1
|
Csata E, Pérez-Escudero A, Laury E, Leitner H, Latil G, Heinze J, Simpson SJ, Cremer S, Dussutour A. Fungal infection alters collective nutritional intake of ant colonies. Curr Biol 2024; 34:902-909.e6. [PMID: 38307022 DOI: 10.1016/j.cub.2024.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 02/04/2024]
Abstract
In animals, parasitic infections impose significant fitness costs.1,2,3,4,5,6 Infected animals can alter their feeding behavior to resist infection,7,8,9,10,11,12 but parasites can manipulate animal foraging behavior to their own benefits.13,14,15,16 How nutrition influences host-parasite interactions is not well understood, as studies have mainly focused on the host and less on the parasite.9,12,17,18,19,20,21,22,23 We used the nutritional geometry framework24 to investigate the role of amino acids (AA) and carbohydrates (C) in a host-parasite system: the Argentine ant, Linepithema humile, and the entomopathogenic fungus, Metarhizium brunneum. First, using 18 diets varying in AA:C composition, we established that the fungus performed best on the high-amino-acid diet 1:4. Second, we found that the fungus reached this optimal diet when given various diet pairings, revealing its ability to cope with nutritional challenges. Third, we showed that the optimal fungal diet reduced the lifespan of healthy ants when compared with a high-carbohydrate diet but had no effect on infected ants. Fourth, we revealed that infected ant colonies, given a choice between the optimal fungal diet and a high-carbohydrate diet, chose the optimal fungal diet, whereas healthy colonies avoided it. Lastly, by disentangling fungal infection from host immune response, we demonstrated that infected ants foraged on the optimal fungal diet in response to immune activation and not as a result of parasite manipulation. Therefore, we revealed that infected ant colonies chose a diet that is costly for survival in the long term but beneficial in the short term-a form of collective self-medication.
Collapse
Affiliation(s)
- Enikő Csata
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France; Museum and Institute of Zoology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warsaw, Poland; Institute for Zoology, University of Regensburg, Universitätsstraße 31, 93040 Regensburg, Germany.
| | - Alfonso Pérez-Escudero
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Emmanuel Laury
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Hanna Leitner
- ISTA (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Gérard Latil
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Jürgen Heinze
- Museum and Institute of Zoology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warsaw, Poland
| | - Stephen J Simpson
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Sylvia Cremer
- ISTA (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Audrey Dussutour
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 31062 Toulouse, France
| |
Collapse
|
2
|
Rissanen J, Nyckees D, Will T, Helanterä H, Freitak D. Formica fusca ants use aphid supplemented foods to alleviate effects during the acute phase of a fungal infection. Biol Lett 2023; 19:20230415. [PMID: 37964577 PMCID: PMC10646462 DOI: 10.1098/rsbl.2023.0415] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 10/24/2023] [Indexed: 11/16/2023] Open
Abstract
The modulation of nutritional intake by animals to combat pathogens is a behaviour that is receiving increasing attention. Ant studies using isolated compounds or nutrients in artificial diets have revealed a lot of the dynamics of the behaviour, but natural sources of medicine are yet to be confirmed. Here we explored whether Formica fusca ants exposed to a fungal pathogen can use an artificial diet containing foods spiked with different concentrations of crushed aphids for a medicinal benefit. We show that pathogen exposed colonies adjusted their diet to include more aphid supplemented foods during the acute phase of the infection, reducing the mortality caused by the disease. However, the benefit was only attained when having access to a varied diet, suggesting that while aphids contain nutrients or compounds beneficial against infection, it is a part of a complex nutritional system where costs and benefits of compounds and nutrients need to be moderated.
