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Hardman RH, Reinert LK, Irwin KJ, Oziminski K, Rollins-Smith L, Miller DL. Disease state associated with chronic toe lesions in hellbenders may alter anti-chytrid skin defenses. Sci Rep 2023; 13:1982. [PMID: 36737574 PMCID: PMC9898527 DOI: 10.1038/s41598-023-28334-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Hellbenders (Cryptobranchus alleganiensis) are large, aquatic salamanders from the eastern United States. Both subspecies, eastern and Ozark hellbenders, have experienced declines resulting in federal listing of Ozark hellbenders. The globally distributed chytrid fungus, Batrachochytrium dendrobatidis (Bd) has been detected in both subspecies, and Batrachochytrium salamandrivorans (Bsal) poses a new threat if introduced into North America. Ozark hellbenders also suffer a high prevalence of toe lesions of unknown etiology, with changes in host immunocompetence hypothesized to contribute. Antimicrobial peptides (AMPs) secreted from dermal granular glands may play a role in hellbender health. We collected skin secretions from free-ranging hellbenders and enriched them for small cationic peptides used for growth inhibition assays against Bd and Bsal. Generalized linear mixed models revealed the presence of active toe lesions as the strongest and only significant predictor of decreased Bd inhibition by skin peptides. We also found skin secretions were more inhibitory of Bsal than Bd. MALDI-TOF mass spectrometry revealed candidate peptides responsible for anti-chytrid activity. Results support the hypothesis that hellbender skin secretions are important for innate immunity against chytrid pathogens, and decreased production or release of skin peptides may be linked to other sub-lethal effects of disease associated with toe lesions.
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Affiliation(s)
- Rebecca H Hardman
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA. .,Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, St. Petersburg, FL, 33701, USA.
| | - Laura K Reinert
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Kelly J Irwin
- Arkansas Game and Fish Commission, Benton, AR, 72015, USA
| | - Kendall Oziminski
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA
| | - Louise Rollins-Smith
- Department of Pathology, Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Debra L Miller
- Department of Biomedical and Diagnostic Sciences, University of Tennessee College of Veterinary Medicine, Knoxville, TN, 37996, USA.,School of Natural of Resources, University of Tennessee, Knoxville, Tennessee, 37996, USA
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2
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Kaganer AW, Ossiboff RJ, Keith NI, Schuler KL, Comizzoli P, Hare MP, Fleischer RC, Gratwicke B, Bunting EM. Immune priming prior to pathogen exposure sheds light on the relationship between host, microbiome and pathogen in disease. ROYAL SOCIETY OPEN SCIENCE 2023; 10:220810. [PMID: 36756057 PMCID: PMC9890126 DOI: 10.1098/rsos.220810] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 01/04/2023] [Indexed: 06/18/2023]
Abstract
Dynamic interactions between host, pathogen and host-associated microbiome dictate infection outcomes. Pathogens including Batrachochytrium dendrobatidis (Bd) threaten global biodiversity, but conservation efforts are hindered by limited understanding of amphibian host, Bd and microbiome interactions. We conducted a vaccination and infection experiment using Eastern hellbender salamanders (Cryptobranchus alleganiensis alleganiensis) challenged with Bd to observe infection, skin microbial communities and gene expression of host skin, pathogen and microbiome throughout the experiment. Most animals survived high Bd loads regardless of their vaccination status and vaccination did not affect pathogen load, but host gene expression differed based on vaccination. Oral vaccination (exposure to killed Bd) stimulated immune gene upregulation while topically and sham-vaccinated animals did not significantly upregulate immune genes. In early infection, topically vaccinated animals upregulated immune genes but orally and sham-vaccinated animals downregulated immune genes. Bd increased pathogenicity-associated gene expression in late infection when Bd loads were highest. The microbiome was altered by Bd, but there was no correlation between anti-Bd microbe abundance or richness and pathogen burden. Our observations suggest that hellbenders initially generate a vigorous immune response to Bd, which is ineffective at controlling disease and is subsequently modulated. Interactions with antifungal skin microbiota did not influence disease progression.
