51
|
Figueroa LL, Blinder M, Grincavitch C, Jelinek A, Mann EK, Merva LA, Metz LE, Zhao AY, Irwin RE, McArt SH, Adler LS. Bee pathogen transmission dynamics: deposition, persistence and acquisition on flowers. Proc Biol Sci 2019; 286:20190603. [PMID: 31138075 PMCID: PMC6545085 DOI: 10.1098/rspb.2019.0603] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/03/2019] [Indexed: 12/24/2022] Open
Abstract
Infectious diseases are a primary driver of bee decline worldwide, but limited understanding of how pathogens are transmitted hampers effective management. Flowers have been implicated as hubs of bee disease transmission, but we know little about how interspecific floral variation affects transmission dynamics. Using bumblebees ( Bombus impatiens), a trypanosomatid pathogen ( Crithidia bombi) and three plant species varying in floral morphology, we assessed how host infection and plant species affect pathogen deposition on flowers, and plant species and flower parts impact pathogen survival and acquisition at flowers. We found that host infection with Crithidia increased defaecation rates on flowers, and that bees deposited faeces onto bracts of Lobelia siphilitica and Lythrum salicaria more frequently than onto Monarda didyma bracts . Among flower parts, bracts were associated with the lowest pathogen survival but highest resulting infection intensity in bee hosts. Additionally, we found that Crithidia survival across flower parts was reduced with sun exposure. These results suggest that efficiency of pathogen transmission depends on where deposition occurs and the timing and place of acquisition, which varies among plant species and environmental conditions. This information could be used for development of wildflower mixes that maximize forage while minimizing disease spread.
Collapse
Affiliation(s)
| | - Malcolm Blinder
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Cali Grincavitch
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Angus Jelinek
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Emilia K. Mann
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Liam A. Merva
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Lucy E. Metz
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Amy Y. Zhao
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Rebecca E. Irwin
- Department of Applied Ecology, North Carolina State University, 127 David Clark Laboratories, Raleigh, NC 27695, USA
| | - Scott H. McArt
- Department of Entomology, Cornell University, Ithaca, NY 14853, USA
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts, Amherst, MA 01003, USA
| |
Collapse
|
52
|
Liu Q, Lei J, Kadowaki T. Gene Disruption of Honey Bee Trypanosomatid Parasite, Lotmaria passim, by CRISPR/Cas9 System. Front Cell Infect Microbiol 2019; 9:126. [PMID: 31080782 PMCID: PMC6497781 DOI: 10.3389/fcimb.2019.00126] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 04/10/2019] [Indexed: 11/13/2022] Open
Abstract
Two trypanosomatid species, Lotmaria passim and Crithidia mellificae, have been shown to parasitize honey bees to date. L. passim appears to be more prevalent than C. mellificae and specifically infects the honey bee hindgut. Although the genomic DNA has been sequenced, the effects of infection on honey bee health and colony are poorly understood. To identify the genes that are important for infecting honey bees and to understand their functions, we applied the CRISPR/Cas9 system to establish a method to manipulate L. passim genes. By electroporation of plasmid DNA and subsequent selection by drug, we first established an L. passim clone expressing tdTomato or Cas9. We also successfully disrupted the endogenous miltefosine transporter and tyrosine aminotransferase genes by replacement with drug (hygromycin) resistant gene using the CRISPR/Cas9-induced homology-directed repair pathway. The L. passim clone expressing fluorescent marker, as well as the simple method for editing specific genes, could become useful approaches to understand the underlying mechanisms of honey bee-trypanosomatid parasite interactions.
Collapse
Affiliation(s)
| | | | - Tatsuhiko Kadowaki
- Department of Biological Sciences, Xi'an Jiaotong-Liverpool University, Suzhou, China
| |
Collapse
|
53
|
Binning SA, Roche DG, Grutter AS, Colosio S, Sun D, Miest J, Bshary R. Cleaner wrasse indirectly affect the cognitive performance of a damselfish through ectoparasite removal. Proc Biol Sci 2019. [PMID: 29514969 DOI: 10.1098/rspb.2017.2447] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cleaning organisms play a fundamental ecological role by removing ectoparasites and infected tissue from client surfaces. We used the well-studied cleaning mutualisms involving the cleaner wrasse, Labroides dimidiatus, to test how client cognition is affected by ectoparasites and whether these effects are mitigated by cleaners. Ambon damselfish (Pomacentrus amboinensis) collected from experimental reef patches without cleaner wrasse performed worse in a visual discrimination test than conspecifics from patches with cleaners. Endoparasite abundance also negatively influenced success in this test. Visual discrimination performance was also impaired in damselfish experimentally infected with gnathiid (Crustacea: Isopoda) ectoparasites. Neither cleaner absence nor gnathiid infection affected performance in spatial recognition or reversal learning tests. Injection with immune-stimulating lipopolysaccharide did not affect visual discrimination performance relative to saline-injected controls, suggesting that cognitive impairments are not due to an innate immune response. Our results highlight the complex, indirect role of cleaning organisms in promoting the health of their clients via ectoparasite removal and emphasize the negative impact of parasites on host's cognitive abilities.
Collapse
Affiliation(s)
- Sandra A Binning
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland .,School of Biological Sciences, The University of Queensland, St-Lucia, Australia.,Département de sciences biologiques, Université de Montréal, Montréal, QC, Canada
| | - Dominique G Roche
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland.,School of Biological Sciences, The University of Queensland, St-Lucia, Australia
| | - Alexandra S Grutter
- School of Biological Sciences, The University of Queensland, St-Lucia, Australia
| | - Simona Colosio
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| | - Derek Sun
- School of Biological Sciences, The University of Queensland, St-Lucia, Australia
| | - Joanna Miest
- Department of Life and Sports Sciences, University of Greenwich, Kent, UK
| | - Redouan Bshary
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
| |
Collapse
|
54
|
Dunlap AS, Austin MW, Figueiredo A. Components of change and the evolution of learning in theory and experiment. Anim Behav 2019. [DOI: 10.1016/j.anbehav.2018.05.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
55
|
Adler LS, Michaud KM, Ellner SP, McArt SH, Stevenson PC, Irwin RE. Disease where you dine: plant species and floral traits associated with pathogen transmission in bumble bees. Ecology 2018; 99:2535-2545. [PMID: 30155907 DOI: 10.1002/ecy.2503] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 06/15/2018] [Accepted: 07/05/2018] [Indexed: 11/11/2022]
Abstract
Hotspots of disease transmission can strongly influence pathogen spread. Bee pathogens may be transmitted via shared floral use, but the role of plant species and floral trait variation in shaping transmission dynamics is almost entirely unexplored. Given the importance of pathogens for the decline of several bee species, understanding whether and how plant species and floral traits affect transmission could give us important tools for predicting which plant species may be hotspots for disease spread. We assessed variation in transmission via susceptibility (probability of infection) and mean intensity (cell count of infected bees) of the trypanosomatid gut pathogen Crithidia bombi to uninfected Bombus impatiens workers foraging on 14 plant species, and assessed the role of floral traits, bee size and foraging behavior on transmission. We also conducted a manipulative experiment to determine how the number of open flowers affected transmission on three plant species, Penstemon digitalis, Monarda didyma, and Lythrum salicaria. Plant species differed fourfold in the overall mean abundance of Crithidia in foraging bumble bees (mean including infected and uninfected bees). Across plant species, bee susceptibility and mean intensity increased with the number of reproductive structures per inflorescence (buds, flowers and fruits); smaller bees and those that foraged longer were also more susceptible. Trait-based models were as good or better than species-based models at predicting susceptibility and mean intensity based on AIC values. Surprisingly, floral size and morphology did not significantly predict transmission across species. In the manipulative experiment, more open flowers increased mean pathogen abundance fourfold in Monarda, but had no effect in the other two plant species. Our results suggest that variation among plant species, through their influence on pathogen transmission, may shape bee disease dynamics. Given widespread investment in pollinator-friendly plantings to support pollinators, understanding how plant species affect disease transmission is important for recommending plant species that optimize pollinator health.
Collapse
Affiliation(s)
- Lynn S Adler
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Kristen M Michaud
- Department of Biology, University of Massachusetts, Amherst, Massachusetts, 01003, USA
| | - Stephen P Ellner
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, 14853, USA
| | - Scott H McArt
- Department of Entomology, Cornell University, Ithaca, New York, 14853, USA
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Richmond, TW9 3AB, UK.,Natural Resources Institute, University of Greenwich, Chatham, ME4 4TB, UK
| | - Rebecca E Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, 27695, USA
| |
Collapse
|
56
|
Sánchez CA, Becker DJ, Teitelbaum CS, Barriga P, Brown LM, Majewska AA, Hall RJ, Altizer S. On the relationship between body condition and parasite infection in wildlife: a review and meta-analysis. Ecol Lett 2018; 21:1869-1884. [PMID: 30369000 DOI: 10.1111/ele.13160] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/18/2018] [Accepted: 07/25/2018] [Indexed: 12/28/2022]
Abstract
Body condition metrics are widely used to infer animal health and to assess costs of parasite infection. Since parasites harm their hosts, ecologists might expect negative relationships between infection and condition in wildlife, but this assumption is challenged by studies showing positive or null condition-infection relationships. Here, we outline common condition metrics used by ecologists in studies of parasitism, and consider mechanisms that cause negative, positive, and null condition-infection relationships in wildlife systems. We then perform a meta-analysis of 553 condition-infection relationships from 187 peer-reviewed studies of animal hosts, analysing observational and experimental records separately, and noting whether authors measured binary infection status or intensity. Our analysis finds substantial heterogeneity in the strength and direction of condition-infection relationships, a small, negative average effect size that is stronger in experimental studies, and evidence for publication bias towards negative relationships. The strongest predictors of variation in study outcomes are host thermoregulation and the methods used to evaluate body condition. We recommend that studies aiming to assess parasite impacts on body condition should consider host-parasite biology, choose condition measures that can change during the course of infection, and employ longitudinal surveys or manipulate infection status when feasible.
