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Bodawatta KH, Hu H, Schalk F, Daniel JM, Maiah G, Koane B, Iova B, Beemelmanns C, Poulsen M, Jønsson KA. Multiple mutations in the Nav1.4 sodium channel of New Guinean toxic birds provide autoresistance to deadly batrachotoxin. Mol Ecol 2024; 33:e16878. [PMID: 36779590 DOI: 10.1111/mec.16878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 02/02/2023] [Accepted: 02/07/2023] [Indexed: 02/14/2023]
Abstract
Toxicity has evolved multiple times across the tree of life and serves important functions related to hunting, defence and parasite deterrence. Toxins are produced either in situ by the toxic organism itself or associated symbionts, or acquired through diet. The ability to exploit toxins from external sources requires adaptations that prevent toxic effects on the consumer (autoresistance). Here, we examine genomic adaptations that could facilitate autoresistance to the diet-acquired potent neurotoxic alkaloid batrachotoxin (BTX) in New Guinean toxic birds. Our work documents two new toxic bird species and shows that toxic birds carry multiple mutations in the SCN4A gene that are under positive selection. This gene encodes the most common vertebrate muscle Nav channel (Nav1.4). Molecular docking results indicate that some of the mutations that are present in the pore-forming segment of the Nav channel, where BTX binds, could reduce its binding affinity. These mutations should therefore prevent the continuous opening of the sodium channels that BTX binding elicits, thereby preventing muscle paralysis and ultimately death. Although these mutations are different from those present in Neotropical Phyllobates poison dart frogs, they occur in the same segments of the Nav1.4 channel. Consequently, in addition to uncovering a greater diversity of toxic bird species than previously known, our work provides an intriguing example of molecular-level convergent adaptations allowing frogs and birds to ingest and use the same neurotoxin. This suggests that genetically modified Nav1.4 channels represent a key adaptation to BTX tolerance and exploitation across vertebrates.
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Affiliation(s)
- Kasun H Bodawatta
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Haofu Hu
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Felix Schalk
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology e. V., Hans-Knöll-Institute, Jena, Germany
| | - Jan-Martin Daniel
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology e. V., Hans-Knöll-Institute, Jena, Germany
- Institute for Pharmaceutical Microbiology, University of Bonn, Bonn, Germany
| | - Gibson Maiah
- The New Guinea Binatang Research Centre, Madang, Papua New Guinea
| | - Bonny Koane
- The New Guinea Binatang Research Centre, Madang, Papua New Guinea
| | - Bulisa Iova
- PNG National Museum and Art Gallery, Port Moresby, Papua New Guinea
| | - Christine Beemelmanns
- Chemical Biology of Microbe-Host Interactions, Leibniz Institute for Natural Product Research and Infection Biology e. V., Hans-Knöll-Institute, Jena, Germany
- Department Anti-infectives from Microbiota, Helmholtz-Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Saarbrücken, Germany
- Universität des Saarlandes, Saarbrücken, Germany
| | - Michael Poulsen
- Section for Ecology and Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Knud A Jønsson
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
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2
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Betz A, Bischoff R, Petschenka G. Late-instar monarch caterpillars sabotage milkweed to acquire toxins, not to disarm plant defence. Proc Biol Sci 2024; 291:20232721. [PMID: 38378155 PMCID: PMC10878802 DOI: 10.1098/rspb.2023.2721] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024] Open
Abstract
Sabotaging milkweed by monarch caterpillars (Danaus plexippus) is a famous textbook example of disarming plant defence. By severing leaf veins, monarchs are thought to prevent the flow of toxic latex to their feeding site. Here, we show that sabotaging by monarch caterpillars is not only an avoidance strategy. While young caterpillars appear to avoid latex, late-instar caterpillars actively ingest exuding latex, presumably to increase sequestration of cardenolides used for defence against predators. Comparisons with caterpillars of the related but non-sequestering common crow butterfly (Euploea core) revealed three lines of evidence supporting our hypothesis. First, monarch caterpillars sabotage inconsistently and therefore the behaviour is not obligatory to feed on milkweed, whereas sabotaging precedes each feeding event in Euploea caterpillars. Second, monarch caterpillars shift their behaviour from latex avoidance in younger to eager drinking in later stages, whereas Euploea caterpillars consistently avoid latex and spit it out during sabotaging. Third, monarchs reared on detached leaves without latex sequestered more cardenolides when caterpillars imbibed latex offered with a pipette. Thus, we conclude that monarch caterpillars have transformed the ancestral 'sabotage to avoid' strategy into a 'sabotage to consume' strategy, implying a novel behavioural adaptation to increase sequestration of cardenolides for defence.
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Affiliation(s)
- Anja Betz
- Department of Applied Entomology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Robert Bischoff
- Department of Applied Entomology, University of Hohenheim, 70599 Stuttgart, Germany
| | - Georg Petschenka
- Department of Applied Entomology, University of Hohenheim, 70599 Stuttgart, Germany
- KomBioTa—Center for Biodiversity and Integrative Taxonomy, University of Hohenheim and State Museum of Natural History, 70599 Stuttgart, Germany
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3
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Johnson AE, Cornell A, Hermann S, Zhu F, Hoover K. Using community science to identify predators of spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), in North America. BULLETIN OF ENTOMOLOGICAL RESEARCH 2023; 113:637-644. [PMID: 37614127 DOI: 10.1017/s0007485323000317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
Spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), is an invasive insect that was first detected in the United States in 2014 and feeds on a wide variety of plants, with economic impacts on the agricultural, ornamental, and timber industries. Part of what likely contributes to the success of L. delicatula in its invaded range is that it appears to be chemically defended by sequestering toxins from its host plant(s), which may deter predators in the introduced range. To determine the identity and behavior of North American predators that feed on spotted lanternfly, we performed a community science study in which we asked members of the public to contribute reports of animals feeding on spotted lanternfly through a Facebook page. The largest group of reported predators was arthropods followed by birds. Araneae was the arthropod order with the most reports and Phasianidae was the most frequently reported bird family. Using Pearson's χ2 tests, we also identified significant relationships between predator behavior and (1) taxonomic group of the predator, (2) L. delicatula life stage, and (3) host plant L. delicatula was observed on. These results can help to guide future research on predator host shifting to spotted lanternfly and potential for biocontrol as a management tactic.
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Affiliation(s)
- Anne E Johnson
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802
| | - Alison Cornell
- Division of Mathematics and Natural Sciences, The Pennsylvania State University, Altoona, PA 16601
| | - Sara Hermann
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802
| | - Fang Zhu
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802
| | - Kelli Hoover
- Department of Entomology, The Pennsylvania State University, University Park, PA 16802
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4
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Lawrence JP, Rojas B, Blanchette A, Saporito RA, Mappes J, Fouquet A, Noonan BP. Linking Predator Responses to Alkaloid Variability in Poison Frogs. J Chem Ecol 2023; 49:195-204. [PMID: 36854928 DOI: 10.1007/s10886-023-01412-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/11/2023] [Accepted: 02/15/2023] [Indexed: 03/02/2023]
Abstract
Many chemically-defended/aposematic species rely on diet for sequestering the toxins with which they defend themselves. This dietary acquisition can lead to variable chemical defenses across space, as the community composition of chemical sources is likely to vary across the range of (an aposematic) species. We characterized the alkaloid content of two populations of the Dyeing Poison Frog (Dendrobates tinctorius) in northeastern French Guiana. Additionally, we conducted unpalatability experiments with naive predators, Blue Tits (Cyanistes caeruleus), using whole-skin secretion cocktails to assess how a model predator would respond to the defense of individuals from each population. While there was some overlap between the two D. tinctorius populations in terms of alkaloid content, our analysis revealed that these two populations are markedly distinct in terms of overall alkaloid profiles. Predator responses to skin secretions differed between the populations. We identified 15 candidate alkaloids (including three previously undescribed) in seven classes that are correlated with predator response in one frog population. We describe alkaloid profile differences between populations for D. tinctorius and provide a novel method for assessing unpalatability of skin secretions and identifying which toxins may contribute to the predator response. In one population, our results suggest 15 alkaloids that are implicated in predator aversive response. This method is the first step in identifying the causal link between alkaloids and behavioral responses of predators, and thus makes sense of how varying alkaloid combinations are capable of eliciting consistent behavioral responses, and eventually driving evolutionary change in aposematic characters (or characteristics).
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Affiliation(s)
- J P Lawrence
- Department of Biology, University of Mississippi, University, MS, 38677, USA. .,Lyman Briggs College, Michigan State University, East Lansing, MI, 48825, USA.
| | - Bibiana Rojas
- Department of Biology and Environmental Science, University of Jyväskylä, P.O. Box 35, 40014, Jyväskylä, Finland.,Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Savoyenstraße 1, 1160, Vienna, Austria
| | - Annelise Blanchette
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA.,Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, 70118, USA
| | - Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA
| | - Johanna Mappes
- Department of Biology and Environmental Science, University of Jyväskylä, P.O. Box 35, 40014, Jyväskylä, Finland.,Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental Sciences, Helsinki University, Helsinki, Finland
| | - Antoine Fouquet
- Laboratoire Evolution et Diversité Biologique, UMR5174, Université Paul Sabatier, 31062, Toulouse Cedex 9, France
| | - Brice P Noonan
- Department of Biology, University of Mississippi, University, MS, 38677, USA
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5
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Burdfield-Steel E, Burdfield C. How to fail in advertising: The potential of marketing theory to predict the community-level selection of defended prey. J Evol Biol 2023. [PMID: 36820741 DOI: 10.1111/jeb.14160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 12/14/2022] [Accepted: 01/16/2023] [Indexed: 02/24/2023]
Abstract
Economics and ecology both present us with a key challenge: scaling up from individual behaviour to community-level effects. As a result, biologists have frequently utilized theories and frameworks from economics in their attempt to better understand animal behaviour. In the study of predator-prey interactions, we face a particularly difficult task-understanding how predator choices and strategies will impact the ecology and evolution not just of individual prey species, but whole communities. However, a similar challenge has been encountered, and largely solved, in Marketing, which has created frameworks that successfully predict human consumer behaviour at the community level. We argue that by applying these frameworks to non-human consumers, we can leverage this predictive power to understand the behaviour of these key ecological actors in shaping the communities they act upon. We here use predator-prey interactions, as a case study, to demonstrate and discuss the potential of marketing and human-consumer theory in helping us bridge the gap from laboratory experiments to complex community dynamics.
