1
|
Pan Q, Lv T, Xu H, Fang H, Li M, Zhu J, Wang Y, Fan X, Xu P, Wang X, Wang Q, Matsumoto H, Wang M. Gut pathobiome mediates behavioral and developmental disorders in biotoxin-exposed amphibians. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 21:100415. [PMID: 38577706 PMCID: PMC10992726 DOI: 10.1016/j.ese.2024.100415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 03/15/2024] [Accepted: 03/16/2024] [Indexed: 04/06/2024]
Abstract
Emerging evidence suggests a link between alterations in the gut microbiome and adverse health outcomes in the hosts exposed to environmental pollutants. Yet, the causal relationships and underlying mechanisms remain largely undefined. Here we show that exposure to biotoxins can affect gut pathobiome assembly in amphibians, which in turn triggers the toxicity of exogenous pollutants. We used Xenopus laevis as a model in this study. Tadpoles exposed to tropolone demonstrated notable developmental impairments and increased locomotor activity, with a reduction in total length by 4.37%-22.48% and an increase in swimming speed by 49.96%-84.83%. Fusobacterium and Cetobacterium are predominant taxa in the gut pathobiome of tropolone-exposed tadpoles. The tropolone-induced developmental and behavioral disorders in the host were mediated by assembly of the gut pathobiome, leading to transcriptome reprogramming. This study not only advances our understanding of the intricate interactions between environmental pollutants, the gut pathobiome, and host health but also emphasizes the potential of the gut pathobiome in mediating the toxicological effects of environmental contaminants.
Collapse
Affiliation(s)
- Qianqian Pan
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Tianxing Lv
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Haorong Xu
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Hongda Fang
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Meng Li
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Jiaping Zhu
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Yue Wang
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Xiaoyan Fan
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Ping Xu
- Institution of Tea Science, Zhejiang University, Hangzhou, 310058, China
| | - Xiuguo Wang
- The Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Qiangwei Wang
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Haruna Matsumoto
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
| | - Mengcen Wang
- Ministry of Agricultural and Rural Affairs Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou, 310058, China
- Institute of Pesticide and Environmental Toxicology, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310058, China
- Global Education Program for AgriScience Frontiers, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| |
Collapse
|
2
|
Rowley JJL, Symons A, Doyle C, Hall J, Rose K, Stapp L, Lettoof DC. Broad-scale pesticide screening finds anticoagulant rodenticide and legacy pesticides in Australian frogs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172526. [PMID: 38636866 DOI: 10.1016/j.scitotenv.2024.172526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 03/20/2024] [Accepted: 04/14/2024] [Indexed: 04/20/2024]
Abstract
Pesticide contamination poses a significant threat to non-target wildlife, including amphibians, many of which are already highly threatened. This study assessed the extent of pesticide exposure in dead frogs collected during a mass mortality event across eastern New South Wales, Australia between July 2021 and March 2022. Liver tissue from 77 individual frogs of six species were analysed for >600 legacy and contemporary pesticides, including rodenticides. More than a third (36 %) of the liver samples contained at least one of the following pesticides: brodifacoum, dieldrin, DDE, heptachlor/heptachlor epoxide, fipronil sulfone, and 2-methyl-4-chlorophenoxyacetic acid (MCPA). Brodifacoum, a second-generation anticoagulant rodenticide, was found in four of the six frog species analysed: the eastern banjo frog (Limnodynastes dumerilii), cane toad (Rhinella marina), green tree frog (Litoria caerulea) and Peron's tree frog (Litoria peronii). This is the first report of anticoagulant rodenticide detected in wild amphibians, raising concerns about potential impacts on frogs and extending the list of taxa shown to accumulate rodenticides. Dieldrin, a banned legacy pesticide, was also detected in two species: striped marsh frog (Limnodynastes peronii) and green tree frog (Litoria caerulea). The toxicological effects of these pesticides on frogs are difficult to infer due to limited comparable studies; however, due to the low frequency of detection the presence of these pesticides was not considered a major contributing factor to the mass mortality event. Additional research is needed to investigate the effects of pesticide exposure on amphibians, particularly regarding the impacts of second-generation anticoagulant rodenticides. There is also need for continued monitoring and improved conservation management strategies for the mitigation of the potential threat of pesticide exposure and accumulation in amphibian populations.
Collapse
Affiliation(s)
- Jodi J L Rowley
- Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, New South Wales 2010, Australia; Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences (BEES), University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrew Symons
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Christopher Doyle
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Jane Hall
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW 2088, Australia
| | - Karrie Rose
- Australian Registry of Wildlife Health, Taronga Conservation Society Australia, Bradley's Head Road, Mosman, NSW 2088, Australia
| | - Laura Stapp
- New South Wales Department of Climate Change, Energy, the Environment and Water, Environment Protection Science Branch, 480 Weeroona Road, Lidcombe, New South Wales 2141, Australia
| | - Damian C Lettoof
- Environment, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Centre for Environment and Life Sciences, Floreat, Western Australia 6014, Australia; School of Molecular and Life Sciences, Curtin University, Brand Drive, Bentley, Western Australia 6102, Australia
| |
Collapse
|
3
|
Chew A, West M, Berger L, Brannelly LA. The impacts of water quality on the amphibian chytrid fungal pathogen: A systematic review. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13274. [PMID: 38775382 PMCID: PMC11110485 DOI: 10.1111/1758-2229.13274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 04/06/2024] [Indexed: 05/25/2024]
Abstract
The pathogenic fungus Batrachochytrium dendrobatidis has caused declines of amphibians worldwide. Yet our understanding of how water quality influences fungal pathogenicity is limited. Here, we reviewed experimental studies on the effect of water quality on this pathogen to determine which parameters impacted disease dynamics consistently. The strongest evidence for protective effects is salinity which shows strong antifungal properties in hosts at natural levels. Although many fungicides had detrimental effects on the fungal pathogen in vitro, their impact on the host is variable and they can worsen infection outcomes. However, one fungicide, epoxiconazole, reduced disease effects experimentally and likely in the field. While heavy metals are frequently studied, there is weak evidence that they influence infection outcomes. Nitrogen and phosphorous do not appear to impact pathogen growth or infection in the amphibian host. The effects of other chemicals, like pesticides and disinfectants on infection were mostly unclear with mixed results or lacking an in vivo component. Our study shows that water chemistry does impact disease dynamics, but the effects of specific parameters require more investigation. Improving our understanding of how water chemistry influences disease dynamics will help predict the impact of chytridiomycosis, especially in amphibian populations affected by land use changes.
Collapse
Affiliation(s)
- Adeline Chew
- School of BiosciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Matt West
- School of BiosciencesThe University of MelbourneParkvilleVictoriaAustralia
| | - Lee Berger
- Melbourne Veterinary SchoolThe University of MelbourneWerribeeVictoriaAustralia
| | - Laura A. Brannelly
- Melbourne Veterinary SchoolThe University of MelbourneWerribeeVictoriaAustralia
| |
Collapse
|
4
|
Hardy BM, Muths E, Funk WC, Bailey LL. Quantifying intraspecific variation in host resistance and tolerance to a lethal pathogen. J Anim Ecol 2024. [PMID: 38773788 DOI: 10.1111/1365-2656.14106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 03/14/2024] [Indexed: 05/24/2024]
Abstract
Testing for intraspecific variation for host tolerance or resistance in wild populations is important for informing conservation decisions about captive breeding, translocation, and disease treatment. Here, we test the importance of tolerance and resistance in multiple populations of boreal toads (Anaxyrus boreas boreas) against Batrachochytrium dendrobatidis (Bd), the amphibian fungal pathogen responsible for the greatest host biodiversity loss due to disease. Boreal toads have severely declined in Colorado (CO) due to Bd, but toad populations challenged with Bd in western Wyoming (WY) appear to be less affected. We used a common garden infection experiment to expose post-metamorphic toads sourced from four populations (2 in CO and 2 in WY) to Bd and monitored changes in mass, pathogen burden and survival for 8 weeks. We used a multi-state modelling approach to estimate weekly survival and transition probabilities between infected and cleared states, reflecting a dynamic infection process that traditional approaches fail to capture. We found that WY boreal toads are more tolerant to Bd infection with higher survival probabilities than those in CO when infected with identical pathogen burdens. WY toads also appeared more resistant to Bd with a higher probability of infection clearance and an average of 5 days longer to reach peak infection burdens. Our results demonstrate strong intraspecific differences in tolerance and resistance that likely contribute to why population declines vary regionally across this species. Our multi-state framework allowed us to gain inference on typically hidden disease processes when testing for host tolerance or resistance. Our findings demonstrate that describing an entire host species as 'tolerant' or 'resistant' (or lack thereof) is unwise without testing for intraspecific variation.
Collapse
Affiliation(s)
- Bennett M Hardy
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, USA
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Erin Muths
- United States Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, USA
| | - W Chris Funk
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Larissa L Bailey
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
5
|
Böning P, Lötters S, Barzaghi B, Bock M, Bok B, Bonato L, Ficetola GF, Glaser F, Griese J, Grabher M, Leroux C, Munimanda G, Manenti R, Ludwig G, Preininger D, Rödel MO, Seibold S, Smith S, Tiemann L, Thein J, Veith M, Plewnia A. Alpine salamanders at risk? The current status of an emerging fungal pathogen. PLoS One 2024; 19:e0298591. [PMID: 38758948 PMCID: PMC11101120 DOI: 10.1371/journal.pone.0298591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 01/28/2024] [Indexed: 05/19/2024] Open
Abstract
Amphibians globally suffer from emerging infectious diseases like chytridiomycosis caused by the continuously spreading chytrid fungi. One is Batrachochytrium salamandrivorans (Bsal) and its disease ‒ the 'salamander plague' ‒ which is lethal to several caudate taxa. Recently introduced into Western Europe, long distance dispersal of Bsal, likely through human mediation, has been reported. Herein we study if Alpine salamanders (Salamandra atra and S. lanzai) are yet affected by the salamander plague in the wild. Members of the genus Salamandra are highly susceptible to Bsal leading to the lethal disease. Moreover, ecological modelling has shown that the Alps and Dinarides, where Alpine salamanders occur, are generally suitable for Bsal. We analysed skin swabs of 818 individuals of Alpine salamanders and syntopic amphibians at 40 sites between 2017 to 2022. Further, we compiled those with published data from 319 individuals from 13 sites concluding that Bsal infections were not detected. Our results suggest that the salamander plague so far is absent from the geographic ranges of Alpine salamanders. That means that there is still a chance to timely implement surveillance strategies. Among others, we recommend prevention measures, citizen science approaches, and ex situ conservation breeding of endemic salamandrid lineages.
Collapse
Affiliation(s)
- Philipp Böning
- Department of Biogeography, Trier University, Trier, Germany
| | - Stefan Lötters
- Department of Biogeography, Trier University, Trier, Germany
| | - Benedetta Barzaghi
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | - Marvin Bock
- Department of Biogeography, Trier University, Trier, Germany
| | - Bobby Bok
- St. Michael College, Zaandam, Netherlands
| | - Lucio Bonato
- Department of Biology, University of Padova, Padova, Italy
- National Biodiversity Future Center, Palermo, Italy
| | | | | | | | | | - Camille Leroux
- Centre d’Ecologie et des Sciences de la Conservation (CESCO), Muséum National d’Histoire Naturelle, Centre National de la Recherche Scientifique, Sorbonne Université, Paris, France
- Auddicé Biodiversité–ZAC du Chevalement, Roost-Warendin, France
- Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Gopikrishna Munimanda
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Raoul Manenti
- Department of Environmental Science and Policy, University of Milan, Milan, Italy
| | | | | | - Mark-Oliver Rödel
- Museum für Naturkunde–Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany
| | - Sebastian Seibold
- Forest Zoology, Technische Universität Dresden, Tharandt, Germany
- Berchtesgaden National Park, Berchtesgaden, Germany
- Ecosystem Dynamics and Forest Management, Technical University of Munich, Freising, Germany
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Laura Tiemann
- Department of Neurology, TUM School of Medicine, Technical University of Munich, Munich, Germany
| | - Jürgen Thein
- Büro für Faunistik und Umweltbildung, Haßfurt, Germany
| | - Michael Veith
- Department of Biogeography, Trier University, Trier, Germany
| | - Amadeus Plewnia
- Department of Biogeography, Trier University, Trier, Germany
| |
Collapse
|
6
|
Sauer EL, Venesky MD, McMahon TA, Cohen JM, Bessler S, Brannelly LA, Brem F, Byrne AQ, Halstead N, Hyman O, Johnson PTJ, Richards-Zawacki CL, Rumschlag SL, Sears B, Rohr JR. Are novel or locally adapted pathogens more devastating and why? Resolving opposing hypotheses. Ecol Lett 2024; 27:e14431. [PMID: 38712705 DOI: 10.1111/ele.14431] [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: 06/13/2023] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 05/08/2024]
Abstract
There is a rich literature highlighting that pathogens are generally better adapted to infect local than novel hosts, and a separate seemingly contradictory literature indicating that novel pathogens pose the greatest threat to biodiversity and public health. Here, using Batrachochytrium dendrobatidis, the fungus associated with worldwide amphibian declines, we test the hypothesis that there is enough variance in "novel" (quantified by geographic and phylogenetic distance) host-pathogen outcomes to pose substantial risk of pathogen introductions despite local adaptation being common. Our continental-scale common garden experiment and global-scale meta-analysis demonstrate that local amphibian-fungal interactions result in higher pathogen prevalence, pathogen growth, and host mortality, but novel interactions led to variable consequences with especially virulent host-pathogen combinations still occurring. Thus, while most pathogen introductions are benign, enough variance exists in novel host-pathogen outcomes that moving organisms around the planet greatly increases the chance of pathogen introductions causing profound harm.