Collapse
Affiliation(s)
- Jason Rissanen
- Institute of Biology, University of Graz, Graz, Styria 8010, Austria
- Tvärminne Zoological Station, University of Helsinki, Hanko 10900, Finland
| | - Danaë Nyckees
- Laboratory of Entomology, Wageningen University, Wageningen 6700, The Netherlands
| | - Torsten Will
- Institute for Resistance Research and Stress Tolerance, Julius Kühn Institute (JKI) – Federal Research Centre for Cultivated Plants, Quedlinburg 06484, Germany
| | - Heikki Helanterä
- Tvärminne Zoological Station, University of Helsinki, Hanko 10900, Finland
- Ecology and Genetics Research Unit, University of Oulu, Oulu 90014, Finland
| | - Dalial Freitak
- Institute of Biology, University of Graz, Graz, Styria 8010, Austria
- Tvärminne Zoological Station, University of Helsinki, Hanko 10900, Finland
| |
Collapse
|
3
|
Rissanen J, Helanterä H, Will T, Freitak D. Lack of Self-Medication by Fungus Infected Lasius platythorax (Formicidae, Formicinae) Ants in a Multitrophic Experiment. ANN ZOOL FENN 2022. [DOI: 10.5735/086.059.0117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- Jason Rissanen
- Institute of Biology, University of Graz, Universitätsplatz 2, AT-8010 Graz, Austria
| | - Heikki Helanterä
- Ecology and Genetics Research Unit, P.O. Box 3000, FI-90014 University of Oulu, Finland
| | - Torsten Will
- Institute for Resistance Research and Stress Tolerance, Julius Kühn Institute (JKI) — Federal Research Centre for Cultivated Plants, Erwin-Baur-Str. 2, DE-06484 Quedlinburg, Germany
| | - Dalial Freitak
- Institute of Biology, University of Graz, Universitätsplatz 2, AT-8010 Graz, Austria
| |
Collapse
|
4
|
Rissanen J, Helanterä H, Freitak D. Pathogen Prevalence Modulates Medication Behavior in Ant Formica fusca. FRONTIERS IN INSECT SCIENCE 2022; 2:870971. [PMID: 38468809 PMCID: PMC10926551 DOI: 10.3389/finsc.2022.870971] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/15/2022] [Indexed: 03/13/2024]
Abstract
Ants face unique challenges regarding pathogens, as the sociality which has allowed them to form large and complex colonies also raises the potential for transmission of disease within them. To cope with the threat of pathogens, ants have developed a variety of behavioral and physiological strategies. One of these strategies is self-medication, in which animals use biologically active compounds to combat pathogens in a way which would be harmful in the absence of infection. Formica fusca are the only ants that have previously been shown to successfully self-medicate against an active infection caused by a fungal pathogen by supplementing their diet with food containing hydrogen peroxide. Here, we build on that research by investigating how the prevalence of disease in colonies of F. fusca affects the strength of the self-medication response. We exposed either half of the workers of each colony or all of them to a fungal pathogen and offered them different combinations of diets. We see that workers of F. fusca engage in self-medication behavior even if exposed to a low lethal dose of a pathogen, and that the strength of that response is affected by the prevalence of the disease in the colonies. We also saw that the infection status of the individual foragers did not significantly affect their decision to forage on either control food or medicinal food as uninfected workers were also foraging on hydrogen peroxide food, which opens up the possibility of kin medication in partially infected colonies. Our results further affirm the ability of ants to self-medicate against fungal pathogens, shed new light on plasticity of self-medication and raise new questions to be investigated on the role self-medication has in social immunity.
Collapse
Affiliation(s)
- Jason Rissanen
- Institute of Biology, University of Graz, Graz, Austria
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland
| | - Heikki Helanterä
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
| | - Dalial Freitak
- Institute of Biology, University of Graz, Graz, Austria
- Tvärminne Zoological Station, University of Helsinki, Hanko, Finland
| |
Collapse
|
5
|
Bell O, Jones ME, Cunningham CX, Ruiz‐Aravena M, Hamilton DG, Comte S, Hamede RK, Bearhop S, McDonald RA. Isotopic niche variation in Tasmanian devils Sarcophilus harrisii with progression of devil facial tumor disease. Ecol Evol 2021; 11:8038-8053. [PMID: 34188870 PMCID: PMC8216929 DOI: 10.1002/ece3.7636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 04/12/2021] [Accepted: 04/15/2021] [Indexed: 12/11/2022] Open
Abstract
Devil facial tumor disease (DFTD) is a transmissible cancer affecting Tasmanian devils Sarcophilus harrisii. The disease has caused severe population declines and is associated with demographic and behavioral changes, including earlier breeding, younger age structures, and reduced dispersal and social interactions. Devils are generally solitary, but social encounters are commonplace when feeding upon large carcasses. DFTD tumors can disfigure the jaw and mouth and so diseased individuals might alter their diets to enable ingestion of alternative foods, to avoid conspecific interactions, or to reduce competition. Using stable isotope analysis (δ13C and δ15N) of whiskers, we tested whether DFTD progression, measured as tumor volume, affected the isotope ratios and isotopic niches of 94 infected Tasmanian devils from six sites in Tasmania, comprising four eucalypt plantations, an area of smallholdings and a national park. Then, using tissue from 10 devils sampled before and after detection of tumors and 8 devils where no tumors were detected, we examined whether mean and standard deviation of δ13C and δ15N of the same individuals changed between healthy and diseased states. δ13C and δ15N values were generally not related to tumor volume in infected devils, though at one site, Freycinet National Park, δ15N values increased significantly as tumor volume increased. Infection with DFTD was not associated with significant changes in the mean or standard deviation of δ13C and δ15N values in individual devils sampled before and after detection of tumors. Our analysis suggests that devils tend to maintain their isotopic niche in the face of DFTD infection and progression, except where ecological conditions facilitate a shift in diets and feeding behaviors, demonstrating that ecological context, alongside disease severity, can modulate the behavioral responses of Tasmanian devils to DFTD.