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Affiliation(s)
- Alyssa W. Kaganer
- Department of Natural Resources and the Environment, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
| | - Robert J. Ossiboff
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32611, USA
| | - Nicole I. Keith
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
- Biology Department, Hamilton College, Clinton, NY, 13323, USA
| | - Krysten L. Schuler
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
| | - Pierre Comizzoli
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
| | - Matthew P. Hare
- Department of Natural Resources and the Environment, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, 14853, USA
| | - Robert C. Fleischer
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, 20008, USA
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Front Royal, VA, 22630, USA
| | - Elizabeth M. Bunting
- Cornell Wildlife Health Laboratory, Animal Health Diagnostic Center, Cornell University, Ithaca, NY, 14853, USA
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14853, USA
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3
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McKnight DT, Huerlimann R, Bower DS, Schwarzkopf L, Alford RA, Zenger KR. The interplay of fungal and bacterial microbiomes on rainforest frogs following a disease outbreak. Ecosphere 2022. [DOI: 10.1002/ecs2.4037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Donald T. McKnight
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Roger Huerlimann
- College of Science and Engineering James Cook University Townsville Queensland Australia
- Marine Climate Change Unit Okinawa Institute of Science and Technology Onnason Okinawa Japan
| | - Deborah S. Bower
- College of Science and Engineering James Cook University Townsville Queensland Australia
- School of Environmental and Rural Science University of New England Armidale New South Wales Australia
| | - Lin Schwarzkopf
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Ross A. Alford
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Kyall R. Zenger
- College of Science and Engineering James Cook University Townsville Queensland Australia
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4
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Besedin D, Turner BJ, Deo P, Lopes MDB, Williams CR. Effect of captivity and water salinity on culture-dependent frog skin microbiota and Batrachochytrium dendrobatidis ( Bd) infection. T ROY SOC SOUTH AUST 2022. [DOI: 10.1080/03721426.2022.2086358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Darislav Besedin
- UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brandon J. Turner
- UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Permal Deo
- UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
- Health and Biomedical Innovation, UniSA Clinical and Health Science, University of South Australia, Adelaide, South Australia, Australia
| | - Miguel De Barros Lopes
- UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
- Health and Biomedical Innovation, UniSA Clinical and Health Science, University of South Australia, Adelaide, South Australia, Australia
| | - Craig R. Williams
- UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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5
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Wakeman W, Long A, Estes AM, Jozwick AKS. Zebrafish, Danio rerio, Skin Mucus Harbors a Distinct Bacterial Community Dominated by Actinobacteria. Zebrafish 2021; 18:354-362. [PMID: 34935499 DOI: 10.1089/zeb.2021.0040] [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: 11/13/2022] Open
Abstract
The skin mucus of teleost fish harbors a complex microbial community that is continually interacting with the aquatic environment. Despite zebrafish, Danio rerio, serving as a model organism in a myriad of research fields, very little is known about the composition and role of the skin mucus microbiome. The purpose of this study was to determine a simple sampling method for the skin mucus microbiome, identify prominent bacterial members, and compare its composition to the microbial community of the surrounding environment. Next-generation sequencing of the V3-V4 region of the 16S rRNA gene was performed on skin mucus and filtered tank water samples. Results show that prominent bacterial members of the skin mucus in zebrafish include Actinobacteria (Mycobacteriaceae) and Gammaproteobacteria (Aeromonadaceae), followed by Alphaproteobacteria and Betaproteobacteria. The tank water contained much higher bacterial diversity and was clearly different from the skin mucus microbiome, despite continuous interaction. This study identifies a straightforward sampling method for the zebrafish skin mucus microbiome, enabling hypothesis generation on the role of ectosymbionts on host and microbiome health.
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Affiliation(s)
- Wren Wakeman
- Center for Natural Sciences, Goucher College, Baltimore, Maryland, USA
| | - Alyssa Long
- Center for Natural Sciences, Goucher College, Baltimore, Maryland, USA
| | - Anne M Estes
- Department of Biological Sciences, Towson University, Baltimore, Maryland, USA
| | - Anna K S Jozwick
- Center for Natural Sciences, Goucher College, Baltimore, Maryland, USA
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6
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Carrasco GH, de Souza MB, de Souza Santos LR. Effect of multiple stressors and population decline of frogs. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:59519-59527. [PMID: 34505245 DOI: 10.1007/s11356-021-16247-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 08/25/2021] [Indexed: 06/13/2023]
Abstract
The ongoing decline in anuran populations is linked primarily to the effects of stressor agents such as pathogens, pesticides, alterations of natural landscapes, and the introduction of exotic species. Most studies that have evaluated the effects of these stressors have focused on a single component, which is the opposite of the reality of most natural environments, where anuran populations tend to suffer the influence of multiple agents simultaneously. Studies of the effects of the interaction between these components are extremely important, given that one agent may potentialize (synergistic effect) or weaken another (antagonistic effect) or, in some cases, have a neutral effect. The present study is based on the scientometric analysis of three bibliographic databases (ISI Web of Science, Scopus, and PubMed), which identified 1376 papers that reported on the global decline of anuran populations, although only 172 of these studies focused on the interactive effects of environmental stressors. Synergistic effects were the most frequent type of interaction, followed by antagonistic effects, and a small number of studies that found no clear interaction between the stressors. Pathogens and pesticides were the classes of stressor studied most frequently, while climate-pathogen and pathogen-pesticide interactions were the combinations that featured in the largest number of studies. Overall, we would recommend a more systematic focus on the dynamics of the interactions among the stressors that impact anuran populations, in particular for the elaboration of conservation programs, given that these agents tend to have complex combined effects.