Collapse
Affiliation(s)
- Cecilia A Sánchez
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Daniel J Becker
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA.,Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Claire S Teitelbaum
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Paola Barriga
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Leone M Brown
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Department of Biology, Tufts University, Medford, MA, USA
| | - Ania A Majewska
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Richard J Hall
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| |
Collapse
|
57
|
Egan PA, Adler LS, Irwin RE, Farrell IW, Palmer-Young EC, Stevenson PC. Crop Domestication Alters Floral Reward Chemistry With Potential Consequences for Pollinator Health. FRONTIERS IN PLANT SCIENCE 2018; 9:1357. [PMID: 30319666 PMCID: PMC6169423 DOI: 10.3389/fpls.2018.01357] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/28/2018] [Indexed: 05/29/2023]
Abstract
Crop domestication can lead to weakened expression of plant defences, with repercussions for herbivore and pathogen susceptibility. However, little is known about how domestication alters traits that mediate other important ecological interactions in crops, such as pollination. Secondary metabolites, which underpin many defence responses in plants, also occur widely in nectar and pollen and influence plant-pollinator interactions. Thus, domestication may also affect secondary compounds in floral rewards, with potential consequences for pollinators. To test this hypothesis, we chemically analysed nectar and pollen from wild and cultivated plants of highbush blueberry (Vaccinium corymbosum L.), before conducting an artificial diet bioassay to examine pollinator-pathogen interactions. Our results indicated that domestication has significantly altered the chemical composition of V. corymbosum nectar and pollen, and reduced pollen chemical diversity in cultivated plants. Of 20 plant metabolites identified in floral rewards, 13 differed significantly between wild and cultivated plants, with a majority showing positive associations with wild compared to cultivated plants. These included the amino acid phenylalanine (4.5 times higher in wild nectar, 11 times higher in wild pollen), a known bee phagostimulant and essential nutrient; and the antimicrobial caffeic acid ester 4-O-caffeoylshikimic acid (two times higher in wild nectar). We assessed the possible biological relevance of variation in caffeic acid esters in bioassays, using the commercially available 3-O-caffeoylquinic acid. This compound reduced Bombus impatiens infection by a prominent gut pathogen (Crithidia) at concentrations that occurred in wild but not cultivated plants, suggesting that domestication may influence floral traits with consequences for bee health. Appreciable levels of genetic variation and heritability were found for most floral reward chemical traits, indicating good potential for selective breeding. Our study provides the first assessment of plant domestication effects on floral reward chemistry and its potential repercussions for pollinator health. Given the central importance of pollinators for agriculture, we discuss the need to extend such investigations to pollinator-dependent crops more generally and elaborate on future research directions to ascertain wider trends, consequences for pollinators, mechanisms, and breeding solutions.
Collapse
Affiliation(s)
- Paul A. Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Rebecca E. Irwin
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States
| | | | - Evan C. Palmer-Young
- Department of Biology, University of Massachusetts Amherst, Amherst, MA, United States
| | - Philip C. Stevenson
- Royal Botanic Gardens, Kew, Richmond, United Kingdom
- Natural Resources Institute, University of Greenwich, London, United Kingdom
| |
Collapse
|
58
|
Davidson GL, Cooke AC, Johnson CN, Quinn JL. The gut microbiome as a driver of individual variation in cognition and functional behaviour. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170286. [PMID: 30104431 PMCID: PMC6107574 DOI: 10.1098/rstb.2017.0286] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2018] [Indexed: 12/30/2022] Open
Abstract
Research into proximate and ultimate mechanisms of individual cognitive variation in animal populations is a rapidly growing field that incorporates physiological, behavioural and evolutionary investigations. Recent studies in humans and laboratory animals have shown that the enteric microbial community plays a central role in brain function and development. The 'gut-brain axis' represents a multi-directional signalling system that encompasses neurological, immunological and hormonal pathways. In particular it is tightly linked with the hypothalamic-pituitary-adrenal axis (HPA), a system that regulates stress hormone release and influences brain development and function. Experimental examination of the microbiome through manipulation of diet, infection, stress and exercise, suggests direct effects on cognition, including learning and memory. However, our understanding of these processes in natural populations is extremely limited. Here, we outline how recent advances in predominantly laboratory-based microbiome research can be applied to understanding individual differences in cognition. Experimental manipulation of the microbiome across natal and adult environments will help to unravel the interplay between cognitive variation and the gut microbial community. Focus on individual variation in the gut microbiome and cognition in natural populations will reveal new insight into the environmental and evolutionary constraints that drive individual cognitive variation.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.
Collapse
Affiliation(s)
- Gabrielle L Davidson
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland T12 XF62
| | - Amy C Cooke
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland T12 XF62
| | - Crystal N Johnson
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Teagasc Food Research Centre, Moorepark, Fermoy, Ireland P61 C996
| | - John L Quinn
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland T12 XF62
| |
Collapse
|
59
|
Abstract
Gut symbionts can augment resistance to pathogens by stimulating host-immune responses, competing for space and nutrients, or producing antimicrobial metabolites. Gut microbiota of social bees, which pollinate many crops and wildflowers, protect hosts against diverse infections and might counteract pathogen-related bee declines. Bumble bee gut microbiota, and specifically abundance of Lactobacillus 'Firm-5' bacteria, can enhance resistance to the trypanosomatid parasite Crithidia bombi. However, the mechanism underlying this effect remains unknown. We hypothesized that the Firm-5 bacterium Lactobacillus bombicola, which produces lactic acid, inhibits C. bombi via pH-mediated effects. Consistent with our hypothesis, L. bombicola spent medium inhibited C. bombi growth via reduction in pH that was both necessary and sufficient for inhibition. Inhibition of all parasite strains occurred within the pH range documented in honey bees, though sensitivity to acidity varied among strains. Spent medium was slightly more potent than HCl, d- and l-lactic acids for a given pH, suggesting that other metabolites also contribute to inhibition. Results implicate symbiont-mediated reduction in gut pH as a key determinant of trypanosomatid infection in bees. Future investigation into in vivo effects of gut microbiota on pH and infection intensity would test the relevance of these findings for bees threatened by trypanosomatids.
Collapse
|
60
|
Malfi RL, Walter JA, Roulston TH, Stuligross C, McIntosh S, Bauer L. The influence of conopid flies on bumble bee colony productivity under different food resource conditions. ECOL MONOGR 2018. [DOI: 10.1002/ecm.1327] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Rosemary L. Malfi
- Department of Environmental Sciences; University of Virginia; Charlottesville Virginia 22904 USA
| | - Jonathan A. Walter
- Department of Environmental Sciences; University of Virginia; Charlottesville Virginia 22904 USA
- Department of Biology; Virginia Commonwealth University; Richmond Virginia 23284 USA
| | - T'ai H. Roulston
- Department of Environmental Sciences; University of Virginia; Charlottesville Virginia 22904 USA
| | - Clara Stuligross
- Department of Environmental Studies; Earlham College; Richmond Indiana 47374 USA
| | - Sarah McIntosh
- Department of Environmental Sciences; University of Virginia; Charlottesville Virginia 22904 USA
| | - Lewis Bauer
- Charlottesville City Public Schools; Charlottesville Virginia 22903 USA
| |
Collapse
|
61
|
The origins of global invasions of the German wasp (Vespula germanica) and its infection with four honey bee viruses. Biol Invasions 2018. [DOI: 10.1007/s10530-018-1786-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
62
|
Pamminger T, Botías C, Goulson D, Hughes WOH. A mechanistic framework to explain the immunosuppressive effects of neurotoxic pesticides on bees. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13119] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
| | - Christina Botías
- School of Life SciencesUniversity of Sussex Brighton UK
- Estación Biológica de Doñana (EBD‐CSIC) Seville Spain
| | - Dave Goulson
- School of Life SciencesUniversity of Sussex Brighton UK
| | | |
Collapse
|
63
|
Immune-cognitive system connectivity reduces bumblebee foraging success in complex multisensory floral environments. Sci Rep 2018; 8:5953. [PMID: 29654316 PMCID: PMC5899130 DOI: 10.1038/s41598-018-24372-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 04/03/2018] [Indexed: 02/07/2023] Open
Abstract
Bumblebees are declining at alarming rate worldwide, posing a significant threat to the function and diversity of temperate ecosystems. These declines have been attributed, in part, to the direct effect of specific pathogens on bumblebee survival. However, pathogens may also have a negative impact on host populations indirectly through immune-induced cognitive deficits in infected individuals. To gain greater insight into mechanisms and potential conservation implications of such 'immune-brain crosstalk' in bumblebees, we non-pathogenetically activated humoral and cellular immune pathways in individuals and then tested for long-term reductions in cognitive performance and foraging proficiency. We show that chronic activation of humoral, but not a cellular, immune pathways and effectors in foragers significantly reduces their ability to flexibly and efficiently harvest resources in multi-sensory floral environments for at least 7 days post-treatment. Humoral defense responses thus have the potential to confer significant foraging costs to bumblebee foragers over timeframes that would negatively impact colony growth and reproductive output under natural conditions. Our findings indicate that fitness effects of immune-brain crosstalk should be considered before attributing wild bumblebee decline to a particular pathogen species.