Collapse
Affiliation(s)
- Olivia Bell
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
| | - Menna E. Jones
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | | | - Manuel Ruiz‐Aravena
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
- Department of Microbiology and ImmunologyMontana State UniversityBozemanMTUSA
| | - David G. Hamilton
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Sebastien Comte
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
- Vertebrate Pest Research UnitNSW Department of Primary IndustriesOrangeNSWAustralia
| | - Rodrigo K. Hamede
- School of Natural SciencesUniversity of TasmaniaHobartTasmaniaAustralia
| | - Stuart Bearhop
- Centre for Ecology and ConservationUniversity of ExeterPenrynUK
| | | |
Collapse
|
6
|
Novgorodova T. Preventing Transmission of Lethal Disease: Removal Behaviour of Lasius fuliginosus (Hymenoptera: Formicidae) Towards Fungus Contaminated Aphids. INSECTS 2021; 12:insects12020099. [PMID: 33498832 PMCID: PMC7911655 DOI: 10.3390/insects12020099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/16/2021] [Accepted: 01/21/2021] [Indexed: 11/16/2022]
Abstract
The ability of ants to detect and remove conidia-contaminated aphids, aimed at limiting contacts with potentially dangerous entities, is an effective antifungal mechanism to prevent the spread of infection among both their nestmates and aphids, their main suppliers of carbohydrates. However, the spread and the scale of this quarantining behaviour among ants are still scarcely studied. Among seven ant species studied, active usage of quarantining behaviour was found only in Formica ants. The behaviour of Lasius fuliginosus (Latreille) aphid milkers towards Chaitophorus populeti (Panzer) aphids covered with conidia of Beauveria bassiana (Balsamo-Crivelli) Vuillemin was studied in the field. Most aggressive milkers quickly detected and removed conidia-contaminated aphids from the plant, carrying them down and placing them some distance away from the experimental aspen trees. In general, active usage of quarantining behaviour towards conidia-contaminated aphids was found to be not limited to the genus Formica, but typical of L. fuliginosus as well. The response of milkers of L. fuliginosus and Formica s. str. ants to living aphids covered with conidia is quite similar. Removal of most fungus-contaminated aphids from the plant enables these ants to reduce the risk of infection transmission among both their nestmates and aphids.
Collapse
Affiliation(s)
- Tatiana Novgorodova
- Institute of Systematics and Ecology of Animals, Siberian Branch of the Russian Academy of Sciences, Frunze str. 11, Novosibirsk 630091, Russia
| |
Collapse
|
7
|
Pull CD, McMahon DP. Superorganism Immunity: A Major Transition in Immune System Evolution. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00186] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
|
8
|
The Effects of Trichoderma Fungi on the Tunneling, Aggregation, and Colony-Initiation Preferences of Black-Winged Subterranean Termites, Odontotermes formosanus (Blattodea: Termitidae). FORESTS 2019. [DOI: 10.3390/f10111020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The black-winged subterranean termite, Odontotermes formosanus Shiraki, is a severe pest of plantations and forests in China. This termite cultures symbiotic Termitomyces in the fungal combs, which are challenged by antagonistic microbes such as Trichoderma fungi. In a previous study we showed that O. formosanus workers made significantly fewer tunnels in sand containing commercially formulated conidia of Trichoderma viride Pers. ex Fries compared with untreated sand. Herein, we hypothesize that fungi in the genus Trichoderma exert repellent effects on O. formosanus. Different choice tests were conducted to evaluate the tunneling and aggregation behaviors of O. formosanus workers reacting to sand/soil containing the unformulated conidia of seven Trichoderma fungi (Trichoderma longibrachiatum Rifai, Trichoderma koningii Oud., Trichoderma harzianum Rifai, Trichoderma hamatum (Bon.) Bain, Trichoderma atroviride Karsten, Trichoderma spirale Indira and Kamala, and T. viride). We also investigated the colony-initiation preference of paired O. formosanus adults to soil treated with Trichoderma conidia (T. koningii or T. longibrachiatum) versus untreated soil. Tunneling-choice tests showed that sand containing conidia of nearly all Trichoderma fungi tested (except T. harzianum) significantly decreased tunneling activity in O. formosanus workers compared with untreated sand. Aggregation-choice test showed that T. koningii, T. atroviride and T. spirale repelled O. formosanus workers, whereas T. longibrachiatum and T. hamatum attracted termites. There was no significant difference in proportions of paired adults that stayed and laid eggs in the soil blocks treated with conidia of Trichoderma fungi and untreated ones. Our study showed that Trichoderma fungi generally repelled tunneling in O. formosanus, but may exert varied effects on aggregation preference by workers.