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Affiliation(s)
- Emily Burdfield-Steel
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Claire Burdfield
- Sheffield University Management School, University of Sheffield, Sheffield, UK
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6
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Blount JD, Rowland HM, Mitchell C, Speed MP, Ruxton GD, Endler JA, Brower LP. The price of defence: toxins, visual signals and oxidative state in an aposematic butterfly. Proc Biol Sci 2023; 290:20222068. [PMID: 36651049 PMCID: PMC9845971 DOI: 10.1098/rspb.2022.2068] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
In a variety of aposematic species, the conspicuousness of an individual's warning signal and the quantity of its chemical defence are positively correlated. This apparent honest signalling is predicted by resource competition models which assume that the production and maintenance of aposematic defences compete for access to antioxidant molecules that have dual functions as pigments and in protecting against oxidative damage. To test for such trade-offs, we raised monarch butterflies (Danaus plexippus) on different species of their milkweed host plants (Apocynaceae) that vary in quantities of cardenolides to test whether (i) the sequestration of cardenolides as a secondary defence is associated with costs in the form of oxidative lipid damage and reduced antioxidant defences; and (ii) lower oxidative state is associated with a reduced capacity to produce aposematic displays. In male monarchs conspicuousness was explained by an interaction between oxidative damage and sequestration: males with high levels of oxidative damage became less conspicuous with increased sequestration of cardenolides, whereas those with low oxidative damage became more conspicuous with increased levels of cardenolides. There was no significant effect of oxidative damage or concentration of sequestered cardenolides on female conspicuousness. Our results demonstrate a physiological linkage between the production of coloration and oxidative state, and differential costs of sequestration and signalling in monarch butterflies.
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Affiliation(s)
- Jonathan D. Blount
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Hannah M. Rowland
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, 07745, Germany
| | - Christopher Mitchell
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10 9FE, UK
| | - Michael P. Speed
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7BE, UK
| | - Graeme D. Ruxton
- School of Biology, Sir Harold Mitchell Building, Greenside Place, St Andrews, UK
| | - John A. Endler
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria 3216, Australia
| | - Lincoln P. Brower
- Department of Biology, Sweet Briar College, Sweet Briar, VA 24595, USA
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7
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Rubiano-Buitrago P, Pradhan S, Paetz C, Rowland HM. New Structures, Spectrometric Quantification, and Inhibitory Properties of Cardenolides from Asclepias curassavica Seeds. Molecules 2022; 28:molecules28010105. [PMID: 36615300 PMCID: PMC9822358 DOI: 10.3390/molecules28010105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/14/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
Cardiac glycosides are a large class of secondary metabolites found in plants. In the genus Asclepias, cardenolides in milkweed plants have an established role in plant-herbivore and predator-prey interactions, based on their ability to inhibit the membrane-bound Na+/K+-ATPase enzyme. Milkweed seeds are eaten by specialist lygaeid bugs, which are the most cardenolide-tolerant insects known. These insects likely impose natural selection for the repeated derivatisation of cardenolides. A first step in investigating this hypothesis is to conduct a phytochemical profiling of the cardenolides in the seeds. Here, we report the concentrations of 10 purified cardenolides from the seeds of Asclepias curassavica. We report the structures of new compounds: 3-O-β-allopyranosyl coroglaucigenin (1), 3-[4'-O-β-glucopyranosyl-β-allopyranosyl] coroglaucigenin (2), 3'-O-β-glucopyranosyl-15-β-hydroxycalotropin (3), and 3-O-β-glucopyranosyl-12-β-hydroxyl coroglaucigenin (4), as well as six previously reported cardenolides (5-10). We test the in vitro inhibition of these compounds on the sensitive porcine Na+/K+-ATPase. The least inhibitory compound was also the most abundant in the seeds-4'-O-β-glucopyranosyl frugoside (5). Gofruside (9) was the most inhibitory. We found no direct correlation between the number of glycosides/sugar moieties in a cardenolide and its inhibitory effect. Our results enhance the literature on cardenolide diversity and concentration among tissues eaten by insects and provide an opportunity to uncover potential evolutionary relationships between tissue-specific defense expression and insect adaptations in plant-herbivore interactions.
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Affiliation(s)
- Paola Rubiano-Buitrago
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
- Correspondence: (P.R.-B.); (H.M.R.)
| | - Shrikant Pradhan
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
| | - Christian Paetz
- Research Group Biosynthesis/NMR, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
| | - Hannah M. Rowland
- Research Group Predators and Toxic Prey, Max Planck Institute for Chemical Ecology, Hans Knöll Straße 8, 07745 Jena, Germany
- Correspondence: (P.R.-B.); (H.M.R.)
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8
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Jeckel AM, Beran F, Züst T, Younkin G, Petschenka G, Pokharel P, Dreisbach D, Ganal-Vonarburg SC, Robert CAM. Metabolization and sequestration of plant specialized metabolites in insect herbivores: Current and emerging approaches. Front Physiol 2022; 13:1001032. [PMID: 36237530 PMCID: PMC9552321 DOI: 10.3389/fphys.2022.1001032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
Herbivorous insects encounter diverse plant specialized metabolites (PSMs) in their diet, that have deterrent, anti-nutritional, or toxic properties. Understanding how they cope with PSMs is crucial to understand their biology, population dynamics, and evolution. This review summarizes current and emerging cutting-edge methods that can be used to characterize the metabolic fate of PSMs, from ingestion to excretion or sequestration. It further emphasizes a workflow that enables not only to study PSM metabolism at different scales, but also to tackle and validate the genetic and biochemical mechanisms involved in PSM resistance by herbivores. This review thus aims at facilitating research on PSM-mediated plant-herbivore interactions.
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Affiliation(s)
- Adriana Moriguchi Jeckel
- Laboratory of Chemical Ecology, Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Franziska Beran
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Tobias Züst
- Department of Systematic and Evolutionary Botany, University of Zürich, Zürich, Switzerland
| | - Gordon Younkin
- Boyce Thompson Institute, Ithaca, NY, United States
- Plant Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, United States
| | - Georg Petschenka
- Department of Applied Entomology, Institute of Phytomedicine, University of Hohenheim, Stuttgart, Germany
| | - Prayan Pokharel
- Department of Applied Entomology, Institute of Phytomedicine, University of Hohenheim, Stuttgart, Germany
| | - Domenic Dreisbach
- Institute for Inorganic and Analytical Chemistry, Justus Liebig University Giessen, Giessen, Germany
| | - Stephanie Christine Ganal-Vonarburg
- Department of Visceral Surgery and Medicine, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, Visceral Surgery and Medicine, University of Bern, Bern, Switzerland
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9
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Mohammadi S, Yang L, Bulbert M, Rowland HM. Defence mitigation by predators of chemically defended prey integrated over the predation sequence and across biological levels with a focus on cardiotonic steroids. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220363. [PMID: 36133149 PMCID: PMC9449480 DOI: 10.1098/rsos.220363] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/17/2022] [Indexed: 05/10/2023]
Abstract
Predator-prey interactions have long served as models for the investigation of adaptation and fitness in natural environments. Anti-predator defences such as mimicry and camouflage provide some of the best examples of evolution. Predators, in turn, have evolved sensory systems, cognitive abilities and physiological resistance to prey defences. In contrast to prey defences which have been reviewed extensively, the evolution of predator counter-strategies has received less attention. To gain a comprehensive view of how prey defences can influence the evolution of predator counter-strategies, it is essential to investigate how and when selection can operate. In this review we evaluate how predators overcome prey defences during (i) encounter, (ii) detection, (iii) identification, (iv) approach, (v) subjugation, and (vi) consumption. We focus on prey that are protected by cardiotonic steroids (CTS)-defensive compounds that are found in a wide range of taxa, and that have a specific physiological target. In this system, coevolution is well characterized between specialist insect herbivores and their host plants but evidence for coevolution between CTS-defended prey and their predators has received less attention. Using the predation sequence framework, we organize 574 studies reporting predators overcoming CTS defences, integrate these counter-strategies across biological levels of organization, and discuss the costs and benefits of attacking CTS-defended prey. We show that distinct lineages of predators have evolved dissecting behaviour, changes in perception of risk and of taste perception, and target-site insensitivity. We draw attention to biochemical, hormonal and microbiological strategies that have yet to be investigated as predator counter-adaptations to CTS defences. We show that the predation sequence framework will be useful for organizing future studies of chemically mediated systems and coevolution.
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Affiliation(s)
- Shabnam Mohammadi
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
- Institut für Zell- und Systembiologie der Tiere, Universität Hamburg, Hamburg, Germany
- Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Lu Yang
- Wellcome Sanger Institute, Cambridge, UK
| | - Matthew Bulbert
- Department of Biological Sciences, Macquarie University North Ryde, New South Wales, Australia
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, University of Oxford Brookes, Oxford, UK
- Max Planck Institute for Chemical Ecology, Jena, Germany
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10
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Mohammadi S, Yang L, Bulbert M, Rowland HM. Defence mitigation by predators of chemically defended prey integrated over the predation sequence and across biological levels with a focus on cardiotonic steroids. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220363. [PMID: 36133149 DOI: 10.6084/m9.figshare.c.6168216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/17/2022] [Indexed: 05/25/2023]
Abstract
Predator-prey interactions have long served as models for the investigation of adaptation and fitness in natural environments. Anti-predator defences such as mimicry and camouflage provide some of the best examples of evolution. Predators, in turn, have evolved sensory systems, cognitive abilities and physiological resistance to prey defences. In contrast to prey defences which have been reviewed extensively, the evolution of predator counter-strategies has received less attention. To gain a comprehensive view of how prey defences can influence the evolution of predator counter-strategies, it is essential to investigate how and when selection can operate. In this review we evaluate how predators overcome prey defences during (i) encounter, (ii) detection, (iii) identification, (iv) approach, (v) subjugation, and (vi) consumption. We focus on prey that are protected by cardiotonic steroids (CTS)-defensive compounds that are found in a wide range of taxa, and that have a specific physiological target. In this system, coevolution is well characterized between specialist insect herbivores and their host plants but evidence for coevolution between CTS-defended prey and their predators has received less attention. Using the predation sequence framework, we organize 574 studies reporting predators overcoming CTS defences, integrate these counter-strategies across biological levels of organization, and discuss the costs and benefits of attacking CTS-defended prey. We show that distinct lineages of predators have evolved dissecting behaviour, changes in perception of risk and of taste perception, and target-site insensitivity. We draw attention to biochemical, hormonal and microbiological strategies that have yet to be investigated as predator counter-adaptations to CTS defences. We show that the predation sequence framework will be useful for organizing future studies of chemically mediated systems and coevolution.