Collapse
|
64
|
Martin CD, Fountain MT, Brown MJF. Bumblebee olfactory learning affected by task allocation but not by a trypanosome parasite. Sci Rep 2018; 8:5809. [PMID: 29643344 PMCID: PMC5895637 DOI: 10.1038/s41598-018-24007-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 03/26/2018] [Indexed: 01/20/2023] Open
Abstract
Parasites can induce behavioural changes in their host organisms. Several parasite species are known to infect bumblebees, an important group of pollinators. Task allocation within bumblebee colonies can also cause differences in behaviour. Thus, task allocation may lead to context-dependent impacts of parasites on host behaviour. This study uses Bombus terrestris and its gut trypanosome Crithidia bombi, to investigate the effects of parasitism, task allocation (foraging or nest-work) and their interactions, on olfactory learning. Prior to undergoing the olfactory learning task, bees were orally infected with a field-realistic dose of C. bombi, and observed to determine task allocation. Parasitism did not significantly affect olfactory learning, but task allocation did, with foragers being significantly more likely to learn than nest bees. There was no significant interaction between parasitism and task. These results suggest that C. bombi is unlikely to affect pollination services via changes in olfactory learning of its host if bees are under no environmental or nutritional stress. However, wild and commercial colonies are likely to face such stressors. Future studies in the field are needed to extrapolate our results to real world effects.
Collapse
Affiliation(s)
- Callum D Martin
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom.
| | | | - Mark J F Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, United Kingdom
| |
Collapse
|
65
|
Theodorou P, Radzevičiūtė R, Settele J, Schweiger O, Murray TE, Paxton RJ. Pollination services enhanced with urbanization despite increasing pollinator parasitism. Proc Biol Sci 2017; 283:rspb.2016.0561. [PMID: 27335419 PMCID: PMC4936033 DOI: 10.1098/rspb.2016.0561] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/25/2016] [Indexed: 11/12/2022] Open
Abstract
Animal-mediated pollination is required for the reproduction of the majority of angiosperms, and pollinators are therefore essential for ecosystem functioning and the economy. Two major threats to insect pollinators are anthropogenic land-use change and the spread of pathogens, whose effects may interact to impact pollination. Here, we investigated the relative effects on the ecosystem service of pollination of (i) land-use change brought on by agriculture and urbanization as well as (ii) the prevalence of pollinator parasites, using experimental insect pollinator-dependent plant species in natural pollinator communities. We found that pollinator habitat (i.e. availability of nesting resources for ground-nesting bees and local flower richness) was strongly related to flower visitation rates at the local scale and indirectly influenced plant pollination success. At the landscape scale, pollination was positively related to urbanization, both directly and indirectly via elevated visitation rates. Bumblebees were the most abundant pollinator group visiting experimental flowers. Prevalence of trypanosomatids, such as the common bumblebee parasite Crithidia bombi, was higher in urban compared with agricultural areas, a relationship which was mediated through higher Bombus abundance. Yet, we did not find any top-down, negative effects of bumblebee parasitism on pollination. We conclude that urban areas can be places of high transmission of both pollen and pathogens.
Collapse
Affiliation(s)
- 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 Department of Community Ecology, Helmholtz Centre for Environmental Research-UFZ Halle, Theodor-Lieser-Strasse 4, 06120 Halle, Germany
| | - Rita Radzevičiūtė
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany Molecular Evolution and Animal Systematics, Institute of Biology, University of Leipzig, Talstrasse 33, 04103 Leipzig, Germany ESCALATE, Department of Computational Landscape Ecology, Helmholtz Centre for Environmental Research-UFZ Leipzig, Permoserstrasse 15, 04318 Leipzig, Germany Department of Zoology, Faculty of Natural Sciences, Vilnius University, M.K. Čiurlionio 21/27, 03101 Vilnius, Lithuania
| | - Josef Settele
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany Department of Community Ecology, Helmholtz Centre for Environmental Research-UFZ Halle, Theodor-Lieser-Strasse 4, 06120 Halle, Germany
| | - Oliver Schweiger
- Department of Community Ecology, Helmholtz Centre for Environmental Research-UFZ Halle, Theodor-Lieser-Strasse 4, 06120 Halle, Germany
| | - Tomás E Murray
- General Zoology, Institute for Biology, Martin Luther University Halle-Wittenberg, Hoher Weg 8, 06120 Halle (Saale), Germany National Biodiversity Data Centre, Beechfield House, WIT West Campus, Waterford, Co., Waterford, Ireland
| | - 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
|
66
|
Kishani Farahani H, Ashouri A, Goldansaz SH, Shapiro MS, Pierre JS, van Baaren J. Decrease of memory retention in a parasitic wasp: an effect of host manipulation by Wolbachia? INSECT SCIENCE 2017; 24:569-583. [PMID: 27090067 DOI: 10.1111/1744-7917.12348] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 02/24/2016] [Accepted: 03/13/2016] [Indexed: 06/05/2023]
Abstract
Several factors, such as cold exposure, aging, the number of experiences and viral infection, have been shown to affect learning ability in different organisms. Wolbachia has been found worldwide as an arthropod parasite/mutualist symbiont in a wide range of species, including insects. Differing effects have been identified on physiology and behavior by Wolbachia. However, the effect of Wolbachia infection on the learning ability of their host had never previously been studied. The current study carried out to compare learning ability and memory duration in 2 strains of the parasitoid Trichogramma brassicae: 1 uninfected and 1 infected by Wolbachia. Both strains were able to associate the novel odors with the reward of an oviposition into a host egg. However, the percentage of females that responded to the experimental design and displayed an ability to learn in these conditions was higher in the uninfected strain. Memory duration was longer in uninfected wasps (23.8 and 21.4 h after conditioning with peppermint and lemon, respectively) than in infected wasps (18.9 and 16.2 h after conditioning with peppermint and lemon, respectively). Memory retention increased in response to the number of conditioning sessions in both strains, but memory retention was always shorter in the infected wasps than in the uninfected ones. Wolbachia infection may select for reduced memory retention because shorter memory induces infected wasps to disperse in new environments and avoid competition with uninfected wasps by forgetting cues related to previously visited environments, thus increasing transmission of Wolbachia in new environments.
Collapse
Affiliation(s)
- Hossein Kishani Farahani
- Faculty of Agriculture and Natural Resources, Department of Plant Protection, University of Tehran, Karaj, Iran
| | - Ahmad Ashouri
- Faculty of Agriculture and Natural Resources, Department of Plant Protection, University of Tehran, Karaj, Iran
| | - Seyed Hossein Goldansaz
- Faculty of Agriculture and Natural Resources, Department of Plant Protection, University of Tehran, Karaj, Iran
| | - Martin S Shapiro
- Department of Psychology, California State University, Fresno, USA
| | - Jean-Sebastien Pierre
- UMR-CNRS 6553 EcoBio, University of Rennes 1, Avenue du Général Leclerc, Campus de Beaulieu, 35042, Rennes Cedex, France
| | - Joan van Baaren
- UMR-CNRS 6553 EcoBio, University of Rennes 1, Avenue du Général Leclerc, Campus de Beaulieu, 35042, Rennes Cedex, France
| |
Collapse
|
67
|
Koch H, Brown MJ, Stevenson PC. The role of disease in bee foraging ecology. CURRENT OPINION IN INSECT SCIENCE 2017; 21:60-67. [PMID: 28822490 DOI: 10.1016/j.cois.2017.05.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/03/2017] [Accepted: 05/10/2017] [Indexed: 06/07/2023]
Abstract
Diseases have important but understudied effects on bee foraging ecology. Bees transmit and contract diseases on flowers, but floral traits including plant volatiles and inflorescence architecture may affect transmission. Diseases spill over from managed or invasive pollinators to native wild bee species, and impacts of emerging diseases are of particular concern, threatening pollinator populations and pollination services. Here we review how parasites can alter the foraging behaviour of bees by changing floral preferences and impairing foraging efficiency. We also consider how changes to pollinator behaviours alter or reduce pollination services. The availability of diverse floral resources can, however, ameliorate bee diseases and their impacts through better nutrition and antimicrobial effects of plant compounds in pollen and nectar.