Collapse
|
9
|
de Roode JC, Hunter MD. Self-medication in insects: when altered behaviors of infected insects are a defense instead of a parasite manipulation. CURRENT OPINION IN INSECT SCIENCE 2019; 33:1-6. [PMID: 31358187 DOI: 10.1016/j.cois.2018.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/05/2018] [Accepted: 12/07/2018] [Indexed: 06/10/2023]
Abstract
Studies have demonstrated that medication behaviors by insects are much more common than previously thought. Bees, ants, flies, and butterflies can use a wide range of toxic and nutritional compounds to medicate themselves or their genetic kin. Medication occurs either in response to active infection (therapy) or high infection risk (prophylaxis), and can be used to increase resistance or tolerance to infection. While much progress has been made over the last few years, there are also key areas that require in-depth investigation. These include quantifying the costs of medication, especially at the colony level of social insects, and formulating theoretical models that can predict the role of infection risk in driving micro-evolutionary and macro-evolutionary patterns of animal medication behaviors.
Collapse
Affiliation(s)
- Jacobus C de Roode
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA 30322, United States.
| | - Mark D Hunter
- Department of Ecology and Evolutionary Biology, University of Michigan, 1105 N University Avenue, Ann Arbor, MI 48109, United States
| |
Collapse
|
10
|
Spivak M, Goblirsch M, Simone-Finstrom M. Social-medication in bees: the line between individual and social regulation. CURRENT OPINION IN INSECT SCIENCE 2019; 33:49-55. [PMID: 31358195 DOI: 10.1016/j.cois.2019.02.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 02/16/2019] [Accepted: 02/23/2019] [Indexed: 06/10/2023]
Abstract
We use the term social-medication to describe the deliberate consumption or use of plant compounds by social insects that are detrimental to a pathogen or parasite at the colony level, result in increased inclusive fitness to the colony, and have potential costs either at the individual or colony level in the absence of parasite infection. These criteria for social-medication differ from those for self-medication in that inclusive fitness costs and benefits are distinguished from individual costs and benefits. The consumption of pollen and nectar may be considered a form of social immunity if they help fight infection, resulting in a demonstrated increase in colony health and survival. However, the dietary use of pollen and nectar per se is likely not a form of social-medication unless there is a detriment or cost to their consumption in the absence of parasite infection, such as when they contain phytochemicals that are toxic at certain doses. We provide examples among social bees (bumblebees, stingless bees and honey bees) in which the consumption or use of plant compounds have a demonstrated role in parasite defense and health of the colony. We indicate where more work is needed to distinguish between prophylactic and therapeutic effects of these compounds, and whether the effects are observed at the individual or colony level.
Collapse
Affiliation(s)
- Marla Spivak
- Department of Entomology, 1980 Folwell Ave, University of Minnesota, St Paul, MN, 55108, United States.
| | - Michael Goblirsch
- Department of Entomology, 1980 Folwell Ave, University of Minnesota, St Paul, MN, 55108, United States
| | - Michael Simone-Finstrom
- USDA-ARS, Honey Bee Breeding, Genetics, and Physiology Research, 1157 Ben Hur Rd Baton Rouge, LA, 70820, United States
| |
Collapse
|
11
|
Bonadies E, Wcislo WT, Gálvez D, Hughes WOH, Fernández-Marín H. Hygiene Defense Behaviors Used by a Fungus-Growing Ant Depend on the Fungal Pathogen Stages. INSECTS 2019; 10:insects10050130. [PMID: 31060310 PMCID: PMC6572560 DOI: 10.3390/insects10050130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 11/24/2022]
Abstract
Parasites and their hosts use different strategies to overcome the defenses of the other, often resulting in an evolutionary arms race. Limited animal studies have explored the differential responses of hosts when challenged by differential parasite loads and different developmental stages of a parasite. The fungus-growing ant Trachymyrmex sp. 10 employs three different hygienic strategies to control fungal pathogens: Grooming the antibiotic-producing metapleural glands (MGs) and planting or weeding their mutualistic fungal crop. By inoculating Trachymyrmex colonies with different parasite concentrations (Metarhizium) or stages (germinated conidia or ungermianted conidia of Metarhizium and Escovopsis), we tested whether ants modulate and change hygienic strategies depending on the nature of the parasite challenge. There was no effect of the concentration of parasite on the frequencies of the defensive behaviors, indicating that the ants did not change defensive strategy according to the level of threat. However, when challenged with conidia of Escovopsis sp. and Metarhizium brunneum that were germinated or not-germinated, the ants adjusted their thygienic behavior to fungal planting and MG grooming behaviors using strategies depending on the conidia germination status. Our study suggests that fungus-growing ants can adjust the use of hygienic strategies based on the nature of the parasites.
