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Caty SN, Alvarez-Buylla A, Vasek C, Tapia EE, Martin NA, McLaughlin T, Weber PK, Mayali X, Coloma LA, Morris MM, O'Connell LA. A toxic environment selects for specialist microbiome in poison frogs. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.10.574901. [PMID: 38260330 PMCID: PMC10802471 DOI: 10.1101/2024.01.10.574901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Shifts in microbiome community composition can have large effects on host health. It is therefore important to understand how perturbations, like those caused by the introduction of exogenous chemicals, modulate microbiome community composition. In poison frogs within the family Dendrobatidae, the skin microbiome is exposed to the alkaloids that the frogs sequester from their diet and use for defense. Given the demonstrated antimicrobial effects of these poison frog alkaloids, these compounds may be structuring the skin microbial community. To test this, we first characterized microbial communities from chemically defended and closely related non-defended frogs from Ecuador. Then we conducted a laboratory experiment to monitor the effect of the alkaloid decahydroquinoline (DHQ) on the microbiome of a single frog species. In both the field and lab experiments, we found that alkaloid-exposed microbiomes are more species rich and phylogenetically diverse, with an increase in rare taxa. To better understand the strain-specific behavior in response to alkaloids, we cultured microbial strains from poison frog skin and found the majority of strains exhibited either enhanced growth or were not impacted by the addition of DHQ. Additionally, stable isotope tracing coupled to nanoSIMS suggests that some of these strains are able to metabolize DHQ. Taken together, these data suggest that poison frog chemical defenses open new niches for skin-associated microbes with specific adaptations, including the likely metabolism of alkaloids, that enable their survival in this toxic environment. This work helps expand our understanding of how exposure to exogenous compounds like alkaloids can impact host microbiomes.
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Affiliation(s)
| | | | - Cooper Vasek
- Department of Biology, Stanford University, Stanford CA, USA
| | - Elicio E Tapia
- Leibniz Institute for the Analysis of Biodiversity Change Martin-Luther-King-Platz 3 20146 Hamburg, Germany
| | - Nora A Martin
- Department of Biology, Stanford University, Stanford CA, USA
| | - Theresa McLaughlin
- Stanford University Mass Spectrometry, Stanford University, Stanford CA, USA
| | - Peter K Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA, USA
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA, USA
| | - Luis A Coloma
- Centro Jambatu de Investigación y Conservación de Anfibios, Fundación Jambatu, San Rafael, Quito, Ecuador
| | - Megan M Morris
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore CA, USA
| | - Lauren A O'Connell
- Department of Biology, Stanford University, Stanford CA, USA
- Sarafan ChEM-H, Stanford University, Stanford, CA, USA
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2
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Dos Santos Arraes DR, Rodrigues ABL, Sanches PR, Costa Campos CE, Moreira da Silva de Almeida SS, Reis Ferreira Lima J, Dias Lima J, da Silva GA. Bioactive alkaloids from the venom of Dendrobatoidea Cope, 1865: a scoping review. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2024; 27:1-20. [PMID: 37889647 DOI: 10.1080/10937404.2023.2270408] [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: 10/29/2023]
Abstract
Bioactive compounds derived from secondary metabolism in animals have refined selectivity and potency for certain biological targets. The superfamily Dendrobatoidea is adapted to the dietary sequestration and secretion of toxic alkaloids, which play a role in several biological activities, and thus serve as a potential source for pharmacological and biotechnological applications. This article constitutes a scoping review to understand the trends in experimental research involving bioactive alkaloids derived from Dendrobatoidea based upon scientometric approaches. Forty-eight (48) publications were found in 30 journals in the period of 60 years, between 1962 and 2022. More than 23 structural classes of alkaloids were cited, with 27.63% for batrachotoxins, 13.64% for pyridinics, with an emphasis on epibatidine, 16.36% for pumiliotoxins, and 11.82% for histrionicotoxins. These tests included in vivo (54.9%), in vitro (39.4%), and in silico simulations (5.6%). Most compounds (54.8%) were isolated from skin extracts, whereas the remainder were obtained through molecular synthesis. Thirteen main biological activities were identified, including acetylcholinesterase inhibitors (27.59%), sodium channel inhibitors (12.07%), cardiac (12.07%), analgesic (8.62%), and neuromuscular effects (8.62%). The substances were cited as being of natural origin in the "Dendrobatidae" family, genus "Phyllobates," "Dendrobates," and seven species: Epipedobates tricolor, Phyllobates aurotaenia, Oophaga histrionica, Oophaga pumilio, Phyllobates terribilis, Epipedobates anthonyi, and Ameerega flavopicta. To date, only a few biological activities have been experimentally tested; hence, further studies on the bioprospecting of animal compounds and ecological approaches are needed.
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Affiliation(s)
| | | | | | | | | | - Janaina Reis Ferreira Lima
- Herpetology Laboratory, Institute of Scientific and Technological Research of the State of Amapá, Macapá, Amapá, Brazil
| | - Jucivaldo Dias Lima
- Herpetology Laboratory, Institute of Scientific and Technological Research of the State of Amapá, Macapá, Amapá, Brazil
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3
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Gonzalez M, Carazzone C. Eco-Metabolomics Applied to the Chemical Ecology of Poison Frogs (Dendrobatoidea). J Chem Ecol 2023; 49:570-598. [PMID: 37594619 PMCID: PMC10725362 DOI: 10.1007/s10886-023-01443-0] [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: 04/14/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 08/19/2023]
Abstract
Amphibians are one of the most remarkable sources of unique natural products. Biogenic amines, peptides, bufodienolides, alkaloids, and volatile organic compounds have been characterized in different species. The superfamily Dendrobatoidea represents one of the most enigmatic cases of study in chemical ecology because their skin secretome is composed by a complex mixture (i.e. cocktail) of highly lethal and noxious unique alkaloid structures. While chemical defences from dendrobatoids (families Dendrobatidae and Aromobatidae) have been investigated employing ecological, behavioral, phylogenetic and evolutionary perspectives, studies about the analytical techniques needed to perform the chemical characterization have been neglected for many years. Therefore, our aim is to summarize the current methods applied for the characterization of chemical profiles in dendrobatoids and to illustrate innovative Eco-metabolomics strategies that could be translated to this study model. This approach could be extended to natural products other than alkaloids and implemented for the chemical analysis of different species of dendrobatoids employing both low- and high-resolution mass spectrometers. Here, we overview important biological features to be considered, procedures that could be applied to perform the chemical characterization, steps and tools to perform an Eco-metabolomic analysis, and a final discussion about future perspectives.