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Affiliation(s)
- Shabnam Mohammadi
- School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
- Institut für Zell- und Systembiologie der Tiere, Universität Hamburg, Hamburg, Germany
- Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Lu Yang
- Wellcome Sanger Institute, Cambridge, UK
| | - Matthew Bulbert
- Department of Biological Sciences, Macquarie University North Ryde, New South Wales, Australia
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, University of Oxford Brookes, Oxford, UK
- Max Planck Institute for Chemical Ecology, Jena, Germany
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11
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Gilmour SM, Kharouba HM. Eastern monarch larval performance may not be affected by shifts in phenological synchrony with milkweed. Ecol Evol 2022; 12:e9131. [PMID: 35949530 PMCID: PMC9351326 DOI: 10.1002/ece3.9131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 05/22/2022] [Accepted: 06/27/2022] [Indexed: 11/25/2022] Open
Abstract
Interacting species are experiencing disruptions in the relative timing of their key life-history events due to climate change. These shifts can sometimes be detrimental to the fitness of the consumer in trophic interactions but not always.The potential consequences of phenological asynchrony for the monarch butterfly (Danaus plexippus) and its host plant (Asclepias spp.) have not been well-studied. Given that plants generally undergo seasonal declines in quality, if climate change delays the timing of the larval stage relative to the availability of younger milkweed plants, monarch performance could be negatively affected.Here, we explore the potential consequences for the eastern monarch population due to probable asynchrony with milkweed. We used field surveys around Ottawa, Canada, to determine monarch oviposition preference on common milkweed (Asclepias syriaca) plants and the seasonal availability of these plants. To determine the potential fitness consequences when females oviposit on nonpreferred plants, we conducted a field experiment to assess the effect of milkweed size on monarch larval performance (e.g., development time and final size).Preferred oviposition plants (earlier stages of development and better condition) were consistently available in large proportion over the summer season. We also found that declines in leaf quality (more latex and thicker leaves) with plant size did not translate into decreases in larval performance.Our results suggest that even if asynchrony of the monarch-milkweed interaction occurs due to climate change, the larval stage of the eastern monarch may not face negative consequences. Future studies should determine how the relative timing of the interaction will change in the region.
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12
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Teoh MC, Singham GV. Bacterial diversity and community structure shapes pederin polymorphism but lacks association with host genotype specificity in the rove beetle, Paederus fuscipes. FEMS Microbiol Ecol 2022; 98:6650347. [PMID: 35883232 DOI: 10.1093/femsec/fiac087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 07/06/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
Paederus beetles are notorious for their irritant haemolymph toxin pederin synthesized by an unculturable bacterial symbiont which causes dermatitis when in contact with human skin. Pederin polymorphism is observed when (+) females carrying the toxin pederin and (-) females lacking this, co-occur in natural populations. Despite reports detecting pederin polymorphism in several Paederina beetles, symbiont infection frequencies in their natural populations and the bacterial diversity differences underlying the polymorphism between these female types are understudied. Herein we report a high prevalence (>80%) of female Paederus fuscipes carrying bacterial ped genes in all six study populations. This finding suggests selection pressure favouring pederin-producing females is crucial for survival in the natural environment. 16S rRNA metabarcoding analysis revealed significant dominance of the unculturable pederin-producing Pseudomonas-like bacterium (Gammaproteobacteria) in (+) females consistent with previous studies. The microbial diversity of the (-) females revealed significant abundance of Apibacter (Bacteroidia) previously undocumented suggesting its importance in the functionality of (-) females. Predicted functions related to metabolisms are enriched in (-) females suggesting fitness advantage possibilities in sustaining the population in the absence of predation. Further investigations on possible genetic basis of host genotype revealed no association of host mtDNA and pederin polymorphism in P. fuscipes.
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Affiliation(s)
- Miao-Ching Teoh
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, 11900 Penang, Malaysia
| | - G Veera Singham
- Centre for Chemical Biology, Universiti Sains Malaysia, Bayan Lepas, 11900 Penang, Malaysia
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13
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Greenstein L, Steele C, Taylor CM. Host plant specificity of the monarch butterfly Danaus plexippus: A systematic review and meta-analysis. PLoS One 2022; 17:e0269701. [PMID: 35700160 PMCID: PMC9197062 DOI: 10.1371/journal.pone.0269701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 05/25/2022] [Indexed: 11/26/2022] Open
Abstract
The preference-performance hypothesis explains host specificity in phytophagous insects, positing that host plants chosen by adults confer the greatest larval fitness. However, adults sometimes oviposit on plants supporting low larval success because the components of host specificity (adult preference, plant palatability, and larval survival) are non-binary and not necessarily correlated. Palatability (willingness to eat) is governed by chemical cues and physical barriers such as trichomes, while survival (ability to complete development) depends upon nutrition and toxicity. Absence of a correlation between the components of host specificity results in low-performance hosts supporting limited larval development. Most studies of specificity focus on oviposition behavior leaving the importance and basis of palatability and survival under-explored. We conducted a comprehensive review of 127 plant species that have been claimed or tested to be hosts for the monarch butterfly Danaus plexippus to classify them as non-hosts, low performance, or high performance. We performed a meta-analysis to test if performance status could be explained by properties of neurotoxic cardenolides or trichome density. We also conducted a no-choice larval feeding experiment to identify causes of low performance. We identified 34 high performance, 42 low performance, 33 non-hosts, and 18 species with unsubstantiated claims. Mean cardenolide concentration was greater in high- than low-performance hosts and a significant predictor of host status, suggesting possible evolutionary trade-offs in monarch specialization. Other cardenolide properties and trichome density were not significant predictors of host status. In the experiment, we found, of the 62% of larvae that attempted to eat low-performance hosts, only 3.5% survived to adult compared to 85% of those on the high-performance host, demonstrating that multiple factors affect larval host plant specificity. Our study is the first to classify all known host plants for monarchs and has conservation implications for this threatened species.
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Affiliation(s)
- Lewis Greenstein
- Illinois Natural History Survey, University of Illinois at Urbana-Champaign, Champaign, Illinois, United States of America
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, United States of America
- * E-mail:
| | - Christen Steele
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, United States of America
| | - Caz M. Taylor
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, United States of America
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14
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Abstract
Aposematism and mimicry are complex phenomena which have been studied extensively; however, much of our knowledge comes from just a few focal groups, especially butterflies. Aposematic species combine a warning signal with a secondary defense that reduces their profitability as prey. Aculeate hymenopterans are an extremely diverse lineage defined by the modification of the ovipositor into a stinger which represents a potent defense against predators. Aculeates are often brightly colored and broadly mimicked by members of other arthropod groups including Diptera, Lepidoptera, Coleoptera, and Araneae. However, aculeates are surprisingly understudied as aposematic and mimetic model organisms. Recent studies have described novel pigments contributing to warning coloration in insects and identified changes in cis-regulatory elements as potential drivers of color pattern evolution. Many biotic and abiotic factors contribute to the evolution and maintenance of conspicuous color patterns. Predator distribution and diversity seem to influence the phenotypic diversity of aposematic velvet ants while studies on bumble bees underscore the importance of intermediate mimetic phenotypes in transition zones between putative mimicry rings. Aculeate hymenopterans are attractive models for studying sex-based intraspecific mimicry as male aculeates lack the defense conferred by the females’ stinger. In some species, evolution of male and female color patterns appears to be decoupled. Future studies on aposematic aculeates and their associated mimics hold great promise for unraveling outstanding questions about the evolution of conspicuous color patterns and the factors which determine the composition and distribution of mimetic communities.
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15
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Petschenka G, Halitschke R, Züst T, Roth A, Stiehler S, Tenbusch L, Hartwig C, Gámez JFM, Trusch R, Deckert J, Chalušová K, Vilcinskas A, Exnerová A. Sequestration of defenses against predators drives specialized host plant associations in preadapted milkweed bugs (Heteroptera: Lygaeinae). Am Nat 2022; 199:E211-E228. [DOI: 10.1086/719196] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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16
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Beran F, Petschenka G. Sequestration of Plant Defense Compounds by Insects: From Mechanisms to Insect-Plant Coevolution. ANNUAL REVIEW OF ENTOMOLOGY 2022; 67:163-180. [PMID: 34995091 DOI: 10.1146/annurev-ento-062821-062319] [Citation(s) in RCA: 36] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Plant defense compounds play a key role in the evolution of insect-plant associations by selecting for behavioral, morphological, and physiological insect adaptations. Sequestration, the ability of herbivorous insects to accumulate plant defense compounds to gain a fitness advantage, represents a complex syndrome of adaptations that has evolved in all major lineages of herbivorous insects and involves various classes of plant defense compounds. In this article, we review progress in understanding how insects selectively accumulate plant defense metabolites and how the evolution of specific resistance mechanisms to these defense compounds enables sequestration. These mechanistic considerations are further integrated into the concept of insect-plant coevolution. Comparative genome and transcriptome analyses, combined with approaches based on analytical chemistry that are centered in phylogenetic frameworks, will help to reveal adaptations underlying the sequestration syndrome, which is essential to understanding the influence of sequestration on insect-plant coevolution.