Collapse
Affiliation(s)
- Erin L Sauer
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Matthew D Venesky
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Department of Biology, Allegheny College, Meadville, Pennsylvania, USA
| | - Taegan A McMahon
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Biology Department, Connecticut College, New London, Connecticut, USA
| | - Jeremy M Cohen
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, USA
| | - Scott Bessler
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Laura A Brannelly
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, USA
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Forrest Brem
- Biology Department, University of Memphis, Memphis, Tennessee, USA
| | - Allison Q Byrne
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA
| | - Neal Halstead
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Wildlands Conservation, Tampa, Florida, USA
| | - Oliver Hyman
- Biology Department, James Madison University, Harrisonburg, Virginia, USA
| | - Pieter T J Johnson
- Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado, USA
| | - Corinne L Richards-Zawacki
- Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana, USA
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Samantha L Rumschlag
- Department of Biology, Miami University, Oxford, Ohio, USA
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Computational Toxicology and Exposure, Great Lakes Toxicology and Ecology Division, Duluth, Minnesota, USA
| | - Brittany Sears
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Jason R Rohr
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
- Department of Biological Sciences, University of Notre Dame, South Bend, Indiana, USA
| |
Collapse
|
7
|
Wacker T, Helmstetter N, Studholme DJ, Farrer RA. Genome variation in the Batrachochytrium pathogens of amphibians. PLoS Pathog 2024; 20:e1012218. [PMID: 38781266 PMCID: PMC11115238 DOI: 10.1371/journal.ppat.1012218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024] Open
Affiliation(s)
- Theresa Wacker
- Biosciences, University of Exeter, Exeter, United Kingdom
| | - Nicolas Helmstetter
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| | | | - Rhys A. Farrer
- Medical Research Council Centre for Medical Mycology at the University of Exeter, Exeter, United Kingdom
| |
Collapse
|
8
|
Wilber MQ, DeMarchi JA, Briggs CJ, Streipert S. Rapid Evolution of Resistance and Tolerance Leads to Variable Host Recoveries following Disease-Induced Declines. Am Nat 2024; 203:535-550. [PMID: 38635360 DOI: 10.1086/729437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
AbstractRecoveries of populations that have suffered severe disease-induced declines are being observed across disparate taxa. Yet we lack theoretical understanding of the drivers and dynamics of recovery in host populations and communities impacted by infectious disease. Motivated by disease-induced declines and nascent recoveries in amphibians, we developed a model to ask the following question: How does the rapid evolution of different host defense strategies affect the transient recovery trajectories of hosts following pathogen invasion and disease-induced declines? We found that while host life history is predictably a major driver of variability in population recovery trajectories (including declines and recoveries), populations that use different host defense strategies (i.e., tolerance, avoidance resistance, and intensity-reduction resistance) experience notably different recoveries. In single-species host populations, populations evolving tolerance recovered on average four times slower than populations evolving resistance. Moreover, while populations using avoidance resistance strategies had the fastest potential recovery rates, these populations could get trapped in long transient states at low abundance prior to recovery. In contrast, the recovery of populations evolving intensity-reduction resistance strategies were more consistent across ecological contexts. Overall, host defense strategies strongly affect the transient dynamics of population recovery and may affect the ultimate fate of real populations recovering from disease-induced declines.
Collapse
|
9
|
Garcia Neto PG, Titon SCM, Muxel SM, Titon B, Figueiredo ACD, Floreste FR, Lima AS, Assis VR, Gomes FR. Immune and endocrine alterations at the early stage of inflammatory assemblage in toads after stimulation with heat-killed bacteria (Aeromonas hydrophila). Comp Biochem Physiol A Mol Integr Physiol 2024; 291:111606. [PMID: 38354902 DOI: 10.1016/j.cbpa.2024.111606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/07/2024] [Accepted: 02/10/2024] [Indexed: 02/16/2024]
Abstract
The red-leg syndrome in amphibians is a condition commonly associated with the bacteria Aeromonas hydrophila and has led to population declines. However, there is little information concerning the inflammatory assemblage in infected anurans. We evaluated immune and endocrine alterations induced by stimulation with heat-killed A. hydrophila injected in Rhinella diptycha toads. Control animals were not manipulated, while the others were separated into groups that received intraperitoneal injection of 300 μl of saline or heat-killed bacteria: groups A1 (3 × 107 cells), A2 (3 × 108 cells), and A3 (3 × 109 cells). Animals were bled and euthanized six hours post-injection. We evaluated neutrophil: lymphocyte ratio (NLR), plasma bacterial killing ability (BKA), testosterone (T), melatonin (MEL), and corticosterone (CORT) plasma levels. Heat-killed A. hydrophila increased CORT and NLR, and decreased MEL, especially at higher concentrations. There was no effect of treatment on T and BKA. We then selected the saline and A3 groups to conduct mRNA expression of several genes including glucocorticoid receptor (GR), toll-like receptor-4 (TLR-4), interferon-γ (IFN-γ), interleukin (IL)-1β, IL-6, and IL-10. We found higher expression of IL-6, IL-1β, IL-10, and IFN-γ in group A3 compared to the saline group. These results indicate the beginning of an inflammatory assemblage, notably at the two highest concentrations of bacteria, and give a better understanding of how anurans respond to an infection within an integrated perspective, evaluating different physiological aspects. Future studies should investigate later phases of the immune response to elucidate more about the inflammation in amphibians challenged with A. hydrophila.
Collapse
Affiliation(s)
- Patrício G Garcia Neto
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil.
| | - Stefanny C M Titon
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil
| | - Sandra M Muxel
- Laboratório de Neuroimunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes n° 1730, Cidade Universitária, São Paulo, SP CEP 05508-000, Brazil.
| | - Braz Titon
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil
| | - Aymam C de Figueiredo
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil
| | - Felipe R Floreste
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil
| | - Alan S Lima
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil
| | - Vania R Assis
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil; Global Health and Interdisciplinary Disease Research Center and Center for Genomics, College of Public Health, Interdisciplinary Research Building (IDRB), 3720 Spectrum Boulevard. Tampa, FL 33612-9415, United States. https://twitter.com/VaniaRAssis1
| | - Fernando R Gomes
- Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão - Travessa 14 - n° 101, Cidade Universitária, São Paulo, SP CEP 05508-900, Brazil.
| |
Collapse
|
10
|
Mu Y, Zhang J, Yang J, Wu J, Zhang Y, Yu H, Zhang X. Enhancing amphibian biomonitoring through eDNA metabarcoding. Mol Ecol Resour 2024; 24:e13931. [PMID: 38345249 DOI: 10.1111/1755-0998.13931] [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: 05/08/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 02/17/2024]
Abstract
Surveying biodiversity has taken a quantum leap with environmental DNA (eDNA) metabarcoding, an immensely powerful approach lauded for its efficiency, sensitivity, and non-invasiveness. This approach emerges as a game-changer for the elusive realm of endangered and rare species-think nocturnal, environmentally elusive amphibians. Here, we have established a framework for constructing a reliable metabarcoding pipeline for amphibians, covering primer design, performance evaluation, laboratory validation, and field validation processes. The Am250 primer, located on the mitochondrial 16S gene, was optimal for the eDNA monitoring of amphibians, which demonstrated higher taxonomic resolution, smaller species amplification bias, and more extraordinary detection ability compared to the other primers tested. Am250 primer exhibit an 83.8% species amplification rate and 75.4% accurate species identification rate for Chinese amphibians in the in silico PCR and successfully amplified all tested species of the standard samples in the in vitro assay. Furthermore, the field-based mesocosm experiment showed that DNA can still be detected by metabarcoding even days to weeks after organisms have been removed from the mesocosm. Moreover, field mesocosm findings indicate that eDNA metabarcoding primers exhibit different read abundances, which can affect the relative biomass of species. Thus, appropriate primers should be screened and evaluated by three experimental approaches: in silico PCR simulation, target DNA amplification, and mesocosm eDNA validation. The selection of a single primer set or multiple primers' combination should be based on the monitoring groups to improve the species detection rate and the credibility of results.
Collapse
Affiliation(s)
- Yawen Mu
- State Key Laboratory of Pollution Control & Resource, School of the Environment, Nanjing University, Nanjing, China
- Jiangsu Provincial Environmental Monitoring Center, Nanjing, China
| | - Jingwen Zhang
- State Key Laboratory of Pollution Control & Resource, School of the Environment, Nanjing University, Nanjing, China
| | - Jianghua Yang
- State Key Laboratory of Pollution Control & Resource, School of the Environment, Nanjing University, Nanjing, China
- School of Marine Science and Engineering, Nanjing Normal University, Nanjing, China
| | - Jun Wu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of China, Nanjing, China
| | - Yong Zhang
- Jiangsu Provincial Environmental Monitoring Center, Nanjing, China
| | - Hongxia Yu
- State Key Laboratory of Pollution Control & Resource, School of the Environment, Nanjing University, Nanjing, China
| | - Xiaowei Zhang
- State Key Laboratory of Pollution Control & Resource, School of the Environment, Nanjing University, Nanjing, China
| |
Collapse
|
11
|
McGrath-Blaser SE, McGathey N, Pardon A, Hartmann AM, Longo AV. Invasibility of a North American soil ecosystem to amphibian-killing fungal pathogens. Proc Biol Sci 2024; 291:20232658. [PMID: 38628130 PMCID: PMC11021929 DOI: 10.1098/rspb.2023.2658] [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: 12/07/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
North American salamanders are threatened by intercontinental spread of chytridiomycosis, a deadly disease caused by the fungal pathogen Batrachochytrium salamandrivorans (Bsal). To predict potential dispersal of Bsal spores to salamander habitats, we evaluated the capacity of soil microbial communities to resist invasion. We determined the degree of habitat invasibility using soils from five locations throughout the Great Smoky Mountains National Park, a region with a high abundance of susceptible hosts. Our experimental design consisted of replicate soil microcosms exposed to different propagule pressures of the non-native pathogen, Bsal, and an introduced but endemic pathogen, B. dendrobatidis (Bd). To compare growth and competitive interactions, we used quantitative PCR, live/dead cell viability assays, and full-length 16S rRNA sequencing. We found that soil microcosms with intact bacterial communities inhibited both Bsal and Bd growth, but inhibitory capacity diminished with increased propagule pressure. Bsal showed greater persistence than Bd. Linear discriminant analysis (LDA) identified the family Burkolderiaceae as increasing in relative abundance with the decline of both pathogens. Although our findings provide evidence of environmental filtering in soils, such barriers weakened in response to pathogen type and propagule pressure, showing that habitats vary their invasibility based on properties of their local microbial communities.
Collapse
Affiliation(s)
| | - Natalie McGathey
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Allison Pardon
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Arik M. Hartmann
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Ana V. Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
12
|
Chaganti T, Tsai CY, Juang YP, Abdelalim M, Cernak T. Medicinal Chemistry Gone Wild. J Med Chem 2024. [PMID: 38662285 DOI: 10.1021/acs.jmedchem.3c02334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Earth is currently experiencing a mass extinction event. The flora and fauna of our planet are experiencing mass die-offs from a multitude of factors, with wildlife disease emerging as one parameter where medicinal chemists are equipped to intervene. While contemporary medicinal chemistry focuses on human health, many traditional pharmaceutical companies have historic roots in human health, animal health, and plant health. This trifecta of health sciences perfectly maps to the current field of One Health, which recognizes that optimal health outcomes can only be achieved through the health of humans, plants, animals, and their shared environments. This Perspective imagines a world where state-of-the-art medicinal chemistry tactics are used to prevent the extinction of endangered species and points to preliminary work in the emerging area of conservation medicine.
Collapse
Affiliation(s)
- Tesko Chaganti
- Canton High School, Canton, Michigan 48187, United States
| | - Chun-Yi Tsai
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yu-Pu Juang
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Mohamed Abdelalim
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Tim Cernak
- Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
13
|
Humphries JE, Lanctôt CM, McCallum HI, Newell DA, Grogan LF. Chytridiomycosis causes high amphibian mortality prior to the completion of metamorphosis. ENVIRONMENTAL RESEARCH 2024; 247:118249. [PMID: 38244972 DOI: 10.1016/j.envres.2024.118249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/09/2024] [Accepted: 01/17/2024] [Indexed: 01/22/2024]
Abstract
Amphibian populations are undergoing extensive declines globally. The fungal disease chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), is a primary contributor to these declines. The amphibian metamorphic stages (Gosner stages 42-46) are particularly vulnerable to a range of stressors, including Bd. Despite this, studies that explicitly examine host response to chytridiomycosis throughout the metamorphic stages are lacking. We aimed to determine how Bd exposure during the larval stages impacts metamorphic development and infection progression in the endangered Fleay's barred frog (Mixophyes fleayi). We exposed M. fleayi to Bd during pro-metamorphosis (Gosner stages 35-38) and monitored infection dynamics throughout metamorphosis. We took weekly morphological measurements (weight, total body length, snout-vent-length and Gosner stage) and quantified Bd load using qPCR. While we observed minimal impact of Bd infection on animal growth and development, Bd load varied throughout ontogeny, with an infection load plateau during the tadpole stages (Gosner stages 35-41) and temporary infection clearance at Gosner stage 42. Bd load increased exponentially between Gosner stages 42 and 45, with most exposed animals becoming moribund at Gosner stage 45, prior to the completion of metamorphosis. There was variability in infection outcome of exposed individuals, with a subgroup of animals (n = 5/29) apparently clearing their infection while the majority (n = 21/29) became moribund with high infection burdens. This study demonstrates the role that metamorphic restructuring plays in shaping Bd infection dynamics and raises the concern that substantial Bd-associated mortality could be overlooked in the field due to the often cryptic nature of these latter metamorphic stages. We recommend future studies that directly examine the host immune response to Bd infection throughout metamorphosis, incorporating histological and molecular methods to elucidate the mechanisms responsible for the observed trends.
Collapse
Affiliation(s)
- Josephine E Humphries
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland 4222, Australia.
| | - Chantal M Lanctôt
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia; Australian Rivers Institute, Griffith University, Southport, Queensland 4222, Australia
| | - Hamish I McCallum
- Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland 4222, Australia
| | - David A Newell
- Faculty of Science and Engineering, Southern Cross University, Lismore, New South Wales 2480, Australia
| | - Laura F Grogan
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia; Centre for Planetary Health and Food Security, Griffith University, Southport, Queensland 4222, Australia
| |
Collapse
|
14
|
Rahman MM, Kim ES, Sung HC. Microplastics as an emerging threat to amphibians: Current status and future perspectives. Heliyon 2024; 10:e28220. [PMID: 38560268 PMCID: PMC10979166 DOI: 10.1016/j.heliyon.2024.e28220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 02/29/2024] [Accepted: 03/13/2024] [Indexed: 04/04/2024] Open
Abstract
Given their pervasiveness in the environment, particularly in aquatic ecosystems, plastics are posing a growing concern worldwide. Many vertebrates and invertebrates in marine, freshwater, and terrestrial ecosystems exhibit microplastic (MP) uptake and accumulation. Some studies have indicated the fatal impacts of MPs on animals and their possible transfer through food chains. Thus, it is crucial to study MP pollution and its impacts on environment-sensitive and globally threatened animal groups, such as amphibians, which also play an important role in the energy transfer between ecosystems. Unfortunately, research in this field is lacking and sources of organized information are also scarce. Hence, we systematically reviewed published literature on MPs in amphibians to fill the existing knowledge gap. Our review revealed that most of the previous studies have focused on MP bioaccumulation in amphibians, whereas, only a few research highlighted its impacts. We found that more than 80% of the studied species exhibited MP accumulation. MPs were reported to persist in different organs for a long time and get transferred to other trophic levels. They can also exhibit cytotoxic and mutagenic effects and may have fatal impacts. Moreover, they can increase the disease susceptibility of amphibians. Our study concludes the MPs as a potential threat to amphibians and urges increasing the scope and frequency of research on MP pollution and its impacts on this vulnerable animal group. We also provide a generalized method for studying MPs in amphibians with future perspectives and research directions. Our study is significant for extending the knowledge of MPs and their impacts on amphibians and guiding prospective research.