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Affiliation(s)
- Mabel Gonzalez
- Department of Chemistry, Universidad de los Andes, 4976, Bogotá, AA, Colombia.
- Department of Biology, Stanford University, Palo Alto, CA, 94305, USA.
| | - Chiara Carazzone
- Department of Chemistry, Universidad de los Andes, 4976, Bogotá, AA, Colombia.
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4
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Brooks OL, James JJ, Saporito RA. Maternal chemical defenses predict offspring defenses in a dendrobatid poison frog. Oecologia 2023; 201:385-396. [PMID: 36637523 DOI: 10.1007/s00442-023-05314-z] [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: 07/09/2022] [Accepted: 01/03/2023] [Indexed: 01/14/2023]
Abstract
Within and among populations, alkaloid defenses of the strawberry poison frog (Oophaga pumilio) vary spatially, temporally, and with life history stage. Natural variation in defense has been implicated as a critical factor in determining the level of protection afforded against predators and pathogens. Oophaga pumilio tadpoles sequester alkaloids from nutritive eggs and are, thus, entirely dependent on their mothers for their defense. However, it remains unclear how tadpole alkaloid composition relates to that of its mother and how variation in maternally provisioned defenses might result in varying levels of protection against predators. Here, we demonstrate that natural variation in the alkaloid composition of a mother frog is reflected as variation in her tadpole's alkaloid composition. Tadpoles, like mother frogs, varied in their alkaloid composition but always contained the identical alkaloids found in their mother. Alkaloid quantity in tadpoles was highly correlated with alkaloid quantity in their mothers. Additionally, alkaloid quantity was the best predictor of tadpole palatability, wherein tadpoles with higher alkaloid quantities were less palatable. Mother frogs with greater quantities of alkaloids are, thus, providing better protection for their offspring by provisioning chemical defenses during one of the most vulnerable periods of life.
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Affiliation(s)
- Olivia L Brooks
- School of Biological Sciences, Illinois State University, Normal, IL, 61701, USA.,Department of Biology, John Carroll University, University Heights, OH, 44118, USA
| | - Jessie J James
- Department of Biology, San Francisco State University, San Francisco, CA, 94132, USA
| | - Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA.
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5
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Jeckel AM, Bolton SK, Waters KR, Antoniazzi MM, Jared C, Matsumura K, Nishikawa K, Morimoto Y, Grant T, Saporito RA. Dose-dependent alkaloid sequestration and N-methylation of decahydroquinoline in poison frogs. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2022; 337:537-546. [PMID: 35201668 DOI: 10.1002/jez.2587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 12/22/2021] [Accepted: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Sequestration of chemical defenses from dietary sources is dependent on the availability of compounds in the environment and the mechanism of sequestration. Previous experiments have shown that sequestration efficiency varies among alkaloids in poison frogs, but little is known about the underlying mechanism. The aim of this study was to quantify the extent to which alkaloid sequestration and modification are dependent on alkaloid availability and/or sequestration mechanism. To do this, we administered different doses of histrionicotoxin (HTX) 235A and decahydroquinoline (DHQ) to captive-bred Adelphobates galactonotus and measured alkaloid quantity in muscle, kidney, liver, and feces. HTX 235A and DHQ were detected in all organs, whereas only DHQ was present in trace amounts in feces. For both liver and skin, the quantity of alkaloid accumulated increased at higher doses for both alkaloids. Accumulation efficiency in the skin increased at higher doses for HTX 235A but remained constant for DHQ. In contrast, the efficiency of HTX 235A accumulation in the liver was inversely related to dose and a similar, albeit statistically nonsignificant, pattern was observed for DHQ. We identified and quantified the N-methylation of DHQ in A. galactonotus, which represents a previously unknown example of alkaloid modification in poison frogs. Our study suggests that variation in alkaloid composition among individuals and species can result from differences in sequestration efficiency related to the type and amount of alkaloids available in the environment.