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Affiliation(s)
- Guilherme Henrique Carrasco
- Laboratório de Ecotoxicologia e Sistemática Animal - Instituto Federal Goiano - IF Goiano, Rodovia Sul Goiana, Km 01, Zona Rural, Rio Verde, GO, 75.901-970, Brazil.
| | - Marcelino Benvindo de Souza
- Laboratório de Mutagênese, Instituto de Ciências Biológicas, ICB I - Universidade Federal de Goiás, Campus Samambaia, Goiânia, GO, 74690-900, Brazil
| | - Lia Raquel de Souza Santos
- Laboratório de Ecotoxicologia e Sistemática Animal - Instituto Federal Goiano - IF Goiano, Rodovia Sul Goiana, Km 01, Zona Rural, Rio Verde, GO, 75.901-970, Brazil.
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Chimetto Tonon LA, Rua C, Crnkovic CM, Bernardi DI, Pires Junior OR, Haddad CFB, Pedrosa CSG, Souza LRQ, Rehen SK, de Azevedo GPR, Thompson CC, Thompson FL, Berlinck RGS. Microbiome associated with the tetrodotoxin-bearing anuran Brachycephalus pitanga. Toxicon 2021; 203:139-146. [PMID: 34653444 DOI: 10.1016/j.toxicon.2021.10.002] [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: 03/11/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 11/15/2022]
Abstract
The genus Brachycephalus includes small species of aposematic anurans known as microendemic, occurring in the mountains of the Atlantic Forest. Brachycephalus ephippium, B. nodoterga and B. pernix have been reported to contain the neurotoxin tetrodotoxin in skin and viscera. The biological conservation of several Brachycephalus species is currently threatened by climate change, deforestation, and the pandemic caused by the fungus Batrachochytrium dendrobatidis (Bd). Despite the well-known importance of amphibians' associated bacteria in the defensive role against pathogens, there is still a poor understanding of amphibian microbiome composition. The present study investigated the composition of B. pitanga microbial community and the presence of TTX in the host and in cultures of bacterial isolates, using a combination of metagenomics, bacterial culture isolation, mass spectrometry and metabolomic analyses. Results of culture-dependent and -independent analyses characterized the microbial communities associated with the skin and viscera of B. pitanga. Mass spectrometry analysis indicated the presence of TTX in host tissues, while bacterial production of TTX was not observed under the experimental conditions used in this investigation. This is the first report confirming the occurrence of TTX in B. pitanga.
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Affiliation(s)
- Luciane A Chimetto Tonon
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil; Instituto de Biologia, SAGE-COPPE, Universidade Federal do Rio de Janeiro (UFRJ), RJ, Brazil.
| | - Cintia Rua
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil; Instituto de Biologia, SAGE-COPPE, Universidade Federal do Rio de Janeiro (UFRJ), RJ, Brazil
| | - Camila M Crnkovic
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil; Departamento de Tecnologia Bioquímico-Farmacêutica (FBT), Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Darlon I Bernardi
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil
| | - Osmindo R Pires Junior
- Laboratório de Toxinologia, Instituto de Biologia, Universidade de Brasília, Brasília, DF, Brazil
| | - Célio F B Haddad
- Departamento de Biodiversidade e Centro de Aquicultura, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rio Claro, SP, Brazil
| | | | | | - Stevens K Rehen
- Instituto D'Or de Pesquisa e Ensino (IDOR), RJ, Brazil; Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro (UFRJ), RJ, Brazil
| | - Gustavo P R de Azevedo
- Instituto de Biologia, SAGE-COPPE, Universidade Federal do Rio de Janeiro (UFRJ), RJ, Brazil
| | - Cristiane C Thompson
- Instituto de Biologia, SAGE-COPPE, Universidade Federal do Rio de Janeiro (UFRJ), RJ, Brazil
| | - Fabiano L Thompson
- Instituto de Biologia, SAGE-COPPE, Universidade Federal do Rio de Janeiro (UFRJ), RJ, Brazil.