Collapse
Affiliation(s)
- Md Mizanur Rahman
- Department of Biological Sciences, Chonnam National University, 61186, Gwangju, Republic of Korea
| | - Eung-Sam Kim
- Department of Biological Sciences, Chonnam National University, 61186, Gwangju, Republic of Korea
- Research Center of Ecomimetics, Chonnam National University, Gwangju, 61186, Republic of Korea
- Center for Next Generation Sensor Research and Development, Chonnam National University, Gwangju, 61186, Republic of Korea
- Institute of Sustainable Ecological Environment, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Ha-Cheol Sung
- Department of Biological Sciences, Chonnam National University, 61186, Gwangju, Republic of Korea
- Research Center of Ecomimetics, Chonnam National University, Gwangju, 61186, Republic of Korea
- Institute of Sustainable Ecological Environment, Chonnam National University, Gwangju, 61186, Republic of Korea
| |
Collapse
|
15
|
Romero-Contreras YJ, González-Serrano F, Bello-López E, Formey D, Aragón W, Cevallos MÁ, Rebollar EA, Serrano M. Bacteria from the skin of amphibians promote growth of Arabidopsis thaliana and Solanum lycopersicum by modifying hormone-related transcriptome response. PLANT MOLECULAR BIOLOGY 2024; 114:39. [PMID: 38615069 PMCID: PMC11016013 DOI: 10.1007/s11103-024-01444-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/11/2024] [Indexed: 04/15/2024]
Abstract
Plants and microorganisms establish beneficial associations that can improve their development and growth. Recently, it has been demonstrated that bacteria isolated from the skin of amphibians can contribute to plant growth and defense. However, the molecular mechanisms involved in the beneficial effect for the host are still unclear. In this work, we explored whether bacteria isolated from three tropical frogs species can contribute to plant growth. After a wide screening, we identified three bacterial strains with high biostimulant potential, capable of modifying the root structure of Arabidopsis thaliana plants. In addition, applying individual bacterial cultures to Solanum lycopersicum plants induced an increase in their growth. To understand the effect that these microorganisms have over the host plant, we analysed the transcriptomic profile of A. thaliana during the interaction with the C32I bacterium, demonstrating that the presence of the bacteria elicits a transcriptional response associated to plant hormone biosynthesis. Our results show that amphibian skin bacteria can function as biostimulants to improve agricultural crops growth and development by modifying the plant transcriptomic responses.
Collapse
Affiliation(s)
- Yordan J Romero-Contreras
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
- Programa de Doctorado en Ciencias Biomédicas, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
| | | | - Elena Bello-López
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Damien Formey
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Wendy Aragón
- Instituto de Biociencias, Universidad Autónoma de Chiapas, Blvd. Príncipe Akishino s/n, 30798, Tapachula, Chiapas, Mexico
| | - Miguel Ángel Cevallos
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Eria A Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mario Serrano
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
| |
Collapse
|
16
|
Clemons RA, Yacoub MN, Faust E, Toledo LF, Jenkinson TS, Carvalho T, Simmons DR, Kalinka E, Fritz-Laylin LK, James TY, Stajich JE. An endogenous DNA virus in an amphibian-killing fungus associated with pathogen genotype and virulence. Curr Biol 2024; 34:1469-1478.e6. [PMID: 38490202 DOI: 10.1016/j.cub.2024.02.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 12/18/2023] [Accepted: 02/26/2024] [Indexed: 03/17/2024]
Abstract
The global panzootic lineage (GPL) of the pathogenic fungus Batrachochytrium dendrobatidis (Bd) has caused severe amphibian population declines, yet the drivers underlying the high frequency of GPL in regions of amphibian decline are unclear. Using publicly available Bd genome sequences, we identified multiple non-GPL Bd isolates that contain a circular Rep-encoding single-stranded (CRESS)-like DNA virus, which we named Bd DNA virus 1 (BdDV-1). We further sequenced and constructed genome assemblies with long read sequences to find that the virus is integrated into the nuclear genome in some strains. Attempts to cure virus-positive isolates were unsuccessful; however, phenotypic differences between naturally virus-positive and virus-negative Bd isolates suggested that BdDV-1 decreases the growth of its host in vitro but increases the virulence of its host in vivo. BdDV-1 is the first-described CRESS DNA mycovirus of zoosporic true fungi, with a distribution inversely associated with the emergence of the panzootic lineage.
Collapse
Affiliation(s)
- Rebecca A Clemons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Mark N Yacoub
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA 92521, USA
| | - Evelyn Faust
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal Instituto de Biologia (IB), Universidade Estadual de Campinas, Campinas, SP 13083-862, Brazil
| | - Thomas S Jenkinson
- Department of Biological Sciences, California State University, East Bay, Hayward, CA 94592, USA
| | - Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - D Rabern Simmons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Erik Kalinka
- Department of Biology, University of Massachusetts, Amherst, Amherst, MA 01003, USA
| | | | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA 92521, USA.
| |
Collapse
|
17
|
Miller JL, Erickson L, Fork S, Roderick CL, Grear DA, Cole RA. Morbidity in California giant salamander ( Dicamptodon ensatus Eschscholtz, 1833) caused by Euryhelmis sp. Poche, 1926 (Trematoda: Heterophyiidae). Int J Parasitol Parasites Wildl 2024; 23:100908. [PMID: 38405673 PMCID: PMC10885628 DOI: 10.1016/j.ijppaw.2024.100908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/27/2024]
Abstract
In the fall of 2021, California Department of Fish and Wildlife reported larval and adult California giant salamanders (Dicamptodon ensatus Eschscholtz, 1833) with skin lesions at multiple creeks in Santa Clara and Santa Cruz Counties, California, USA. Field signs in both stages included rough, lumpy textured skin, and larvae with tails that were disproportionately long, flat, wavy, and flaccid. Presence of large-bodied larvae suggested delayed metamorphosis, with some larvae having cloudy eyes and suspected blindness. To determine the cause of the disease, three first-of-the-year salamanders from one location were collected, euthanized with 20% benzocaine, and submitted for necropsy to the U.S. Geological Survey, National Wildlife Health Center. Upon gross examination, all salamanders were emaciated with no internal fat stores, and had multiple pinpoint to 1.5-mm diameter raised nodules in the skin over the body, including the head, gills, dorsum, ventrum, all four limbs, and the tail; one also had nodules in the oral cavity and tongue. Histologically all salamanders had multiple encysted metacercariae in the dermis, subcutis, and skeletal muscles of the head, body, and tail that were often associated with granulomatous and granulocytic inflammation and edema. A small number of encysted metacercariae or empty cysts were present in the gills with minimal inflammation, and rarely in the kidney with no associated inflammation. Morphology of live metacercariae (Trematoda: Heterophyiidae), and sequencing of the 28S rRNA gene identified a species of Euryhelmis (Poche, 1926). Artificial digestion of a 1.65 g, decapitated, eviscerated carcass yielded 773 metacercariae, all of similar size and morphology as the live specimens. Based on these findings, the poor body condition of these salamanders was concluded to be due to heavy parasite burden. Environmental factors such as drought, increased temperature, and overcrowded conditions may be exacerbating parasite infections in these populations of salamander.
Collapse
Affiliation(s)
- Jaimie L. Miller
- U.S. Geological Survey National Wildlife Health Center, Madison, WI, USA
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - Lawrence Erickson
- Elkhorn Slough National Estuarine Research Reserve, Watsonville, CA, USA
| | | | | | - Daniel A. Grear
- U.S. Geological Survey National Wildlife Health Center, Madison, WI, USA
| | - Rebecca A. Cole
- U.S. Geological Survey National Wildlife Health Center, Madison, WI, USA
| |
Collapse
|
18
|
Carvalho T, Belasen AM, Toledo LF, James TY. Coevolution of a generalist pathogen with many hosts: the case of the amphibian chytrid Batrachochytrium dendrobatidis. Curr Opin Microbiol 2024; 78:102435. [PMID: 38387210 DOI: 10.1016/j.mib.2024.102435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 12/22/2023] [Accepted: 01/21/2024] [Indexed: 02/24/2024]
Abstract
Generalist pathogens maintain infectivity in numerous hosts; how this broad ecological niche impacts host-pathogen coevolution remains to be widely explored. Batrachochytrium dendrobatidis (Bd) is a highly generalist pathogenic fungus that has caused devastating declines in hundreds of amphibian species worldwide. This review examines amphibian chytridiomycosis host-pathogen interactions and available evidence for coevolution between Bd and its numerous hosts. We summarize recent evidence showing that Bd genotypes vary in geographic distribution and virulence, and that amphibian species also vary in Bd susceptibility according to their geographic distribution. How much variation can be explained by phenotypic plasticity or genetic differences remains uncertain. Recent research suggests that Bd genotypes display preferences for specific hosts and that some hosts are undergoing evolution as populations rebound from Bd outbreaks. Taken together, these findings suggest the potential for coevolution to occur and illuminate a path for addressing open questions through integrating historical and contemporary genetic data.
Collapse
Affiliation(s)
- Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States
| | - Anat M Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, United States
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Unicamp, Campinas, São Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, United States.
| |
Collapse
|
19
|
Riascos-Flores LR, Bonilla J, Naranjo-Briceño L, Apunte-Ramos K, Reyes-Ortega GC, Cabrera M, Cáceres-Andrade JF, Carrera-Gonzalez A, Yánez-Galarza JK, Siavichay Pesántez F, Oyagata-Cachimuel LA, Goethals P, Celi J, Van der Heyden C, Ortega-Andrade HM. Field-based molecular detection of Batrachochytrium dendrobatidis in critically endangered Atelopus toads and aquatic habitats in Ecuador. PLoS One 2024; 19:e0299246. [PMID: 38484016 PMCID: PMC10939218 DOI: 10.1371/journal.pone.0299246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Accepted: 02/06/2024] [Indexed: 03/17/2024] Open
Abstract
Batrachochytrium dendrobatidis (Bd) is a lethal fungal species that parasitizes vertebrates and is associated with the worldwide decline of amphibian populations. The development of sensitive, rapid detection methods, particularly DNA-based techniques, is critical for effective management strategies. This study evaluates the efficacy of DNA extraction and a portable PCR device in a mountable field laboratory setup for detecting Bd near the habitats of three critically endangered Atelopus toad species in Ecuador. We collected skin swabs from Atelopus balios, A. nanay, and A. bomolochos, and environmental DNA (eDNA) samples from streams in Andean and coastal regions of Ecuador. For eDNA, a comparison was made with duplicates of the samples that were processed in the field and in a standard university laboratory. Our findings revealed Bd detection in eDNA and swabs from 6 of 12 water samples and 10 of 12 amphibian swab samples. The eDNA results obtained in the field laboratory were concordant with those obtained under campus laboratory conditions. These findings highlight the potential of field DNA-based monitoring techniques for detecting Bd in amphibian populations and their aquatic habitats, particularly in remote areas. Furthermore, this research aligns with the National Action Plan for the Conservation of Ecuadorian Amphibians and contributes to the global effort to control this invasive and deadly fungus.
Collapse
Affiliation(s)
- Lenin R. Riascos-Flores
- Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Gent University, Gent, Belgium
- Escuela Superior Politécnica del Litoral, ESPOL/Facultad de Ciencias de la Vida, Centro de Investigaciones Biotecnológicas del Ecuador, Campus Gustavo Galindo Guayaquil, Guayaquil, Ecuador
| | - Julio Bonilla
- Escuela Superior Politécnica del Litoral, ESPOL/Facultad de Ciencias de la Vida, Centro de Investigaciones Biotecnológicas del Ecuador, Campus Gustavo Galindo Guayaquil, Guayaquil, Ecuador
| | - Leopoldo Naranjo-Briceño
- Applied Microbiology Research Group, Life Sciences Faculty, Universidad Regional Amazónica IKIAM, Tena, Ecuador
- Fungal Biotech Lab, Spora Biotech, Huechuraba, Santiago, Región Metropolitana, Chile
| | - Katherine Apunte-Ramos
- Molecular Biology and Biochemistry Lab, Universidad Regional Amazónica IKIAM, Tena, Ecuador
| | - Grace C. Reyes-Ortega
- Biogeography and Spatial Ecology Research Group, Life Sciences Faculty, Universidad Regional Amazónica IKIAM, Tena, Ecuador
| | - Marcela Cabrera
- Laboratorio Nacional de Referencia del Agua, Universidad Regional Amazónica Ikiam, Tena, Ecuador
- University of Valencia, Paterna, Spain
| | | | | | - Jomira K. Yánez-Galarza
- Applied Microbiology Research Group, Life Sciences Faculty, Universidad Regional Amazónica IKIAM, Tena, Ecuador
- Biogeography and Spatial Ecology Research Group, Life Sciences Faculty, Universidad Regional Amazónica IKIAM, Tena, Ecuador
| | | | | | - Peter Goethals
- Department of Animal Sciences and Aquatic Ecology, Faculty of Bioscience Engineering, Gent University, Gent, Belgium
| | - Jorge Celi
- Water and Aquatic Resources Research Group, School of Earth and Water Sciences, Universidad Regional Amazónica Ikiam, Tena, Ecuador
| | - Christine Van der Heyden
- Department of Biosciences and Industrial Technology, Health and Water Technology Research Centre, HOGENT—University of Applied Sciences and Arts, Gent, Belgium
| | - H. Mauricio Ortega-Andrade
- Biogeography and Spatial Ecology Research Group, Life Sciences Faculty, Universidad Regional Amazónica IKIAM, Tena, Ecuador
- Herpetology Division, Instituto Nacional de Biodiversidad, Quito, Pichincha, Ecuador
| |
Collapse
|
20
|
Thumsová B, González-Miras E, Rubio Á, Granados I, Bates KA, Bosch J. Chemical disinfection as a simple and reliable method to control the amphibian chytrid fungus at breeding points of endangered amphibians. Sci Rep 2024; 14:5151. [PMID: 38431740 PMCID: PMC10908824 DOI: 10.1038/s41598-024-55946-1] [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: 11/27/2023] [Accepted: 02/29/2024] [Indexed: 03/05/2024] Open
Abstract
Chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is pushing amphibians towards extinction. Whilst mitigation methods were suggested a decade ago, we lack field trials testing their efficacy. We used the agrochemical fungicide, tebuconazole, to treat Bd infected breeding waterbodies of an endangered species that is highly susceptible to the fungus. Just two applications of tebuconazole led to a significant reduction in infection loads in the vast majority of sites, and at six sites the disinfection remained one/two-years post-application. Tebuconazole values drastically decreased in the waterbodies within a week after application, with no significant effects on their hydrochemical and hydrobiological characteristics. Although the use of chemicals in natural populations is undesirable, the growing existential threat to amphibians all over the world indicates that effective interventions in selected populations of endangered species are urgently needed.