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Affiliation(s)
- Adriana M Jeckel
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Sarah K Bolton
- Department of Biology, Notre Dame College, South Euclid, Ohio, USA
| | - Katherine R Waters
- Department of Biology, John Carroll University, University Heights, Ohio, USA
| | - Marta M Antoniazzi
- Structural Biology Lab, Butantan Institute, São Paulo, São Paulo, Brazil
| | - Carlos Jared
- Structural Biology Lab, Butantan Institute, São Paulo, São Paulo, Brazil
| | - Kunihiro Matsumura
- Department of Chemistry, Graduate School of Science, Osaka City University, Osaka, Japan
| | - Keisuke Nishikawa
- Department of Chemistry, Graduate School of Science, Osaka City University, Osaka, Japan
| | - Yoshiki Morimoto
- Department of Chemistry, Graduate School of Science, Osaka City University, Osaka, Japan
| | - Taran Grant
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, Ohio, USA
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Lan Y, He L, Dong X, Tang R, Li W, Wang J, Wang L, Yue B, Price M, Guo T, Fan Z. Comparative transcriptomes of three different skin sites for the Asiatic toad ( Bufo gargarizans). PeerJ 2022; 10:e12993. [PMID: 35223212 PMCID: PMC8877344 DOI: 10.7717/peerj.12993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 02/02/2022] [Indexed: 01/11/2023] Open
Abstract
Toads release toxic dry secretions from glands in their skin. Toxin possesses a wide range of biological effects, but little is known about its specific gene expression pattern and regulatory mechanisms. The Asiatic toad (Bufo gargarizans) is widely used to produce toxin. Here, we explored the gene expression of 30 tissue samples from three different skin sites (parotoid gland, dorsal skin, and abdomen skin) of B. gargarizans. After de novo assembly, 783,130 unigenes with an average length of 489 bp (N50 = 556 bp) were obtained. A total of 9,248 significant differentially expressed genes (DEGs) were detected. There were 8,819 DEGs between the parotoid gland and abdomen skin and 1,299 DEGs between the dorsal skin and abdomen skin, while only 1,283 DEGs were obtained between the parotoid gland and dorsal skin. Through enrichment analysis, it was found that the detected differential gene expressions corresponded to the different functions of different skin sites. Our key findings were the genetic expression of toxin secretion, the protection function of skin, and the related genes such as HSD3B, Cyp2c, and CAT, LGALS9. In conclusion, we provide useful transcript resources to study the gene expression and gene function of B. gargarizans and other amphibians. The detected DEGs between different sites of the skin provided better insights into the genetic mechanisms of toxin secretion and the protection function of skin for amphibians.
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Affiliation(s)
- Yue Lan
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Lewei He
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Xue Dong
- Department of Ambulatory surgery, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ruixiang Tang
- Sichuan Key Laboratory of Conservation Biology on Endangered Wildlife, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Wanyu Li
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Jiao Wang
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Lei Wang
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China,Sichuan Engineering Research Center for Medicinal Animals, Xichang, Sichuan, China
| | - Bisong Yue
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China,Sichuan Engineering Research Center for Medicinal Animals, Xichang, Sichuan, China
| | - Megan Price
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
| | - Tao Guo
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, kChengdu, Sichuan, China
| | - Zhenxin Fan
- Key Laboratory of Bioresources and Eco-Environment (Ministry of Education), College of Life Sciences, Sichuan University, Chengdu, Sichuan, China
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Hanifin CT, Kudo Y, Yotsu-Yamashita M. Chemical Ecology of the North American Newt Genera Taricha and Notophthalmus. PROGRESS IN THE CHEMISTRY OF ORGANIC NATURAL PRODUCTS 2022; 118:101-130. [PMID: 35416518 DOI: 10.1007/978-3-030-92030-2_3] [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: 06/14/2023]
Abstract
The North American newt genera Taricha and Notophthalmus (order Caudata) are well known for the combination of potent toxicity, aposematic coloration, and striking defense postures that protects these animals from predation. This suite of traits is centered around the neurotoxin tetrodotoxin, which causes paralysis and death in metazoans by disrupting the initiation and propagation of electrical signals in the nerves and muscles. Tetrodotoxin defends newts from predation across multiple life history stages and its role in generating arms-race coevolution between Taricha newts and garter snake (genus Thamnophis) predators is well studied. However, understanding the broader picture of chemical defenses in Taricha and Notophthalmus requires an expanded comprehension of the defensive chemical ecology of tetrodotoxin that includes possible coevolutionary interactions with insect egg predators, protection against parasites, as well as mimicry complexes associated with tetrodotoxin and aposematic coloration in both genera. Herein the authors review what is known about the structure, function, and pharmacology of tetrodotoxin to explore its evolution and chemical ecology in the North American newt. Focus is made specifically on the origin and possible biosynthesis of tetrodotoxin in these taxa as well as providing an expanded picture of the web of interactions that contribute to landscape level patterns of toxicity and defense in Taricha and Notophthalmus.
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Affiliation(s)
- Charles T Hanifin
- Department of Biology, Utah State University, 320 N. Aggie Blvd, Vernal, UT, 84078, USA.
| | - Yuta Kudo
- Graduate School of Agricultural Science, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science & Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 468-1 Aramaki-Aza-Aoba, Aoba-ku, Sendai, Miyagi, 980-8572, Japan
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8
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Gonzalez M, Palacios-Rodriguez P, Hernandez-Restrepo J, González-Santoro M, Amézquita A, Brunetti AE, Carazzone C. First characterization of toxic alkaloids and volatile organic compounds (VOCs) in the cryptic dendrobatid Silverstoneia punctiventris. Front Zool 2021; 18:39. [PMID: 34446035 PMCID: PMC8390233 DOI: 10.1186/s12983-021-00420-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/14/2021] [Indexed: 11/24/2022] Open
Abstract
Background Poison frogs are known for the outstanding diversity of alkaloid-based chemical defences with promising therapeutic applications. However, current knowledge about chemical defences in Dendrobatoidea superfamily has two sources of bias. First, cryptic, brown-colored species have been neglected in comparison to those conspicuously colored, and second, there has been little interest in characterizing metabolites other than alkaloids mediating defensive functions. In an effort to contribute to fill the gap of knowledge about cryptic species and broadening the spectrum of compounds analyzed we have applied head-space solid phase microextraction coupled to gas chromatography and mass spectrometry (HS-SPME/GC-MS) for extracting amphibian alkaloids and volatile organic compounds (VOCs) from Silverstoneia punctiventris. Results Using the skin from 8 specimens in 4 biological replicates we have found 33 different compounds. Twenty of them were classified as VOCs into 15 chemical classes including alkanes, alcohols, carbonyl compounds, methylpyridines, benzothiazoles, N-alkylpyrrolidines, pyrazines, and sesquiterpenoids, some of which were previously reported as repellents, defence compounds or defence pheromones in other organisms, and as sex pheromones in a treefrog. Interestingly, six of the remaining compounds were identified as alkaloids previously reported in other toxic/unpalatable dendrobatid frogs. Conclusions This is the first report of alkaloids and VOCs found in the Silverstoneia genus, which has been assumed for decades as non-chemically defended. This study establishes HS-SPME/GC-MS as a new application for a simultaneous approach to amphibian alkaloids and VOCs in poison frogs while opens up new research questions to assess the co-occurrence of both type of compounds and to investigate the evolutionary significance of a defence gradient that includes olfactory avoidance, unpalatability, and toxicity in dendrobatids. In addition, our results show that amphibian alkaloids could have a dual function (olfactory at distance, taste by contact) never explored before neither in Silverstonaeia nor in any other dendrobatid species. Supplementary Information The online version contains supplementary material available at 10.1186/s12983-021-00420-1.