| | - Roberto G S Berlinck
- Instituto de Química de São Carlos, Universidade de São Paulo, CP 780, CEP 13560-970, São Carlos, SP, Brazil.
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Keller AG, Apprill A, Lebaron P, Robbins J, Romano TA, Overton E, Rong Y, Yuan R, Pollara S, Whalen KE. Characterizing the culturable surface microbiomes of diverse marine animals. FEMS Microbiol Ecol 2021; 97:6157762. [PMID: 33681975 PMCID: PMC8012112 DOI: 10.1093/femsec/fiab040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 03/01/2021] [Indexed: 11/14/2022] Open
Abstract
Biofilm-forming bacteria have the potential to contribute to the health, physiology, behavior and ecology of the host and serve as its first line of defense against adverse conditions in the environment. While metabarcoding and metagenomic information furthers our understanding of microbiome composition, fewer studies use cultured samples to study the diverse interactions among the host and its microbiome, as cultured representatives are often lacking. This study examines the surface microbiomes cultured from three shallow-water coral species and two whale species. These unique marine animals place strong selective pressures on their microbial symbionts and contain members under similar environmental and anthropogenic stress. We developed an intense cultivation procedure, utilizing a suite of culture conditions targeting a rich assortment of biofilm-forming microorganisms. We identified 592 microbial isolates contained within 15 bacterial orders representing 50 bacterial genera, and two fungal species. Culturable bacteria from coral and whale samples paralleled taxonomic groups identified in culture-independent surveys, including 29% of all bacterial genera identified in the Megaptera novaeangliae skin microbiome through culture-independent methods. This microbial repository provides raw material and biological input for more nuanced studies which can explore how members of the microbiome both shape their micro-niche and impact host fitness.
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Affiliation(s)
- Abigail G Keller
- Department of Biology, Haverford College, 370 Lancaster Ave., Haverford, PA, 19041-1392, USA
| | - Amy Apprill
- Marine Chemistry & Geochemistry Department, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA, 02543, USA
| | - Philippe Lebaron
- Laboratoire de Biodiversité et Biotechnologies Microbiennes, USR 3579 Sorbonne Université (UPMC) Paris 6 et CNRS Observatoire Océanologique, Banyuls-sur-Mer, France
| | - Jooke Robbins
- Center for Coastal Studies, 5 Holway Ave., Provincetown, MA, 02657, USA
| | - Tracy A Romano
- Mystic Aquarium, a division of Sea Research Foundation Inc., 55 Coogan Blvd., Mystic, CT, 06355, USA
| | - Ellysia Overton
- Department of Biology, Haverford College, 370 Lancaster Ave., Haverford, PA, 19041-1392, USA
| | - Yuying Rong
- Department of Biology, Haverford College, 370 Lancaster Ave., Haverford, PA, 19041-1392, USA
| | - Ruiyi Yuan
- Department of Biology, Haverford College, 370 Lancaster Ave., Haverford, PA, 19041-1392, USA
| | - Scott Pollara
- Department of Biology, Haverford College, 370 Lancaster Ave., Haverford, PA, 19041-1392, USA
| | - Kristen E Whalen
- Department of Biology, Haverford College, 370 Lancaster Ave., Haverford, PA, 19041-1392, USA
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Piccinni MZ, Watts JEM, Fourny M, Guille M, Robson SC. The skin microbiome of Xenopus laevis and the effects of husbandry conditions. Anim Microbiome 2021; 3:17. [PMID: 33546771 PMCID: PMC7866774 DOI: 10.1186/s42523-021-00080-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 01/22/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Historically the main source of laboratory Xenopus laevis was the environment. The increase in genetically altered animals and evolving governmental constraints around using wild-caught animals for research has led to the establishment of resource centres that supply animals and reagents worldwide, such as the European Xenopus Resource Centre. In the last decade, centres were encouraged to keep animals in a "low microbial load" or "clean" state, where embryos are surface sterilized before entering the housing system; instead of the conventional, "standard" conditions where frogs and embryos are kept without prior surface treatment. Despite Xenopus laevis having been kept in captivity for almost a century, surprisingly little is known about the frogs as a holobiont and how changing the microbiome may affect resistance to disease. This study examines how the different treatment conditions, "clean" and "standard" husbandry in recirculating housing, affects the skin microbiome of tadpoles and female adults. This is particularly important when considering the potential for poor welfare caused by a change in husbandry method as animals move from resource centres to smaller research colonies. RESULTS We found strong evidence for developmental control of the surface microbiome on Xenopus laevis; adults had extremely similar microbial communities independent of their housing, while both tadpole and environmental microbiome communities were less resilient and showed greater diversity. CONCLUSIONS Our findings suggest that the adult Xenopus laevis microbiome is controlled and selected by the host. This indicates that the surface microbiome of adult Xenopus laevis is stable and defined independently of the environment in which it is housed, suggesting that the use of clean husbandry conditions poses little risk to the skin microbiome when transferring adult frogs to research laboratories. This will have important implications for frog health applicable to Xenopus laevis research centres throughout the world.