Collapse
Affiliation(s)
- Ernesto Bonadies
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Apartado 0843-01103, Panamá, República de Panamá.
- Programa de Maestría en Entomología, Vicerrectoría de Investigación y Postgrado, Estafeta Universitaria 0824, Universidad de Panamá, República de Panamá.
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, República de Panamá.
| | - William T Wcislo
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Panamá, República de Panamá.
| | - Dumas Gálvez
- Programa de Maestría en Entomología, Vicerrectoría de Investigación y Postgrado, Estafeta Universitaria 0824, Universidad de Panamá, República de Panamá.
| | | | - Hermógenes Fernández-Marín
- Centro de Biodiversidad y Descubrimiento de Drogas, Instituto de Investigaciones Científicas y Servicios de Alta Tecnología (INDICASAT AIP), Apartado 0843-01103, Panamá, República de Panamá.
| |
Collapse
|
12
|
Easton-Calabria A, Demary KC, Oner NJ. Beyond Pollination: Honey Bees (Apis mellifera) as Zootherapy Keystone Species. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2018.00161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
13
|
Giehr J, Heinze J. Queens stay, workers leave: caste-specific responses to fatal infections in an ant. BMC Evol Biol 2018; 18:202. [PMID: 30587108 PMCID: PMC6307282 DOI: 10.1186/s12862-018-1320-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/04/2018] [Indexed: 01/13/2023] Open
Abstract
Background The intense interactions among closely related individuals in animal societies provide perfect conditions for the spread of pathogens. Social insects have therefore evolved counter-measures on the cellular, individual, and social level to reduce the infection risk. One striking example is altruistic self-removal, i.e., lethally infected workers leave the nest and die in isolation to prevent the spread of a contagious disease to their nestmates. Because reproductive queens and egg-laying workers behave less altruistically than non-laying workers, e.g., when it comes to colony defense, we wondered whether moribund egg-layers would show the same self-removal as non-reproductive workers. Furthermore, we investigated how a lethal infection affects reproduction and studied if queens and egg-laying workers intensify their reproductive efforts when their residual reproductive value decreases (“terminal investment”). Results We treated queens, egg-laying workers from queenless colonies, and non-laying workers from queenright colonies of the monogynous (single-queened) ant Temnothorax crassispinus either with a control solution or a solution containing spores of the entomopathogenic fungus Metarhizium brunneum. Lethally infected workers left the nest and died away from it, regardless of their reproductive status. In contrast, infected queens never left the nest and were removed by workers only after they had died. The reproductive investment of queens strongly decreased after the treatment with both, the control solution and the Metarhizium brunneum suspension. The egg laying rate in queenless colonies was initially reduced in infected colonies but not in control colonies. Egg number increased again with decreasing number of infected workers. Conclusions Queens and workers of the ant Temnothorax crassispinus differ in their reaction to an infection risk and a reduced life expectancy. Workers isolate themselves to prevent contagion inside the colony, whereas queens stay in the nest. We did not find terminal investment; instead it appeared that egg-layers completely shut down egg production in response to the lethal infection. Workers in queenless colonies resumed reproduction only after all infected individuals had died, probably again to minimize the risk of infecting the offspring. Electronic supplementary material The online version of this article (10.1186/s12862-018-1320-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Julia Giehr
- Department of Zoology/ Evolutionary Biology, University of Regensburg, 93053, Regensburg, Germany.
| | - Jürgen Heinze
- Department of Zoology/ Evolutionary Biology, University of Regensburg, 93053, Regensburg, Germany
| |
Collapse
|
14
|
Bernardo MA, Singer MS. Parasite-altered feeding behavior in insects: integrating functional and mechanistic research frontiers. ACTA ACUST UNITED AC 2018; 220:2848-2857. [PMID: 28814608 DOI: 10.1242/jeb.143800] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Research on parasite-altered feeding behavior in insects is contributing to an emerging literature that considers possible adaptive consequences of altered feeding behavior for the host or the parasite. Several recent ecoimmunological studies show that insects can adaptively alter their foraging behavior in response to parasitism. Another body of recent work shows that infection by parasites can change the behavior of insect hosts to benefit the parasite; manipulations of host feeding behavior may be part of this phenomenon. Here, we address both the functional and the underlying physiological frontiers of parasite-altered feeding behavior in order to spur research that better integrates the two. Functional categories of parasite-altered behavior that are adaptive for the host include prophylaxis, therapy and compensation, while host manipulation is adaptive for the parasite. To better understand and distinguish prophylaxis, therapy and compensation, further study of physiological feedbacks affecting host sensory systems is especially needed. For host manipulation in particular, research on mechanisms by which parasites control host feedbacks will be important to integrate with functional approaches. We see this integration as critical to advancing the field of parasite-altered feeding behavior, which may be common in insects and consequential for human and environmental health.