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Affiliation(s)
- Mabel Gonzalez
- Department of Chemistry, Universidad de los Andes, Bogotá, AA, 4976, Colombia
| | | | | | | | - Adolfo Amézquita
- Department of Biological Sciences, Universidad de los Andes, Bogotá, AA, 4976, Colombia
| | - Andrés E Brunetti
- Laboratorio de Genética Evolutiva, Instituto de Biología Subtropical (CONICET - UNaM), Facultad de Ciencias Exactas, Universidad Nacional de Misiones, N3300, Posadas, Argentina.,Departamento de Ciências Biomoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903, Ribeirão Preto, SP, Brazil
| | - Chiara Carazzone
- Department of Chemistry, Universidad de los Andes, Bogotá, AA, 4976, Colombia.
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DE Meester G, Šunje E, Prinsen E, Verbruggen E, VAN Damme R. Toxin variation among salamander populations: discussing potential causes and future directions. Integr Zool 2020; 16:336-353. [PMID: 32965720 DOI: 10.1111/1749-4877.12492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Amphibians produce defensive chemicals which provide protection against both predators and infections. Within species, populations can differ considerably in the composition and amount of these chemical defenses. Studying intraspecific variation in toxins and linking it to environmental variables may help us to identify the selective drivers of toxin evolution, such as predation pressure and infection risk. Recently, there has been a renewed interest in the unique toxins produced by salamanders from the genus Salamandra: the samandarines. Despite this attention, intraspecific variation has largely been ignored within Salamandra-species. The aim of this study was to investigate whether geographic variation in profiles of samandarines exists, by sampling 4 populations of Salamandra atra over its range in the Dinaric Alps. In addition, we preliminary explored whether potential variation could be explained by predation (counting the number of snake species) and infection risk (cultivation and genomic analyses of collected soil samples). Salamanders from the 4 populations differed in toxin composition and in the size of their poison glands, although not in overall toxin quantity. Nor predation nor infection risk could explain this variation, as populations barely differed in these variables. Sampling over a much broader geographic range, using better estimators for predation and infection risk, will contribute to an improved understanding of how environment may shape variation in chemical defenses. Nevertheless, as the 4 populations of S. atra did differ in their toxin profiles, we propose that this species provides an interesting opportunity for further ecological and evolutionary studies on amphibian toxins.
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Affiliation(s)
- Gilles DE Meester
- Department of Biology, Functional Morphology Group, University of Antwerp, Wilrijk, Belgium
| | - Emina Šunje
- Department of Biology, Functional Morphology Group, University of Antwerp, Wilrijk, Belgium.,Department of Biology, Faculty of Natural Sciences, University of Sarajevo, Sarajevo, Bosnia-Hercegovina.,Herpetological Association in Bosnia and Herzegovina: BHHU: ATRA, Sarajevo, Bosnia-Hercegovina
| | - Els Prinsen
- Department of Biology, Impress, University of Antwerp, Wilrijk, Belgium
| | - Erik Verbruggen
- Department of Biology, Plant and Ecosystems, University of Antwerp, Wilrijk, Belgium
| | - Raoul VAN Damme
- Department of Biology, Functional Morphology Group, University of Antwerp, Wilrijk, Belgium
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10
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Basham EW, Saporito RA, González‐Pinzón M, Romero‐Marcucci A, Scheffers BR. Chemical defenses shift with the seasonal vertical migration of a Panamanian poison frog. Biotropica 2020. [DOI: 10.1111/btp.12842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Edmund W. Basham
- School of Natural Resources and Environment University of Florida Gainesville FL USA
| | - Ralph A. Saporito
- Department of Biology John Carroll University University Heights OH USA
| | - Macario González‐Pinzón
- Escuela de Biología Facultad de Ciencias naturales y Exactas Universidad Autónoma de Chiriquí David República de Panamá
| | - Angel Romero‐Marcucci
- Escuela de Biología Facultad de Ciencias naturales y Exactas Universidad Autónoma de Chiriquí David República de Panamá
| | - Brett R. Scheffers
- School of Natural Resources and Environment University of Florida Gainesville FL USA
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL USA
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11
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Kowalski K, Marciniak P, Rychlik L. Individual variation in cardiotoxicity of parotoid secretion of the common toad, Bufo bufo, depends on body size - first results. ZOOLOGY 2020; 142:125822. [PMID: 32862084 DOI: 10.1016/j.zool.2020.125822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 04/29/2020] [Accepted: 07/14/2020] [Indexed: 12/29/2022]
Abstract
Anurans secrete a wide diversity of toxins from skin glands to defend themselves against predators and pathogens. Bufonids produce potent poison in parotoid macroglands located in the postorbital region. Parotoid secretion is a rich source of bioactive compounds with cardiotoxic, cytotoxic and hemolytic activity. Poison content and toxicity may vary between species, populations, and among conspecifics inhabiting the same area. In the present paper, we pre-analyzed the individual variation in cardiotoxicity of parotoid extract of common toads (Bufo bufo Linnaeus, 1758) and impact of body mass (BM), snout to vent length (SVL), and body condition (BC) of toad on the poison toxicity. We hypothesized that large toads produce poison with higher cardiotoxicity than smaller ones. Parotoid extract was fractionated by reverse phase chromatography, and then in vitro physiological bioassays were carried out on the semi-isolated hearts of the mealworm beetle (Tenebrio molitor Linnaeus, 1758) to determine cardiotoxicity of the whole poison and separated fractions. Generalized linear mixed models were used to determine effects of BM, SVL, and BC on the poison toxicity. We recorded significant changes in the insect heart contractility after treatment with the whole poison and separated fractions. We found an individual variation in cardiotoxicity of the parotoid extract which was explained by the body size of toad. Poison of smaller toads displayed a negative, whereas poison of larger toads positive, chronotropic effect on the heart contractility. Thus, we conclude that the effectiveness of parotoid secretion in repelling predators may vary depending on the toad individual size.