Collapse
Affiliation(s)
- Barbora Thumsová
- Asociación Herpetológica Española (AHE), Madrid, Spain
- Museo Nacional de Ciencias Naturales-CSIC, 28006, Madrid, Spain
- IMIB-Research Unit of Biodiversity (University of Oviedo, CSIC, Principality of Asturias), 33600, Mieres, Spain
| | - Emilio González-Miras
- Agencia de Medio Ambiente y Agua de Andalucía, Consejería de Sostenibilidad, Medio Ambiente y Economía Azul, Junta de Andalucía, Seville, Spain
| | - Ángel Rubio
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain
| | - Ignacio Granados
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain
| | - Kieran A Bates
- Centre for Immunobiology, The Blizard Institute, Queen Mary University of London, London, E1 2AT, UK
| | - Jaime Bosch
- IMIB-Research Unit of Biodiversity (University of Oviedo, CSIC, Principality of Asturias), 33600, Mieres, Spain.
- Centro de Investigación, Seguimiento y Evaluación, Parque Nacional Sierra de Guadarrama, 28740, Rascafría, Spain.
| |
Collapse
|
21
|
Fu M. Evolutionary analysis of major histocompatibility complex variants in chytrid-resistant and susceptible amphibians. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2024; 118:105544. [PMID: 38216106 DOI: 10.1016/j.meegid.2023.105544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 10/09/2023] [Accepted: 12/17/2023] [Indexed: 01/14/2024]
Abstract
An amphibian emerging infectious disease (EID), chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), originated in Asia but primarily led to declines and extinctions in amphibian populations outside of Asia. Host major histocompatibility complex (MHC) molecules exhibit high polymorphism, and the evolution of MHC can be influenced by recombination and pathogens. Previous studies have indicated that host MHC class II is associated with Bd resistance. In this study, I conducted recombination and selection tests on functional MHC IIß1 alleles from an Asian Bd-resistant anuran species (Bufo gargarizans) and an Australasian Bd-susceptible species (Litoria caerulea). Recombination at the same site was identified in both species, supporting the hypothesis that recombination contributes to MHC IIß1 diversity in amphibians. Positive selection was observed in MHC IIß1 alleles in both species. In L. caerulea, at least four amino acid sites were identified under significant positive selection in the MHC IIß1, whereas these sites were either negatively selected or conserved in B. gargarizans. This suggests these sites might be selected for Bd resistance. Hydrophobicity was detected in certain amino acid sites relating to Bd resistance, suggesting this physicochemical property may be a factor selected to counteract Bd infection. These findings of this study provide an evolutionary basis for understanding how amphibian MHC IIß1 may undergo selection in response to chytrid infection.
Collapse
Affiliation(s)
- Minjie Fu
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea; Research Institute of Basic Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| |
Collapse
|
22
|
van der Valk T, Dalèn L. From genomic threat assessment to conservation action. Cell 2024; 187:1038-1041. [PMID: 38428386 DOI: 10.1016/j.cell.2024.01.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/25/2024] [Accepted: 01/25/2024] [Indexed: 03/03/2024]
Abstract
Genomic approaches have the potential to play a pivotal role in conservation, both to detect threats to species and populations and to restore biodiversity through actions. We here separate these approaches into two subdisciplines, vulnerability and restoration genomics, and discuss current applications, outstanding questions, and future potential.
Collapse
Affiliation(s)
- Tom van der Valk
- Centre for Palaeogenetics, Stockholm, Sweden; Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden; Science for Life Laboratory, Stockholm, Sweden
| | - Love Dalèn
- Centre for Palaeogenetics, Stockholm, Sweden; Department of Bioinformatics and Genetics, Swedish Museum of Natural History, Stockholm, Sweden; Department of Zoology, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
23
|
Ma Q, Wan L, Shi S, Wang Z. Impact of Climate Change on the Distribution of Three Rare Salamanders ( Liua shihi, Pseudohynobius jinfo, and Tylototriton wenxianensis) in Chongqing, China, and Their Conservation Implications. Animals (Basel) 2024; 14:672. [PMID: 38473057 DOI: 10.3390/ani14050672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/29/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
The Wushan Salamander (Liua shihi), Jinfo Salamander (Pseudohynobius jinfo), and Wenxian Knobby Salamander (Tylototriton wenxianensis) are rare national Class II protected wild animals in China. We performed MaxEnt modeling to predict and analyze the potential distribution and trends of these species in Chongqing under current and future climate conditions. Species distribution data were primarily obtained from field surveys, supplemented by museum collections and the existing literature. These efforts yielded 636 records, including 43 for P. jinfo, 23 for T. wenxianensis, and 570 for L. shihi. Duplicate records within the same 100 m × 100 m grid cell were removed using ENMTools, resulting in 10, 12, and 58 valid distribution points for P. jinfo, T. wenxianensis, and L. shihi, respectively. The optimization of feature class parameters (FC) and the regularization multiplier (RM) were applied using R package "ENMeval 2.0" to establish the optimal model with MaxEnt. The refined models were applied to simulate the suitable distribution areas for the three species. The results indicate that the current suitable habitat area for L. shihi accounted for 9.72% of the whole region of the Chongqing municipality. It is projected that, by 2050, the proportion of suitable habitat will increase to 12.54% but will decrease to 11.98% by 2070 and further decline to 8.80% by 2090. The current suitable habitat area for P. jinfo accounted for 1.08% of the whole region of the Chongqing municipality, which is expected to decrease to 0.31%% by 2050, 0.20% by 2070, and 0.07% by 2090. The current suitable habitat area for T. wenxianensis accounted for 0.81% of the whole region of the Chongqing municipality, which is anticipated to decrease to 0.37% by 2050, 0.21% by 2070, and 0.06% by 2090. Human disturbance, climate variables, and habitat characteristics are the primary factors influencing the distribution of three salamander species in Chongqing. The proximity to roads significantly impacts L. shihi, while climate conditions mainly affect P. jinfo, and the distance to water sources is crucial for T. wenxianensis. The following suggestions were made based on key variables identified for each species: (1) For L. shihi, it is imperative to minimize human disturbances and preserve areas without roads and the existing vegetation within nature reserves to ensure their continued existence. (2) For P. jinfo, the conservation of high-altitude habitats is of utmost importance, along with the reduction in disturbances caused by roads to maintain the species' ecological niche. (3) For T. wenxianensis, the protection of aquatic habitats is crucial. Additionally, efforts to mitigate the impacts of road construction and enhance public awareness are essential for the preservation of this species and the connectivity of its habitats.
Collapse
Affiliation(s)
- Qi Ma
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, School of Life Sciences, Southwest University, Chongqing 400700, China
- Chongqing Natural History Museum, Chongqing 400700, China
| | - Lipeng Wan
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, School of Life Sciences, Southwest University, Chongqing 400700, China
| | - Shengchao Shi
- Hubei Engineering Research Center for Protection and Utilization of Special Biological Resources in the Hanjiang River Basin, School of Life Science, Jianghan University, Wuhan 430056, China
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | - Zhijian Wang
- State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, School of Life Sciences, Southwest University, Chongqing 400700, China
| |
Collapse
|
24
|
Berger L, Skerratt LF, Kosch TA, Brannelly LA, Webb RJ, Waddle AW. Advances in Managing Chytridiomycosis for Australian Frogs: Gradarius Firmus Victoria. Annu Rev Anim Biosci 2024; 12:113-133. [PMID: 38358840 DOI: 10.1146/annurev-animal-021122-100823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
Extensive knowledge gains from research worldwide over the 25 years since the discovery of chytridiomycosis can be used for improved management. Strategies that have saved populations in the short term and/or enabled recovery include captive breeding, translocation into disease refugia, translocation from resistant populations, disease-free exclosures, and preservation of disease refuges with connectivity to previous habitat, while antifungal treatments have reduced mortality rates in the wild. Increasing host resistance is the goal of many strategies under development, including vaccination and targeted genetic interventions. Pathogen-directed strategies may be more challenging but would have broad applicability. While the search for the silver bullet solution continues, we should value targeted local interventions that stop extinction and buy time for evolution of resistance or development of novel solutions. As for most invasive species and infectious diseases, we need to accept that ongoing management is necessary. For species continuing to decline, proactive deployment and assessment of promising interventions are more valid than a hands-off, do-no-harm approach that will likely allow further extinctions.
Collapse
Affiliation(s)
- Lee Berger
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Tiffany A Kosch
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Laura A Brannelly
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Rebecca J Webb
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
| | - Anthony W Waddle
- One Health Research Group, Melbourne Veterinary School, Faculty of Science, University of Melbourne, Werribee, Victoria, Australia; , , , ,
- Applied Biosciences, Macquarie University, Sydney, New South Wales, Australia;
| |
Collapse
|
25
|
Sun X, Guo N, Gao J, Xiao N. Using eDNA to survey amphibians: Methods, applications, and challenges. Biotechnol Bioeng 2024; 121:456-471. [PMID: 37986625 DOI: 10.1002/bit.28592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/22/2023]
Abstract
In recent years, environmental DNA (eDNA) has received attention from biologists due to its sensitivity, convenience, labor and material efficiency, and lack of damage to organisms. The extensive application of eDNA has opened avenues for the monitoring and biodiversity assessment of amphibians, which are frequently small and difficult to observe in the field, in areas such as biodiversity survey assessment and detection of specific, rare and threatened, or alien invasive species. However, the accuracy of eDNA can be influenced by factors such as ambient temperature, pH, and false positives or false negatives, which makes eDNA an adjunctive tool rather than a replacement for traditional surveys. This review provides a concise overview of the eDNA method and its workflow, summarizes the differences between applying eDNA for detecting amphibians and other organisms, reviews the research progress in eDNA technology for amphibian monitoring, identifies factors influencing detection efficiency, and discusses the challenges and prospects of eDNA. It aims to serve as a reference for future research on the application of eDNA in amphibian detection.
Collapse
Affiliation(s)
- Xiaoxuan Sun
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Ningning Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Jianan Gao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
- Collage of Forestry, Shanxi Agricultural University, Jinzhong, China
| | - Nengwen Xiao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| |
Collapse
|
26
|
Mulder KP, Savage AE, Gratwicke B, Longcore JE, Bronikowski E, Evans M, Longo AV, Kurata NP, Walsh T, Pasmans F, McInerney N, Murray S, Martel A, Fleischer RC. Sequence capture identifies fastidious chytrid fungi directly from host tissue. Fungal Genet Biol 2024; 170:103858. [PMID: 38101696 DOI: 10.1016/j.fgb.2023.103858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 12/04/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered in 1998 as the cause of chytridiomycosis, an emerging infectious disease causing mass declines in amphibian populations worldwide. The rapid population declines of the 1970s-1990s were likely caused by the spread of a highly virulent lineage belonging to the Bd-GPL clade that was introduced to naïve susceptible populations. Multiple genetically distinct and regional lineages of Bd have since been isolated and sequenced, greatly expanding the known biological diversity within this fungal pathogen. To date, most Bd research has been restricted to the limited number of samples that could be isolated using culturing techniques, potentially causing a selection bias for strains that can grow on media and missing other unculturable or fastidious strains that are also present on amphibians. We thus attempted to characterize potentially non-culturable genetic lineages of Bd from distinct amphibian taxa using sequence capture technology on DNA extracted from host tissue and swabs. We focused our efforts on host taxa from two different regions that likely harbored distinct Bd clades: (1) wild-caught leopard frogs (Rana) from North America, and (2) a Japanese Giant Salamander (Andrias japonicus) at the Smithsonian Institution's National Zoological Park that exhibited signs of disease and tested positive for Bd using qPCR, but multiple attempts failed to isolate and culture the strain for physiological and genetic characterization. We successfully enriched for and sequenced thousands of fungal genes from both host clades, and Bd load was positively associated with number of recovered Bd sequences. Phylogenetic reconstruction placed all the Rana-derived strains in the Bd-GPL clade. In contrast, the A. japonicus strain fell within the Bd-Asia3 clade, expanding the range of this clade and generating additional genomic data to confirm its placement. The retrieved ITS locus matched public barcoding data from wild A. japonicus and Bd infections found on other amphibians in India and China, suggesting that this uncultured clade is widespread across Asia. Our study underscores the importance of recognizing and characterizing the hidden diversity of fastidious strains in order to reconstruct the spatiotemporal and evolutionary history of Bd. The success of the sequence capture approach highlights the utility of directly sequencing pathogen DNA from host tissue to characterize cryptic diversity that is missed by culture-reliant approaches.