Collapse
Affiliation(s)
| | - Michael S Singer
- Department of Biology, Wesleyan University, Middletown, CT 06105, USA
| |
Collapse
|
15
|
Johnson PTJ, Calhoun DM, Stokes AN, Susbilla CB, McDevitt-Galles T, Briggs CJ, Hoverman JT, Tkach VV, de Roode JC. Of poisons and parasites-the defensive role of tetrodotoxin against infections in newts. J Anim Ecol 2018; 87:1192-1204. [PMID: 29476541 DOI: 10.1111/1365-2656.12816] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/17/2018] [Indexed: 11/29/2022]
Abstract
Classical research on animal toxicity has focused on the role of toxins in protection against predators, but recent studies suggest these same compounds can offer a powerful defense against parasites and infectious diseases. Newts in the genus Taricha are brightly coloured and contain the potent neurotoxin, tetrodotoxin (TTX), which is hypothesized to have evolved as a defense against vertebrate predators such as garter snakes. However, newt populations often vary dramatically in toxicity, which is only partially explained by predation pressure. The primary aim of this study was to evaluate the relationships between TTX concentration and infection by parasites. By systematically assessing micro- and macroparasite infections among 345 adult newts (sympatric populations of Taricha granulosa and T. torosa), we detected 18 unique taxa of helminths, fungi, viruses and protozoans. For both newt species, per-host concentrations of TTX, which varied from undetectable to >60 μg/cm2 skin, negatively predicted overall parasite richness as well as the likelihood of infection by the chytrid fungus, Batrachochytrium dendrobatidis, and ranavirus. No such effect was found on infection load among infected hosts. Despite commonly occurring at the same wetlands, T. torosa supported higher parasite richness and average infection load than T. granulosa. Host body size and sex (females > males) tended to positively predict infection levels in both species. For hosts in which we quantified leucocyte profiles, total white blood cell count correlated positively with both parasite richness and total infection load. By coupling data on host toxicity and infection by a broad range of micro- and macroparasites, these results suggest that-alongside its effects on predators-tetrodotoxin may help protect newts against parasitic infections, highlighting the importance of integrative research on animal chemistry, immunological defenses and natural enemy ecology.
Collapse
Affiliation(s)
- Pieter T J Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Dana M Calhoun
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Amber N Stokes
- Department of Biology, California State University, Bakersfield, CA, USA
| | - Calvin B Susbilla
- Department of Biology, California State University, Bakersfield, CA, USA
| | - Travis McDevitt-Galles
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Cheryl J Briggs
- Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
| | - Vasyl V Tkach
- Department of Biology, University of North Dakota, Grand Forks, ND, USA
| | | |
Collapse
|
16
|
Palmer-Young EC, Calhoun AC, Mirzayeva A, Sadd BM. Effects of the floral phytochemical eugenol on parasite evolution and bumble bee infection and preference. Sci Rep 2018; 8:2074. [PMID: 29391545 PMCID: PMC5794921 DOI: 10.1038/s41598-018-20369-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/17/2018] [Indexed: 11/09/2022] Open
Abstract
Ecological and evolutionary pressures on hosts and parasites jointly determine infection success. In pollinators, parasite exposure to floral phytochemicals may influence between-host transmission and within-host replication. In the bumble bee parasite Crithidia bombi, strains vary in phytochemical resistance, and resistance increases under in vitro selection, implying that resistance/infectivity trade-offs could maintain intraspecific variation in resistance. We assessed costs and benefits of in vitro selection for resistance to the floral phytochemical eugenol on C. bombi infection in Bombus impatiens fed eugenol-rich and eugenol-free diets. We also assessed infection-induced changes in host preferences for eugenol. In vitro, eugenol-exposed cells initially increased in size, but normalized during adaptation. Selection for eugenol resistance resulted in considerable (55%) but non-significant reductions in infection intensity; bee colony and body size were the strongest predictors of infection. Dietary eugenol did not alter infection, and infected bees preferred eugenol-free over eugenol-containing solutions. Although direct effects of eugenol exposure could influence between-host transmission at flowers, dietary eugenol did not ameliorate infection in bees. Limited within-host benefits of resistance, and possible trade-offs between resistance and infectivity, may relax selection for eugenol resistance and promote inter-strain variation in resistance. However, infection-induced dietary shifts could influence pollinator-mediated selection on floral traits.