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Affiliation(s)
- Krzysztof Kowalski
- Department of Vertebrate Zoology and Ecology, Institute of Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Lwowska 1, Toruń, 87-100, Poland; Department of Systematic Zoology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, Poznań, 61-614, Poland.
| | - Paweł Marciniak
- Department of Animal Physiology and Development, Institute of Experimental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, Poznań, 61-614, Poland.
| | - Leszek Rychlik
- Department of Systematic Zoology, Institute of Environmental Biology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, Poznań, 61-614, Poland.
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12
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Cortázar-Chinarro M, Meyer-Lucht Y, Van der Valk T, Richter-Boix A, Laurila A, Höglund J. Antimicrobial peptide and sequence variation along a latitudinal gradient in two anurans. BMC Genet 2020; 21:38. [PMID: 32228443 PMCID: PMC7106915 DOI: 10.1186/s12863-020-00839-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/06/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND While there is evidence of both purifying and balancing selection in immune defense genes, large-scale genetic diversity in antimicrobial peptides (AMPs), an important part of the innate immune system released from dermal glands in the skin, has remained uninvestigated. Here we describe genetic diversity at three AMP loci (Temporin, Brevinin and Palustrin) in two ranid frogs (Rana arvalis and R. temporaria) along a 2000 km latitudinal gradient. We amplified and sequenced part of the Acidic Propiece domain and the hypervariable Mature Peptide domain (~ 150-200 bp) in the three genes using Illumina Miseq and expected to find decreased AMP genetic variation towards the northern distribution limit of the species similarly to studies on MHC genetic patterns. RESULTS We found multiple loci for each AMP and relatively high gene diversity, but no clear pattern of geographic genetic structure along the latitudinal gradient. We found evidence of trans-specific polymorphism in the two species, indicating a common evolutionary origin of the alleles. Temporin and Brevinin did not form monophyletic clades suggesting that they belong to the same gene family. By implementing codon evolution models we found evidence of strong positive selection acting on the Mature Peptide. We also found evidence of diversifying selection as indicated by divergent allele frequencies among populations and high Theta k values. CONCLUSION Our results suggest that AMPs are an important source of adaptive diversity, minimizing the chance of microorganisms developing resistance to individual peptides.
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Affiliation(s)
- Maria Cortázar-Chinarro
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden.
| | - Yvonne Meyer-Lucht
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden.,Centre for Paleogenetics Svante Arrhenius väg 20C, SE-106 91, Stockholm, Sweden
| | - Tom Van der Valk
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden
| | - Alex Richter-Boix
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden
| | - Anssi Laurila
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden
| | - Jacob Höglund
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236, Uppsala, Sweden
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13
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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: 68] [Impact Index Per Article: 13.6] [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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Pereira KE, Crother BI, Sever DM, Fontenot CL, Pojman JA, Wilburn DB, Woodley SK. Skin glands of an aquatic salamander vary in size and distribution and release antimicrobial secretions effective against chytrid fungal pathogens. ACTA ACUST UNITED AC 2018; 221:jeb.183707. [PMID: 29880633 DOI: 10.1242/jeb.183707] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 05/31/2018] [Indexed: 12/29/2022]
Abstract
Amphibian skin is unique among vertebrate classes, containing a large number of multicellular exocrine glands that vary among species and have diverse functions. The secretions of skin glands contain a rich array of bioactive compounds including antimicrobial peptides (AMPs). Such compounds are important for amphibian innate immune responses and may protect some species from chytridiomycosis, a lethal skin disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). While the bioactivity of skin secretions against Bd has been assessed for many amphibian taxa, similar studies are lacking for Bsal, a chytrid fungus that is especially pathogenic for salamanders. We studied the skin glands and their potential functions in an aquatic salamander, the three-toed amphiuma (Amphiuma tridactylum). Skin secretions of captive adult salamanders were analyzed by RP-HPLC and tested against the growth of Bd and Bsal using in vitro assays. We found that compounds within collected skin secretions were similar between male and female salamanders and inhibited the growth of Bd and Bsal. Thus, skin secretions that protect against Bd may also provide protection against Bsal. Histological examination of the skin glands of preserved salamanders revealed the presence of enlarged granular glands concentrated within caudal body regions. A site of potential gland specialization was identified at the tail base and may indicate specialized granular glands related to courtship and communication.