Collapse
Affiliation(s)
- Kevin P Mulder
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium; Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA.
| | - Anna E Savage
- Department of Biology, University of Central Florida, Orlando, FL, USA
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Joyce E Longcore
- School of Biology and Ecology, University of Maine, Orono, ME, USA
| | - Ed Bronikowski
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Matthew Evans
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Naoko P Kurata
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA; Department of Natural Resources and the Environment, Cornell University, Ithaca, NY, USA; Department of Ichthyology, American Museum of Natural History, New York, NY, USA
| | - Tim Walsh
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Nancy McInerney
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Suzan Murray
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Robert C Fleischer
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| |
Collapse
|
27
|
Verster R, Ghosh PN, Sewell TR, Garner TWJ, Fisher MC, Muller W, Cilliers D, Weldon C. Environment predicts Batrachochytrium dendrobatidis lineage distribution and zones of recombination in South Africa. Ecol Evol 2024; 14:e11037. [PMID: 38390004 PMCID: PMC10883246 DOI: 10.1002/ece3.11037] [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: 06/13/2023] [Revised: 01/10/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024] Open
Abstract
The amphibian-infecting chytrid fungus, Batrachochytrium dendrobatidis (Bd), is widespread throughout Africa and is linked to declines of populations and species across the continent. While it is well established that the lineage of Bd encodes traits which determine disease severity, knowledge around how lineages are distributed according to environmental envelope is unclear. We here studied the distribution of Bd in South Africa based on the two lineages found, BdGPL and BdCAPE, in terms of their genome and environmental envelope statistically associated with their distribution. We used Bd surveillance data from published studies, as well as data collected during fieldwork from across South Africa, Lesotho, and eSwatini with samples collected along a transect spanning most of South Africa from Lesotho to the west coast. We utilized lineage-typing qPCR to resolve the spatial distribution of BdGPL and BdCAPE across South Africa and used the resulting surveillance data to create a predictive ecological niche model for Bd lineages in South Africa. Phylogenomic analyses were performed on isolates sourced from across the transect. We show that BdGPL demonstrates a strong isolation by distance suggestive of stepping-stone dispersal, while BdCAPE showed two distinct clusters within their genomic structure that appear geographically and temporally clustered, indicating two separate invasions. Our predictive niche model revealed that the two lineages tended to occur in different ecotypes; BdGPL was associated with lower altitude, arid regions while BdCAPE occurred across cooler, higher altitude environs. Niche predictions identified a zone of lineage contact, where genomics identified inter-lineage recombinants. We argue that this zone of recombination should be prioritized for disease surveillance as it is a potential hotspot for the evolution of variants of amphibian chytrid with novel traits that may be epidemiologically relevant.
Collapse
Affiliation(s)
- Ruhan Verster
- Unit for Environmental Sciences and Management North-West University Potchefstroom South Africa
| | - Pria N Ghosh
- Unit for Environmental Sciences and Management North-West University Potchefstroom South Africa
- MRC Centre for Global Infectious Disease Analysis, School of Public Health Imperial College London London UK
| | - Tom R Sewell
- MRC Centre for Global Infectious Disease Analysis, School of Public Health Imperial College London London UK
| | - Trenton W J Garner
- Unit for Environmental Sciences and Management North-West University Potchefstroom South Africa
- Institute of Zoology Zoological Society of London London UK
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health Imperial College London London UK
| | - Wynand Muller
- Unit for Environmental Sciences and Management North-West University Potchefstroom South Africa
| | - Dirk Cilliers
- Unit for Environmental Sciences and Management North-West University Potchefstroom South Africa
| | - Ché Weldon
- Unit for Environmental Sciences and Management North-West University Potchefstroom South Africa
| |
Collapse
|
28
|
Moran PA, Bosse M, Mariën J, Halfwerk W. Genomic footprints of (pre) colonialism: Population declines in urban and forest túngara frogs coincident with historical human activity. Mol Ecol 2024; 33:e17258. [PMID: 38153193 DOI: 10.1111/mec.17258] [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: 03/06/2023] [Revised: 11/21/2023] [Accepted: 12/06/2023] [Indexed: 12/29/2023]
Abstract
Urbanisation is rapidly altering ecosystems, leading to profound biodiversity loss. To mitigate these effects, we need a better understanding of how urbanisation impacts dispersal and reproduction. Two contrasting population demographic models have been proposed that predict that urbanisation either promotes (facilitation model) or constrains (fragmentation model) gene flow and genetic diversity. Which of these models prevails likely depends on the strength of selection on specific phenotypic traits that influence dispersal, survival, or reproduction. Here, we a priori examined the genomic impact of urbanisation on the Neotropical túngara frog (Engystomops pustulosus), a species known to adapt its reproductive traits to urban selective pressures. Using whole-genome resequencing for multiple urban and forest populations we examined genomic diversity, population connectivity and demographic history. Contrary to both the fragmentation and facilitation models, urban populations did not exhibit substantial changes in genomic diversity or differentiation compared with forest populations, and genomic variation was best explained by geographic distance rather than environmental factors. Adopting an a posteriori approach, we additionally found both urban and forest populations to have undergone population declines. The timing of these declines appears to coincide with extensive human activity around the Panama Canal during the last few centuries rather than recent urbanisation. Our study highlights the long-lasting legacy of past anthropogenic disturbances in the genome and the importance of considering the historical context in urban evolution studies as anthropogenic effects may be extensive and impact nonurban areas on both recent and older timescales.
Collapse
Affiliation(s)
- Peter A Moran
- A-LIFE, Section Ecology & Evolution, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Mirte Bosse
- A-LIFE, Section Ecology & Evolution, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Animal Breeding and Genomics, Wageningen University and Research, Wageningen, The Netherlands
| | - Janine Mariën
- A-LIFE, Section Ecology & Evolution, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Wouter Halfwerk
- A-LIFE, Section Ecology & Evolution, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| |
Collapse
|
29
|
Chondrelli N, Kuehn E, Meurling S, Cortázar-Chinarro M, Laurila A, Höglund J. Batrachochytrium dendrobatidis strain affects transcriptomic response in liver but not skin in latitudinal populations of the common toad (Bufo bufo). Sci Rep 2024; 14:2495. [PMID: 38291226 PMCID: PMC10828426 DOI: 10.1038/s41598-024-52975-8] [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: 09/07/2023] [Accepted: 01/25/2024] [Indexed: 02/01/2024] Open
Abstract
Batrachochytrium dendrobatidis (Bd) is a fungal pathogen that has decimated amphibian populations worldwide for several decades. We examined the changes in gene expression in response to Bd infection in two populations of the common toad, Bufo bufo, in a laboratory experiment. We collected B. bufo eggs in southern and northern Sweden, and infected the laboratory-raised metamorphs with two strains of the global panzoonotic lineage Bd-GPL. Differential expression analysis showed significant differences between infected and control individuals in both liver and skin. The skin samples showed no discernible differences in gene expression between the two strains used, while liver samples were differentiated by strain, with one of the strains eliciting no immune response from infected toads. Immune system genes were overexpressed in skin samples from surviving infected individuals, while in liver samples the pattern was more diffuse. Splitting samples by population revealed a stronger immune response in northern individuals. Differences in transcriptional regulation between populations are particularly relevant to study in Swedish amphibians, which may have experienced varying exposure to Bd. Earlier exposure to this pathogen and subsequent adaptation or selection pressure may contribute to the survival of some populations over others, while standing genetic diversity in different populations may also affect the infection outcome.
Collapse
Affiliation(s)
- Niki Chondrelli
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
| | - Emily Kuehn
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Sara Meurling
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Maria Cortázar-Chinarro
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- MEMEG/Department of Biology, Faculty of Science, Lund University, Lund, Sweden
| | - Anssi Laurila
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Jacob Höglund
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| |
Collapse
|
30
|
Meng Y, Ni Y, Li Z, Jiang T, Sun T, Li Y, Gao X, Li H, Suo C, Li C, Yang S, Lan T, Liao G, Liu T, Wang P, Ding C. Interplay between acetylation and ubiquitination of imitation switch chromatin remodeler Isw1 confers multidrug resistance in Cryptococcus neoformans. eLife 2024; 13:e85728. [PMID: 38251723 PMCID: PMC10834027 DOI: 10.7554/elife.85728] [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: 12/21/2022] [Accepted: 01/21/2024] [Indexed: 01/23/2024] Open
Abstract
Cryptococcus neoformans poses a threat to human health, but anticryptococcal therapy is hampered by the emergence of drug resistance, whose underlying mechanisms remain poorly understood. Herein, we discovered that Isw1, an imitation switch chromatin remodeling ATPase, functions as a master modulator of genes responsible for in vivo and in vitro multidrug resistance in C. neoformans. Cells with the disrupted ISW1 gene exhibited profound resistance to multiple antifungal drugs. Mass spectrometry analysis revealed that Isw1 is both acetylated and ubiquitinated, suggesting that an interplay between these two modification events exists to govern Isw1 function. Mutagenesis studies of acetylation and ubiquitination sites revealed that the acetylation status of Isw1K97 coordinates with its ubiquitination processes at Isw1K113 and Isw1K441 through modulating the interaction between Isw1 and Cdc4, an E3 ligase. Additionally, clinical isolates of C. neoformans overexpressing the degradation-resistant ISW1K97Q allele showed impaired drug-resistant phenotypes. Collectively, our studies revealed a sophisticated acetylation-Isw1-ubiquitination regulation axis that controls multidrug resistance in C. neoformans.
Collapse
Affiliation(s)
- Yang Meng
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Yue Ni
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Zhuoran Li
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Tianhang Jiang
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Tianshu Sun
- Department of Scientific Research, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Yanjian Li
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Xindi Gao
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Hailong Li
- NHC Key Laboratory of AIDS Immunology, The First Affiliated Hospital of China Medical UniversityShenyangChina
| | - Chenhao Suo
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Chao Li
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Sheng Yang
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Tian Lan
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Guojian Liao
- College of Pharmaceutical Sciences, Southwest UniversityChongqingChina
| | - Tongbao Liu
- Medical Research Institute, Southwest UniversityChongqingChina
| | - Ping Wang
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New OrleansNew OrleansUnited States
| | - Chen Ding
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| |
Collapse
|
31
|
De Jesús Andino F, Davydenko A, Webb RJ, Robert J. The Binding, Infection, and Promoted Growth of Batrachochytrium dendrobatidis by the Ranavirus FV3. Viruses 2024; 16:154. [PMID: 38275964 PMCID: PMC10818972 DOI: 10.3390/v16010154] [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: 12/21/2023] [Revised: 01/12/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
Increasing reports suggest the occurrence of co-infection between Ranaviruses such as Frog Virus 3 (FV3) and the chytrid fungus Batrachochytrium dendrobatidis (Bd) in various amphibian species. However, the potential direct interaction of these two pathogens has not been examined to date. In this study, we investigated whether FV3 can interact with Bd in vitro using qPCR, conventional microscopy, and immunofluorescent microscopy. Our results reveal the unexpected ability of FV3 to bind, promote aggregation, productively infect, and significantly increase Bd growth in vitro. To extend these results in vivo, we assessed the impact of FV3 on Xenopus tropicalis frogs previously infected with Bd. Consistent with in vitro results, FV3 exposure to previously Bd-infected X. tropicalis significantly increased Bd loads and decreased the host's survival.
Collapse
Affiliation(s)
- Francisco De Jesús Andino
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (F.D.J.A.); (A.D.)
| | - Anton Davydenko
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (F.D.J.A.); (A.D.)
| | - Rebecca J. Webb
- Veterinary Biosciences, Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia;
| | - Jacques Robert
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA; (F.D.J.A.); (A.D.)
| |
Collapse
|
32
|
Schuck LK, Neely WJ, Buttimer SM, Moser CF, Barth PC, Liskoski PE, Caberlon CDA, Valiati VH, Tozetti AM, Becker CG. Effects of grassland controlled burning on symbiotic skin microbes in Neotropical amphibians. Sci Rep 2024; 14:959. [PMID: 38200064 PMCID: PMC10781984 DOI: 10.1038/s41598-023-50394-9] [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: 08/11/2023] [Accepted: 12/19/2023] [Indexed: 01/12/2024] Open
Abstract
Climate change has led to an alarming increase in the frequency and severity of wildfires worldwide. While it is known that amphibians have physiological characteristics that make them highly susceptible to fire, the specific impacts of wildfires on their symbiotic skin bacterial communities (i.e., bacteriomes) and infection by the deadly chytrid fungus, Batrachochytrium dendrobatidis, remain poorly understood. Here, we address this research gap by evaluating the effects of fire on the amphibian skin bacteriome and the subsequent risk of chytridiomycosis. We sampled the skin bacteriome of the Neotropical species Scinax squalirostris and Boana leptolineata in fire and control plots before and after experimental burnings. Fire was linked with a marked increase in bacteriome beta dispersion, a proxy for skin microbial dysbiosis, alongside a trend of increased pathogen loads. By shedding light on the effects of fire on amphibian skin bacteriomes, this study contributes to our broader understanding of the impacts of wildfires on vulnerable vertebrate species.
Collapse
Affiliation(s)
- Laura K Schuck
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil.
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Wesley J Neely
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35487, USA
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA
| | - Shannon M Buttimer
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
- Center for Infectious Disease Dynamics and One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Camila F Moser
- Programa de Pos-Graduacão em Zoologia, Universidade Federal do Pará, Belém, PA, 66075-110, Brazil
| | - Priscila C Barth
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Paulo E Liskoski
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Carolina de A Caberlon
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Victor Hugo Valiati
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil
| | - Alexandro M Tozetti
- Programa de Pós-Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022-750, Brazil.
| | - C Guilherme Becker
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
- Center for Infectious Disease Dynamics and One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
| |
Collapse
|
33
|
Porco D, Purnomo CA, Glesener L, Proess R, Lippert S, Jans K, Colling G, Schneider S, Stassen R, Frantz AC. eDNA-based monitoring of Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans with ddPCR in Luxembourg ponds: taking signals below the Limit of Detection (LOD) into account. BMC Ecol Evol 2024; 24:4. [PMID: 38178008 PMCID: PMC10768104 DOI: 10.1186/s12862-023-02189-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 12/09/2023] [Indexed: 01/06/2024] Open
Abstract
BACKGROUND Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) are two pathogenic fungi that are a significant threat to amphibian communities worldwide. European populations are strongly impacted and the monitoring of the presence and spread of these pathogens is crucial for efficient decision-making in conservation management. RESULTS Here we proposed an environmental DNA (eDNA) monitoring of these two pathogenic agents through droplet digital PCR (ddPCR) based on water samples from 24 ponds in Luxembourg. In addition, amphibians were swabbed in eight of the targeted ponds in order to compare the two approaches at site-level detection. This study allowed the development of a new method taking below-Limit of Detection (LOD) results into account thanks to the statistical comparison of the frequencies of false positives in no template controls (NTC) and below-LOD results in technical replicates. In the eDNA-based approach, the use of this method led to an increase in Bd and Bsal detection of 28 and 50% respectively. In swabbing, this resulted in 8% more positive results for Bd. In some samples, the use of technical replicates allowed to recover above-LOD signals and increase Bd detection by 35 and 33% respectively for eDNA and swabbing, and Bsal detection by 25% for eDNA. CONCLUSIONS These results confirmed the usefulness of technical replicates to overcome high levels of stochasticity in very low concentration samples even for a highly sensitive technique such as ddPCR. In addition, it showed that below-LOD signals could be consistently recovered and the corresponding amplification events assigned either to positive or negative detection via the method developed here. This methodology might be particularly worth pursuing in pathogenic agents' detection as false negatives could have important adverse consequences. In total, 15 ponds were found positive for Bd and four for Bsal. This study reports the first record of Bsal in Luxembourg.
Collapse
Affiliation(s)
- David Porco
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg.