Collapse
Affiliation(s)
- Evan C Palmer-Young
- Organismic & Evolutionary Biology Graduate Program, University of Massachusetts at Amherst, Amherst, Massachusetts, 01003, United States.
| | - Austin C Calhoun
- School of Biological Sciences, Illinois State University, Normal, Illinois, 61790, United States
| | - Anastasiya Mirzayeva
- Department of Biology, University of Massachusetts at Amherst, Amherst, Massachusetts, 01003, United States
| | - Ben M Sadd
- School of Biological Sciences, Illinois State University, Normal, Illinois, 61790, United States
| |
Collapse
|
17
|
Diehl JMC, Meunier J. Surrounding pathogens shape maternal egg care but not egg production in the European earwig. Behav Ecol 2017. [DOI: 10.1093/beheco/arx140] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
18
|
Calhoun DM, Bucciarelli GM, Kats LB, Zimmer RK, Johnson PTJ. Noxious newts and their natural enemies: Experimental effects of tetrodotoxin exposure on trematode parasites and aquatic macroinvertebrates. Toxicon 2017; 137:120-127. [PMID: 28755852 PMCID: PMC5578716 DOI: 10.1016/j.toxicon.2017.07.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 07/21/2017] [Accepted: 07/23/2017] [Indexed: 01/04/2023]
Abstract
The dermal glands of many amphibian species secrete toxins or other noxious substances as a defense strategy against natural enemies. Newts in particular possess the potent neurotoxin tetrodotoxin (TTX), for which the highest concentrations are found in species within the genus Taricha. Adult Taricha are hypothesized to use TTX as a chemical defense against vertebrate predators such as garter snakes (Thamnophis spp.). However, less is known about how TTX functions to defend aquatic-developing newt larvae against natural enemies, including trematode parasites and aquatic macroinvertebrates. Here we experimentally investigated the effects of exogenous TTX exposure on survivorship of the infectious stages (cercariae) of five species of trematode parasites that infect larval amphibians. Specifically, we used dose-response curves to test the sensitivity of trematode cercariae to progressively increasing concentrations of TTX (0.0 [control], 0.63, 3.13, 6.26, 31.32, and 62.64 nmol L-1) and how this differed among parasite species. We further compared these results to the effects of TTX exposure (0 and 1000 nmolL-1) over 24 h on seven macroinvertebrate taxa commonly found in aquatic habitats with newt larvae. TTX significantly reduced the survivorship of trematode cercariae for all species, but the magnitude of such effects varied among species. Ribeiroia ondatrae - which causes mortality and limb malformations in amphibians - was the least sensitive to TTX, whereas the kidney-encysting Echinostoma trivolvis was the most sensitive. Among the macroinvertebrate taxa, only mayflies (Ephemeroptera) showed a significant increase in mortality following exogenous TTX exposure, despite the use of a concentration 16x higher than the maximum used for trematodes. Our results suggest that maternal investment of TTX into larval newts may provide protection against certain trematode infections and highlight the importance of future work assessing the effects of newt toxicity on both parasite infection success and the palatability of larval newts to invertebrate predators.
Collapse
Affiliation(s)
- Dana M Calhoun
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology, Ramaley N122, CB334, Boulder, CO 80309, USA.
| | - Gary M Bucciarelli
- University of California, Los Angeles, Department of Ecology and Evolutionary Biology, 610 Charles E. Young Dr. East, Los Angeles, CA 90095, USA; University of California, Los Angeles, La Kretz Center for California Conservation Science, Institute of the Environmental Sustainability, La Kretz Hall, Los Angeles, CA 90095, USA.
| | - Lee B Kats
- Pepperdine University, Natural Science Division Pacific Coast Highway, Malibu, CA 90263, USA.
| | - Richard K Zimmer
- University of California, Los Angeles, Department of Ecology and Evolutionary Biology, 610 Charles E. Young Dr. East, Los Angeles, CA 90095, USA; University of Queensland, Moreton Bay Research Station, Centre for Marine Sciences, School of Biological Sciences, Dunwich, Queensland 4183, Australia.
| | - Pieter T J Johnson
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology, Ramaley N122, CB334, Boulder, CO 80309, USA.
| |
Collapse
|
19
|
Potentiation of hydrogen peroxide toxicity: From catalase inhibition to stable DNA-iron complexes. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2016; 773:274-281. [PMID: 28927535 DOI: 10.1016/j.mrrev.2016.08.006] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/29/2016] [Indexed: 12/15/2022]
Abstract
Hydrogen peroxide (H2O2) is unique among general toxins, because it is stable in abiotic environments at ambient temperature and neutral pH, yet rapidly kills any type of cells by producing highly-reactive hydroxyl radicals. This life-specific reactivity follows the distribution of soluble iron, Fe(II) (which combines with H2O2 to form the famous Fenton's reagent),Fe(II) is concentrated inside cells, but is virtually absent outside them. Because of the immediate danger of H2O2, all cells have powerful H2O2 scavengers, the equally famous catalases, which enable cells to survive thousand-fold higher concentrations of H2O2 and, in combination with adequate movement of H2O2 across membranes, make the killing H2O2 concentrations virtually impractical to generate in vivo. And yet, low concentrations of H2O2 are somehow used as an efficient biological weapon. Here we review several examples of how cells potentiate H2O2 toxicity with other chemicals. At first, these potentiators were thought to simply inhibit catalases, but recent findings with cyanide suggest that potentiators mostly promote the other side of Fenton's reaction, recruiting iron from cell depots into stable DNA-iron complexes that, in the presence of elevated H2O2, efficiently break duplex DNA, pulverizing the chromosome. This multifaceted potentiation of H2O2 toxicity results in robust and efficient killing.
