the toxicological significance of this mutual interplay. In fact, several environmental chemicals have been demonstrated to affect the composition, the biodiversity of the intestinal microbiota together with the underlining modulated metabolic pathways, which may play an important role in tailoring the microbiotype of an individual. In this review, we aimed to discuss the latest updates concerning the environmental chemicals–microbiota dual interaction, toward the identification of a distinctiveness of the gut microbial community, which, in turn, may allow to adopt personalized preventive strategies to improve risk assessment for more susceptible workers.
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Affiliation(s)
- Federica Giambò
- Occupational Medicine Section, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
| | - Chiara Costa
- Clinical and Experimental Medicine Department, University of Messina, Messina, Italy
| | - Michele Teodoro
- Occupational Medicine Section, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
| | - Concettina Fenga
- Occupational Medicine Section, Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Messina, Italy
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15
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Hotchkiss MZ, Poulain AJ, Forrest JRK. Pesticide-induced disturbances of bee gut microbiotas. FEMS Microbiol Rev 2022; 46:6517452. [PMID: 35107129 DOI: 10.1093/femsre/fuab056] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 11/18/2021] [Indexed: 12/19/2022] Open
Abstract
Social bee gut microbiotas play key roles in host health and performance. Worryingly, a growing body of literature shows that pesticide exposure can disturb these microbiotas. Most studies examine changes in taxonomic composition in Western honey bee (Apis mellifera) gut microbiotas caused by insecticide exposure. Core bee gut microbiota taxa shift in abundance after exposure but are rarely eliminated, with declines in Bifidobacteriales and Lactobacillus near melliventris abundance being the most common shifts. Pesticide concentration, exposure duration, season and concurrent stressors all influence whether and how bee gut microbiotas are disturbed. Also, the mechanism of disturbance-i.e. whether a pesticide directly affects microbial growth or indirectly affects the microbiota by altering host health-likely affects disturbance consistency. Despite growing interest in this topic, important questions remain unanswered. Specifically, metabolic shifts in bee gut microbiotas remain largely uninvestigated, as do effects of pesticide-disturbed gut microbiotas on bee host performance. Furthermore, few bee species have been studied other than A. mellifera, and few herbicides and fungicides have been examined. We call for these knowledge gaps to be addressed so that we may obtain a comprehensive picture of how pesticides alter bee gut microbiotas, and of the functional consequences of these changes.
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16
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Abstract
Diet and gut microbiomes are intricately linked on both short and long timescales. Changes in diet can alter the microbiome, while microbes in turn allow hosts to access novel diets. Bees are wasps that switched to a vegetarian lifestyle, and the vast majority of bees feed on pollen and nectar. Some stingless bee species, however, also collect carrion, and a few have fully reverted to a necrophagous lifestyle, relying on carrion for protein and forgoing flower visitation altogether. These “vulture” bees belong to the corbiculate apid clade, which is known for its ancient association with a small group of core microbiome phylotypes. Here, we investigate the vulture bee microbiome, along with closely related facultatively necrophagous and obligately pollinivorous species, to understand how these diets interact with microbiome structure. Via deep sequencing of the 16S rRNA gene and subsequent community analyses, we find that vulture bees have lost some core microbes, retained others, and entered into novel associations with acidophilic microbes found in the environment and on carrion. The abundance of acidophilic bacteria suggests that an acidic gut is important for vulture bee nutrition and health, as has been found in other carrion-feeding animals. Facultatively necrophagous bees have more variable microbiomes than strictly pollinivorous bees, suggesting that bee diet may interact with microbiomes on both short and long timescales. Further study of vulture bees promises to provide rich insights into the role of the microbiome in extreme diet switches.