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Affiliation(s)
- Kenzie E Pereira
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA .,Department of Biology, Southeastern Louisiana University, Hammond, LA 70402, USA
| | - Brian I Crother
- Department of Biology, Southeastern Louisiana University, Hammond, LA 70402, USA
| | - David M Sever
- Department of Biology, Southeastern Louisiana University, Hammond, LA 70402, USA
| | - Clifford L Fontenot
- Department of Biology, Southeastern Louisiana University, Hammond, LA 70402, USA
| | - John A Pojman
- Department of Chemistry, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Damien B Wilburn
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Sarah K Woodley
- Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282, USA
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15
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Johnson PTJ, Calhoun DM, Stokes AN, Susbilla CB, McDevitt-Galles T, Briggs CJ, Hoverman JT, Tkach VV, de Roode JC. Of poisons and parasites-the defensive role of tetrodotoxin against infections in newts. J Anim Ecol 2018; 87:1192-1204. [PMID: 29476541 DOI: 10.1111/1365-2656.12816] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 01/17/2018] [Indexed: 11/29/2022]
Abstract
Classical research on animal toxicity has focused on the role of toxins in protection against predators, but recent studies suggest these same compounds can offer a powerful defense against parasites and infectious diseases. Newts in the genus Taricha are brightly coloured and contain the potent neurotoxin, tetrodotoxin (TTX), which is hypothesized to have evolved as a defense against vertebrate predators such as garter snakes. However, newt populations often vary dramatically in toxicity, which is only partially explained by predation pressure. The primary aim of this study was to evaluate the relationships between TTX concentration and infection by parasites. By systematically assessing micro- and macroparasite infections among 345 adult newts (sympatric populations of Taricha granulosa and T. torosa), we detected 18 unique taxa of helminths, fungi, viruses and protozoans. For both newt species, per-host concentrations of TTX, which varied from undetectable to >60 μg/cm2 skin, negatively predicted overall parasite richness as well as the likelihood of infection by the chytrid fungus, Batrachochytrium dendrobatidis, and ranavirus. No such effect was found on infection load among infected hosts. Despite commonly occurring at the same wetlands, T. torosa supported higher parasite richness and average infection load than T. granulosa. Host body size and sex (females > males) tended to positively predict infection levels in both species. For hosts in which we quantified leucocyte profiles, total white blood cell count correlated positively with both parasite richness and total infection load. By coupling data on host toxicity and infection by a broad range of micro- and macroparasites, these results suggest that-alongside its effects on predators-tetrodotoxin may help protect newts against parasitic infections, highlighting the importance of integrative research on animal chemistry, immunological defenses and natural enemy ecology.
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Affiliation(s)
- Pieter T J Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Dana M Calhoun
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Amber N Stokes
- Department of Biology, California State University, Bakersfield, CA, USA
| | - Calvin B Susbilla
- Department of Biology, California State University, Bakersfield, CA, USA
| | - Travis McDevitt-Galles
- Department of Ecology and Evolutionary Biology, University of Colorado at Boulder, Boulder, CO, USA
| | - Cheryl J Briggs
- Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, USA
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, USA
| | - Vasyl V Tkach
- Department of Biology, University of North Dakota, Grand Forks, ND, USA
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16
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Saporito RA, Grant T. Comment on Amézquita et al. (2017) "Conspicuousness, color resemblance, and toxicity in geographically diverging mimicry: The pan-Amazonian frog Allobates femoralis". Evolution 2018. [PMID: 29524217 DOI: 10.1111/evo.13468] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Amézquita et al. (2017) recently concluded that species of the Allobates femoralis group are toxic to mice at levels equivalent to syntopic alkaloid-containing poison frogs, which they attributed to the presence of alkaloids in skin secretions. However, the chemical composition of skin secretions was not analyzed, and here we present additional data supporting the absence of alkaloids in skin secretions of the Allobates femoralis group. Instead, we suggest the observed toxicity was caused by the anesthetic benzocaine, which was applied to the buccal cavity to euthanize frogs prior to skin removal. We show that orally administered benzocaine is rapidly incorporated into the skin of species that sequester and do not sequester alkaloids, which casts doubt on the conclusion that Allobates femoralis group skin secretions are toxic and makes the results of experiments with alkaloid-containing species of Adelphobates and Ameerega uninterpretable. To prevent experimental errors and misinterpretations in studies of amphibian chemical defense, we encourage researchers to test the chemical composition of samples prior to experimentation, include all necessary controls to detect false positives, conduct small pilot studies for new methods, and consider the limitations of particular methods and their ability to address the intended research questions.
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Affiliation(s)
- Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, Ohio 44118
| | - Taran Grant
- Department de Zoology, Institute of Biosciences, University of São Paulo, 05508, São Paulo, São Paulo, Brazil
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17
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Hovey KJ, Seiter EM, Johnson EE, Saporito RA. Sequestered Alkaloid Defenses in the Dendrobatid Poison Frog Oophaga pumilio Provide Variable Protection from Microbial Pathogens. J Chem Ecol 2018; 44:312-325. [PMID: 29427191 DOI: 10.1007/s10886-018-0930-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 01/26/2018] [Accepted: 01/29/2018] [Indexed: 11/29/2022]
Abstract
Most amphibians produce their own defensive chemicals; however, poison frogs sequester their alkaloid-based defenses from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. Alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in frog defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in dendrobatid poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect these frogs. Herein, we examined how alkaloid defenses in the dendrobatid poison frog, Oophaga pumilio, affect growth of the known anuran pathogens Aeromonas hydrophila and Klebsiella pneumoniae. Frogs were collected from five locations throughout Costa Rica that are known to vary in their alkaloid profiles. Alkaloids were isolated from individual skins, and extracts were assayed against both pathogens. Microbe subcultures were inoculated with extracted alkaloids to create dose-response curves. Subsequent spectrophotometry and cell counting assays were used to assess growth inhibition. GC-MS was used to characterize and quantify alkaloids in frog extracts, and our results suggest that variation in alkaloid defenses lead to differences in inhibition of these pathogens. The present study provides the first evidence that alkaloid variation in a dendrobatid poison frog is associated with differences in inhibition of anuran pathogens, and offers further support that alkaloid defenses in poison frogs confer protection against both pathogens and predators.
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Affiliation(s)
- Kyle J Hovey
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA
| | - Emily M Seiter
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA
| | - Erin E Johnson
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA
| | - Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA.