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Affiliation(s)
- Maya Z. Piccinni
- grid.4701.20000 0001 0728 6636School of Biological Sciences, University of Portsmouth, Portsmouth, UK
- grid.4701.20000 0001 0728 6636European Xenopus Resource Centre, University of Portsmouth, Portsmouth, UK
| | - Joy E. M. Watts
- grid.4701.20000 0001 0728 6636School of Biological Sciences, University of Portsmouth, Portsmouth, UK
- grid.4701.20000 0001 0728 6636Centre for Enzyme Innovation, University of Portsmouth, Portsmouth, UK
| | - Marie Fourny
- grid.10400.350000 0001 2108 3034University of Rouen-Normandy, Rouen, France
| | - Matt Guille
- grid.4701.20000 0001 0728 6636School of Biological Sciences, University of Portsmouth, Portsmouth, UK
- grid.4701.20000 0001 0728 6636European Xenopus Resource Centre, University of Portsmouth, Portsmouth, UK
| | - Samuel C. Robson
- grid.4701.20000 0001 0728 6636Centre for Enzyme Innovation, University of Portsmouth, Portsmouth, UK
- grid.4701.20000 0001 0728 6636School of Pharmacy and Biomedical Sciences, University of Portsmouth, Portsmouth, UK
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10
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Abarca JG, Whitfield SM, Zuniga-Chaves I, Alvarado G, Kerby J, Murillo-Cruz C, Pinto-Tomás AA. Genotyping and differential bacterial inhibition of Batrachochytrium dendrobatidis in threatened amphibians in Costa Rica. MICROBIOLOGY-SGM 2021; 167. [PMID: 33529150 DOI: 10.1099/mic.0.001017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized - genetically and morphologically - several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL-2, which has been related to massive amphibian deaths worldwide; however, the isolates obtained showed genetic and morphological variation. Furthermore, we isolated epidermal bacteria from 12 amphibian species of surviving populations, some in danger of extinction, and evaluated their inhibitory activity against the collection of chytrid isolates. Through bioassays we confirmed the presence of chytrid-inhibitory bacterial genera in Costa Rican amphibians. However, we observed that the inhibition varied between different isolates of the same bacterial genus, and each bacterial isolation inhibited fungal isolation differently. In total, 14 bacterial isolates belonging to the genera Stenotrophomonas, Streptomyces, Enterobacter, Pseudomonas and Klebsiella showed inhibitory activity against all Bd isolates. Given the observed variation both in the pathogen and in the bacterial inhibition capacity, it is highly relevant to include local isolates and to consider the origin of the microorganisms when performing in vivo infection tests aimed at developing and implementing mitigation strategies for chytridiomycosis.