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17
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Abstract
Bumblebees (Bombus) are charismatic and important pollinators. They are one of the best studied insect groups, especially in terms of ecology, behavior, and social structure. As many species are declining, there is a clear need to understand more about them. Microbial symbionts, which can influence many dimensions of animal life, likely have an outsized role in bumblebee biology. Recent research has shown that a conserved set of beneficial gut bacterial symbionts is ubiquitous across bumblebees. These bacteria are related to gut symbionts of honeybees, but have not been studied as intensively. Here we synthesize studies of bumblebee gut microbiota, highlight major knowledge gaps, and suggest future directions. Several patterns emerge, such as symbiont-host specificity maintained by sociality, frequent symbiont loss from individual bees, symbiont-conferred protection from trypanosomatid parasites, and divergence between bumblebee and honeybee microbiota in several key traits. For many facets of bumblebee-microbe interactions, however, underlying mechanisms and ecological functions remain unclear. Such information is important if we are to understand how bumblebees shape, and are shaped by, their gut microbiota. Bumblebees may provide a useful system for microbiome scientists, providing insights into general principles of host-microbe interactions. We also note how microbiota could influence bumblebee traits and responses to stressors. Finally, we propose that tinkering with the microbiota could be one way to aid bumblebee resilience in the face of global change.
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Affiliation(s)
- Tobin J. Hammer
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78703
- Corresponding author:
| | - Eli Le
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78703
| | - Alexia N. Martin
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78703
| | - Nancy A. Moran
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78703
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18
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Przybyla K, Michez D, Zambra E, Anselmo A, Hennebert E, Rasmont P, Martinet B. Effects of Heat Stress on Mating Behavior and Colony Development in Bombus terrestris (Hymenoptera: Apidae). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.748405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Climate change is related to an increase in the frequency and intensity of extreme events such as heatwaves. In insect pollinators, heat exposure is associated with direct physiological perturbations, and in several species, could lead to a decrease of fitness related to a decrease in fertility. Here we developed a new experimental protocol in controlled conditions to assess if the exposure to high temperatures could modify the attractiveness and fertility of Bombus terrestris males. Our results show that virgin queens of B. terrestris do not have preferences between the pheromonal secretions of heat-exposed and control males. Moreover, mating with a heat-exposed male has no impact on the copulation behavior and the development of the nest (brood composition). We advise to extend trials to cover a range of wild and heat-sensitive species on multiple generations to better understand the impact of heat waves on the bumblebee communities.
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19
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Sánchez-Bayo F. Indirect Effect of Pesticides on Insects and Other Arthropods. TOXICS 2021; 9:177. [PMID: 34437495 PMCID: PMC8402326 DOI: 10.3390/toxics9080177] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 12/04/2022]
Abstract
Pesticides released to the environment can indirectly affect target and non-target species in ways that are often contrary to their intended use. Such indirect effects are mediated through direct impacts on other species or the physical environment and depend on ecological mechanisms and species interactions. Typical mechanisms are the release of herbivores from predation and release from competition among species with similar niches. Application of insecticides to agriculture often results in subsequent pest outbreaks due to the elimination of natural enemies. The loss of floristic diversity and food resources that result from herbicide applications can reduce populations of pollinators and natural enemies of crop pests. In aquatic ecosystems, insecticides and fungicides often induce algae blooms as the chemicals reduce grazing by zooplankton and benthic herbivores. Increases in periphyton biomass typically result in the replacement of arthropods with more tolerant species such as snails, worms and tadpoles. Fungicides and systemic insecticides also reduce nutrient recycling by impairing the ability of detritivorous arthropods. Residues of herbicides can reduce the biomass of macrophytes in ponds and wetlands, indirectly affecting the protection and breeding of predatory insects in that environment. The direct impacts of pesticides in the environment are therefore either amplified or compensated by their indirect effects.
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Affiliation(s)
- Francisco Sánchez-Bayo
- School of Life and Environmental Sciences, The University of Sydney, Eveleigh, NSW 2015, Australia
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Giambò F, Teodoro M, Costa C, Fenga C. Toxicology and Microbiota: How Do Pesticides Influence Gut Microbiota? A Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18115510. [PMID: 34063879 PMCID: PMC8196593 DOI: 10.3390/ijerph18115510] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/07/2021] [Accepted: 05/19/2021] [Indexed: 02/07/2023]
Abstract
In recent years, new targets have been included between the health outcomes induced by pesticide exposure. The gastrointestinal tract is a key physical and biological barrier and it represents a primary site of exposure to toxic agents. Recently, the intestinal microbiota has emerged as a notable factor regulating pesticides’ toxicity. However, the specific mechanisms related to this interaction are not well known. In this review, we discuss the influence of pesticide exposure on the gut microbiota, discussing the factors influencing gut microbial diversity, and we summarize the updated literature. In conclusion, more studies are needed to clarify the host–microbial relationship concerning pesticide exposure and to define new prevention interventions, such as the identification of biomarkers of mucosal barrier function.