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18
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Grant T, Rada M, Anganoy-Criollo M, Batista A, Dias PH, Jeckel AM, Machado DJ, Rueda-Almonacid JV. Phylogenetic Systematics of Dart-Poison Frogs and Their Relatives Revisited (Anura: Dendrobatoidea). SOUTH AMERICAN JOURNAL OF HERPETOLOGY 2017. [DOI: 10.2994/sajh-d-17-00017.1] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Taran Grant
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, SP, Brazil
- Amphibian Collection, Museum of Zoology of the University of São Paulo, 04263-000, São Paulo, SP, Brazil
| | - Marco Rada
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, SP, Brazil
| | - Marvin Anganoy-Criollo
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, SP, Brazil
| | - Abel Batista
- Universidad Autónoma de Chiriquí, David, Republic of Panama
- Los Naturalistas, David 0426-01459, Chiriquí, Panama
| | - Pedro Henrique Dias
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, SP, Brazil
| | - Adriana Moriguchi Jeckel
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, SP, Brazil
| | - Denis Jacob Machado
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090, São Paulo, SP, Brazil
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19
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von Byern J, Grunwald I, Kosok M, Saporito RA, Dicke U, Wetjen O, Thiel K, Borcherding K, Kowalik T, Marchetti-Deschmann M. Chemical characterization of the adhesive secretions of the salamander Plethodon shermani (Caudata, Plethodontidae). Sci Rep 2017; 7:6647. [PMID: 28751633 PMCID: PMC5532285 DOI: 10.1038/s41598-017-05473-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 05/26/2017] [Indexed: 11/09/2022] Open
Abstract
Salamanders have developed a wide variety of antipredator mechanisms, including tail autotomy, colour patterns, and noxious skin secretions. As an addition to these tactics, the red-legged salamander (Plethodon shermani) uses adhesive secretions as part of its defensive strategy. The high bonding strength, the fast-curing nature, and the composition of the biobased materials makes salamander adhesives interesting for practical applications in the medical sector. To understand the adhesive secretions of P. shermani, its components were chemically analysed by energy dispersive X-ray spectroscopy (EDX), inductively coupled plasma mass spectrometry (ICP-MS), amino acid analysis, and spectroscopy (ATR-IR, Raman). In addition, proteins were separated by gel-electrophoresis and selected spots were characterised by peptide mass fingerprinting. The salamander secretion contains a high amount of water and predominantly proteins (around 77% in the dry stage). The gel-electrophoresis and peptide mass fingerprint analyses revealed a de novo set of peptides/proteins, largely with a pI between 5.0 and 8.0 and a molecular mass distribution between 10 and 170 kDa. Only low homologies with other proteins present in known databases could be identified. The results indicate that the secretions of the salamander Plethodon clearly differ chemically from those shown for other glue-producing terrestrial or marine species and thus represent a unique glue system.
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Affiliation(s)
- Janek von Byern
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Austrian Cluster for Tissue Regeneration, Donaueschingenstrasse 13, 1200, Vienna, Austria
- University of Vienna, Faculty of Life Science, Core Facility Cell Imaging and Ultrastructure Research, Althanstrasse 14, 1090, Vienna, Austria
| | - Ingo Grunwald
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Department of Adhesive Bonding Technology and Surfaces, Adhesives and Polymer Chemistry, Wiener Straße 12, 28359, Bremen, Germany.
| | - Max Kosok
- Vienna University of Technology, Institute of Chemical Technologies and Analytics, Karlsplatz 13, 1040, Vienna, Austria
| | - Ralph A Saporito
- John Carroll University, Department of Biology, University Heights, Ohio, 44118, USA
| | - Ursula Dicke
- University of Bremen, Brain Research Institute, Department of Behavioral Physiology, Bibliothekstraße 1, 28359, Bremen, Germany
| | - Oliver Wetjen
- University of Bremen, Brain Research Institute, Department of Behavioral Physiology, Bibliothekstraße 1, 28359, Bremen, Germany
| | - Karsten Thiel
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Department of Adhesive Bonding Technology and Surfaces, Adhesives and Polymer Chemistry, Wiener Straße 12, 28359, Bremen, Germany
| | - Kai Borcherding
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Department of Adhesive Bonding Technology and Surfaces, Adhesives and Polymer Chemistry, Wiener Straße 12, 28359, Bremen, Germany
| | - Thomas Kowalik
- Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Department of Adhesive Bonding Technology and Surfaces, Adhesives and Polymer Chemistry, Wiener Straße 12, 28359, Bremen, Germany
| | - Martina Marchetti-Deschmann
- Vienna University of Technology, Institute of Chemical Technologies and Analytics, Karlsplatz 13, 1040, Vienna, Austria
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20
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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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21
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Developmental morphology of granular skin glands in pre-metamorphic egg-eating poison frogs. ZOOMORPHOLOGY 2017. [DOI: 10.1007/s00435-017-0344-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Schulte LM, Saporito RA, Davison I, Summers K. The palatability of Neotropical poison frogs in predator-prey systems: do alkaloids make the difference? Biotropica 2016. [DOI: 10.1111/btp.12404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lisa M. Schulte
- Department of Biology; East Carolina University; 1001 E Tenth Street Greenville NC 27858 USA
| | - Ralph A. Saporito
- Department of Biology; John Carroll University; University Heights OH 44118 USA
| | - Ian Davison
- Department of Biology; East Carolina University; 1001 E Tenth Street Greenville NC 27858 USA
| | - Kyle Summers
- Department of Biology; East Carolina University; 1001 E Tenth Street Greenville NC 27858 USA
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Bufadienolide and alkaloid-based chemical defences in two different species of neotropical anurans are equally effective against the same arthropod predators. JOURNAL OF TROPICAL ECOLOGY 2016. [DOI: 10.1017/s0266467416000055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Abstract:Defensive chemicals in anuran skin secretions function in protection against potential predators. Although studies have demonstrated that particular chemicals are effective against certain predators, very little is known about how different chemicals from different species function against the same predators. Understanding how different chemicals function as a defence against similar predators is fundamental to the ecology and evolution of chemical defences in frogs. In the present study, the defensive function of bufadienolide-based defences in adult Rhaebo haematiticus (Bufonidae) were compared with alkaloid-based defences in adult and juvenile Dendrobates auratus (Dendrobatidae) against the same predators. Most bufonids contain synthesized bufadienolides, whereas dendrobatids contain dietary-derived alkaloids. Predation trials were performed with two potential invertebrate predators, Paraponera clavata (bullet ant) and Cupiennius coccineus (ctenid spider), to determine how these predators respond to two different types of frog chemical defence. The non-chemically defended frog Craugastor fitzingeri served as a control in all predation trials. Our results suggest that bufadienolide defences of R. haematiticus and alkaloid defences of D. auratus are equally effective towards bullet ant and ctenid spider predators. The similar avoidance and cleaning behaviours exhibited by these ants and spiders after contact with bufadienolides and alkaloids suggest that both types of defence are unpalatable to these arthropod predators.