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Affiliation(s)
- Franziska Beran
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena 07745, Germany;
| | - Georg Petschenka
- Department of Applied Entomology, University of Hohenheim, Stuttgart 70599, Germany;
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17
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Hämäläinen L, M. Rowland H, Mappes J, Thorogood R. Social information use by predators: expanding the information ecology of prey defences. OIKOS 2021. [DOI: 10.1111/oik.08743] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Hannah M. Rowland
- Max Planck Inst. for Chemical Ecology Jena Germany
- Dept of Zoology, Univ. of Cambridge Cambridge UK
| | - Johanna Mappes
- Research Programme in Organismal&Evolutionary Biology, Faculty of Biological and Environmental Sciences, Univ. of Helsinki Helsinki Finland
- Dept of Biological and Environmental Sciences, Univ. of Jyväskylä Jyväskylä Finland
| | - Rose Thorogood
- Research Programme in Organismal&Evolutionary Biology, Faculty of Biological and Environmental Sciences, Univ. of Helsinki Helsinki Finland
- HiLIFE Helsinki Inst. of Life Science, Univ. of Helsinki Helsinki Finland
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18
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Sculfort O, McClure M, Nay B, Elias M, Llaurens V. Assessing the Role of Developmental and Environmental Factors in Chemical Defence Variation in Heliconiini Butterflies. J Chem Ecol 2021; 47:577-587. [PMID: 34003420 PMCID: PMC8217024 DOI: 10.1007/s10886-021-01278-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/21/2021] [Accepted: 04/27/2021] [Indexed: 11/12/2022]
Abstract
Chemical defences in animals are both incredibly widespread and highly diverse. Yet despite the important role they play in mediating interactions between predators and prey, extensive differences in the amounts and types of chemical compounds can exist between individuals, even within species and populations. Here we investigate the potential role of environment and development on the chemical defences of warningly coloured butterfly species from the tribe Heliconiini, which can both synthesize and sequester cyanogenic glycosides (CGs). We reared 5 Heliconiini species in captivity, each on a single species-specific host plant as larvae, and compared them to individuals collected in the wild to ascertain whether the variation in CG content observed in the field might be the result of differences in host plant availability. Three of these species were reared as larvae on the same host plant, Passiflora riparia, to further test how species, sex, and age affected the type and amount of different defensive CGs, and how they affected the ratio of synthesized to sequestered compounds. Then, focusing on the generalist species Heliconius numata, we specifically explored variation in chemical profiles as a result of the host plant consumed by caterpillars and their brood line, using rearing experiments carried out on two naturally co-occurring host plants with differing CG profiles. Our results show significant differences in both the amount of synthesized and sequestered compounds between butterflies reared in captivity and those collected in the field. We also found a significant effect of species and an effect of sex in some, but not all, species. We show that chemical defences in H. numata continue to increase throughout their life, likely because of continued biosynthesis, and we suggest that variation in the amount of synthesized CGs in this species does not appear to stem from larval host plants, although this warrants further study. Interestingly, we detected a significant effect of brood lines, consistent with heritability influencing CG concentrations in H. numata. Altogether, our results point to multiple factors resulting in chemical defence variation in Heliconiini butterflies and highlight the overlooked effect of synthesis capabilities, which may be genetically determined to some extent.
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Affiliation(s)
- Ombeline Sculfort
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National D'Histoire Naturelle, CNRS, Sorbonne-Université, EPHE, Université Des Antilles, 45 rue Buffon, 75005, Paris, France. .,Unité Molécules de Communication Et Adaptations Des Micro-Organismes (MCAM), Muséum National D'Histoire Naturelle, CNRS, 57 rue Cuvier (BP 54), 75005, Paris, France. .,Laboratoire Écologie, Évolution, Interactions Des Systèmes Amazoniens (LEEISA), Université de Guyane, CNRS, IFREMER, 97300, Cayenne, France.
| | - Melanie McClure
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National D'Histoire Naturelle, CNRS, Sorbonne-Université, EPHE, Université Des Antilles, 45 rue Buffon, 75005, Paris, France.,Laboratoire Écologie, Évolution, Interactions Des Systèmes Amazoniens (LEEISA), Université de Guyane, CNRS, IFREMER, 97300, Cayenne, France
| | - Bastien Nay
- Unité Molécules de Communication Et Adaptations Des Micro-Organismes (MCAM), Muséum National D'Histoire Naturelle, CNRS, 57 rue Cuvier (BP 54), 75005, Paris, France.,Laboratoire de Synthèse Organique, Ecole Polytechnique, CNRS, ENSTA, Route de Saclay, 91128, Palaiseau Cedex, France
| | - Marianne Elias
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National D'Histoire Naturelle, CNRS, Sorbonne-Université, EPHE, Université Des Antilles, 45 rue Buffon, 75005, Paris, France
| | - Violaine Llaurens
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National D'Histoire Naturelle, CNRS, Sorbonne-Université, EPHE, Université Des Antilles, 45 rue Buffon, 75005, Paris, France
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19
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Kowalski P, Baum M, Körten M, Donath A, Dobler S. ABCB transporters in a leaf beetle respond to sequestered plant toxins. Proc Biol Sci 2020; 287:20201311. [PMID: 32873204 PMCID: PMC7542790 DOI: 10.1098/rspb.2020.1311] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/10/2020] [Indexed: 12/17/2022] Open
Abstract
Phytophagous insects can tolerate and detoxify toxic compounds present in their host plants and have evolved intricate adaptations to this end. Some insects even sequester the toxins for their defence. This necessitates specific mechanisms, especially carrier proteins that regulate uptake and transport to specific storage sites or protect sensitive tissues from noxious compounds. We identified three ATP-binding cassette subfamily B (ABCB) transporters from the transcriptome of the cardenolide-sequestering leaf beetle Chrysochus auratus and analysed their functional role in the sequestration process. These were heterologously expressed and tested for their ability to interact with various potential substrates: verapamil (standard ABCB substrate), the cardenolides digoxin (commonly used), cymarin (present in the species's host plant) and calotropin (present in the ancestral host plants). Verapamil stimulated all three ABCBs and each was activated by at least one cardenolide, however, they differed as to which they were activated by. While the expression of the most versatile transporter fits with a protective role in the blood-brain barrier, the one specific for cymarin shows an extreme abundance in the elytra, coinciding with the location of the defensive glands. Our data thus suggest a key role of ABCBs in the transport network needed for cardenolide sequestration.
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Affiliation(s)
- Paulina Kowalski
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Michael Baum
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Marcel Körten
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
| | - Alexander Donath
- ZFMK, Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere, Adenauerallee 160, 53113 Bonn, Germany
| | - Susanne Dobler
- Molecular Evolutionary Biology, Institute of Zoology, Universität Hamburg, Martin-Luther-King Platz 3, 20146 Hamburg, Germany
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20
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Pokharel P, Sippel M, Vilcinskas A, Petschenka G. Defense of Milkweed Bugs (Heteroptera: Lygaeinae) against Predatory Lacewing Larvae Depends on Structural Differences of Sequestered Cardenolides. INSECTS 2020; 11:E485. [PMID: 32752003 PMCID: PMC7469174 DOI: 10.3390/insects11080485] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/22/2020] [Accepted: 07/28/2020] [Indexed: 11/17/2022]
Abstract
Predators and parasitoids regulate insect populations and select defense mechanisms such as the sequestration of plant toxins. Sequestration is common among herbivorous insects, yet how the structural variation of plant toxins affects defenses against predators remains largely unknown. The palearctic milkweed bug Lygaeus equestris (Heteroptera: Lygaeinae) was recently shown to sequester cardenolides from Adonis vernalis (Ranunculaceae), while its relative Horvathiolus superbus also obtains cardenolides but from Digitalis purpurea (Plantaginaceae). Remarkably, toxin sequestration protects both species against insectivorous birds, but only H. superbus gains protection against predatory lacewing larvae. Here, we used a full factorial design to test whether this difference was mediated by the differences in plant chemistry or by the insect species. We raised both species of milkweed bugs on seeds from both species of host plants and carried out predation assays using the larvae of the lacewing Chrysoperla carnea. In addition, we analyzed the toxins sequestered by the bugs via liquid chromatography (HPLC). We found that both insect species gained protection by sequestering cardenolides from D. purpurea but not from A. vernalis. Since the total amount of toxins stored was not different between the plant species in H. superbus and even lower in L. equestris from D. purpurea compared to A. vernalis, the effect is most likely mediated by structural differences of the sequestered toxins. Our findings indicate that predator-prey interactions are highly context-specific and that the host plant choice can affect the levels of protection to various predator types based on structural differences within the same class of chemical compounds.
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Affiliation(s)
- Prayan Pokharel
- Institute of Phytomedicine, University of Hohenheim, 70599 Stuttgart, Germany;
| | - Marlon Sippel
- Institute for Insect Biotechnology, Justus Liebig University Giessen, 35392 Giessen, Germany; (M.S.); (A.V.)
| | - Andreas Vilcinskas
- Institute for Insect Biotechnology, Justus Liebig University Giessen, 35392 Giessen, Germany; (M.S.); (A.V.)
| | - Georg Petschenka
- Institute of Phytomedicine, University of Hohenheim, 70599 Stuttgart, Germany;
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21
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Al Sulaibi MAM, Thiemann C, Thiemann T. Chemical Constituents and Uses of Calotropis Procera and Calotropis Gigantea – A Review (Part I – The Plants as Material and Energy Resources). ACTA ACUST UNITED AC 2020. [DOI: 10.2174/1874842202007010001] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The traditional and current use of Calotropis procera and C. gigantea, two soft-wooded, xerophytic shrubs of the family Apocynaceae, are reviewed against the background of the plants' chemical constituents and their biological properties. The focus is on the usage of the plants for building materials, natural pesticides, animal feed and bioremediative purposes.