Collapse
|
20
|
Tao L, Hoang KM, Hunter MD, de Roode JC. Fitness costs of animal medication: antiparasitic plant chemicals reduce fitness of monarch butterfly hosts. J Anim Ecol 2016; 85:1246-54. [PMID: 27286503 DOI: 10.1111/1365-2656.12558] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/25/2016] [Indexed: 12/01/2022]
Abstract
The emerging field of ecological immunology demonstrates that allocation by hosts to immune defence against parasites is constrained by the costs of those defences. However, the costs of non-immunological defences, which are important alternatives to canonical immune systems, are less well characterized. Estimating such costs is essential for our understanding of the ecology and evolution of alternative host defence strategies. Many animals have evolved medication behaviours, whereby they use antiparasitic compounds from their environment to protect themselves or their kin from parasitism. Documenting the costs of medication behaviours is complicated by natural variation in the medicinal components of diets and their covariance with other dietary components, such as macronutrients. In the current study, we explore the costs of the usage of antiparasitic compounds in monarch butterflies (Danaus plexippus), using natural variation in concentrations of antiparasitic compounds among plants. Upon infection by their specialist protozoan parasite Ophryocystis elektroscirrha, monarch butterflies can selectively oviposit on milkweed with high foliar concentrations of cardenolides, secondary chemicals that reduce parasite growth. Here, we show that these antiparasitic cardenolides can also impose significant costs on both uninfected and infected butterflies. Among eight milkweed species that vary substantially in their foliar cardenolide concentration and composition, we observed the opposing effects of cardenolides on monarch fitness traits. While high foliar cardenolide concentrations increased the tolerance of monarch butterflies to infection, they reduced the survival rate of caterpillars to adulthood. Additionally, although non-polar cardenolide compounds decreased the spore load of infected butterflies, they also reduced the life span of uninfected butterflies, resulting in a hump-shaped curve between cardenolide non-polarity and the life span of infected butterflies. Overall, our results suggest that the use of antiparasitic compounds carries substantial costs, which could constrain host investment in medication behaviours.
Collapse
Affiliation(s)
- Leiling Tao
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA, 30322, USA
| | - Kevin M Hoang
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA, 30322, USA
| | - Mark D Hunter
- Department of Ecology and Evolutionary Biology, University of Michigan, 830 N University Avenue, Ann Arbor, MI, 48109, USA
| | - Jacobus C de Roode
- Department of Biology, Emory University, 1510 Clifton Road, Atlanta, GA, 30322, USA
| |
Collapse
|
21
|
Cheong P, Glare TR, Rostás M, Haines SR. Measuring Chitinase and Protease Activity in Cultures of Fungal Entomopathogens. Methods Mol Biol 2016; 1477:177-189. [PMID: 27565500 DOI: 10.1007/978-1-4939-6367-6_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Entomopathogenic fungi produce a variety of destructive enzymes and metabolites to overcome the unique defense mechanisms of insects. In a first step, fungal chitinases and proteinases need to break down the insect's cuticle. Both enzyme classes support the infection process by weakening the chitin barrier and by producing nutritional cleavage products for the fungus. In a second step, the pathogen can now mechanically penetrate the weakened cuticle and reach the insect's hemolymph where it starts proliferating. The critical enzymes chitinase and proteinase are also excreted into the supernatants of fungal cultures and can be used as indicators of virulence. Chromogenic assays adapted for 96-well microtiter plates that measure these enzymes provide a sensitive, fast, and easy screening method for evaluating the potential biocontrol activity of fungal isolates and may be considered as an alternative to laborious and time-consuming bioassays. Furthermore, monitoring fungal enzyme production in dependence of time, nutrient sources, or other factors can facilitate in establishing optimal growth and harvesting conditions for selected isolates with the aim of achieving maximum biocontrol activity.
Collapse
Affiliation(s)
- Peter Cheong
- Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand.
- Biotelliga Limited, 4 Austen Place, Pukekohe, 2120, New Zealand.
| | - Travis R Glare
- Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand
| | - Michael Rostás
- Bio-Protection Research Centre, Lincoln University, PO Box 85084, Lincoln, 7647, New Zealand
| | - Stephen R Haines
- AgResearch, Lincoln Research Centre, Private Bag 4749, Christchurch, 8140, New Zealand
| |
Collapse
|