Collapse
Affiliation(s)
| | - Mark Jf Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, UK
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Surrey, UK; Natural Resources Institute, University of Greenwich, Kent, UK
| |
Collapse
|
68
|
Byrne PG, Silla AJ. Testing the effect of dietary carotenoids on larval survival, growth and development in the critically endangered southern corroboree frog. Zoo Biol 2017; 36:161-169. [PMID: 28198035 DOI: 10.1002/zoo.21352] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 01/09/2017] [Accepted: 01/17/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Phillip G. Byrne
- Centre for Sustainable Ecosystem SolutionsSchool of Biological SciencesUniversity of WollongongWollongongNew South WalesAustralia
| | - Aimee J. Silla
- Centre for Sustainable Ecosystem SolutionsSchool of Biological SciencesUniversity of WollongongWollongongNew South WalesAustralia
| |
Collapse
|
69
|
Piiroinen S, Goulson D. Chronic neonicotinoid pesticide exposure and parasite stress differentially affects learning in honeybees and bumblebees. Proc Biol Sci 2016; 283:rspb.2016.0246. [PMID: 27053744 DOI: 10.1098/rspb.2016.0246] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 03/14/2016] [Indexed: 12/17/2022] Open
Abstract
Learning and memory are crucial functions which enable insect pollinators to efficiently locate and extract floral rewards. Exposure to pesticides or infection by parasites may cause subtle but ecologically important changes in cognitive functions of pollinators. The potential interactive effects of these stressors on learning and memory have not yet been explored. Furthermore, sensitivity to stressors may differ between species, but few studies have compared responses in different species. Here, we show that chronic exposure to field-realistic levels of the neonicotinoid clothianidin impaired olfactory learning acquisition in honeybees, leading to potential impacts on colony fitness, but not in bumblebees. Infection by the microsporidian parasite Nosema ceranae slightly impaired learning in honeybees, but no interactive effects were observed. Nosema did not infect bumblebees (3% infection success). Nevertheless, Nosema-treated bumblebees had a slightly lower rate of learning than controls, but faster learning in combination with neonicotinoid exposure. This highlights the potential for complex interactive effects of stressors on learning. Our results underline that one cannot readily extrapolate findings from one bee species to others. This has important implications for regulatory risk assessments which generally use honeybees as a model for all bees.
Collapse
Affiliation(s)
- Saija Piiroinen
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - Dave Goulson
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| |
Collapse
|
70
|
|
71
|
Cauchard L, Angers B, Boogert NJ, Doligez B. Effect of an anti-malaria drug on behavioural performance on a problem-solving task: an experiment in wild great tits. Behav Processes 2016; 133:S0376-6357(16)30321-7. [PMID: 27984082 DOI: 10.1016/j.beproc.2016.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 10/18/2016] [Accepted: 10/27/2016] [Indexed: 10/20/2022]
Abstract
Malaria parasites have been shown to decrease host fitness in several species in the wild and their detrimental effects on host cognitive ability are well established in humans. However, experimental demonstrations of detrimental effects on non-human host behaviour are currently limited. In this study, we experimentally tested whether injections of an anti-malaria drug affected short-term behavioural responses to a problem-solving task during breeding in a wild population of great tits (Parus major) naturally infected with malaria. Adult females treated against malaria were more active than control females, even though they were not more likely to solve the task or learn how to do so, suggesting that energetic constraints could shape differences in some behaviours while changes in cognitive performances might require more time for the neural system to recover or may depend mainly on infection at the developmental stage. Alternatively, parasite load might be a consequence, rather than a cause, of inter-individual variation in cognitive performance. These results also suggest that inter-individual as well as inter-population differences in some behavioural traits may be linked to blood parasite load.
Collapse
Affiliation(s)
- Laure Cauchard
- Département de Sciences Biologiques, Université de Montréal, Pavillon Marie-Victorin, bureau D-221, C.P. 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada.
| | - Bernard Angers
- Département de Sciences Biologiques, Université de Montréal, Pavillon Marie-Victorin, bureau D-221, C.P. 6128, succ. Centre-ville, Montréal, Québec, H3C 3J7, Canada
| | - Neeltje J Boogert
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, UK
| | - Blandine Doligez
- CNRS, Université Lyon 1, Department of Biometry and Evolutionary Biology, UMR 5558, Villeurbanne, France; Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| |
Collapse
|
72
|
Conroy TJ, Palmer-Young EC, Irwin RE, Adler LS. Food Limitation Affects Parasite Load and Survival of Bombus impatiens (Hymenoptera: Apidae) Infected With Crithidia (Trypanosomatida: Trypanosomatidae). ENVIRONMENTAL ENTOMOLOGY 2016; 45:1212-1219. [PMID: 27523087 DOI: 10.1093/ee/nvw099] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/17/2016] [Indexed: 06/06/2023]
Abstract
Bumble bees (genus Bombus) are globally important insect pollinators, and several species have experienced marked declines in recent years. Both nutritional limitation and pathogens may have contributed to these declines. While each of these factors may be individually important, there may also be synergisms where nutritional stress could decrease pathogen resistance. Understanding interactions between bumble bees, their parasites, and food availability may provide new insight into the causes of declines. In this study, we examined the combined impacts of pollen and nectar limitation on Crithidia, a common gut parasite in Bombus impatiens Cresson. Individual worker bees were inoculated with Crithidia and then assigned in a factorial design to two levels of pollen availability (pollen or no pollen) and two nectar sugar concentrations (high [30%] or low [15%] sucrose). We found that lack of pollen and low nectar sugar both reduced Crithidia cell counts, with the most dramatic effect from lack of pollen. Both pollen availability and nectar sugar concentration were also important for bee survival. The proportion of bees that died after seven days of infection was ∼25% lower in bees with access to pollen and high nectar sugar concentration than any other treatment. Thus, nectar and pollen availability are both important for bee survival, but may come at a cost of higher parasite loads. Our results illustrate the importance of understanding environmental context, such as resource availability, when examining a host-parasite interaction.
Collapse
Affiliation(s)
- Taylor J Conroy
- Department of Biology, 221 Morrill Science Center, University of Massachusetts Amherst, 611 N. Pleasant St, Amherst, MA 01003 (; ; )
| | - Evan C Palmer-Young
- Department of Biology, 221 Morrill Science Center, University of Massachusetts Amherst, 611 N. Pleasant St, Amherst, MA 01003 (; ; )
| | - Rebecca E Irwin
- Department of Applied Ecology, David Clark Labs, North Carolina State University, Raleigh, NC 27695
| | - Lynn S Adler
- Department of Biology, 221 Morrill Science Center, University of Massachusetts Amherst, 611 N. Pleasant St, Amherst, MA 01003 (; ; )
| |
Collapse
|
73
|
Klemme I, Karvonen A. Learned parasite avoidance is driven by host personality and resistance to infection in a fish-trematode interaction. Proc Biol Sci 2016; 283:20161148. [PMID: 27605504 PMCID: PMC5031654 DOI: 10.1098/rspb.2016.1148] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/16/2016] [Indexed: 12/22/2022] Open
Abstract
Cognitive abilities related to the assessment of risk improve survival. While earlier studies have examined the ability of animals to learn to avoid predators, learned parasite avoidance has received little interest. In a series of behavioural trials with the trematode parasite Diplostomum pseudospathaceum, we asked whether sea trout (Salmo trutta trutta) hosts show associative learning in the context of parasitism and if so, whether learning capacity is related to the likelihood of infection mediated through host personality and resistance. We show that animals are capable of learning to avoid visual cues associated with the presence of parasites. However, avoidance behaviour ceased after the likely activation of host resistance following consecutive exposures during learning, suggesting that resistance to infection outweighs avoidance. Further, we found a positive relationship between learning ability and boldness, suggesting a compensation of risky lifestyles through increased investment in cognitive abilities. By contrast, an increased risk of infection due to low resistance was not balanced by learning ability. Instead, these traits were positively related, which may be explained by inherent physiological qualities controlling both traits. Overall, the results demonstrate that parasitism, in addition to other biological interactions such as predation, is an important selective factor in the evolution of animal cognition.
Collapse
Affiliation(s)
- Ines Klemme
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, 40014 University of Jyvaskyla, Finland
| | - Anssi Karvonen
- Department of Biological and Environmental Science, University of Jyvaskyla, PO Box 35, 40014 University of Jyvaskyla, Finland
| |
Collapse
|
74
|
Zhang YY, Guo XL, Liu YL, Liu F, Wang HF, Guo XQ, Xu BH. Functional and mutational analyses of an omega-class glutathione S-transferase (GSTO2) that is required for reducing oxidative damage in Apis cerana cerana. INSECT MOLECULAR BIOLOGY 2016; 25:470-486. [PMID: 27170478 DOI: 10.1111/imb.12236] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Glutathione S-transferases perform a variety of vital functions, particularly in reducing oxidative damage. Here, we investigated the expression patterns of Apis cerana cerana omega-class glutathione S-transferase 2 (AccGSTO2) under various stresses and explored its connection with antioxidant defences. We found that AccGSTO2 knockdown by RNA interference triggered increased mortality in Ap. cerana cerana, and immunohistochemistry revealed significantly decreased AccGSTO2 expression, particularly in the midgut and fat body. Further analyses indicated that AccGSTO2 knockdown resulted in decreases in catalase and glutathione reductase activities, ascorbate content and the ratio of reduced to oxidized glutathione, and increases in H2 O2 , malondialdehyde and carbonyl contents. We also analysed the transcripts of other antioxidant genes and found that many genes were down-regulated in the AccGSTO2 knockdown samples, revealing that AccGSTO2 may be indispensable for attaining a normal lifespan by enhancing cellular oxidative resistance. In addition, the roles of cysteine residues in AccGSTO2 were explored using site-directed mutagenesis. Mutants of Cys(28) and Cys(124) significantly affected the enzyme and antioxidant activities of AccGSTO2, which may be attributed to the changes in the spatial structures of mutants as determined by homology modelling. In summary, these observations provide novel insight into the structural and functional characteristics of GSTOs.