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22
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Hämäläinen L, Mappes J, Rowland HM, Thorogood R. Social information use about novel aposematic prey is not influenced by a predator's previous experience with toxins. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13395] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Johanna Mappes
- Department of Biological and Environmental Science University of Jyväskylä Jyväskylä Finland
| | - Hannah M. Rowland
- Department of Zoology University of Cambridge Cambridge UK
- Max Planck Institute for Chemical Ecology Jena Germany
- Institute of Zoology Zoological Society of London London UK
| | - Rose Thorogood
- Department of Zoology University of Cambridge Cambridge UK
- HiLIFE Helsinki Institute of Life Sciences, University of Helsinki Helsinki Finland
- Research Programme in Organismal & Evolutionary Biology, Faculty of Biological and Environmental Sciences University of Helsinki Helsinki Finland
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23
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Weitemier K, Straub SC, Fishbein M, Bailey CD, Cronn RC, Liston A. A draft genome and transcriptome of common milkweed ( Asclepias syriaca) as resources for evolutionary, ecological, and molecular studies in milkweeds and Apocynaceae. PeerJ 2019; 7:e7649. [PMID: 31579586 PMCID: PMC6756140 DOI: 10.7717/peerj.7649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 08/09/2019] [Indexed: 02/06/2023] Open
Abstract
Milkweeds (Asclepias) are used in wide-ranging studies including floral development, pollination biology, plant-insect interactions and co-evolution, secondary metabolite chemistry, and rapid diversification. We present a transcriptome and draft nuclear genome assembly of the common milkweed, Asclepias syriaca. This reconstruction of the nuclear genome is augmented by linkage group information, adding to existing chloroplast and mitochondrial genomic resources for this member of the Apocynaceae subfamily Asclepiadoideae. The genome was sequenced to 80.4× depth and the draft assembly contains 54,266 scaffolds ≥1 kbp, with N50 = 3,415 bp, representing 37% (156.6 Mbp) of the estimated 420 Mbp genome. A total of 14,474 protein-coding genes were identified based on transcript evidence, closely related proteins, and ab initio models, and 95% of genes were annotated. A large proportion of gene space is represented in the assembly, with 96.7% of Asclepias transcripts, 88.4% of transcripts from the related genus Calotropis, and 90.6% of proteins from Coffea mapping to the assembly. Scaffolds covering 75 Mbp of the Asclepias assembly formed 11 linkage groups. Comparisons of these groups with pseudochromosomes in Coffea found that six chromosomes show consistent stability in gene content, while one may have a long history of fragmentation and rearrangement. The progesterone 5β-reductase gene family, a key component of cardenolide production, is likely reduced in Asclepias relative to other Apocynaceae. The genome and transcriptome of common milkweed provide a rich resource for future studies of the ecology and evolution of a charismatic plant family.
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Affiliation(s)
- Kevin Weitemier
- Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR, USA
| | | | - Mark Fishbein
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, OK, USA
| | - C. Donovan Bailey
- Department of Biology, New Mexico State University, Las Cruces, NM, USA
| | - Richard C. Cronn
- Pacific Northwest Research Station, USDA Forest Service, Corvallis, OR, USA
| | - Aaron Liston
- Department of Botany & Plant Pathology, Oregon State University, Corvallis, OR, USA
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24
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Ramos BDCM, Trigo JR, Rodrigues D. The specialization continuum: Decision-making in butterflies with different diet requirements. Behav Processes 2019; 165:14-22. [PMID: 31176684 DOI: 10.1016/j.beproc.2019.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 05/27/2019] [Accepted: 06/03/2019] [Indexed: 11/30/2022]
Abstract
Differences in diet requirements may be reflected in how floral visitors make decisions when probing nectar sources that differ in chemical composition. We examined decision-making in butterflies that form a specialization continuum involving pyrrolizidine alkaloids (PAs) when interacting with PA and non-PA plants: Agraulis vanillae (non-specialist), Danaus erippus (low demanding PA-specialist) and D. gilippus (high demanding PA-specialist). In addition, we assessed whether experience affected decision-making. Butterflies were tested on either Tridax procumbens (absence of PAs in nectar) or Ageratum conyzoides flowers (presence of PAs in nectar). Agraulis vanillae showed more acceptance for T. procumbens and more rejection for A. conyzoides; no differences were recorded for both Danaus species. Agraulis vanillae fed less on A. conyzoides than both Danaus species, which did not differ in this regard. In all butterfly species, experience on PA flowers did not affect feeding time. In the field, butterflies rarely visited PA flowers, regardless of the specialization degree. Our findings reveal that the specialization continuum seen in butterflies explains, at least in part, decision-making processes related to feeding. Additional factors as local adaptation mediated by the use of alternative nectar sources can affect flower visitation by specialist butterflies.
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Affiliation(s)
- Bruna de Cássia Menezes Ramos
- Laboratório de Interações Inseto-Planta and Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, PO Box 68020. 21941-902. Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil.
| | - José Roberto Trigo
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, PO Box 6109, 13083-970, Campinas, SP, Brazil
| | - Daniela Rodrigues
- Laboratório de Interações Inseto-Planta and Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, PO Box 68020. 21941-902. Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil
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25
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Oberhauser KS, Alonso A, Malcolm SB, Williams EH, Zalucki MP. Lincoln Brower, Champion for Monarchs. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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26
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Briolat ES, Burdfield‐Steel ER, Paul SC, Rönkä KH, Seymoure BM, Stankowich T, Stuckert AMM. Diversity in warning coloration: selective paradox or the norm? Biol Rev Camb Philos Soc 2019; 94:388-414. [PMID: 30152037 PMCID: PMC6446817 DOI: 10.1111/brv.12460] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 01/03/2023]
Abstract
Aposematic theory has historically predicted that predators should select for warning signals to converge on a single form, as a result of frequency-dependent learning. However, widespread variation in warning signals is observed across closely related species, populations and, most problematically for evolutionary biologists, among individuals in the same population. Recent research has yielded an increased awareness of this diversity, challenging the paradigm of signal monomorphy in aposematic animals. Here we provide a comprehensive synthesis of these disparate lines of investigation, identifying within them three broad classes of explanation for variation in aposematic warning signals: genetic mechanisms, differences among predators and predator behaviour, and alternative selection pressures upon the signal. The mechanisms producing warning coloration are also important. Detailed studies of the genetic basis of warning signals in some species, most notably Heliconius butterflies, are beginning to shed light on the genetic architecture facilitating or limiting key processes such as the evolution and maintenance of polymorphisms, hybridisation, and speciation. Work on predator behaviour is changing our perception of the predator community as a single homogenous selective agent, emphasising the dynamic nature of predator-prey interactions. Predator variability in a range of factors (e.g. perceptual abilities, tolerance to chemical defences, and individual motivation), suggests that the role of predators is more complicated than previously appreciated. With complex selection regimes at work, polytypisms and polymorphisms may even occur in Müllerian mimicry systems. Meanwhile, phenotypes are often multifunctional, and thus subject to additional biotic and abiotic selection pressures. Some of these selective pressures, primarily sexual selection and thermoregulation, have received considerable attention, while others, such as disease risk and parental effects, offer promising avenues to explore. As well as reviewing the existing evidence from both empirical studies and theoretical modelling, we highlight hypotheses that could benefit from further investigation in aposematic species. Finally by collating known instances of variation in warning signals, we provide a valuable resource for understanding the taxonomic spread of diversity in aposematic signalling and with which to direct future research. A greater appreciation of the extent of variation in aposematic species, and of the selective pressures and constraints which contribute to this once-paradoxical phenomenon, yields a new perspective for the field of aposematic signalling.
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Affiliation(s)
- Emmanuelle S. Briolat
- Centre for Ecology & Conservation, College of Life & Environmental SciencesUniversity of ExeterPenryn Campus, Penryn, Cornwall, TR10 9FEU.K.
| | - Emily R. Burdfield‐Steel
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskylä, 40014Finland
| | - Sarah C. Paul
- Centre for Ecology & Conservation, College of Life & Environmental SciencesUniversity of ExeterPenryn Campus, Penryn, Cornwall, TR10 9FEU.K.
- Department of Chemical EcologyBielefeld UniversityUniversitätsstraße 25, 33615, BielefeldGermany
| | - Katja H. Rönkä
- Centre of Excellence in Biological Interactions, Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskylä, 40014Finland
- Organismal and Evolutionary Biology Research Programme, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinki, 00014Finland
| | - Brett M. Seymoure
- Department of BiologyColorado State UniversityFort CollinsCO 80525U.S.A.
- Department of Fish, Wildlife, and Conservation BiologyColorado State UniversityFort CollinsCO 80525U.S.A.
| | - Theodore Stankowich
- Department of Biological SciencesCalifornia State UniversityLong BeachCA 90840U.S.A.
| | - Adam M. M. Stuckert
- Department of BiologyEast Carolina University1000 E Fifth St, GreenvilleNC 27858U.S.A.
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27
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Jones PL, Petschenka G, Flacht L, Agrawal AA. Cardenolide Intake, Sequestration, and Excretion by the Monarch Butterfly along Gradients of Plant Toxicity and Larval Ontogeny. J Chem Ecol 2019; 45:264-277. [PMID: 30793231 DOI: 10.1007/s10886-019-01055-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 12/24/2018] [Accepted: 02/12/2019] [Indexed: 11/29/2022]
Abstract
Monarch butterflies, Danaus plexippus, migrate long distances over which they encounter host plants that vary broadly in toxic cardenolides. Remarkably little is understood about the mechanisms of sequestration in Lepidoptera that lay eggs on host plants ranging in such toxins. Using closely-related milkweed host plants that differ more than ten-fold in cardenolide concentrations, we mechanistically address the intake, sequestration, and excretion of cardenolides by monarchs. We show that on high cardenolide plant species, adult butterflies saturate in cardenolides, resulting in lower concentrations than in leaves, while on low cardenolide plants, butterflies concentrate toxins. Butterflies appear to focus their sequestration on particular compounds, as the diversity of cardenolides is highest in plant leaves, lower in frass, and least in adult butterflies. Among the variety of cardenolides produced by the plant, sequestered compounds may be less toxic to the butterflies themselves, as they are more polar on average than those in leaves. In accordance with this, results from an in vitro assay based on inhibition of Na+/K+ ATPase (the physiological target of cardenolides) showed that on two milkweed species, including the high cardenolide A. perennis, extracts from butterflies have lower inhibitory effects than leaves when standardized by cardenolide concentration, indicating selective sequestration of less toxic compounds from these host plants. To understand how ontogeny shapes sequestration, we examined cardenolide concentrations in caterpillar body tissues and hemolymph over the course of development. Caterpillars sequestered higher concentrations of cardenolides as early instars than as late instars, but within the fifth instar, concentration increased with body mass. Although it appears that large amounts of sequestration occurs in early instars, a host switching experiment revealed that caterpillars can compensate for feeding on low cardenolide host plants with substantial sequestration in the fifth instar. We highlight commonalities and striking differences in the mechanisms of sequestration depending on host plant chemistry and developmental stage, which have important implications for monarch defense.