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg.
| | - Chanistya Ayu Purnomo
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Liza Glesener
- Naturschutzsyndikat SICONA, 12, rue de Capellen, L-8393 Olm, Luxembourg, Luxembourg
| | - Roland Proess
- Umweltplanungsbüro Ecotop, 45, Schlassuecht, L-7435 Hollenfels, Luxembourg, Luxembourg
| | - Stéphanie Lippert
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Kevin Jans
- Natur&ëmwelt Fondation Hëllef fir d'Natur, 5, Route de Luxembourg, L-1899, Kockelscheuer, Luxembourg
| | - Guy Colling
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg
| | - Simone Schneider
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Naturschutzsyndikat SICONA, 12, rue de Capellen, L-8393 Olm, Luxembourg, Luxembourg
| | - Raf Stassen
- Biota.lu, 9a, Rue Principale, L-6990, Hostert, Luxembourg
| | - Alain C Frantz
- Musée national d'histoire naturelle du Luxembourg, 25, rue Münster, Luxembourg, L-2160, Luxembourg
- Fondation Faune Flore, 24, rue Münster, Luxembourg, L-2160, Luxembourg
| |
Collapse
|
34
|
Belasen AM, Peek RA, Adams AJ, Russell ID, De León ME, Adams MJ, Bettaso J, Breedveld KGH, Catenazzi A, Dillingham CP, Grear DA, Halstead BJ, Johnson PG, Kleeman PM, Koo MS, Koppl CW, Lauder JD, Padgett-Flohr G, Piovia-Scott J, Pope KL, Vredenburg V, Westphal M, Wiseman K, Kupferberg SJ. Chytrid infections exhibit historical spread and contemporary seasonality in a declining stream-breeding frog. ROYAL SOCIETY OPEN SCIENCE 2024; 11:231270. [PMID: 38298390 PMCID: PMC10827429 DOI: 10.1098/rsos.231270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024]
Abstract
Species with extensive geographical ranges pose special challenges to assessing drivers of wildlife disease, necessitating collaborative and large-scale analyses. The imperilled foothill yellow-legged frog (Rana boylii) inhabits a wide geographical range and variable conditions in rivers of California and Oregon (USA), and is considered threatened by the pathogen Batrachochytrium dendrobatidis (Bd). To assess drivers of Bd infections over time and space, we compiled over 2000 datapoints from R. boylii museum specimens (collected 1897-2005) and field samples (2005-2021) spanning 9° of latitude. We observed a south-to-north spread of Bd detections beginning in the 1940s and increase in prevalence from the 1940s to 1970s, coinciding with extirpation from southern latitudes. We detected eight high-prevalence geographical clusters through time that span the species' geographical range. Field-sampled male R. boylii exhibited the highest prevalence, and juveniles sampled in autumn exhibited the highest loads. Bd infection risk was highest in lower elevation rain-dominated watersheds, and with cool temperatures and low stream-flow conditions at the end of the dry season. Through a holistic assessment of relationships between infection risk, geographical context and time, we identify the locations and time periods where Bd mitigation and monitoring will be critical for conservation of this imperilled species.
Collapse
Affiliation(s)
- A. M. Belasen
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - R. A. Peek
- California Department of Fish and Wildlife, West Sacramento, CA, USA
| | - A. J. Adams
- Earth Research Institute, University of California, Santa Barbara, CA, USA
| | - I. D. Russell
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - M. E. De León
- Genome Center, University of California, Davis, CA, USA
| | - M. J. Adams
- U.S. Geological Survey, Forest and Rangeland Ecosystem Science Center, Corvallis, OR, USA
| | - J. Bettaso
- Six Rivers National Forest, Lower Trinity Ranger District, USDA Forest Service, P.O. Box 68, Willow Creek, CA, USA
| | | | - A. Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL, USA
| | | | - D. A. Grear
- U.S. Geological Survey, National Wildlife Health Center, Madison, WI, USA
| | - B. J. Halstead
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - P. G. Johnson
- Pinnacles National Park, National Park Service, Paicines, CA, USA
| | - P. M. Kleeman
- Point Reyes Field Station, U.S. Geological Survey, Western Ecological Research Center, Point Reyes Station, CA, USA
| | - M. S. Koo
- Museum of Vertebrate Zoology, University of California, Berkeley, CA
| | - C. W. Koppl
- Plumas National Forest, USDA Forest Service, Quincy, CA, USA
| | | | | | - J. Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
| | - K. L. Pope
- Pacific Southwest Research Station, USDA Forest Service, Arcata, CA, USA
| | - V. Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA, USA
| | - M. Westphal
- Central Coast Field Office, United States Bureau of Land Management, Marina, CA, USA
| | - K. Wiseman
- Department of Herpetology, California Academy of Sciences, San Francisco, CA, USA
| | - S. J. Kupferberg
- Department of Integrative Biology, University of California, Berkeley, CA, USA
| |
Collapse
|
35
|
Lindken T, Anderson CV, Ariano-Sánchez D, Barki G, Biggs C, Bowles P, Chaitanya R, Cronin DT, Jähnig SC, Jeschke JM, Kennerley RJ, Lacher TE, Luedtke JA, Liu C, Long B, Mallon D, Martin GM, Meiri S, Pasachnik SA, Reynoso VH, Stanford CB, Stephenson PJ, Tolley KA, Torres-Carvajal O, Waldien DL, Woinarski JCZ, Evans T. What factors influence the rediscovery of lost tetrapod species? GLOBAL CHANGE BIOLOGY 2024; 30. [PMID: 38273552 DOI: 10.1111/gcb.17107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/24/2023] [Accepted: 12/07/2023] [Indexed: 01/27/2024]
Abstract
We created a database of lost and rediscovered tetrapod species, identified patterns in their distribution and factors influencing rediscovery. Tetrapod species are being lost at a faster rate than they are being rediscovered, due to slowing rates of rediscovery for amphibians, birds and mammals, and rapid rates of loss for reptiles. Finding lost species and preventing future losses should therefore be a conservation priority. By comparing the taxonomic and spatial distribution of lost and rediscovered tetrapod species, we have identified regions and taxa with many lost species in comparison to those that have been rediscovered-our results may help to prioritise search effort to find them. By identifying factors that influence rediscovery, we have improved our ability to broadly distinguish the types of species that are likely to be found from those that are not (because they are likely to be extinct). Some lost species, particularly those that are small and perceived to be uncharismatic, may have been neglected in terms of conservation effort, and other lost species may be hard to find due to their intrinsic characteristics and the characteristics of the environments they occupy (e.g. nocturnal species, fossorial species and species occupying habitats that are more difficult to survey such as wetlands). These lost species may genuinely await rediscovery. However, other lost species that possess characteristics associated with rediscovery (e.g. large species) and that are also associated with factors that negatively influence rediscovery (e.g. those occupying small islands) are more likely to be extinct. Our results may foster pragmatic search protocols that prioritise lost species likely to still exist.
Collapse
Affiliation(s)
- Tim Lindken
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - Christopher V Anderson
- Department of Biology, University of South Dakota, Vermillion, South Dakota, USA
- IUCN SSC Chameleon Specialist Group, Gland, Switzerland
| | - Daniel Ariano-Sánchez
- Centro de Estudios Ambientales y Biodiversidad, Universidad del Valle de Guatemala, Guatemala City, Guatemala
- Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Notodden, Norway
| | - Goni Barki
- Albert Katz International School for Desert Studies, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
- Mitrani Department of Desert Ecology, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | | | - Philip Bowles
- IUCN SSC Snake and Lizard Red List Authority, Gland, Switzerland
| | - Ramamoorthi Chaitanya
- The School of Zoology and The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Israel
| | | | - Sonja C Jähnig
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- Geography Department, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jonathan M Jeschke
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- IUCN SSC Invasive Species Specialist Group, Gland, Switzerland
| | - Rosalind J Kennerley
- Durrell Wildlife Conservation Trust, Jersey, UK
- IUCN SSC Small Mammal Specialist Group, Gland, Switzerland
| | - Thomas E Lacher
- Re:wild, Austin, Texas, USA
- IUCN SSC Small Mammal Specialist Group, Gland, Switzerland
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, Texas, USA
| | - Jennifer A Luedtke
- Re:wild, Austin, Texas, USA
- IUCN SSC Amphibian Specialist Group, Gland, Switzerland
| | - Chunlong Liu
- College of Fisheries, Ocean University of China, Qingdao, China
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | | | - David Mallon
- Department of Natural Sciences, Manchester Metropolitan University, Manchester, UK
| | - Gabriel M Martin
- Centro de Investigación Esquel de Montaña y Estepa Patagónica (CIEMEP), Esquel, Argentina
- IUCN SSC New World Marsupials Specialist Group, Gland, Switzerland
| | - Shai Meiri
- The School of Zoology and The Steinhardt Museum of Natural History, Tel Aviv University, Tel Aviv, Israel
| | | | - Victor Hugo Reynoso
- Departamento de Zoología/Pabellón de la Biodiversidad, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Craig B Stanford
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
- Department of Herpetology, Natural History Museum of Los Angeles County, Los Angeles, California, USA
- IUCN SSC Tortoise and Freshwater Turtle Specialist Group, Gland, Switzerland
| | - P J Stephenson
- Laboratory for Conservation Biology, Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- IUCN SSC Species Monitoring Specialist Group, Gland, Switzerland
- IUCN SSC Afrotheria Specialist Group, Gland, Switzerland
| | - Krystal A Tolley
- IUCN SSC Chameleon Specialist Group, Gland, Switzerland
- Kirstenbosch Research Centre, South African National Biodiversity Institute, Cape Town, South Africa
- Centre for Ecological Genomics and Wildlife Conservation, University of Johannesburg, Johannesburg, South Africa
| | - Omar Torres-Carvajal
- Museo de Zoología, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador
| | - David L Waldien
- IUCN SSC Bat Specialist Group, Gland, Switzerland
- Christopher Newport University, Newport News, Virginia, USA
- Lubee Bat Conservancy, Gainesville, Florida, USA
- Harrison Institute, Kent, UK
| | | | - Thomas Evans
- Institute of Biology, Freie Universität Berlin, Berlin, Germany
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
- IUCN SSC Invasive Species Specialist Group, Gland, Switzerland
- Ecologie Systématique et Evolution, Université Paris-Saclay, Gif-sur-Yvette, France
| |
Collapse
|
36
|
Martínez-Ugalde E, Ávila-Akerberg V, González Martínez TM, Rebollar EA. Gene functions of the Ambystoma altamirani skin microbiome vary across space and time but potential antifungal genes are widespread and prevalent. Microb Genom 2024; 10:001181. [PMID: 38240649 PMCID: PMC10868611 DOI: 10.1099/mgen.0.001181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/02/2024] [Indexed: 01/23/2024] Open
Abstract
Amphibian skin microbiomes can play a critical role in host survival against emerging diseases by protecting their host against pathogens. While a plethora of biotic and abiotic factors have been shown to influence the taxonomic diversity of amphibian skin microbiomes it remains unclear whether functional genomic diversity varies in response to temporal and environmental factors. Here we applied a metagenomic approach to evaluate whether seasonality, distinct elevations/sites, and pathogen presence influenced the functional genomic diversity of the A. altamirani skin microbiome. We obtained a gene catalogue of 92 107 nonredundant annotated genes and a set of 50 unique metagenome assembled genomes (MAGs). Our analysis showed that genes linked to general and potential antifungal traits significantly differed across seasons and sampling locations at different elevations. Moreover, we found that the functional genomic diversity of A. altamirani skin microbiome differed between B. dendrobatidis infected and not infected axolotls only during winter, suggesting an interaction between seasonality and pathogen infection. In addition, we identified the presence of genes and biosynthetic gene clusters (BGCs) linked to potential antifungal functions such as biofilm formation, quorum sensing, secretion systems, secondary metabolite biosynthesis, and chitin degradation. Interestingly genes linked to these potential antifungal traits were mainly identified in Burkholderiales and Chitinophagales MAGs. Overall, our results identified functional traits linked to potential antifungal functions in the A. altamirani skin microbiome regardless of variation in the functional diversity across seasons, elevations/sites, and pathogen presence. Our findings suggest that potential antifungal traits found in Burkholderiales and Chitinophagales taxa could be related to the capacity of A. altamirani to survive in the presence of Bd, although further experimental analyses are required to test this hypothesis.
Collapse
Affiliation(s)
| | - Víctor Ávila-Akerberg
- Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Toluca, Mexico
| | | | - Eria A. Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| |
Collapse
|
37
|
Meurling S, Siljestam M, Cortazar-Chinarro M, Åhlen D, Rödin-Mörch P, Ågren E, Höglund J, Laurila A. Body size mediates latitudinal population differences in the response to chytrid fungus infection in two amphibians. Oecologia 2024; 204:71-81. [PMID: 38097779 PMCID: PMC10830819 DOI: 10.1007/s00442-023-05489-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/14/2023] [Indexed: 02/02/2024]
Abstract
Factors behind intraspecific variation in sensitivity to pathogens remain poorly understood. We investigated how geographical origin in two North European amphibians affects tolerance to infection by the chytrid fungus Batrachochytrium dendrobatidis (Bd), a generalist pathogen which has caused amphibian population declines worldwide. We exposed newly metamorphosed individuals of moor frog Rana arvalis and common toad Bufo bufo from two latitudinal regions to two different BdGPL strains. We measured survival and growth as infections may cause sub-lethal effects in fitness components even in the absence of mortality. Infection loads were higher in B. bufo than in R. arvalis, and smaller individuals had generally higher infection loads. B. bufo had high mortality in response to Bd infection, whereas there was little mortality in R. arvalis. Bd-mediated mortality was size-dependent and high-latitude individuals were smaller leading to high mortality in the northern B. bufo. Bd exposure led to sub-lethal effects in terms of reduced growth suggesting that individuals surviving the infection may have reduced fitness mediated by smaller body size. In both host species, the Swedish Bd strain caused stronger sublethal effects than the British strain. We suggest that high-latitude populations can be more vulnerable to chytrids than those from lower latitudes and discuss the possible mechanisms how body size and host geographical origin contribute to the present results.
