1
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Eskew EA, Fraser D, Vonhof MJ, Pinsky ML, Maslo B. Host gene expression in wildlife disease: making sense of species-level responses. Mol Ecol 2021; 30:6517-6530. [PMID: 34516689 DOI: 10.1111/mec.16172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 08/16/2021] [Accepted: 08/31/2021] [Indexed: 12/11/2022]
Abstract
Emerging infectious diseases are significant threats to wildlife conservation, yet the impacts of pathogen exposure and infection can vary widely among host species. As such, conservation biologists and disease ecologists have increasingly aimed to understand species-specific host susceptibility using molecular methods. In particular, comparative gene expression assays have been used to contrast the transcriptomic responses of disease-resistant and disease-susceptible hosts to pathogen exposure. This work usually assumes that the gene expression responses of disease-resistant species will reveal the activation of molecular pathways contributing to host defence. However, results often show that disease-resistant hosts undergo little gene expression change following pathogen challenge. Here, we discuss the mechanistic implications of these "null" findings and offer methodological suggestions for future molecular studies of wildlife disease. First, we highlight that muted transcriptomic responses with minimal immune system recruitment may indeed be protective for nonsusceptible hosts if they limit immunopathology and promote pathogen tolerance in systems where susceptible hosts suffer from genetic dysregulation. Second, we argue that overly narrow investigation of responses to pathogen exposure may overlook important, constitutively active molecular pathways that underlie species-specific defences. Finally, we outline alternative study designs and approaches that complement interspecific transcriptomic comparisons, including intraspecific gene expression studies and genomic methods to detect signatures of selection. Collectively, these insights will help ecologists extract maximal information from conservation-relevant transcriptomic data sets, leading to a deeper understanding of host defences and, ultimately, the implementation of successful conservation interventions.
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Affiliation(s)
- Evan A Eskew
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA.,Department of Biology, Pacific Lutheran University, Tacoma, Washington, USA
| | - Devaughn Fraser
- Wildlife Genetics Research Laboratory, California Department of Fish and Wildlife, Sacramento, California, USA
| | - Maarten J Vonhof
- Department of Biological Sciences, Western Michigan University, Kalamazoo, Michigan, USA
| | - Malin L Pinsky
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
| | - Brooke Maslo
- Department of Ecology, Evolution and Natural Resources, Rutgers, The State University of New Jersey, New Brunswick, New Jersey, USA
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2
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Ruthsatz K, Lyra ML, Lambertini C, Belasen AM, Jenkinson TS, da Silva Leite D, Becker CG, Haddad CFB, James TY, Zamudio KR, Toledo LF, Vences M. Skin microbiome correlates with bioclimate and Batrachochytrium dendrobatidis infection intensity in Brazil's Atlantic Forest treefrogs. Sci Rep 2020; 10:22311. [PMID: 33339839 PMCID: PMC7749163 DOI: 10.1038/s41598-020-79130-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/04/2020] [Indexed: 12/20/2022] Open
Abstract
In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to the rapid loss of amphibian populations here and worldwide. The impact of Bd on amphibians is determined by the host's immune system, of which the skin microbiome is a critical component. The richness and diversity of such cutaneous bacterial communities are known to be shaped by abiotic factors which thus may indirectly modulate host susceptibility to Bd. This study aimed to contribute to understanding the environment-host–pathogen interaction determining skin bacterial communities in 819 treefrogs (Anura: Hylidae and Phyllomedusidae) from 71 species sampled across the AF. We investigated whether abiotic factors influence the bacterial community richness and structure on the amphibian skin. We further tested for an association between skin bacterial community structure and Bd co-occurrence. Our data revealed that temperature, precipitation, and elevation consistently correlate with richness and diversity of the skin microbiome and also predict Bd infection status. Surprisingly, our data suggest a weak but significant positive correlation of Bd infection intensity and bacterial richness. We highlight the prospect of future experimental studies on the impact of changing environmental conditions associated with global change on environment-host–pathogen interactions in the AF.