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Affiliation(s)
| | - Georg Petschenka
- Institute for Insect Biotechnology, Justus-Liebig-Universität Giessen, Giessen, Germany
| | - Lara Flacht
- Department for Structural Infection Biology, Centre for Structural Systems Biology, Hamburg, Germany & Helmholtz-Centre for Infection Research, Braunschweig, Germany
- Heinrich Pette Institute, Leibniz Institute for Experimental Virology, Hamburg, Germany
| | - Anurag A Agrawal
- Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, NY, USA
- Department of Entomology, Cornell University, Ithaca, NY, USA
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28
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Jones PL, Agrawal AA. Beyond preference and performance: host plant selection by monarch butterflies,
Danaus plexippus. OIKOS 2019. [DOI: 10.1111/oik.06001] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Anurag A. Agrawal
- Dept of Ecology and Evolutionary Biology, Cornell Univ Ithaca NY USA
- Dept of Entomology, Cornell Univ Ithaca NY USA
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29
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Malcolm SB, Vargas NR, Rowe L, Stevens J, Armagost JE, Johnson AC. Sequential Partial Migration Across Monarch Generations in Michigan. ANIMAL MIGRATION 2018. [DOI: 10.1515/ami-2018-0007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
Running title: Monarch alternative migration: We collected 434 adult monarchs and surveyed milkweeds for immature monarchs in southwest Michigan, USA in order to test the hypothesis that monarchs are temporally variable, sequential partial migrants rather than partial migrants that may be spatially separated. Adult size, wing wear, female egg counts, fat content and sequestered chemical defenses were measured in monarchs across an entire season from spring migrant arrival, through breeding, until autumn migrant departure. We predicted that a population characterized by starting from all migrants and no residents, through breeding residents, to all migrants and no residents should show life history measures consistent with changes in these proportions. Results show that female monarch spring migrants arrive with chorionated eggs and high wing loads in both intact and fat-extracted adults. Wing loads of both males and females decrease during the summer and increase again immediately before autumn departure, when the fat content of all adults increases markedly. The high fat content of spring arrivals is also characteristic of migrants. Cardenolide content of adults showed a similar pattern of high content in spring arrivals, a decrease in the summer and then an accumulation of cardenolide defenses in adults in late summer just before migratory departure. We conclude that these results are consistent with temporally variable, sequential partial migration in a short-lived insect that contrasts with spatially variable partial migration in longer-lived vertebrates.
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30
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Senft M, Clancy MV, Weisser WW, Schnitzler J, Zytynska SE. Additive effects of plant chemotype, mutualistic ants and predators on aphid performance and survival. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13227] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Matthias Senft
- Department of Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Terrestrial Ecology Research GroupTechnical University of Munich Freising Germany
| | - Mary V. Clancy
- Helmholtz Zentrum München GmbH, Research Unit Environmental Simulations (EUS)Institute of Biochemical Plant Pathology Neuherberg Germany
| | - Wolfgang W. Weisser
- Department of Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Terrestrial Ecology Research GroupTechnical University of Munich Freising Germany
| | - Jörg‐Peter Schnitzler
- Helmholtz Zentrum München GmbH, Research Unit Environmental Simulations (EUS)Institute of Biochemical Plant Pathology Neuherberg Germany
| | - Sharon E. Zytynska
- Department of Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Terrestrial Ecology Research GroupTechnical University of Munich Freising Germany
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31
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Evaluating an Alleged Mimic of the Monarch Butterfly: Neophasia (Lepidoptera: Pieridae) Butterflies are Palatable to Avian Predators. INSECTS 2018; 9:insects9040150. [PMID: 30380597 PMCID: PMC6316671 DOI: 10.3390/insects9040150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/13/2018] [Accepted: 10/22/2018] [Indexed: 11/16/2022]
Abstract
Some taxa have adopted the strategy of mimicry to protect themselves from predation. Butterflies are some of the best representatives used to study mimicry, with the monarch butterfly, Danaus plexippus (Lepidoptera: Nymphalidae) a well-known model. We are the first to empirically investigate a proposed mimic of the monarch butterfly: Neophasia terlooii, the Mexican pine white butterfly (Lepidoptera: Pieridae). We used captive birds to assess the palatability of N. terlooii and its sister species, N. menapia, to determine the mimicry category that would best fit this system. The birds readily consumed both species of Neophasia and a palatable control species but refused to eat unpalatable butterflies such as D. plexippus and Heliconius charithonia (Lepidoptera: Nymphalidae). Given some evidence for mild unpalatability of Neophasia, we discuss the results considering modifications to classic mimicry theory, i.e., a palatability-based continuum between Batesian and Müllerian mimicry, with a quasi-Batesian intermediate. Understanding the ecology of Neophasia in light of contemporary and historical sympatry with D. plexippus could shed light on the biogeography of, evolution of, and predation pressure on the monarch butterfly, whose migration event has become a conservation priority.
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32
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Petschenka G, Fei CS, Araya JJ, Schröder S, Timmermann BN, Agrawal AA. Relative Selectivity of Plant Cardenolides for Na +/K +-ATPases From the Monarch Butterfly and Non-resistant Insects. FRONTIERS IN PLANT SCIENCE 2018; 9:1424. [PMID: 30323822 PMCID: PMC6172315 DOI: 10.3389/fpls.2018.01424] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/07/2018] [Indexed: 05/31/2023]
Abstract
A major prediction of coevolutionary theory is that plants may target particular herbivores with secondary compounds that are selectively defensive. The highly specialized monarch butterfly (Danaus plexippus) copes well with cardiac glycosides (inhibitors of animal Na+/K+-ATPases) from its milkweed host plants, but selective inhibition of its Na+/K+-ATPase by different compounds has not been previously tested. We applied 17 cardiac glycosides to the D. plexippus-Na+/K+-ATPase and to the more susceptible Na+/K+-ATPases of two non-adapted insects (Euploea core and Schistocerca gregaria). Structural features (e.g., sugar residues) predicted in vitro inhibitory activity and comparison of insect Na+/K+-ATPases revealed that the monarch has evolved a highly resistant enzyme overall. Nonetheless, we found evidence for relative selectivity of individual cardiac glycosides reaching from 4- to 94-fold differences of inhibition between non-adapted Na+/K+-ATPase and D. plexippus-Na+/K+-ATPase. This toxin receptor specificity suggests a mechanism how plants could target herbivores selectively and thus provides a strong basis for pairwise coevolutionary interactions between plants and herbivorous insects.
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Affiliation(s)
- Georg Petschenka
- Institute for Insect Biotechnology, Justus-Liebig-Universität, Giessen, Germany
| | - Colleen S. Fei
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
| | - Juan J. Araya
- Centro de Investigaciones en Productos Naturales, Escuela de Química, Instituto de Investigaciones Farmacéuticas, Facultad de Farmacia, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Susanne Schröder
- Institut für Medizinische Biochemie und Molekularbiologie, Universität Rostock, Rostock, Germany
| | - Barbara N. Timmermann
- Department of Medicinal Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS, United States
| | - Anurag A. Agrawal
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States
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33
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Bramer C, Schweizer C, Dobler S. Cardenolide-defended milkweed bugs do not evoke learning inNephila senegalensisspiders. Ethology 2018. [DOI: 10.1111/eth.12757] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Christiane Bramer
- Johann-Friedrich-Blumenbach-Institut; Georg-August-Universität; Göttingen Germany
- Institut für Zoologie; Universität Hamburg; Hamburg Germany
| | | | - Susanne Dobler
- Institut für Zoologie; Universität Hamburg; Hamburg Germany
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34
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Faldyn MJ, Hunter MD, Elderd BD. Climate change and an invasive, tropical milkweed: an ecological trap for monarch butterflies. Ecology 2018; 99:1031-1038. [PMID: 29618170 DOI: 10.1002/ecy.2198] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/07/2018] [Accepted: 02/15/2018] [Indexed: 11/09/2022]
Abstract
While it is well established that climate change affects species distributions and abundances, the impacts of climate change on species interactions has not been extensively studied. This is particularly important for specialists whose interactions are tightly linked, such as between the monarch butterfly (Danaus plexippus) and the plant genus Asclepias, on which it depends. We used open-top chambers (OTCs) to increase temperatures in experimental plots and placed either nonnative Asclepias curassavica or native A. incarnata in each plot along with monarch larvae. We found, under current climatic conditions, adult monarchs had higher survival and mass when feeding on A. curassavica. However, under future conditions, monarchs fared much worse on A. curassavica. The decrease in adult survival and mass was associated with increasing cardenolide concentrations under warmer temperatures. Increased temperatures alone reduced monarch forewing length. Cardenolide concentrations in A. curassavica may have transitioned from beneficial to detrimental as temperature increased. Thus, the increasing cardenolide concentrations may have pushed the larvae over a tipping point into an ecological trap; whereby past environmental cues associated with increased fitness give misleading information. Given the ubiquity of specialist plant-herbivore interactions, the potential for such ecological traps to emerge as temperatures increase may have far-reaching consequences.
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Affiliation(s)
- Matthew J Faldyn
- Department of Biological Sciences, Louisiana State University, 202 Louisiana State University Life Sciences Building, Baton Rouge, Louisiana, 70803, USA
| | - Mark D Hunter
- Department of Ecology and Evolutionary Biology and School of Natural Resources and Environment, University of Michigan, 2053 Natural Sciences Building, 830 North University, Ann Arbor, Michigan, 48109-1048, USA
| | - Bret D Elderd
- Department of Biological Sciences, Louisiana State University, 202 Louisiana State University Life Sciences Building, Baton Rouge, Louisiana, 70803, USA
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35
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Best R, Ruxton GD, Gardner A. Intragroup and intragenomic conflict over chemical defense against predators. Ecol Evol 2018; 8:3322-3329. [PMID: 29607027 PMCID: PMC5869269 DOI: 10.1002/ece3.3926] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 01/13/2018] [Accepted: 01/23/2018] [Indexed: 01/24/2023] Open
Abstract
Insects are often chemically defended against predators. There is considerable evidence for a group-beneficial element to their defenses, and an associated potential for individuals to curtail their own investment in costly defense while benefitting from the investments of others, termed "automimicry." Although females in chemically defended taxa often lay their eggs in clusters, leading to siblings living in close proximity, current models of automimicry have neglected kin-selection effects, which may be expected to curb the evolution of such selfishness. Here, we develop a general theory of automimicry that explicitly incorporates kin selection. We investigate how female promiscuity modulates intragroup and intragenomic conflicts overinvestment into chemical defense, finding that individuals are favored to invest less than is optimal for their group, and that maternal-origin genes favor greater investment than do paternal-origin genes. We translate these conflicts into readily testable predictions concerning gene expression patterns and the phenotypic consequences of genomic perturbations, and discuss how our results may inform gene discovery in relation to economically important agricultural products.