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Affiliation(s)
- Juan G Abarca
- Laboratorio de Recursos Naturales y Vida Silvestre (LARNAVISI), Escuela de Ciencias Biológicas, Universidad Nacional, Heredia, Costa Rica
| | - Steven M Whitfield
- Conservation and Research Department, Zoo Miami, St, Miami, FL 33177, USA
| | - Ibrahim Zuniga-Chaves
- Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica, San Pedro, Costa Rica.,Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Gilbert Alvarado
- Laboratorio de Patología Experimental y Comparada (LAPECOM), Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica
| | - Jacob Kerby
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA
| | - Catalina Murillo-Cruz
- Centro de Investigación en Estructuras Microscópicas (CIEMic), Universidad de Costa Rica, San Pedro, Costa Rica.,Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica, San Pedro, Costa Rica
| | - Adrián A Pinto-Tomás
- Centro de Investigación en Estructuras Microscópicas (CIEMic), Universidad de Costa Rica, San Pedro, Costa Rica.,Centro de Investigación en Biología Celular y Molecular (CIBCM), Universidad de Costa Rica, San Pedro, Costa Rica.,Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San Pedro, Costa Rica
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11
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Bell SC, Heard GW, Berger L, Skerratt LF. Connectivity over a disease risk gradient enables recovery of rainforest frogs. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2020; 30:e02152. [PMID: 32343856 DOI: 10.1002/eap.2152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 02/14/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Chytridiomycosis has been a key driver of global frog declines and extinctions, particularly for high-altitude populations across Australia and the Americas. While recent evidence shows some species are recovering, the extent of such recoveries and the mechanisms underpinning them remain poorly resolved. We surveyed the historical latitudinal and elevational range of four Australian rainforest frogs that disappeared from upland sites between 1989 and 1994 to establish their contemporary distribution and elevational limits, and investigate factors affecting population recovery. Five rainforest streams were surveyed from mountain-base to summit (30 sites in total), with swabs collected from the target species (Litoria dayi, L. nannotis, L. rheocola, and L. serrata) to determine their infection status, and data loggers deployed to measure microclimatic variation across the elevational gradient. Infection probability increased with elevation and canopy cover as it was tightly and inversely correlated with stream-side air temperature. Occupancy patterns suggest varying responses to this disease threat gradient. Two species, L. rheocola and L. serrata, were found over their full historical elevational range (≥1,000 m above sea level [asl]), while L. dayi was not detected above 400 m (formerly known up to 900 m asl) and L. nannotis was not detected above 800 m (formerly known up to 1,200 m asl). Site occupancy probability was negatively related to predicted infection prevalence for L. dayi, L. nannotis, and L. rheocola, but not L. serrata, which appears to now tolerate high fungal burdens. This study highlights the importance of environmental refuges and connectivity across disease risk gradients for the persistence and natural recovery of frogs susceptible to chytridiomycosis. Likewise, in documenting both interspecific variation in recovery rates and intraspecific differences between sites, this study suggests interactions between disease threats and host selection exist that could be manipulated. For example, translocations may be warranted where connectivity is poor or the increase in disease risk is too steep to allow recolonization, combined with assisted selection or use of founders from populations that have already undergone natural selection.
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Affiliation(s)
- Sara C Bell
- College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland, 4811, Australia
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Geoffrey W Heard
- Institute of Land, Water and Society, Charles Sturt University, Albury, New South Wales, 2640, Australia
- Victorian Department of Environment, Land, Water and Planning, Arthur Rylah Institute for Environmental Research, Heidelberg, Victoria, 3084, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Werribee, Victoria, 3030, Australia
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Jiménez RR, Alvarado G, Sandoval J, Sommer S. Habitat disturbance influences the skin microbiome of a rediscovered neotropical-montane frog. BMC Microbiol 2020; 20:292. [PMID: 32962670 PMCID: PMC7509932 DOI: 10.1186/s12866-020-01979-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 09/15/2020] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The skin microbiome serves as a first line defense against pathogens in vertebrates. In amphibians, it has the potential to protect against the chytrid fungus Batrachochytrium dendrobatis (Bd), a likely agent of amphibian declines. Alteration of the microbiome associated with unfavorable environmental changes produced by anthropogenic activities may make the host more susceptible to pathogens. Some amphibian species that were thought to be "extinct" have been rediscovered years after population declines in the late 1980s probably due to evolved Bd-resistance and are now threatened by anthropogenic land-use changes. Understanding the effects of habitat disturbance on the host skin microbiome is relevant for understanding the health of these species, along with its susceptibility to pathogens such as Bd. Here, we investigate the influence of habitat alteration on the skin bacterial communities as well as specifically the putative Bd-inhibitory bacterial communities of the montane frog Lithobates vibicarius. This species, after years of not being observed, was rediscovered in small populations inhabiting undisturbed and disturbed landscapes, and with continuous presence of Bd. RESULTS We found that cutaneous bacterial communities of tadpoles and adults differed between undisturbed and disturbed habitats. The adults from disturbed habitats exhibited greater community dispersion than those from undisturbed habitats. We observed a higher richness of putative Bd-inhibitory bacterial strains in adults from disturbed habitats than in those from undisturbed habitats, as well as a greater number of these potential protective bacteria with a high relative abundance. CONCLUSIONS Our findings support the microbial "Anna Karenina principle", in which disturbance is hypothesized to cause greater microbial dispersion in communities, a so-called dysbiosis, which is a response of animal microbiomes to stress factors that decrease the ability of the host or its microbiome to regulate community composition. On the positive side, the high richness and relative abundance of putative Bd-inhibitory bacteria may indicate the development of a defense mechanism that enhances Bd-protection, attributed to a co-occurrence of more than 30-years of host and pathogen in these disturbed habitats. Our results provide important insight into the influence of human-modified landscapes on the skin microbiome and health implications of Bd-survivor species.