Collapse
Affiliation(s)
- Y-Y Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
- School of Basic Medical Sciences, Taishan Medical University, Taian, Shandong, China
| | - X-L Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
| | - Y-L Liu
- School of Basic Medical Sciences, Taishan Medical University, Taian, Shandong, China
| | - F Liu
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China
| | - H-F Wang
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China
| | - X-Q Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong, China
| | - B-H Xu
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong, China
| |
Collapse
|
75
|
Early gut colonizers shape parasite susceptibility and microbiota composition in honey bee workers. Proc Natl Acad Sci U S A 2016; 113:9345-50. [PMID: 27482088 DOI: 10.1073/pnas.1606631113] [Citation(s) in RCA: 133] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Microbial symbionts living within animal guts are largely composed of resident bacterial species, forming communities that often provide benefits to the host. Gut microbiomes of adult honey bees (Apis mellifera) include core residents such as the betaproteobacterium Snodgrassella alvi, alongside transient parasites such as the protozoan Lotmaria passim To test how these species affect microbiome composition and host physiology, we administered S alvi and/or L passim inocula to newly emerged worker bees from four genetic backgrounds (GH) and reared them in normal (within hives) or stressed (protein-deficient, asocial) conditions. Microbiota acquired by normal bees were abundant but quantitatively differed across treatments, indicating treatment-associated dysbiosis. Pretreatment with S. alvi made normal bees more susceptible to L. passim and altered developmental and detoxification gene expression. Stressed bees were more susceptible to L. passim and were depauperate in core microbiota, yet supplementation with S. alvi did not alter this susceptibility. Microbiomes were generally more variable by GH in stressed bees, which also showed opposing and comparatively reduced modulation of gene expression responses to treatments compared with normal bees. These data provide experimental support for a link between altered gut microbiota and increased parasite and pathogen prevalence, as observed from honey bee colony collapse disorder.
Collapse
|
76
|
Piiroinen S, Botías C, Nicholls E, Goulson D. No effect of low-level chronic neonicotinoid exposure on bumblebee learning and fecundity. PeerJ 2016; 4:e1808. [PMID: 27014515 PMCID: PMC4806594 DOI: 10.7717/peerj.1808] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 02/23/2016] [Indexed: 11/22/2022] Open
Abstract
In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems. One of the most debated factors proposed to be contributing to pollinator declines is exposure to pesticides, particularly neonicotinoids, a widely used class of systemic insecticide. Also, newly emerging parasites and diseases, thought to be spread via contact with managed honeybees, may pose threats to other pollinators such as bumblebees. Compared to honeybees, bumblebees could be particularly vulnerable to the effects of stressors due to their smaller and more short-lived colonies. Here, we studied the effect of field-realistic, chronic clothianidin exposure and inoculation with the parasite Nosema ceranae on survival, fecundity, sugar water collection and learning using queenless Bombus terrestris audax microcolonies in the laboratory. Chronic exposure to 1 ppb clothianidin had no significant effects on the traits studied. Interestingly, pesticide exposure in combination with additional stress caused by harnessing bees for Proboscis Extension Response (PER) learning assays, led to an increase in mortality. In contrast to previous findings, the bees did not become infected by N. ceranae after experimental inoculation with the parasite spores, suggesting variability in host resistance or parasite virulence. However, this treatment induced a slight, short-term reduction in sugar water collection, potentially through stimulation of the immune system of the bees. Our results suggest that chronic exposure to 1 ppb clothianidin does not have adverse effects on bumblebee fecundity or learning ability.
Collapse
Affiliation(s)
- Saija Piiroinen
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Cristina Botías
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | | | - Dave Goulson
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| |
Collapse
|
77
|
Effects of Nosema apis, N. ceranae, and coinfections on honey bee (Apis mellifera) learning and memory. Sci Rep 2016; 6:22626. [PMID: 26961062 PMCID: PMC4785390 DOI: 10.1038/srep22626] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 10/20/2015] [Indexed: 11/30/2022] Open
Abstract
Western honey bees (Apis mellifera) face an increasing number of challenges that in recent years have led to significant economic effects on apiculture, with attendant consequences for agriculture. Nosemosis is a fungal infection of honey bees caused by either Nosema apis or N. ceranae. The putative greater virulence of N. ceranae has spurred interest in understanding how it differs from N. apis. Little is known of effects of N. apis or N. ceranae on honey bee learning and memory. Following a Pavlovian model that relies on the proboscis extension reflex, we compared acquisition learning and long-term memory recall of uninfected (control) honey bees versus those inoculated with N. apis, N. ceranae, or both. We also tested whether spore intensity was associated with variation in learning and memory. Neither learning nor memory differed among treatments. There was no evidence of a relationship between spore intensity and learning, and only limited evidence of a negative effect on memory; this occurred only in the co-inoculation treatment. Our results suggest that if Nosema spp. are contributing to unusually high colony losses in recent years, the mechanism by which they may affect honey bees is probably not related to effects on learning or memory, at least as assessed by the proboscis extension reflex.
Collapse
|
78
|
Biller OM, Adler LS, Irwin RE, McAllister C, Palmer-Young EC. Possible Synergistic Effects of Thymol and Nicotine Against Crithidia bombi Parasitism in Bumble Bees. PLoS One 2015; 10:e0144668. [PMID: 26657643 PMCID: PMC4686078 DOI: 10.1371/journal.pone.0144668] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Accepted: 11/20/2015] [Indexed: 02/06/2023] Open
Abstract
Floral nectar contains secondary compounds with antimicrobial properties that can affect not only plant-pollinator interactions, but also interactions between pollinators and their parasites. Although recent work has shown that consumption of plant secondary compounds can reduce pollinator parasite loads, little is known about the effects of dosage or compound combinations. We used the generalist pollinator Bombus impatiens and its obligate gut parasite Crithidia bombi to study the effects of nectar chemistry on host-parasite interactions. In two experiments we tested (1) whether the secondary compounds thymol and nicotine act synergistically to reduce parasitism, and (2) whether dietary thymol concentration affects parasite resistance. In both experiments, uninfected Bombus impatiens were inoculated with Crithidia and then fed particular diet treatments for 7 days, after which infection levels were assessed. In the synergism experiment, thymol and nicotine alone and in combination did not significantly affect parasite load or host mortality. However, the thymol-nicotine combination treatment reduced log-transformed parasite counts by 30% relative to the control group (P = 0.08). For the experiment in which we manipulated thymol concentration, we found no significant effect of any thymol concentration on Crithidia load, but moderate (2 ppm) thymol concentrations incurred a near-significant increase in mortality (P = 0.054). Our results tentatively suggest the value of a mixed diet for host immunity, yet contrast with research on the antimicrobial activity of dietary thymol and nicotine in vertebrate and other invertebrate systems. We suggest that future research evaluate genetic variation in Crithidia virulence, multi-strain competition, and Crithidia interactions with the gut microbe community that may mediate antimicrobial activities of secondary compounds.
Collapse
Affiliation(s)
- Olivia Masi Biller
- Department of Biology, University of Massachusetts at Amherst, Amherst, Massachusetts, United States of America
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts at Amherst, Amherst, Massachusetts, United States of America
| | - Rebecca E. Irwin
- Department of Biology, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Caitlin McAllister
- Department of Biology, University of Massachusetts at Amherst, Amherst, Massachusetts, United States of America
| | - Evan C. Palmer-Young
- Department of Biology, University of Massachusetts at Amherst, Amherst, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
79
|
Anthony WE, Palmer-Young EC, Leonard AS, Irwin RE, Adler LS. Testing Dose-Dependent Effects of the Nectar Alkaloid Anabasine on Trypanosome Parasite Loads in Adult Bumble Bees. PLoS One 2015; 10:e0142496. [PMID: 26545106 PMCID: PMC4636389 DOI: 10.1371/journal.pone.0142496] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/22/2015] [Indexed: 12/02/2022] Open
Abstract
The impact of consuming biologically active compounds is often dose-dependent, where small quantities can be medicinal while larger doses are toxic. The consumption of plant secondary compounds can be toxic to herbivores in large doses, but can also improve survival in parasitized herbivores. In addition, recent studies have found that consuming nectar secondary compounds may decrease parasite loads in pollinators. However, the effect of compound dose on bee survival and parasite loads has not been assessed. To determine how secondary compound consumption affects survival and pathogen load in Bombus impatiens, we manipulated the presence of a common gut parasite, Crithidia bombi, and dietary concentration of anabasine, a nectar alkaloid produced by Nicotiana spp. using four concentrations naturally observed in floral nectar. We hypothesized that increased consumption of secondary compounds at concentrations found in nature would decrease survival of uninfected bees, but improve survival and ameliorate parasite loads in infected bees. We found medicinal effects of anabasine in infected bees; the high-anabasine diet decreased parasite loads and increased the probability of clearing the infection entirely. However, survival time was not affected by any level of anabasine concentration, or by interactive effects of anabasine concentration and infection. Crithidia infection reduced survival time by more than two days, but this effect was not significant. Our results support a medicinal role for anabasine at the highest concentration; moreover, we found no evidence for a survival-related cost of anabasine consumption across the concentration range found in nectar. Our results suggest that consuming anabasine at the higher levels of the natural range could reduce or clear pathogen loads without incurring costs for healthy bees.