Collapse
Affiliation(s)
- Sara Meurling
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Mattias Siljestam
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Maria Cortazar-Chinarro
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- MEMEG/Department of Biology, Lund University, Lund, Sweden
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada
| | - David Åhlen
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Uppsala, Sweden
| | - Patrik Rödin-Mörch
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Erik Ågren
- Department of Pathology and Wildlife Diseases, National Veterinary Institute, Uppsala, Sweden
| | - Jacob Höglund
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - Anssi Laurila
- Animal Ecology/ Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.
| |
Collapse
|
38
|
Cortazar-Chinarro M, Richter-Boix A, Rödin-Mörch P, Halvarsson P, Logue JB, Laurila A, Höglund J. Association between the skin microbiome and MHC class II diversity in an amphibian. Mol Ecol 2024; 33:e17198. [PMID: 37933583 DOI: 10.1111/mec.17198] [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: 04/03/2023] [Revised: 10/20/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023]
Abstract
Microbiomes play an important role in determining the ecology and behaviour of their hosts. However, questions remain pertaining to how host genetics shape microbiomes, and how microbiome composition influences host fitness. We explored the effects of geography, evolutionary history and host genetics on the skin microbiome diversity and structure in a widespread amphibian. More specifically, we examined the association between bacterial diversity and composition and the major histocompatibility complex class II exon 2 diversity in 12 moor frog (Rana arvalis) populations belonging to two geographical clusters that show signatures of past and ongoing differential selection. We found that while bacterial alpha diversity did not differ between the two clusters, MHC alleles/supertypes and genetic diversity varied considerably depending on geography and evolutionary history. Bacterial alpha diversity was positively correlated with expected MHC heterozygosity and negatively with MHC nucleotide diversity. Furthermore, bacterial community composition showed significant variation between the two geographical clusters and between specific MHC alleles/supertypes. Our findings emphasize the importance of historical demographic events on hologenomic variation and provide new insights into how immunogenetic host variability and microbial diversity may jointly influence host fitness with consequences for disease susceptibility and population persistence.
Collapse
Affiliation(s)
- M Cortazar-Chinarro
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
- MEMEG/Department of Biology, Lund University, Lund, Sweden
- Department of Earth Ocean and Atmospheric Sciences, Faculty of Science 2020-2207, University of British Columbia, Vancouver, British Columbia, Canada
| | - A Richter-Boix
- Department of Political and Social Science, Pompeu Fabra University, Barcelona, Spain
| | - P Rödin-Mörch
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - P Halvarsson
- Parasitology/Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - J B Logue
- Aquatic Ecology/Department of Biology, Lund University, Lund, Sweden
- SLU University Library, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - A Laurila
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| | - J Höglund
- Animal Ecology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
| |
Collapse
|
39
|
Herrera-Alva V, Catenazzi A, Aguilar-Puntriano C. A new cryptic species of terrestrial breeding frog of the Pristimantisdanae Group (Anura, Strabomantidae) from montane forests in Ayacucho, Peru. Zookeys 2023; 1187:1-29. [PMID: 38161710 PMCID: PMC10756142 DOI: 10.3897/zookeys.1187.104536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/21/2023] [Indexed: 01/03/2024] Open
Abstract
Based on morphological and molecular characters, we describe a new species of terrestrial breeding frog of the Pristimantisdanae Group from montane forests of La Mar Province, Ayacucho Department in southern Peru, at elevations from 1200 to 2000 m a.s.l. The phylogenetic analysis, based on concatenated sequences of gene fragments of 16S rRNA, RAG1, COI and TYR suggests that the new species is a sister taxon of a clade that includes one undescribed species of Pristimantis from Cusco, Pristimantispharangobates and Pristimantisrhabdolaemus. The new species is most similar to P.rhabdolaemus, which differs by lacking scapular tubercules and by its smaller size (17.0-18.6 mm in males [n = 5], 20.8-25.2 mm in females [n = 5] in the new species vs. 22.8-26.3 mm in males [n = 19], 26.0-31.9 mm in females [n = 30] of P.rhabdolaemus). Additionally, we report the prevalence of Batrachochytriumdendrobatidis (Bd) in this species.
Collapse
Affiliation(s)
- Valia Herrera-Alva
- Departamento de Herpetología, Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos, Lima, PeruMuseo de Historia Natural de la Universidad Nacional Mayor de San MarcosLimaPeru
- Laboratorio de Sistemática y Ecología de Vertebrados, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, PeruUniversidad Nacional Mayor de San MarcosLimaPeru
| | - Alessandro Catenazzi
- Florida International University, Department of Biological Sciences, 11200 SW 8th Street, Miami, FL 33199, USAFlorida International UniversityMiamiUnited States of America
| | - César Aguilar-Puntriano
- Departamento de Herpetología, Museo de Historia Natural de la Universidad Nacional Mayor de San Marcos, Lima, PeruMuseo de Historia Natural de la Universidad Nacional Mayor de San MarcosLimaPeru
- Laboratorio de Sistemática y Ecología de Vertebrados, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, PeruUniversidad Nacional Mayor de San MarcosLimaPeru
| |
Collapse
|
40
|
Laumeier R, Brändle M, Rödel MO, Brunzel S, Brandl R, Pinkert S. The global importance and interplay of colour-based protective and thermoregulatory functions in frogs. Nat Commun 2023; 14:8117. [PMID: 38114472 PMCID: PMC10730650 DOI: 10.1038/s41467-023-43729-7] [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: 03/24/2023] [Accepted: 11/10/2023] [Indexed: 12/21/2023] Open
Abstract
Small-scale studies have shown that colour lightness variation can have important physiological implications in ectotherms, with darker species having greater heating rates, as well as protection against pathogens and photooxidative damage. Using data for 41% (3059) of all known frog and toad species (Anura) from across the world, we reveal ubiquitous and strong clines of decreasing colour lightness towards colder regions and regions with higher pathogen pressure and UVB radiation. The relative importance of pathogen resistance is higher in the tropics and that of thermoregulation is higher in temperate regions. The results suggest that these functions influence colour lightness evolution in anurans and filtered for more similarly coloured species under climatic extremes, while their concurrent importance resulted in high within-assemblage variation in productive regions. Our findings indicate three important functions of colour lightness in anurans - thermoregulation, pathogen and UVB protection - and broaden support for colour lightness-environment relationships in ectotherms.
Collapse
Affiliation(s)
- Ricarda Laumeier
- Department of Animal Ecology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35043, Marburg, Germany.
- Department of Biodiversity and Species Conservation, Faculty of Landscape Architecture, Horticulture and Forestry, University of Applied Science Erfurt, Leipziger Straße 77, 99085, Erfurt, Germany.
| | - Martin Brändle
- Department of Animal Ecology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35043, Marburg, Germany
| | - Mark-Oliver Rödel
- Department of Evolutionary Diversity Dynamics, Museum für Naturkunde-Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115, Berlin, Germany
| | - Stefan Brunzel
- Department of Biodiversity and Species Conservation, Faculty of Landscape Architecture, Horticulture and Forestry, University of Applied Science Erfurt, Leipziger Straße 77, 99085, Erfurt, Germany
| | - Roland Brandl
- Department of Animal Ecology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35043, Marburg, Germany
| | - Stefan Pinkert
- Department of Ecology and Evolutionary Biology, Yale University, 165 Prospect Street, 06511, New Haven, CT, USA
- Department of Conservation Ecology, Faculty of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35043, Marburg, Germany
| |
Collapse
|
41
|
Webb RJ, Rush C, Berger L, Skerratt LF, Roberts AA. Glutathione is required for growth and cadmium tolerance in the amphibian chytrid fungus, Batrachochytrium dendrobatidis. Biochimie 2023; 220:22-30. [PMID: 38104714 DOI: 10.1016/j.biochi.2023.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 11/24/2023] [Accepted: 12/12/2023] [Indexed: 12/19/2023]
Abstract
Batrachochytrium dendrobatidis (Bd) is a lethal amphibian pathogen, partly due to its ability to evade the immune system of susceptible frog species. In many pathogenic fungi, the antioxidant glutathione is a virulence factor that helps neutralise oxidative stressors generated from host immune cells, as well as other environmental stressors such as heavy metals. The role of glutathione in stress tolerance in Bd has not been investigated. Here, we examine the changes in the glutathione pool after stress exposure and quantify the effect of glutathione depletion on cell growth and stress tolerance. Depletion of glutathione repressed growth and release of zoospores, suggesting that glutathione is essential for life cycle completion in Bd. Supplementation with <2 mM exogenous glutathione accelerated zoospore development, but concentrations >2 mM were strongly inhibitory to Bd cells. While hydrogen peroxide exposure lowered the total cellular glutathione levels by 42 %, glutathione depletion did not increase the sensitivity to hydrogen peroxide. Exposure to cadmium increased total cellular glutathione levels by 93 %. Glutathione-depleted cells were more sensitive to cadmium, and this effect was attenuated by glutathione supplementation, suggesting that glutathione plays an important role in cadmium tolerance. The effects of heat and salt were exacerbated by the addition of exogenous glutathione. The impact of glutathione levels on Bd stress sensitivity may help explain differences in host susceptibility to chytridiomycosis and may provide opportunities for synergistic therapeutics.
Collapse
Affiliation(s)
- Rebecca J Webb
- James Cook University, Townsville, QLD, 4811, Australia; Melbourne Veterinary School, University of Melbourne, Werribee, VIC, 3030, Australia.
| | | | - Lee Berger
- Melbourne Veterinary School, University of Melbourne, Werribee, VIC, 3030, Australia
| | - Lee F Skerratt
- Melbourne Veterinary School, University of Melbourne, Werribee, VIC, 3030, Australia
| | | |
Collapse
|
42
|
Neely WJ, Martins RA, Mendonça da Silva CM, Ferreira da Silva T, Fleck LE, Whetstone RD, Woodhams DC, Cook WH, Prist PR, Valiati VH, Greenspan SE, Tozetti AM, Earley RL, Becker CG. Linking microbiome and stress hormone responses in wild tropical treefrogs across continuous and fragmented forests. Commun Biol 2023; 6:1261. [PMID: 38087051 PMCID: PMC10716138 DOI: 10.1038/s42003-023-05600-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
The amphibian skin microbiome is an important component of anti-pathogen defense, but the impact of environmental change on the link between microbiome composition and host stress remains unclear. In this study, we used radiotelemetry and host translocation to track microbiome composition and function, pathogen infection, and host stress over time across natural movement paths for the forest-associated treefrog, Boana faber. We found a negative correlation between cortisol levels and putative microbiome function for frogs translocated to forest fragments, indicating strong integration of host stress response and anti-pathogen potential of the microbiome. Additionally, we observed a capacity for resilience (resistance to structural change and functional loss) in the amphibian skin microbiome, with maintenance of putative pathogen-inhibitory function despite major temporal shifts in microbiome composition. Although microbiome community composition did not return to baseline during the study period, the rate of microbiome change indicated that forest fragmentation had more pronounced effects on microbiome composition than translocation alone. Our findings reveal associations between stress hormones and host microbiome defenses, with implications for resilience of amphibians and their associated microbes facing accelerated tropical deforestation.
Collapse
Affiliation(s)
- Wesley J Neely
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA.
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA.
| | - Renato A Martins
- Department of Biology, and Center for Infectious Disease Dynamics, One Health Microbiome Center, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Camila M Mendonça da Silva
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Tainá Ferreira da Silva
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Lucas E Fleck
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Ross D Whetstone
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - W Harrison Cook
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Paula R Prist
- EcoHealth Alliance, 520 Eight Avenue, Suite 1200, New York, NY, 10018, USA
| | - Victor H Valiati
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Sasha E Greenspan
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Alexandro M Tozetti
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Ryan L Earley
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - C Guilherme Becker
- Department of Biology, and Center for Infectious Disease Dynamics, One Health Microbiome Center, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
| |
Collapse
|
43
|
Hawley L, Smalling KL, Glaberman S. Critical review of the phytohemagglutinin assay for assessing amphibian immunity. CONSERVATION PHYSIOLOGY 2023; 11:coad090. [PMID: 38090122 PMCID: PMC10714196 DOI: 10.1093/conphys/coad090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 09/15/2023] [Accepted: 10/26/2023] [Indexed: 04/26/2024]
Abstract
Infectious diseases are a major driver of the global amphibian decline. In addition, many factors, including genetics, stress, pollution, and climate change can influence the response to pathogens. Therefore, it is important to be able to evaluate amphibian immunity in the laboratory and in the field. The phytohemagglutinin (PHA) assay is an inexpensive and relatively non-invasive tool that has been used extensively to assess immunocompetence, especially in birds, and more recently in amphibians. However, there is substantial variation in experimental methodology among amphibian PHA studies in terms of species and life stages, PHA doses and injection sites, and use of experimental controls. Here, we compile and compare all known PHA studies in amphibians to identify knowledge gaps and develop best practices for future work. We found that research has only been conducted on a limited number of species, which may not reflect the diversity of amphibians. There is also a lack of validation studies in most species, so that doses and timing of PHA injection and subsequent swelling measurements may not effectively evaluate immunocompetence. Based on these and other findings, we put forward a set of recommendations to make future PHA studies more consistent and improve the ability to utilize this assay in wild populations, where immune surveillance is greatly needed.
Collapse
Affiliation(s)
- Lauren Hawley
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA
| | - Kelly L Smalling
- New Jersey Water Science Center, U.S. Geological Survey, Lawrenceville, NJ, USA
| | - Scott Glaberman
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, USA
| |
Collapse
|
44
|
Campos PM, Lucid MK, Ehlers S, Walke JB. Low-level pathogen infection and geographic location correlate with the skin microbiomes of Columbia spotted frogs ( Rana luteiventris) in a montane landscape. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 6:100213. [PMID: 38187998 PMCID: PMC10770434 DOI: 10.1016/j.crmicr.2023.100213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024] Open
Abstract
The skin microbiome of amphibians can influence host susceptibility towards the fungal pathogen Batrachochytrium dendrobatidis (Bd), while simultaneously having the potential to be altered by Bd. Severe Bd infections are known to alter the amphibian skin microbiome; however, little is known about microbiome interactions in amphibians with low infection intensity. In addition to disease dynamics, environmental factors may influence the microbiome. To test for patterns in bacterial diversity based on pathogen infection and environmental factors, 399 Columbia spotted frogs (Rana luteiventris) were sampled throughout northern Idaho and northeastern Washington across two years. Bd prevalence and intensity were measured in 376 frogs, revealing a prevalence of 69%, but generally low infection intensity (Mean = 127 Bd zoospore equivalents among infected frogs). Skin bacterial communities were characterized in 92 frogs using 16S rRNA gene amplicon sequencing. Our results indicated correlations of decreasing Shannon diversity and evenness as infection intensity increased. Latitude was correlated with bacterial richness and Faith's Phylogenetic Diversity measures, indicating increased diversity in northern locations. Beta diversity (UniFrac) analyses revealed that skin microbiomes were distinct between infected and uninfected frogs, and infection intensity had a significant effect on microbiome composition. Site explained the majority of microbiome variation (weighted UniFrac: 57.5%), suggesting a combination of local habitat conditions explain variation, as only small proportions of variation could be explained by year, month, temperature, elevation, and latitude individually. Bacterial genera with potential for Bd-inhibitory properties were found with differential relative abundance in infected and uninfected frogs, with higher Stenotrophomonas and lower Pseudomonas relative abundance observed in infected frogs. Further study may indicate if Bd inhibition by members of the skin microbiome is an influence behind the low infection intensities observed and whether low Bd infection intensities are capable of altering skin microbiome composition.