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Affiliation(s)
- Randall R Jiménez
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein Allee 11, 89069, Ulm, Germany.
| | - Gilbert Alvarado
- Laboratory of Comparative Wildlife Pathology, School of Veterinary Medicine and Animal Sciences, University of São Paulo, Av. Orlando Marques de Paiva 87, São Paulo, Brazil
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - José Sandoval
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Albert-Einstein Allee 11, 89069, Ulm, Germany
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Kruger A. Functional Redundancy of Batrachochytrium dendrobatidis Inhibition in Bacterial Communities Isolated from Lithobates clamitans Skin. MICROBIAL ECOLOGY 2020; 79:231-240. [PMID: 31165187 DOI: 10.1007/s00248-019-01387-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
The cutaneous microbial community can influence the health of amphibians exposed to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that has contributed to recent amphibian declines. Resistance to Bd in amphibian populations is correlated with the presence of anti-Bd cutaneous microbes, which confer disease resistance by inhibiting Bd growth. I aimed to determine if green frogs (Lithobates clamitans), an abundant and widely distributed species in New Jersey, harbored bacteria that inhibit Bd and whether the presence and identity of these microbes varied among sites. I used in vitro challenge assays to determine if bacteria isolated from green frog skin could inhibit or enhance the growth of Bd. I found that green frogs at all sites harbored anti-Bd bacteria. However, there were differences in Bd inhibition capabilities among bacterial isolates identified as the same operational taxonomic unit (OTU), lending support to the idea that phylogenetic relatedness does not always predict Bd inhibition status. Additionally, anti-Bd bacterial richness did not vary by site, but the composition of anti-Bd bacterial taxa was distinct at each site. This suggests that there is functional redundancy of Bd inhibition across unique communities of anti-Bd symbionts found on frogs at different sites. These findings highlight the need to better elucidate the structure-function relationship of microbiomes and their role in disease resistance.
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Affiliation(s)
- Ariel Kruger
- Graduate Program in Ecology and Evolution, Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA.
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Woodhams DC, Rollins-Smith LA, Reinert LK, Lam BA, Harris RN, Briggs CJ, Vredenburg VT, Patel BT, Caprioli RM, Chaurand P, Hunziker P, Bigler L. Probiotics Modulate a Novel Amphibian Skin Defense Peptide That Is Antifungal and Facilitates Growth of Antifungal Bacteria. MICROBIAL ECOLOGY 2020; 79:192-202. [PMID: 31093727 DOI: 10.1007/s00248-019-01385-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/25/2019] [Indexed: 06/09/2023]
Abstract
Probiotics can ameliorate diseases of humans and wildlife, but the mechanisms remain unclear. Host responses to interventions that change their microbiota are largely uncharacterized. We applied a consortium of four natural antifungal bacteria to the skin of endangered Sierra Nevada yellow-legged frogs, Rana sierrae, before experimental exposure to the pathogenic fungus Batrachochytrium dendrobatidis (Bd). The probiotic microbes did not persist, nor did they protect hosts, and skin peptide sampling indicated immune modulation. We characterized a novel skin defense peptide brevinin-1Ma (FLPILAGLAANLVPKLICSITKKC) that was downregulated by the probiotic treatment. Brevinin-1Ma was tested against a range of amphibian skin cultures and found to inhibit growth of fungal pathogens Bd and B. salamandrivorans, but enhanced the growth of probiotic bacteria including Janthinobacterium lividum, Chryseobacterium ureilyticum, Serratia grimesii, and Pseudomonas sp. While commonly thought of as antimicrobial peptides, here brevinin-1Ma showed promicrobial function, facilitating microbial growth. Thus, skin exposure to probiotic bacterial cultures induced a shift in skin defense peptide profiles that appeared to act as an immune response functioning to regulate the microbiome. In addition to direct microbial antagonism, probiotic-host interactions may be a critical mechanism affecting disease resistance.