Collapse
Affiliation(s)
- Winston E. Anthony
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Evan C. Palmer-Young
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Anne S. Leonard
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| | - Rebecca E. Irwin
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
- Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Lynn S. Adler
- Department of Biology, University of Massachusetts Amherst, Amherst, Massachusetts, United States of America
| |
Collapse
|
80
|
Hess A, McAllister C, DeMarchi J, Zidek M, Murone J, Venesky MD. Salamanders increase their feeding activity when infected with the pathogenic chytrid fungus Batrachochytrium dendrobatidis. DISEASES OF AQUATIC ORGANISMS 2015; 116:205-212. [PMID: 26503775 DOI: 10.3354/dao02915] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Immune function is a costly line of defense against parasitism. When infected with a parasite, hosts frequently lose mass due to these costs. However, some infected hosts (e.g. highly resistant individuals) can clear infections with seemingly little fitness losses, but few studies have tested how resistant hosts mitigate these costly immune defenses. We explored this topic using eastern red-backed salamanders Plethodon cinereus and the fungal pathogen Batrachochytrium dendrobatidis (Bd). Bd is generally lethal for amphibians, and stereotypical symptoms of infection include loss in mass and deficits in feeding. However, individuals of P. cinereus can clear their Bd infections with seemingly few fitness costs. We conducted an experiment in which we repeatedly observed the feeding activity of Bd-infected and non-infected salamanders. We found that Bd-infected salamanders generally increased their feeding activity compared to non-infected salamanders. The fact that we did not observe any differences in mass change between the treatments suggests that increased feeding might help Bd-infected salamanders minimize the costs of an effective immune response.
Collapse
Affiliation(s)
- Alexandra Hess
- Department of Biology, Allegheny College, Meadville, PA 16335, USA
| | | | | | | | | | | |
Collapse
|
81
|
Graystock P, Goulson D, Hughes WOH. Parasites in bloom: flowers aid dispersal and transmission of pollinator parasites within and between bee species. Proc Biol Sci 2015; 282:20151371. [PMID: 26246556 PMCID: PMC4632632 DOI: 10.1098/rspb.2015.1371] [Citation(s) in RCA: 171] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/15/2015] [Indexed: 01/02/2023] Open
Abstract
The dispersal of parasites is critical for epidemiology, and the interspecific vectoring of parasites when species share resources may play an underappreciated role in parasite dispersal. One of the best examples of such a situation is the shared use of flowers by pollinators, but the importance of flowers and interspecific vectoring in the dispersal of pollinator parasites is poorly understood and frequently overlooked. Here, we use an experimental approach to show that during even short foraging periods of 3 h, three bumblebee parasites and two honeybee parasites were dispersed effectively onto flowers by their hosts, and then vectored readily between flowers by non-host pollinator species. The results suggest that flowers are likely to be hotspots for the transmission of pollinator parasites and that considering potential vector, as well as host, species will be of general importance for understanding the distribution and transmission of parasites in the environment and between pollinators.
Collapse
Affiliation(s)
| | - Dave Goulson
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | | |
Collapse
|
82
|
Baracchi D, Brown MJF, Chittka L. Weak and contradictory effects of self-medication with nectar nicotine by parasitized bumblebees. F1000Res 2015; 4:73. [PMID: 25949807 PMCID: PMC4406194 DOI: 10.12688/f1000research.6262.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/17/2015] [Indexed: 11/20/2022] Open
Abstract
The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solenaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication , using a series of toxicological, microbiological and behavioural experiments. Caged bees infected with Crithidia bombi [TI1] had a slight preference for sucrose solution laced with the alkaloid and behavioural tests showed that the parasite infection induced an increased consumption of nicotine during foraging activity. When ingested, nicotine delayed the progression of a gut infection in bumblebees by a few days, but dietary nicotine did not clear the infection, and after 10 days the parasite load approached that of control bees. Moreover, when pathogens were exposed to the alkaloid prior to host ingestion the protozoan's viability was not directly affected, suggesting that anti-parasite effects were relatively weak. Nicotine consumption in a single dose did not impose any cost even in food-stressed bees (starved) but the alkaloid had detrimental effects on healthy bees if consistently consumed for weeks. These toxic effects disappeared in infected bees suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the infection. Nonetheless we did not find a benefit of nicotine consumption in terms of life expectancy of infected bees, making these findings difficult to interpret. Our results indicate that caution is warranted in interpreting impacts of plant metabolites on insect parasites and suggest that the conditions under which nicotine consumption provides benefits to either bees or plants remain to be identified. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed.
Collapse
Affiliation(s)
- David Baracchi
- Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mark J. F. Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Lars Chittka
- Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| |
Collapse
|
83
|
Abstract
The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solanaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication , using a series of toxicological, microbiological and behavioural experiments. Caged bees infected with Crithidia bombi had a slight preference for sucrose solution laced with the alkaloid and behavioural tests showed that the parasite infection induced an increased consumption of nicotine during foraging activity, though nicotine had an appetite-reducing effect overall. When ingested, nicotine delayed the progression of a gut infection in bumblebees by a few days, but dietary nicotine did not clear the infection, and after 10 days the parasite load approached that of control bees. Moreover, when pathogens were exposed to the alkaloid prior to host ingestion, the protozoan's viability was not directly affected, suggesting that anti-parasite effects were relatively weak. Nicotine consumption in a single dose did not impose any cost even in starved bees but the alkaloid had detrimental effects on healthy bees if consistently consumed for weeks. These toxic effects disappeared in infected bees, suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the infection. Nicotine consumption did not affect bee lifespan but the reduction in the parasite load may have other likely unexplored subtle benefits both for individual bees and their colony. Potential evidence for self-medication is discussed. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed.
Collapse
Affiliation(s)
- David Baracchi
- Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mark J. F. Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Lars Chittka
- Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| |
Collapse
|
84
|
Abstract
The presence of antimicrobial secondary metabolites in nectar suggests that pollinators, which are threatened globally by emergent disease, may benefit from the consumption of nectars rich in these metabolites. We tested whether nicotine, a nectar secondary metabolite common in Solanaceae and Tilia species, is used by parasitized bumblebees as a source of self-medication , using a series of toxicological, microbiological and behavioural experiments. Caged bees infected with Crithidia bombi had a slight preference for sucrose solution laced with the alkaloid and behavioural tests showed that the parasite infection induced an increased consumption of nicotine during foraging activity, though nicotine had an appetite-reducing effect overall. When ingested, nicotine delayed the progression of a gut infection in bumblebees by a few days, but dietary nicotine did not clear the infection, and after 10 days the parasite load approached that of control bees. Moreover, when pathogens were exposed to the alkaloid prior to host ingestion, the protozoan's viability was not directly affected, suggesting that anti-parasite effects were relatively weak. Nicotine consumption in a single dose did not impose any cost even in starved bees but the alkaloid had detrimental effects on healthy bees if consistently consumed for weeks. These toxic effects disappeared in infected bees, suggesting that detoxification costs might have been counterbalanced by the advantages in slowing the progression of the infection. Nicotine consumption did not affect bee lifespan but the reduction in the parasite load may have other likely unexplored subtle benefits both for individual bees and their colony. Potential evidence for self-medication is discussed. The contention that secondary metabolites in nectar may be under selection from pollinators, or used by plants to enhance their own reproductive success, remains to be confirmed.
Collapse
Affiliation(s)
- David Baracchi
- Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Mark J. F. Brown
- School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK
| | - Lars Chittka
- Department of Biological and Experimental Psychology, School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| |
Collapse
|
85
|
Morand-Ferron J, Cole EF, Quinn JL. Studying the evolutionary ecology of cognition in the wild: a review of practical and conceptual challenges. Biol Rev Camb Philos Soc 2015; 91:367-89. [PMID: 25631282 DOI: 10.1111/brv.12174] [Citation(s) in RCA: 154] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 12/11/2014] [Accepted: 12/19/2014] [Indexed: 12/24/2022]
Abstract
Cognition is defined as the processes by which animals collect, retain and use information from their environment to guide their behaviour. Thus cognition is essential in a wide range of behaviours, including foraging, avoiding predators and mating. Despite this pivotal role, the evolutionary processes shaping variation in cognitive performance among individuals in wild populations remain very poorly understood. Selection experiments in captivity suggest that cognitive traits can have substantial heritability and can undergo rapid evolution. However only a handful of studies have attempted to explore how cognition influences life-history variation and fitness in the wild, and direct evidence for the action of natural or sexual selection on cognition is still lacking, reasons for which are diverse. Here we review the current literature with a view to: (i) highlighting the key practical and conceptual challenges faced by the field; (ii) describing how to define and measure cognitive traits in natural populations, and suggesting which species, populations and cognitive traits might be examined to greatest effect; emphasis is placed on selecting traits that are linked to functional behaviour; (iii) discussing how to deal with confounding factors such as personality and motivation in field as well as captive studies; (iv) describing how to measure and interpret relationships between cognitive performance, functional behaviour and fitness, offering some suggestions as to when and what kind of selection might be predicted; and (v) showing how an evolutionary ecological framework, more generally, along with innovative technologies has the potential to revolutionise the study of cognition in the wild. We conclude that the evolutionary ecology of cognition in wild populations is a rapidly expanding interdisciplinary field providing many opportunities for advancing the understanding of how cognitive abilities have evolved.