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Affiliation(s)
- Federica Giambò
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Occupational Medicine Section, University of Messina, 98125 Messina, Italy; (F.G.); (M.T.); (C.F.)
| | - Michele Teodoro
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Occupational Medicine Section, University of Messina, 98125 Messina, Italy; (F.G.); (M.T.); (C.F.)
| | - Chiara Costa
- Clinical and Experimental Medicine Department, University of Messina, 98125 Messina, Italy
- Correspondence: ; Tel.: +39-090-2212052
| | - Concettina Fenga
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Occupational Medicine Section, University of Messina, 98125 Messina, Italy; (F.G.); (M.T.); (C.F.)
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21
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Phillips BB, Bullock JM, Gaston KJ, Hudson‐Edwards KA, Bamford M, Cruse D, Dicks LV, Falagan C, Wallace C, Osborne JL. Impacts of multiple pollutants on pollinator activity in road verges. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13844] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
| | | | - Kevin J. Gaston
- Environment and Sustainability Institute University of Exeter Penryn UK
| | | | - Meg Bamford
- Environment and Sustainability Institute University of Exeter Penryn UK
| | - Dave Cruse
- Environment and Sustainability Institute University of Exeter Penryn UK
| | - Lynn V. Dicks
- School of Biological Sciences University of East Anglia Norwich UK
- Department of Zoology University of Cambridge Cambridge UK
| | - Carmen Falagan
- Environment and Sustainability Institute University of Exeter Penryn UK
| | - Claire Wallace
- School of Biological Sciences University of East Anglia Norwich UK
| | - Juliet L. Osborne
- Environment and Sustainability Institute University of Exeter Penryn UK
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22
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Rothman JA, Russell KA, Leger L, McFrederick QS, Graystock P. The direct and indirect effects of environmental toxicants on the health of bumblebees and their microbiomes. Proc Biol Sci 2020; 287:20200980. [PMID: 33109012 PMCID: PMC7661295 DOI: 10.1098/rspb.2020.0980] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/05/2020] [Indexed: 01/14/2023] Open
Abstract
Bumblebees (Bombus spp.) are important and widespread insect pollinators, but the act of foraging on flowers can expose them to harmful pesticides and chemicals such as oxidizers and heavy metals. How these compounds directly influence bee survival and indirectly affect bee health via the gut microbiome is largely unknown. As toxicants in floral nectar and pollen take many forms, we explored the genomes of bee-associated microbes for their potential to detoxify cadmium, copper, selenate, the neonicotinoid pesticide imidacloprid, and hydrogen peroxide-which have all been identified in floral nectar and pollen. We then exposed Bombus impatiens workers to varying concentrations of these chemicals via their diet and assayed direct effects on bee survival. Using field-realistic doses, we further explored the indirect effects on bee microbiomes. We found multiple putative genes in core gut microbes that may aid in detoxifying harmful chemicals. We also found that while the chemicals are largely toxic at levels within and above field-realistic concentrations, the field-realistic concentrations-except for imidacloprid-altered the composition of the bee microbiome, potentially causing gut dysbiosis. Overall, our study shows that chemicals found in floral nectar and pollen can cause bee mortality, and likely have indirect, deleterious effects on bee health via their influence on the bee microbiome.
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Affiliation(s)
- Jason A. Rothman
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697, USA
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - Kaleigh A. Russell
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | - Laura Leger
- Department of Entomology, University of California, Riverside, CA 92521, USA
| | | | - Peter Graystock
- Department of Entomology, University of California, Riverside, CA 92521, USA
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot SL5 7PY, UK
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