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25
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Saporito RA, Norton RA, Garraffo MH, Spande TF. Taxonomic distribution of defensive alkaloids in Nearctic oribatid mites (Acari, Oribatida). EXPERIMENTAL & APPLIED ACAROLOGY 2015; 67:317-333. [PMID: 26264156 DOI: 10.1007/s10493-015-9962-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 08/05/2015] [Indexed: 06/04/2023]
Abstract
The opisthonotal (oil) glands of oribatid mites are the source of a wide diversity of taxon-specific defensive chemicals, and are likely the location for the more than 90 alkaloids recently identified in oribatids. Although originally recognized in temperate oribatid species, alkaloids have also been detected in related lineages of tropical oribatids. Many of these alkaloids are also present in a worldwide radiation of poison frogs, which are known to sequester these defensive chemicals from dietary arthropods, including oribatid mites. To date, most alkaloid records involve members of the superfamily Oripodoidea (Brachypylina), although few species have been examined and sampling of other taxonomic groups has been highly limited. Herein, we examined adults of more than 60 species of Nearctic oribatid mites, representing 46 genera and 33 families, for the presence of alkaloids. GC-MS analyses of whole body extracts led to the detection of 15 alkaloids, but collectively they occur only in members of the genera Scheloribates (Scheloribatidae) and Protokalumma (Parakalummidae). Most of these alkaloids have also been detected previously in the skin of poison frogs. All examined members of the oripodoid families Haplozetidae and Oribatulidae were alkaloid-free, and no mites outside the Oripodoidea contained alkaloids. Including previous studies, all sampled species of the cosmopolitan oripodoid families Scheloribatidae and Parakalummidae, and the related, mostly tropical families Mochlozetidae and Drymobatidae contain alkaloids. Our findings are consistent with a generalization that alkaloid presence is widespread, but not universal in Oripodoidea. Alkaloid presence in tropical, but not temperate members of some non-oripodoid taxa (in particular Galumnidae) deserves further study.
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Affiliation(s)
- Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, OH, 44118, USA.
| | - Roy A Norton
- College of Environmental Science and Forestry, State University of New York, Syracuse, NY, 13210, USA
| | - Martin H Garraffo
- Clinical Mass Spectrometry Core, NIDDK, NIH, DHHS, Bethesda, MD, 20892, USA
| | - Thomas F Spande
- Laboratory of Medicinal Chemistry, NIDA, NIH, DHHS, Bethesda, MD, 20892, USA
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Jeckel AM, Saporito RA, Grant T. The relationship between poison frog chemical defenses and age, body size, and sex. Front Zool 2015; 12:27. [PMID: 26435730 PMCID: PMC4591705 DOI: 10.1186/s12983-015-0120-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/21/2015] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Amphibians secrete a wide diversity of chemicals from skin glands as defense against predators, parasites, and pathogens. Most defensive chemicals are produced endogenously through biosynthesis, but poison frogs sequester lipophilic alkaloids from dietary arthropods. Alkaloid composition varies greatly, even among conspecific individuals collected at the same time and place, with some individuals having only a few micrograms of one or a few alkaloids and others possessing >1 mg of >30 alkaloids. The paucity of alkaloids in juveniles and their abundance in adults suggests that alkaloids accumulate over time; however, alkaloid diversity is highly variable among adult poison frogs and has never been studied in relation to individual age. Using skeletochronology to infer individual ages and gas chromatography-mass spectrometry and vapor phase Fourier-transform infrared spectral analysis to identify the defensive chemicals of 63 individuals, we tested the relationship between defensive chemicals and age, size, and sex in the Brazilian red-belly toad, Melanophryniscus moreirae, a poison frog that possesses both sequestered alkaloids and the biosynthesized indolealkylamine bufotenine. RESULTS Adult females were, on average, older and larger than adult males. Juveniles were smaller but not necessarily younger than adults and possessed bufotenine and 18 of the 37 alkaloids found in adults. Alkaloid richness was positively related to age, but not size, whereas the quantities of sequestered alkaloids and bufotenine were positively related to size, but not age. Defensive chemicals were unrelated to sex, independent of size. CONCLUSIONS The relationship between alkaloid richness and age appears to result from the gradual accumulation of alkaloids over a frog's lifetime, whereas the relationship between the quantity of defensive chemicals and size appears to be due to the greater storage capacity of larger individuals. The decoupling of age and size effects increases the amount of individual variation that can occur within a population, thereby possibly enhancing anti-predator efficacy. Further, given that both richness and quantity contribute to the overall chemical defense of individual frogs, our results suggest that older, larger individuals are better defended than younger, smaller ones. These considerations underscore the importance of including age in studies of the causes and consequences of variation in poison frog chemical defenses.
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Affiliation(s)
- Adriana M Jeckel
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090 São Paulo, São Paulo Brazil
| | - Ralph A Saporito
- Department of Biology, John Carroll University, University Heights, OH 44118 USA
| | - Taran Grant
- Department of Zoology, Institute of Biosciences, University of São Paulo, 05508-090 São Paulo, São Paulo Brazil
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