Collapse
Affiliation(s)
- Julie Morand-Ferron
- Department of Biology, University of Ottawa, 30 Marie Curie, Gendron Hall, room 160, Ottawa, Ontario K1N 6N5, Canada
| | - Ella F Cole
- Edward Grey Institute, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, U.K
| | - John L Quinn
- School of Biological, Earth and Environmental Sciences, University College Cork, Distillery Fields, North Mall, Cork, Ireland
| |
Collapse
|
86
|
Nepoux V, Babin A, Haag C, Kawecki TJ, Le Rouzic A. Quantitative genetics of learning ability and resistance to stress in Drosophila melanogaster. Ecol Evol 2015; 5:543-56. [PMID: 25691979 PMCID: PMC4328760 DOI: 10.1002/ece3.1379] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 11/19/2014] [Accepted: 11/21/2014] [Indexed: 11/12/2022] Open
Abstract
Even though laboratory evolution experiments have demonstrated genetic variation for learning ability, we know little about the underlying genetic architecture and genetic relationships with other ecologically relevant traits. With a full diallel cross among twelve inbred lines of Drosophila melanogaster originating from a natural population (0.75 < F < 0.93), we investigated the genetic architecture of olfactory learning ability and compared it to that for another behavioral trait (unconditional preference for odors), as well as three traits quantifying the ability to deal with environmental challenges: egg-to-adult survival and developmental rate on a low-quality food, and resistance to a bacterial pathogen. Substantial additive genetic variation was detected for each trait, highlighting their potential to evolve. Genetic effects contributed more than nongenetic parental effects to variation in traits measured at the adult stage: learning, odorant perception, and resistance to infection. In contrast, the two traits quantifying larval tolerance to low-quality food were more strongly affected by parental effects. We found no evidence for genetic correlations between traits, suggesting that these traits could evolve at least to some degree independently of one another. Finally, inbreeding adversely affected all traits.
Collapse
Affiliation(s)
- Virginie Nepoux
- Department of Ecology and Evolution, University of Lausanne Lausanne, CH-1015, Switzerland
| | - Aurélie Babin
- Department of Ecology and Evolution, University of Lausanne Lausanne, CH-1015, Switzerland
| | - Christoph Haag
- Centre d'Écologie Fonctionnelle et Évolutive, UMR 5175, CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHA Montpellier 5, FR-34293, France
| | - Tadeusz J Kawecki
- Department of Ecology and Evolution, University of Lausanne Lausanne, CH-1015, Switzerland
| | - Arnaud Le Rouzic
- Laboratoire Evolution Génome et Spéciation, UPR 9034, CNRS Gif-sur-Yvette, FR-91198, France
| |
Collapse
|
87
|
Zhang Y, Liu Y, Guo X, Li Y, Gao H, Guo X, Xu B. sHsp22.6, an intronless small heat shock protein gene, is involved in stress defence and development in Apis cerana cerana. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 53:1-12. [PMID: 25008786 DOI: 10.1016/j.ibmb.2014.06.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 06/19/2014] [Accepted: 06/21/2014] [Indexed: 05/24/2023]
Abstract
Small heat shock proteins (sHSPs) play an important role in protecting against stress-induced cell damage and fundamental physiological processes. In this study, we identified an intronless sHsp gene from Apis cerana cerana (AccsHsp22.6). The open reading frame of AccsHsp22.6 was 585 bp and encoded a 194 amino acid protein. Furthermore, a 2064 bp 5'-flanking region was isolated, and potential transcription factor binding sites associated with development and stress response were identified. Quantitative PCR and western blot analyses demonstrated that AccsHsp22.6 was detected at higher levels in the midgut than in other tissues tested, and it is highly expressed during the shift to different development stages. Moreover, AccsHsp22.6 was significantly up-regulated by abiotic and biotic stresses, such as 4 °C, 16 °C, 42 °C, cyhalothrin, pyridaben, H2O2, UV, CdCl2, 20-hydroxyecdysone and Ascosphaera apis treatments. However, AccsHsp22.6 was slightly repressed by other stresses, including 25 °C, phoxim, paraquat and HgCl2 treatments. The recombinant AccsHSP22.6 also exhibited significant temperature tolerance, antioxidation and molecular chaperone activity. In addition, we found that knockdown of AccsHsp22.6 by RNA interference remarkably reduced temperature tolerance in A. cerana cerana. Taken together, these results suggest that AccsHsp22.6 plays an essential role in the development stages and defence against cellular stress.
Collapse
Affiliation(s)
- Yuanying Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, PR China; School of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, PR China
| | - Yaling Liu
- School of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, PR China
| | - Xulei Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, PR China
| | - Yalu Li
- School of Basic Medical Sciences, Taishan Medical University, Taian, Shandong 271000, PR China
| | - Hongru Gao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, PR China
| | - Xingqi Guo
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, PR China.
| | - Baohua Xu
- College of Animal Science and Technology, Shandong Agricultural University, Taian, Shandong 271018, PR China.
| |
Collapse
|
88
|
Babin A, Kolly S, Kawecki TJ. Virulent bacterial infection improves aversive learning performance in Drosophila melanogaster. Brain Behav Immun 2014; 41:152-61. [PMID: 24863366 DOI: 10.1016/j.bbi.2014.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 05/02/2014] [Accepted: 05/15/2014] [Indexed: 10/25/2022] Open
Abstract
Virulent infections are expected to impair learning ability, either as a direct consequence of stressed physiological state or as an adaptive response that minimizes diversion of energy from immune defense. This prediction has been well supported for mammals and bees. Here, we report an opposite result in Drosophila melanogaster. Using an odor-mechanical shock conditioning paradigm, we found that intestinal infection with bacterial pathogens Pseudomonas entomophila or Erwinia c. carotovora improved flies' learning performance after a 1h retention interval. Infection with P. entomophila (but not E. c. carotovora) also improved learning performance after 5 min retention. No effect on learning performance was detected for intestinal infections with an avirulent GacA mutant of P. entomophila or for virulent systemic (hemocoel) infection with E. c. carotovora. Assays of unconditioned responses to odorants and shock do not support a major role for changes in general responsiveness to stimuli in explaining the changes in learning performance, although differences in their specific salience for learning cannot be excluded. Our results demonstrate that the effects of pathogens on learning performance in insects are less predictable than suggested by previous studies, and support the notion that immune stress can sometimes boost cognitive abilities.
Collapse
Affiliation(s)
- Aurélie Babin
- Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland
| | - Sylvain Kolly
- Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland
| | - Tadeusz J Kawecki
- Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland.
| |
Collapse
|
89
|
Mallon EB, Alghamdi A, Holdbrook RTK, Rosato E. Immune stimulation reduces sleep and memory ability in Drosophila melanogaster. PeerJ 2014; 2:e434. [PMID: 24949247 PMCID: PMC4060034 DOI: 10.7717/peerj.434] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 05/29/2014] [Indexed: 11/20/2022] Open
Abstract
Psychoneuroimmunology studies the increasing number of connections between neurobiology, immunology and behaviour. We demonstrate the effects of the immune response on two fundamental behaviours: sleep and memory ability in Drosophila melanogaster. We used the Geneswitch system to upregulate peptidoglycan receptor protein (PGRP) expression, thereby stimulating the immune system in the absence of infection. Geneswitch was activated by feeding the steroid RU486, to the flies. We used an aversive classical conditioning paradigm to quantify memory and measures of activity to infer sleep. Immune stimulated flies exhibited reduced levels of sleep, which could not be explained by a generalised increase in waking activity. Immune stimulated flies also showed a reduction in memory abilities. These results lend support to Drosophila as a model for immune–neural interactions and provide a possible role for sleep in the interplay between the immune response and memory.
Collapse
Affiliation(s)
- Eamonn B Mallon
- Department of Biology, University of Leicester , Leicester , United Kingdom
| | | | | | - Ezio Rosato
- Department of Genetics, University of Leicester , Leicester , United Kingdom
| |
Collapse
|
90
|
Babin A, Kolly S, Schneider F, Dolivo V, Zini M, Kawecki TJ. Fruit flies learn to avoid odours associated with virulent infection. Biol Lett 2014; 10:20140048. [PMID: 24598110 DOI: 10.1098/rsbl.2014.0048] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
While learning to avoid toxic food is common in mammals and occurs in some insects, learning to avoid cues associated with infectious pathogens has received little attention. We demonstrate that Drosophila melanogaster show olfactory learning in response to infection with their virulent intestinal pathogen Pseudomonas entomophila. This pathogen was not aversive to taste when added to food. Nonetheless, flies exposed for 3 h to food laced with P. entomophila, and scented with an odorant, became subsequently less likely to choose this odorant than flies exposed to pathogen-laced food scented with another odorant. No such effect occurred after an otherwise identical treatment with an avirulent mutant of P. entomophila, indicating that the response is mediated by pathogen virulence. These results demonstrate that a virulent pathogen infection can act as an aversive unconditioned stimulus which flies can associate with food odours, and thus become less attracted to pathogen-contaminated food.
Collapse
Affiliation(s)
- Aurélie Babin
- Department of Ecology and Evolution, University of Lausanne, , CH 1015 Lausanne, Switzerland
| | | | | | | | | | | |
Collapse
|
91
|
Deshwal S, Mallon EB. Antimicrobial peptides play a functional role in bumblebee anti-trypanosome defense. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2014; 42:240-3. [PMID: 24060502 DOI: 10.1016/j.dci.2013.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 09/10/2013] [Accepted: 09/12/2013] [Indexed: 05/03/2023]
Abstract
Bumblebees, amongst the most important of pollinators, are under enormous population pressures. One of these is disease. The bumblebee and its gut trypanosome Crithidia bombi are one of the fundamental models of ecological immunology. Although there is previous evidence of increased immune gene expression upon Crithidia infection, recent work has focussed on the bumblebee's gut microbiota. Here, by knocking down gene expression using RNAi, we show for the first time that antimicrobial peptides (AMPs) have a functional role in anti-Crithidia defense.