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Affiliation(s)
- Rebekah Best
- School of Biology University of St Andrews St Andrews UK
| | | | - Andy Gardner
- School of Biology University of St Andrews St Andrews UK
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36
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Warashina T, Miyase T. New 8,12;8,20-diepoxy-8,14-secopregnane hexa- and hepta-glycosides from the roots of Asclepias tuberosa. J Nat Med 2017; 72:347-356. [PMID: 29177792 DOI: 10.1007/s11418-017-1155-9] [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: 09/29/2017] [Accepted: 11/12/2017] [Indexed: 11/26/2022]
Abstract
Previously, phytochemical investigation of the roots of Asclepias tuberosa (Asclepiadaceae) led to the isolation of some 8,12;8,20-diepoxy-8,14-secopregnane tri-, tetra-, and penta-glycosides. An additional eight new minor 8,12;8,20-diepoxy-8,14-secopregnane glycosides were afforded in the recent investigation of this plant. These glycosides consisted of six or seven 2,6-dideoxy-hexopyranoses together with the aglycone, tuberogenin. The structures of each of these compounds were established using NMR, mass spectroscopic analysis and chemical evidence. As 8,12;8,20-diepoxy-8,14-secopregnane-type glycosides were observed only in A. tuberosa, these compounds were considered to be characteristic phytochemicals of this plant.
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Affiliation(s)
- Tsutomu Warashina
- School of Food and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan.
| | - Toshio Miyase
- School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
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37
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Holloway GJ, de Jong PW, Ottenheim M. THE GENETICS AND COST OF CHEMICAL DEFENSE IN THE TWO-SPOT LADYBIRD (ADALIA BIPUNCTATA L.). Evolution 2017; 47:1229-1239. [PMID: 28564295 DOI: 10.1111/j.1558-5646.1993.tb02149.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/1992] [Accepted: 12/29/1992] [Indexed: 11/29/2022]
Abstract
Ladybirds (Coccinellidae) defend themselves against attack by vertebrate predators by exuding a fluid from the femero-tibial joints. This fluid carries a noxious or toxic alkaloid. The amount of fluid produced during a single attack can be very high (up to 20% of fresh body weight), and the weight of the self-synthesized alkaloid can amount to several percent of the weight of the fluid. A study was carried out on these two defense characters and two other fitness characters (body weight and growth rate) to demonstrate a cost to defense in the form of genetic trade-offs between characters. The two sexes were analyzed separately, and a jackknife procedure was used to attach errors to the estimates of Va and cova . All four characters were associated with high levels of Va , but the cova values were mixed, some being negative and others positive. Principal-component analysis indicated the operation of factors constraining the cova values in males, and further possible reasons for the appearance of so many positive values are explored. A matrix analysis showed that the genetic variance/covariance matrices of the two sexes were significantly different from each other. Breeding values derived from sons plotted on breeding values from daughters had correlation coefficients significantly less than +1. This finding indicated that a substantial amount of sex-dependent gene expression was occurring.
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Affiliation(s)
- Graham J Holloway
- Department of Pure and Applied Zoology, AMS Building, University of Reading, Whiteknights, P.O. Box 228 Reading, Berkshire, RG6 2AJ, United Kingdom.,Section of Evolutionary Biology, Department of Population Biology, University of Leiden, Schelpenkade 14a, 2313 ZT Leiden, The Netherlands
| | - Peter W de Jong
- Section of Evolutionary Biology, Department of Population Biology, University of Leiden, Schelpenkade 14a, 2313 ZT Leiden, The Netherlands
| | - Mart Ottenheim
- Section of Evolutionary Biology, Department of Population Biology, University of Leiden, Schelpenkade 14a, 2313 ZT Leiden, The Netherlands
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38
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39
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Wiklund C, Sillén-Tullberg B. WHY DISTASTEFUL BUTTERFLIES HAVE APOSEMATIC LARVAE AND ADULTS, BUT CRYPTIC PUPAE: EVIDENCE FROM PREDATION EXPERIMENTS ON THE MONARCH AND THE EUROPEAN SWALLOWTAIL. Evolution 2017; 39:1155-1158. [PMID: 28561515 DOI: 10.1111/j.1558-5646.1985.tb00456.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/1984] [Accepted: 05/13/1985] [Indexed: 11/29/2022]
Affiliation(s)
- Christer Wiklund
- Department of Zoology, University of Stockholm, S-106 91, Stockholm, Sweden
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40
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Bolton SK, Dickerson K, Saporito RA. Variable Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio are Perceived as Differences in Palatability to Arthropods. J Chem Ecol 2017; 43:273-289. [PMID: 28289966 DOI: 10.1007/s10886-017-0827-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/15/2017] [Indexed: 01/27/2023]
Abstract
Conspicuously colored dendrobatid frogs sequester alkaloid defenses from dietary arthropods, resulting in considerable alkaloid variation among populations; however, little is known about how variation is perceived as a defense against predators. Previous studies have found variable alkaloids in the dendrobatid Oophaga pumilio to be associated with differences in toxicity to laboratory mice, suggesting variable defenses are important. Arthropods are natural predators that use chemoreception to detect prey, including frogs, and may therefore perceive variation in alkaloid profiles as differences in palatability. The goal of the present study is to determine how arthropods respond to variable alkaloid defenses in O. pumilio. Frog alkaloids were sampled from individual O. pumilio from ten geographic locations throughout the Bocas del Toro region of Panama and the Caribbean coast of Costa Rica. Alkaloid extracts were used in feeding bioassays with the vinegar fly Drosophila melanogaster and the ant Ectatomma ruidum. Both species of arthropods fed significantly less on frog alkaloid extracts when compared to controls, and differences in alkaloid palatability were observed among frog populations, as well as between sexes and life stages within a population. Differences in alkaloid quantity, richness, and type were the main predictors of arthropod palatability. Our findings also represent the first direct evidence of a palatability spectrum in a vertebrate that sequesters chemical defenses from dietary sources. Further, the presence of a palatability spectrum suggests that variable alkaloid defenses in O. pumilio are ecologically relevant and play an important role in natural predator-prey interactions, particularly with respect to arthropod predators.
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Affiliation(s)
- Sarah K Bolton
- Department of Biology, John Carroll University, 1 John Carroll Boulevard, University Heights, OH, 44118, USA
| | - Kelsie Dickerson
- Department of Environmental Science, Policy, and Management, University of California at Berkeley, 130 Mulford Hall #3114, Berkeley, CA, 94720, USA
| | - Ralph A Saporito
- Department of Biology, John Carroll University, 1 John Carroll Boulevard, University Heights, OH, 44118, USA.
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41
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Arias M, Meichanetzoglou A, Elias M, Rosser N, de-Silva DL, Nay B, Llaurens V. Variation in cyanogenic compounds concentration within a Heliconius butterfly community: does mimicry explain everything? BMC Evol Biol 2016; 16:272. [PMID: 27978820 PMCID: PMC5160018 DOI: 10.1186/s12862-016-0843-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 11/26/2016] [Indexed: 11/10/2022] Open
Abstract
Background Aposematic species advertise their unpalatability using warning signals such as striking coloration. Given that predators need to sample aposematic prey to learn that they are unprofitable, prey with similar warning signals share the cost of predator learning. This reduction in predation risk drives evolutionary convergence of warning signals among chemically defended prey (Müllerian mimicry). Whether such warning signal convergence is associated to similar defence levels among co-mimics is still an open question that has rarely been tested in wild populations. We quantified variation in cyanide-based (CN) chemical protection in wild caught individuals of eight aposematic Heliconius butterfly species belonging to four sympatric mimicry rings. We then tested for correlations between chemical protection and ecological species-specific traits. Results We report significant differences in CN concentrations both within and between sympatric species, even when accounting for the phylogeny, and within and between mimicry rings, even after considering inter-specific variation. We found significant correlations between CN concentration and both hostplant specialization and gregarious behaviour in adults and larvae. However, differences in CN concentrations were not significantly linked to mimicry ring abundance, although the two most toxic species did belong to the rarest mimicry ring. Conclusions Our results suggest that mimicry can explain the variation in the levels of chemical defence to a certain extent, although other ecological factors are also relevant to the evolution of such variability. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0843-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mónica Arias
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France.
| | - Aimilia Meichanetzoglou
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France.,Unité Molécules de Communication et Adaptation des Micro-organismes, UMR 7245 MNHN-CNRS, Sorbonne Universités, Muséum National d'Histoire Naturelle and CNRS, 57 rue Cuvier, CP 54, 75005, Paris, France
| | - Marianne Elias
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France
| | - Neil Rosser
- Department of Biology, University of York, Heslington, York, YO10 5DD, UK
| | - Donna Lisa de-Silva
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France
| | - Bastien Nay
- Unité Molécules de Communication et Adaptation des Micro-organismes, UMR 7245 MNHN-CNRS, Sorbonne Universités, Muséum National d'Histoire Naturelle and CNRS, 57 rue Cuvier, CP 54, 75005, Paris, France
| | - Violaine Llaurens
- Institut Systématique, Evolution, Biodiversité, UMR 7205 MNHN-CNRS-EPHE-UPMC- Sorbonne Universités, Muséum National d'Histoire Naturelle, Bâtiment d'entomologie, CP050, 57 rue Cuvier, 75005, Paris, France
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42
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Petschenka G, Agrawal AA. How herbivores coopt plant defenses: natural selection, specialization, and sequestration. CURRENT OPINION IN INSECT SCIENCE 2016; 14:17-24. [PMID: 27436642 DOI: 10.1016/j.cois.2015.12.004] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/10/2015] [Accepted: 12/20/2015] [Indexed: 05/10/2023]
Abstract
We review progress in understanding sequestration by herbivorous insects, the use of plant chemical defenses for their own defense. We incorporate sequestration into the framework of plant-insect coevolution by integrating three hierarchical issues: (1) the relationship between dietary specialization and sequestration of plant defenses, (2) the physiological mechanisms involved in sequestration, and (3) how sequestration evolves via interactions between trophic levels. Sequestration is often associated with specialization, but even specialized sequestration is not an evolutionary dead-end. Despite considerable progress in understanding physiological mechanisms, detailed knowledge of how plant toxins cross the insect gut epithelium is still largely lacking. Sequestration is likely a major vehicle for coevolutionary escalation in speciose plant-insect-predator interactions, suggesting that a strictly bitrophic view is untenable.