Collapse
Affiliation(s)
- Philip M. Campos
- Department of Biology, Eastern Washington University, 1175 Washington St., Cheney, WA 99004, USA
| | - Michael K. Lucid
- Idaho Department of Fish and Game, 2885 Kathleen Ave., Coeur d'Alene, ID 83815, USA
- Selkirk Wildlife Science, LLC, PO Box 733, Sandpoint, ID 83864, USA
| | - Shannon Ehlers
- Idaho Department of Fish and Game, 2885 Kathleen Ave., Coeur d'Alene, ID 83815, USA
- U.S. Fish and Wildlife Service, 287 Westside Rd., Bonners Ferry, ID 83805, USA
| | - Jenifer B. Walke
- Department of Biology, Eastern Washington University, 1175 Washington St., Cheney, WA 99004, USA
| |
Collapse
|
45
|
Barragan EM, Hoskins TD, Allmon EB, McQuigg JL, Hamilton MT, Christian EN, Coogan GSM, Searle CL, Choi YJ, Lee LS, Hoverman JT, Sepúlveda MS. Toxicities of Legacy and Current-Use PFAS in an Anuran: Do Larval Exposures Influence Responses to a Terrestrial Pathogen Challenge? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:19180-19189. [PMID: 37962853 DOI: 10.1021/acs.est.3c03191] [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: 11/15/2023]
Abstract
Legacy polyfluoroalkyl substances (PFAS) [perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA)] are being replaced by various other fluorinated compounds, such as hexafluoropropylene oxide dimer acid (GenX). These alternatives are thought to be less bioaccumulative and, therefore, less toxic than legacy PFAS. Contaminant exposures occur concurrently with exposure to natural stressors, including the fungal pathogen Batrachocytrium dendrobatidis (Bd). Despite evidence that other pollutants can increase the adverse effects of Bd on anurans, no studies have examined the interactive effects of Bd and PFAS. This study tested the growth and developmental effects of PFOS, PFOA, and GenX on gray treefrog (Hyla versicolor) tadpoles, followed by a Bd challenge after metamorphosis. Despite PFAS exposure only occurring during the larval stage, carry-over effects on growth were observed post metamorphosis. Further, PFAS interacted with Bd exposure to influence growth; Bd-exposed animals had significantly shorter SVL [snout-vent length (mm)] with significantly increased body condition, among other time-dependent effects. Our data suggest that larval exposure to PFAS can continue to impact growth in the juvenile stage after exposure has ended. Contrary to predictions, GenX affected terrestrial performance more consistently than its legacy congener, PFOA. Given the role of Bd in amphibian declines, further investigation of interactions of PFAS with Bd and other environmentally relevant pathogens is warranted.
Collapse
Affiliation(s)
- Evelyn M Barragan
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tyler D Hoskins
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Elizabeth B Allmon
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jessica L McQuigg
- Department of Biology, Drew University, Madison, New Jersey 07940, United States
| | - Matthew T Hamilton
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Erin N Christian
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Grace S M Coogan
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Catherine L Searle
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, United States
| | - Youn Jeong Choi
- Agronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Linda S Lee
- Agronomy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jason T Hoverman
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
| | - Maria S Sepúlveda
- Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, United States
- Sustainability Research Center and PhD in Conservation Medicine, Life Sciences Faculty, Universidad Andres Bello, Santiago 7550196, Chile
| |
Collapse
|
46
|
Rahman MM, Yun J, Lee K, Lee SH, Park SM, Ham CH, Sung HC. Population-level call properties of endangered Dryophytes suweonensissensu lato (Anura: Amphibia) in South Korea. PeerJ 2023; 11:e16492. [PMID: 38054023 PMCID: PMC10695108 DOI: 10.7717/peerj.16492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/30/2023] [Indexed: 12/07/2023] Open
Abstract
Calling is one of the unique amphibian characteristics that facilitates social communication and shows individuality; however, it also makes them vulnerable to predators. Researchers use amphibian call properties to study their population status, ecology, and behavior. This research scope has recently broadened to species identification and taxonomy. Dryophytes flaviventris has been separated from the endangered anuran species, D. suweonensis, based on small variations in genetic, morphometric, and temporal call properties observed in South Korea. The Chilgap Mountain (CM) was considered as the potential geographic barrier for the speciation. However, it initiated taxonomic debates as CM has been hardly used and is considered a potential barrier for other species. The calls of populations from both sides are also apparently similar. Thus, to verify the differences in call properties among populations of D. suweonensis sensu lato (s.l.; both of the species), we sampled and analyzed call data from five localities covering its distribution range, including the southern (S) and northern (N) parts of CM. We found significant differences in many call properties among populations; however, no specific pattern was observed. Some geographically close populations, such as Iksan (S), Wanju (S), and Gunsan (S), had significant differences, whereas many distant populations, such as Pyeongtaek (N) and Wanju (S), had no significant differences. Considering the goal of this study was only to observe the call properties, we cautiously conclude that the differences are at the population level rather than the species level. Our study indicates the necessity of further investigation into the specific status of D. flaviventris using robust integrated taxonomic approaches, including genetic and morphological parameters from a broader array of localities.
Collapse
Affiliation(s)
- Md Mizanur Rahman
- Department of Biological Sciences, Chonnam National University, Gwangju, South Korea
| | - Jiyoung Yun
- Department of Biological Sciences and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - KaHyun Lee
- Department of Biological Sciences and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Seung-Ha Lee
- Department of Biological Sciences, Chonnam National University, Gwangju, South Korea
| | - Seung-Min Park
- Department of Biological Sciences and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Choong-Ho Ham
- Department of Biological Sciences and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Ha-Cheol Sung
- Department of Biological Sciences, Chonnam National University, Gwangju, South Korea
- Research Center of Ecomimetics, Chonnam National University, Gwangju, Republic of Korea
| |
Collapse
|
47
|
Trumbo DR, Hardy BM, Crockett HJ, Muths E, Forester BR, Cheek RG, Zimmerman SJ, Corey-Rivas S, Bailey LL, Funk WC. Conservation genomics of an endangered montane amphibian reveals low population structure, low genomic diversity and selection pressure from disease. Mol Ecol 2023; 32:6777-6795. [PMID: 37864490 DOI: 10.1111/mec.17175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 10/07/2023] [Accepted: 10/11/2023] [Indexed: 10/23/2023]
Abstract
Wildlife diseases are a major global threat to biodiversity. Boreal toads (Anaxyrus [Bufo] boreas) are a state-endangered species in the southern Rocky Mountains of Colorado and New Mexico, and a species of concern in Wyoming, largely due to lethal skin infections caused by the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd). We performed conservation and landscape genomic analyses using single nucleotide polymorphisms from double-digest, restriction site-associated DNA sequencing in combination with the development of the first boreal toad (and first North American toad) reference genome to investigate population structure, genomic diversity, landscape connectivity and adaptive divergence. Genomic diversity (π = 0.00034-0.00040) and effective population sizes (Ne = 8.9-38.4) were low, likely due to post-Pleistocene founder effects and Bd-related population crashes over the last three decades. Population structure was also low, likely due to formerly high connectivity among a higher density of geographically proximate populations. Boreal toad gene flow was facilitated by low precipitation, cold minimum temperatures, less tree canopy, low heat load and less urbanization. We found >8X more putatively adaptive loci related to Bd intensity than to all other environmental factors combined, and evidence for genes under selection related to immune response, heart development and regulation and skin function. These data suggest boreal toads in habitats with Bd have experienced stronger selection pressure from disease than from other, broad-scale environmental variations. These findings can be used by managers to conserve and recover the species through actions including reintroduction and supplementation of populations that have declined due to Bd.
Collapse
Affiliation(s)
- D R Trumbo
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - B M Hardy
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado, USA
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - H J Crockett
- Colorado Parks and Wildlife, Fort Collins, Colorado, USA
| | - E Muths
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, USA
| | - B R Forester
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| | - R G Cheek
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - S J Zimmerman
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado, USA
| | - S Corey-Rivas
- Department of Biology, New Mexico Highlands University, Las Vegas, New Mexico, USA
| | - L L Bailey
- Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado, USA
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| | - W C Funk
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
- Graduate Degree Program in Ecology, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
48
|
Alexiev A, Melie T, Martindale R, Delacey C, Quandt CA, McKenzie VJ. Mr. Toad's Wild Fungi: Fungal Isolate Diversity on Colorado Boreal Toads and their Capacity for Pathogen Inhibition. FUNGAL ECOL 2023; 66:101297. [PMID: 38487623 PMCID: PMC10938945 DOI: 10.1016/j.funeco.2023.101297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2024]
Abstract
The amphibian skin pathogen Batrachochytrium dendrobatidis (Bd) has caused an ongoing biodiversity crisis, including in the locally endangered Colorado boreal toad (Anaxyrus boreas boreas). Although researchers have investigated the bacteria living on amphibian skin and how they interact with Bd, there is less information about fungal community members. This study describes (1) the diversity of culturable fungi from boreal toad skin, (2) which subset of these isolates is Bd-inhibitory, and (3) how Bd affects these isolates' growth and morphology. Most isolates were from the orders Capnodiales, Helotiales, and Pleosporales. Of 16 isolates tested for Bd-inhibition, two from the genus Neobulgaria and three from Pseudeurotium inhibited Bd. Fungal growth in co-culture with Bd varied with weak statistical support for Neobulgaria sp. (isolate BTF_36) and cf Psychrophila (isolate BTF_60) (p-values = 0.076 and 0.092, respectively). Fungal morphology remained unchanged in co-culture with Bd, however, these results could be attributed to low replication per isolate. Nonetheless, two fungal isolates' growth may have been affected by Bd, implying that fungal growth changes in Bd co-culture could be a variable worth measuring in the future (with higher replication). These findings add to the sparse but growing literature on amphibian-associated fungi and suggest further study may uncover the relevance of fungi to amphibian health and Bd infection.
Collapse
Affiliation(s)
- Alexandra Alexiev
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology
| | - Tina Melie
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology
| | - Rachel Martindale
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology
| | - Cameron Delacey
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology
| | - C. Alisha Quandt
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology
| | - Valerie J. McKenzie
- University of Colorado Boulder, Department of Ecology and Evolutionary Biology
| |
Collapse
|
49
|
Carvalho T, Si C, Clemons RA, Faust E, James TY. Amphibian Hymenochirus boettgeri as an experimental model for infection studies with the chytrid fungus Batrachochytrium dendrobatidis. Virulence 2023; 14:2270252. [PMID: 37823610 PMCID: PMC10614710 DOI: 10.1080/21505594.2023.2270252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023] Open
Abstract
Model organisms are crucial in research as they can provide key insights applicable to other species. This study proposes the use of the amphibian species Hymenochirus boettgeri, widely available through the aquarium trade, as a model organism for the study of chytridiomycosis, a disease caused by the fungus Batrachochytrium dendrobatidis (Bd) and linked to amphibian decline and extinction globally. Currently, no model organisms are used in the study of chytridiomycosis, particularly because of the lack of availability and nonstandardized methods. Thus, laboratories around the world use wild local species to conduct Bd infection experiments, which prevents comparisons between studies and reduces reproducibility. Here, we performed a series of Bd infection assays that showed that H. boettgeri has a dose- and genotype-dependent response, can generalize previous findings on virulence estimates in other species, and can generate reproducible results in replicated experimental conditions. We also provided valuable information regarding H. boettgeri husbandry, including care, housing, reproduction, and heat treatment to eliminate previous Bd infections. Together, our results indicate that H. boettgeri is a powerful and low-ecological-impact system for studying Bd pathogenicity and virulence.
Collapse
Affiliation(s)
- Tamilie Carvalho
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Catherine Si
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Rebecca A. Clemons
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Evelyn Faust
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Timothy Y. James
- Department of Ecology and Evolutionary Biology, University of Michigan Herbarium, Ann Arbor, MI, USA
| |
Collapse
|
50
|
Roth SA, Griffis-Kyle KL, Barnes MA. Batrachochytrium dendrobatidis in the Arid and Thermally Extreme Sonoran Desert. ECOHEALTH 2023; 20:370-380. [PMID: 38243042 DOI: 10.1007/s10393-023-01668-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 12/08/2023] [Indexed: 01/21/2024]
Abstract
Batrachochytrium dendrobatidis (Bd), the causative agent of the devastating global amphibian disease chytridiomycosis, was not projected to threaten amphibians in hot and arid regions due to its sensitivity to heat and desiccation. However, Bd is being detected more frequently than ever in hot and arid regions of Australia and the USA, challenging our current understanding of the environmental tolerances of the pathogen under natural conditions. We surveyed for Bd in an extremely hot and arid portion of the Sonoran Desert, where the pathogen is not projected to occur, and related presence and prevalence of the pathogen to local environmental conditions. We collected eDNA samples from isolated desert water sites including six tinajas and 13 catchments in June and August of 2020 and swabbed a total of 281 anurans of three species (red-spotted toad Anaxyrus punctatus, Couch's spadefoot Scaphiopus couchii, and the Sonoran Desert toad Incillius alvarius) across five catchments and six tinajas from June to September of 2020. Overall, Bd occurred at 68.4% of sites, despite extreme heat and aridity routinely exceeding tolerances established in laboratory studies. Average summer maximum air and water temperatures were 40.7°C and 30.7°C, respectively, and sites received an average of just 16.9 mm of precipitation throughout the summer monsoon season. Prevalence was low (5.7%) across species and life stage. Our results demonstrate that Bd is capable of persisting and infecting amphibians beyond its projected range, indicating a need to account for higher thermal tolerances when quantifying risk of Bd presence and infection.
Collapse
Affiliation(s)
- Sadie A Roth
- Department of Natural Resources Management, Texas Tech University, 2500 Broadway, Lubbock, TX, 79409, USA.
| | - Kerry L Griffis-Kyle
- Department of Natural Resources Management, Texas Tech University, 2500 Broadway, Lubbock, TX, 79409, USA
| | - Matthew A Barnes
- Department of Natural Resources Management, Texas Tech University, 2500 Broadway, Lubbock, TX, 79409, USA
| |
Collapse
|