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Affiliation(s)
- Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA.
| | - Louise A Rollins-Smith
- Departments of Pathology, Microbiology and Immunology and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
- Department of Biological Science, Vanderbilt University School of Medicine, Nashville, TN, 37235, USA
| | - Laura K Reinert
- Departments of Pathology, Microbiology and Immunology and Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Briana A Lam
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Reid N Harris
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Cheryl J Briggs
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106-9610, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, 94132-1722, USA
| | - Bhumi T Patel
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Richard M Caprioli
- Mass Spectrometry Research Center and Department of Biochemistry, Vanderbilt University, Nashville, TN, 37232-8575, USA
| | - Pierre Chaurand
- Department of Chemistry, Université de Montréal, Montreal, QC, H3T 1J4, Canada
| | - Peter Hunziker
- Functional Genomics Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Laurent Bigler
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
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15
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Host thermoregulatory constraints predict growth of an amphibian chytrid pathogen (Batrachochytrium dendrobatidis). J Therm Biol 2020; 87:102472. [DOI: 10.1016/j.jtherbio.2019.102472] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 11/11/2019] [Accepted: 11/24/2019] [Indexed: 01/10/2023]
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Jiménez RR, Alvarado G, Estrella J, Sommer S. Moving Beyond the Host: Unraveling the Skin Microbiome of Endangered Costa Rican Amphibians. Front Microbiol 2019; 10:2060. [PMID: 31572313 PMCID: PMC6751270 DOI: 10.3389/fmicb.2019.02060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/21/2019] [Indexed: 01/12/2023] Open
Abstract
Some neotropical amphibians, including a few species in Costa Rica, were presumed to be "extinct" after dramatic population declines in the late 1980s but have been rediscovered in isolated populations. Such populations seem to have evolved a resistance/tolerance to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes a deadly skin disease and is considered one of the main drivers of worldwide amphibian declines. The skin microbiome is an important component of the host's innate immune system and is associated with Bd-resistance. However, the way that the bacterial diversity of the skin microbiome confers protection against Bd in surviving species remains unclear. We studied variation in the skin microbiome and the prevalence of putatively anti-Bd bacterial taxa in four co-habiting species in the highlands of the Juan Castro Blanco National Park in Costa Rica using 16S rRNA amplicon sequencing. Lithobates vibicarius, Craugastor escoces, and Isthmohyla rivularis have recently been rediscovered, whereas Isthmohyla pseudopuma has suffered population fluctuations but has never disappeared. To investigate the life stage at which the protective skin microbiome is shaped and when shifts occur in the diversity of putatively anti-Bd bacteria, we studied the skin microbiome of tadpoles, juveniles and adults of L. vibicarius. We show that the skin bacterial composition of sympatric species and hosts with distinct Bd-infection statuses differs at the phyla, family, and genus level. We detected 94 amplicon sequence variants (ASVs) with putative anti-Bd activity pertaining to distinct bacterial taxa, e.g., Pseudomonas spp., Acinetobacter johnsonii, and Stenotrophomonas maltophilia. Bd-uninfected L. vibicarius harbored 79% more putatively anti-Bd ASVs than Bd-infected individuals. Although microbiome composition and structure differed across life stages, the diversity of putative anti-Bd bacteria was similar between pre- and post-metamorphic stages of L. vibicarius. Despite low sample size, our results support the idea that the skin microbiome is dynamic and protects against ongoing Bd presence in endangered species persisting after their presumed extinction. Our study serves as a baseline to understand the microbial patterns in species of high conservation value. Identification of microbial signatures linked to variation in disease susceptibility might, therefore, inform mitigation strategies for combating the global decline of amphibians.
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Affiliation(s)
- Randall R. Jiménez
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Gilbert Alvarado
- Laboratory of Comparative Wildlife Pathology, School of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Josimar Estrella
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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