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Affiliation(s)
- Georg Petschenka
- Institut für Insektenbiotechnologie, Justus-Liebig-Universität Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
| | - Anurag A Agrawal
- Ecology and Evolutionary Biology, Cornell University, E425 Corson Hall, Ithaca, NY 14853 USA
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Kojima Y, Mori A. Active foraging for toxic prey during gestation in a snake with maternal provisioning of sequestered chemical defences. Proc Biol Sci 2015; 282:20142137. [PMID: 25392472 DOI: 10.1098/rspb.2014.2137] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Many animals sequester dietary defensive compounds and incorporate them into the offspring, which protects the young against predation. One possible but poorly investigated question is whether females of such species actively prey upon toxic diets. The snake Rhabdophis tigrinus sequesters defensive steroids from toads consumed as prey; it also feeds on other amphibians. Females produce chemically armed offspring in direct proportion to their own level of toad-derived toxins by provisioning the toxins to their eggs. Our field observations of movements and stomach contents of radio-tracked R. tigrinus showed that gravid snakes preyed upon toads by actively foraging in the habitat of toads, even though toads were a scarce resource and toad-searching may incur potential costs. Our Y-maze experiments demonstrated that gravid females were more likely to trail the chemical cues of toads than were males or non-gravid females. These results showed behavioural switching in females and active foraging for scarce, toxic prey during gestation. Because exploitation of toads by gravid females results in their offspring being more richly endowed with prey-derived toxins, active foraging for toxic prey is expected to be an adaptive antipredator trait, which may enhance chemical defence in offspring.
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Affiliation(s)
- Yosuke Kojima
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
| | - Akira Mori
- Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan
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Summers K, Speed MP, Blount JD, Stuckert AMM. Are aposematic signals honest? A review. J Evol Biol 2015; 28:1583-99. [DOI: 10.1111/jeb.12676] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 01/22/2023]
Affiliation(s)
- K. Summers
- Department of Biology; East Carolina University; Greenville NC USA
| | - M. P. Speed
- Department of Evolution, Ecology, and Behaviour; University of Liverpool; Liverpool UK
| | - J. D. Blount
- Centre for Ecology and Conservation, Biosciences; University of Exeter; Penryn UK
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Speed MP, Franks DW. Antagonistic evolution in an aposematic predator-prey signaling system. Evolution 2014; 68:2996-3007. [PMID: 25132560 DOI: 10.1111/evo.12498] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 07/02/2014] [Indexed: 11/29/2022]
Abstract
Warning signals within species, such as the bright colors of chemically defended animals, are usually considered mutualistic, monomorphic traits. Such a view is however increasingly at odds with the growing empirical literature, showing nontrivial levels of signal variation within prey populations. Key to understanding this variation, we argue, could be a recognition that toxicity levels frequently vary within populations because of environmental heterogeneity. Inequalities in defense may undermine mutualistic monomorphic signaling, causing evolutionary antagonism between loci that determine appearance of less well-defended and better defended prey forms within species. In this article, we apply a stochastic model of evolved phenotypic plasticity to the evolution of prey signals. We show that when toxicity levels vary, then antagonistic interactions can lead to evolutionary conflict between alleles at different signaling loci, causing signal evolution, "red queen-like" evolutionary chase, and one or more forms of signaling equilibria. A key prediction is that variation in the way that predators use information about toxicity levels in their attack behaviors profoundly affects the evolutionary characteristics of the prey signaling systems. Environmental variation is known to cause variation in many qualities that organisms signal; our approach may therefore have application to other signaling systems.
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Affiliation(s)
- Michael P Speed
- Department of Evolution, Ecology and Behaviour, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Liverpool L69 7ZB, United Kingdom.
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Stuckert AMM, Saporito RA, Venegas PJ, Summers K. Alkaloid defenses of co-mimics in a putative Müllerian mimetic radiation. BMC Evol Biol 2014; 14:76. [PMID: 24707851 DOI: 10.1186/1471-2148-14-76] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 03/31/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Polytypism in aposematic species is unlikely according to theory, but commonly seen in nature. Ranitomeya imitator is a poison frog species exhibiting polytypic mimicry of three congeneric model species (R. fantastica, R. summersi, and two morphs of R. variabilis) across four allopatric populations (a "mimetic radiation"). In order to investigate chemical defenses in this system, a key prediction of Müllerian mimicry, we analyzed the alkaloids of both models and mimics from four allopatric populations. RESULTS In this study we demonstrate distinct differences in alkaloid profiles between co-mimetic species within allopatric populations. We further demonstrate that R. imitator has a greater number of distinct alkaloid types than the model species and more total alkaloids in all but one population. CONCLUSIONS Given that R. imitator is the more abundant species in these populations, R. imitator is likely driving the majority of predator-learned avoidance in these complexes. The success of Ranitomeya imitator as a putative advergent mimic may be a direct result of differences in alkaloid sequestration. Furthermore, we propose that automimicry within co-mimetic species is an important avenue of research.
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Affiliation(s)
- Adam M M Stuckert
- Department of Biology, East Carolina University, 1000 E, Fifth St, Greenville, NC 27858, USA.
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Palatability of aposematic queen butterflies (Danaus gilippus) feeding onSarcostemma clausum (Asclepiadaceae) in Florida. J Chem Ecol 2013; 17:1593-610. [PMID: 24257883 DOI: 10.1007/bf00984691] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/1990] [Accepted: 03/04/1991] [Indexed: 10/25/2022]
Abstract
Queen butterflies (Danaus gilippus) are generally considered unpalatable to predators because they sequester and store toxic cardenolides from their larval food plants. However, a major queen food plant in Florida, the asclepiadaceous vineSarcostemma clausum, is shown here to be a very poor cardenolide source, and queens reared on this plant contain no detectable cardenolide. A direct evaluation of queen palatability using red-winged blackbirds indicates thatS. clausum-reared butterflies are essentially palatable to these predators (85% of abdomens entirely eaten), indicating little protection from either cardenolides, other sequestered phytochemicals, or de novo defensive compounds. Wild-caught queens that presumably fed as larvae uponS. clausum and also had access to adult-obtained chemicals, such as pyrrolizidine alkaloids (PAs), were relatively palatable as well (77% of abdomens eaten); they did not differ significantly in palatability from the labreared butterflies. Together, these findings suggest that; (1)S. clausumfed queens are poorly defended against some avian predators, and (2) for the particular queen sample examined, PAs do not contribute substantially to unpalatability. The discovery thatS. clausum-feeding queens are essentially palatable is of additional significance because it compels a reassessment of the classic mimicry relationship between queen and viceroy butterflies. Viceroys have been shown recently to be moderately unpalatable; therefore, the established roles of model and mimic may be reversed in some cases.
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Petschenka G, Pick C, Wagschal V, Dobler S. Functional evidence for physiological mechanisms to circumvent neurotoxicity of cardenolides in an adapted and a non-adapted hawk-moth species. Proc Biol Sci 2013; 280:20123089. [PMID: 23516239 DOI: 10.1098/rspb.2012.3089] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Because cardenolides specifically inhibit the Na(+)K(+)-ATPase, insects feeding on cardenolide-containing plants need to circumvent this toxic effect. Some insects such as the monarch butterfly rely on target site insensitivity, yet other cardenolide-adapted lepidopterans such as the oleander hawk-moth, Daphnis nerii, possess highly sensitive Na(+)K(+)-ATPases. Nevertheless, larvae of this species and the related Manduca sexta are insensitive to injected cardenolides. By radioactive-binding assays with nerve cords of both species, we demonstrate that the perineurium surrounding the nervous tissue functions as a diffusion barrier for a polar cardenolide (ouabain). By contrast, for non-polar cardenolides such as digoxin an active efflux carrier limits the access to the nerve cord. This barrier can be abolished by metabolic inhibitors and by verapamil, a specific inhibitor of P-glycoproteins (PGPs). This supports that a PGP-like transporter is involved in the active cardenolide-barrier of the perineurium. Tissue specific RT-PCR demonstrated expression of three PGP-like genes in hornworm nerve cords, and immunohistochemistry further corroborated PGP expression in the perineurium. Our results thus suggest that the lepidopteran perineurium serves as a diffusion barrier for polar cardenolides and provides an active barrier for non-polar cardenolides. This may explain the high in vivo resistance to cardenolides observed in some lepidopteran larvae, despite their highly sensitive Na(+)K(+)-ATPases.
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Affiliation(s)
- Georg Petschenka
- Molekulare Evolutionsbiologie, Biozentrum Grindel, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany.
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Flores EE, Stevens M, Moore AJ, Blount JD. Diet, development and the optimization of warning signals in post‐metamorphic green and black poison frogs. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12084] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eric E. Flores
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Cornwall Campus Penryn TR10 9EZ UK
| | - Martin Stevens
- Department of Zoology University of Cambridge Downing Street Cambridge CB2 3EJ UK
| | - Allen J. Moore
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Cornwall Campus Penryn TR10 9EZ UK
- Department of Genetics University of Georgia Athens GA 30602 USA
| | - Jonathan D. Blount
- Centre for Ecology and Conservation College of Life & Environmental Sciences University of Exeter Cornwall Campus Penryn TR10 9EZ UK
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50
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Abstract
Many predators quickly learn to avoid attacking aposematic prey. If the prey vary in toxicity, the predators may alternatively learn to capture and taste-sample prey carefully before ingesting or rejecting them (go-slow behaviour). An increase in prey toxicity is generally thought to decrease predation on prey populations. However, while prey with a higher toxin load are more harmful to ingest, they may also be easier to recognize and reject owing to greater distastefulness, which can facilitate a taste-sampling foraging strategy. Here, the classic diet model is used to study the separate effects of taste and toxicity on predator preferences. The taste-sampling process is modelled using signal detection theory. The model is applicable to automimicry and batesian mimicry. It shows that when the defensive toxin is sufficiently distasteful, a mimicry complex may be less profitable to the predator and better protected against predation if the models are moderately toxic than if they are highly toxic. Moreover, taste mimicry can reduce the profitability of the mimicry complex and increase protection against predation. The results are discussed in relation to the selection pressures acting on prey defences and the evolution of mimicry.
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Affiliation(s)
- Øistein Haugsten Holen
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway.
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