Collapse
Affiliation(s)
- Soni Deshwal
- Biology Department, University of Leicester, Leicester LE1 7RH, UK.
| | | |
Collapse
|
92
|
Fauser-Misslin A, Sadd BM, Neumann P, Sandrock C. Influence of combined pesticide and parasite exposure on bumblebee colony traits in the laboratory. J Appl Ecol 2013. [DOI: 10.1111/1365-2664.12188] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Aline Fauser-Misslin
- Institute of Bee Health; Vetsuisse Faculty and Faculty of Medicine; University of Bern; Länggass-Strasse 109a 3001 Bern Switzerland
| | - Ben M. Sadd
- School of Biological Sciences; Illinois State University; Campus Box 4120 Normal IL 61790 USA
| | - Peter Neumann
- Institute of Bee Health; Vetsuisse Faculty and Faculty of Medicine; University of Bern; Länggass-Strasse 109a 3001 Bern Switzerland
| | - Christoph Sandrock
- Swiss Bee Research Centre; Agroscope Liebefeld-Posieux ALP; Schwarzenburgstrasse 161 3003 Bern Switzerland
| |
Collapse
|
93
|
Emerging dangers: deadly effects of an emergent parasite in a new pollinator host. J Invertebr Pathol 2013; 114:114-9. [PMID: 23816821 DOI: 10.1016/j.jip.2013.06.005] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/13/2013] [Accepted: 06/14/2013] [Indexed: 12/17/2022]
Abstract
There is growing concern about the threats facing many pollinator populations. Emergent diseases are one of the major threats to biodiversity and a microsporidian parasite, Nosema ceranae, has recently jumped host from the Asian to the Western honeybee, spreading rapidly worldwide, and contributing to dramatic colony losses. Bumblebees are ecologically and economically important pollinators of conservation concern, which are likely exposed to N. ceranae by sharing flowers with honeybees. Whilst a further intergeneric jump by N. ceranae to infect bumblebees would be potentially serious, its capacity to do this is unknown. Here we investigate the prevalence of N. ceranae in wild bumblebees in the UK and determine the infectivity of the parasite under controlled conditions. We found N. ceranae in all seven wild bumblebee species sampled, and at multiple sites, with many of the bees having spores from this parasite in their guts. When we fed N. ceranae spores to bumblebees under controlled conditions, we confirmed that the parasite can infect bumblebees. Infections spread from the midgut to other tissues, reduced bumblebee survival by 48% and had sub-lethal effects on behaviour. Although spore production appeared lower in bumblebees than in honeybees, virulence was greater. The parasite N. ceranae therefore represents a real and emerging threat to bumblebees, with the potential to have devastating consequences for their already vulnerable populations.
Collapse
|
94
|
Jaumann S, Scudelari R, Naug D. Energetic cost of learning and memory can cause cognitive impairment in honeybees. Biol Lett 2013; 9:20130149. [PMID: 23784929 DOI: 10.1098/rsbl.2013.0149] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The energetic cost of cognitive functions can lead to either impairments in learning and memory, or to trade-offs with other functions, when the amount of available energy is limited. However, it has been suggested that, under such conditions, social groups such as honeybees might be able to ward off cognitive impairments in individual bees by adjusting resource allocation at the colony level. Using two complementary experiments, one that tests the effect of learning on subsequent energetic state and survival, and another that tests the effect of energetic state on learning and retention, we show that individual bees pay a significant energetic cost for learning and therefore suffer from significant cognitive deficits under energetic stress. We discuss the implications of such cognitive impairments for the recent observations of bees disappearing from their colonies as well as for social life in general.
Collapse
Affiliation(s)
- Sarah Jaumann
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | | | | |
Collapse
|
95
|
Morimoto T, Kojima Y, Yoshiyama M, Kimura K, Yang B, Peng G, Kadowaki T. Molecular detection of protozoan parasites infecting Apis mellifera colonies in Japan. ENVIRONMENTAL MICROBIOLOGY REPORTS 2013; 5:74-77. [PMID: 23757133 DOI: 10.1111/j.1758-2229.2012.00385.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 08/04/2012] [Indexed: 06/02/2023]
Abstract
The role of protozoan parasites in honey bee health and distribution in the world is not well understood. Therefore, we carried out a molecular survey for the presence of Crithidia mellificae and Apicystis bombi in the colonies of both non-native Apis mellifera and native Apis cerana japonica in Japan. We found that A. mellifera, but not A. c. japonica, colonies are parasitized with C. mellificae and A. bombi. Their absence in A. c. japonica colonies indicates that A. mellifera is their native host. Nevertheless, the prevalence in A. mellifera colonies is low compared with other pathogens such as viruses and Nosema microsporidia. Japanese C. mellificae isolates share well-conserved nuclear-encoded gene sequences with Swiss and US isolates. We have found two Japanese haplotypes (A and B) with two nucleotide differences in the kinetoplast-encoded cytochrome b sequence. The haplotype A is identical to Swiss isolate. These results demonstrate that C. mellificae and A. bombi distribute in Asia, Oceania, Europe, and South and North Americas.
Collapse
Affiliation(s)
- Tomomi Morimoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601, Japan
| | | | | | | | | | | | | |
Collapse
|
96
|
Gillespie SD, Adler LS. Indirect effects on mutualisms: parasitism of bumble bees and pollination service to plants. Ecology 2013; 94:454-64. [DOI: 10.1890/12-0406.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
97
|
Ohashi K, Leslie A, Thomson JD. Trapline foraging by bumble bees: VII. Adjustments for foraging success following competitor removal. Behav Ecol 2012. [DOI: 10.1093/beheco/ars200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
98
|
Li J, Qin H, Wu J, Sadd BM, Wang X, Evans JD, Peng W, Chen Y. The prevalence of parasites and pathogens in Asian honeybees Apis cerana in China. PLoS One 2012; 7:e47955. [PMID: 23144838 PMCID: PMC3492380 DOI: 10.1371/journal.pone.0047955] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 09/18/2012] [Indexed: 11/18/2022] Open
Abstract
Pathogens and parasites represent significant threats to the health and well-being of honeybee species that are key pollinators of agricultural crops and flowers worldwide. We conducted a nationwide survey to determine the occurrence and prevalence of pathogens and parasites in Asian honeybees, Apis cerana, in China. Our study provides evidence of infections of A. cerana by pathogenic Deformed wing virus (DWV), Black queen cell virus (BQCV), Nosema ceranae, and C. bombi species that have been linked to population declines of European honeybees, A. mellifera, and bumble bees. However, the prevalence of DWV, a virus that causes widespread infection in A. mellifera, was low, arguably a result of the greater ability of A. cerana to resist the ectoprasitic mite Varroa destructor, an efficient vector of DWV. Analyses of microbial communities from the A. cerana digestive tract showed that Nosema infection could have detrimental effects on the gut microbiota. Workers infected by N. ceranae tended to have lower bacterial quantities, with these differences being significant for the Bifidobacterium and Pasteurellaceae bacteria groups. The results of this nationwide screen show that parasites and pathogens that have caused serious problems in European honeybees can be found in native honeybee species kept in Asia. Environmental changes due to new agricultural practices and globalization may facilitate the spread of pathogens into new geographic areas. The foraging behavior of pollinators that are in close geographic proximity likely have played an important role in spreading of parasites and pathogens over to new hosts. Phylogenetic analyses provide insights into the movement and population structure of these parasites, suggesting a bidirectional flow of parasites among pollinators. The presence of these parasites and pathogens may have considerable implications for an observed population decline of Asian honeybees.
Collapse
Affiliation(s)
- Jilian Li
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing, China
| | - Haoran Qin
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing, China
| | - Jie Wu
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing, China
| | - Ben M. Sadd
- Experimental Ecology, Institute of Integrative Biology, ETH Zürich Universitätstrasse, Zürich, Switzerland
| | - Xiuhong Wang
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing, China
| | - Jay D. Evans
- United States Department of Agriculture (USDA) – Agricultural Research Service (ARS) Bee Research Laboratory, Beltsville, Maryland, United States of America
| | - Wenjun Peng
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agricultural Science, Beijing, China
- * E-mail: (WP); (YC)
| | - Yanping Chen
- United States Department of Agriculture (USDA) – Agricultural Research Service (ARS) Bee Research Laboratory, Beltsville, Maryland, United States of America
- * E-mail: (WP); (YC)
| |
Collapse
|
99
|
Ruiz-González MX, Bryden J, Moret Y, Reber-Funk C, Schmid-Hempel P, Brown MJF. DYNAMIC TRANSMISSION, HOST QUALITY, AND POPULATION STRUCTURE IN A MULTIHOST PARASITE OF BUMBLEBEES. Evolution 2012; 66:3053-66. [DOI: 10.1111/j.1558-5646.2012.01655.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
100
|
Keagy J, Savard JF, Borgia G. Cognitive ability and the evolution of multiple behavioral display traits. Behav Ecol 2011. [DOI: 10.1093/beheco/arr211] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|