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Affiliation(s)
- Katharina Ruthsatz
- Institute of Zoology, Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany. .,Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106, Brunswick, Germany.
| | - Mariana L Lyra
- Laboratório de Herpetologia, Depto de Biodiversidade, Instituto de Biociências and Centro de Aquicultura (CAUNESP), Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo, Brazil
| | - Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, 13083-862, Brazil
| | - Anat M Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA
| | - Thomas S Jenkinson
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Davis, CA, USA
| | - Domingos da Silva Leite
- Laboratório de Antígenos Bacterianos II, Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, Campinas, São Paulo, CEP 13083-862, Brazil
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35847, USA
| | - Célio F B Haddad
- Laboratório de Herpetologia, Depto de Biodiversidade, Instituto de Biociências and Centro de Aquicultura (CAUNESP), Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, 13083-862, Brazil
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106, Brunswick, Germany
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3
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Zamudio KR, McDonald CA, Belasen AM. High Variability in Infection Mechanisms and Host Responses: A Review of Functional Genomic Studies of Amphibian Chytridiomycosis. HERPETOLOGICA 2020. [DOI: 10.1655/0018-0831-76.2.189] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA
| | - Cait A. McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA
| | - Anat M. Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853-2701, USA
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4
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Gupta AK, Carviel J, Shear NH. A Stealthy Fungal Attack Requires an Equally Clandestine Approach to Onychomycosis Treatment. J Am Podiatr Med Assoc 2019; 109:374-378. [PMID: 31599670 DOI: 10.7547/17-080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Onychomycosis is a chronic fungal infection of the nail that is recalcitrant to treatment. It is unclear why normally effective antifungal therapy results in low cure rates. Evidence suggests that there may be a plethora of reasons that include the limited immune presence in the nail, reduced circulation, presence of commensal microbes, and fungal influence on immune signaling. Therefore, treatment should be designed to address these possibilities and work synergistically with both the innate and adaptive immune responses.
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Affiliation(s)
- Aditya K. Gupta
- Mediprobe Research, Inc, London, Ontario, Canada
- Division of Dermatology, Department of Medicine, University of Toronto School of Medicine, Toronto, Canada
| | | | - Neil H. Shear
- Division of Dermatology, Department of Medicine, University of Toronto School of Medicine, Toronto, Canada
- Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
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5
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Rosani U, Young T, Bai CM, Alfaro AC, Venier P. Dual Analysis of Virus-Host Interactions: The Case of Ostreid herpesvirus 1 and the Cupped Oyster Crassostrea gigas. Evol Bioinform Online 2019; 15:1176934319831305. [PMID: 30828244 PMCID: PMC6388457 DOI: 10.1177/1176934319831305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 01/14/2019] [Indexed: 12/20/2022] Open
Abstract
Dual analyses of the interactions between Ostreid herpesvirus 1 (OsHV-1) and the bivalve Crassostrea gigas during infection can unveil events critical to the onset and progression of this viral disease and can provide novel strategies for mitigating and preventing oyster mortality. Among the currently used “omics” technologies, dual transcriptomics (dual RNA-seq) coupled with the analysis of viral DNA in the host tissues has greatly advanced the knowledge of genes and pathways mostly contributing to host defense responses, expression profiles of annotated and unknown OsHV-1 open reading frames (ORFs), and viral genome variability. In addition to dual RNA-seq, proteomics and metabolomics analyses have the potential to add complementary information, needed to understand how a malacoherpesvirus can redirect and exploit the vital processes of its host. This review explores our current knowledge of “omics” technologies in the study of host-pathogen interactions and highlights relevant applications of these fields of expertise to the complex case of C gigas infections by OsHV-1, which currently threaten the mollusk production sector worldwide.
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Affiliation(s)
- Umberto Rosani
- Department of Biology, University of Padova, Padova, Italy
| | - Tim Young
- Aquaculture Biotechnology Research Group, School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Chang-Ming Bai
- Key Laboratory of Maricultural Organism Disease Control, Ministry of Agriculture, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Andrea C Alfaro
- Aquaculture Biotechnology Research Group, School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand
| | - Paola Venier
- Department of Biology, University of Padova, Padova, Italy
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6
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Eskew EA, Shock BC, LaDouceur EEB, Keel K, Miller MR, Foley JE, Todd BD. Gene expression differs in susceptible and resistant amphibians exposed to Batrachochytrium dendrobatidis. ROYAL SOCIETY OPEN SCIENCE 2018; 5:170910. [PMID: 29515828 PMCID: PMC5830717 DOI: 10.1098/rsos.170910] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Chytridiomycosis, the disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has devastated global amphibian biodiversity. Nevertheless, some hosts avoid disease after Bd exposure even as others experience near-complete extirpation. It remains unclear whether the amphibian adaptive immune system plays a role in Bd defence. Here, we describe gene expression in two host species-one susceptible to chytridiomycosis and one resistant-following exposure to two Bd isolates that differ in virulence. Susceptible wood frogs (Rana sylvatica) had high infection loads and mortality when exposed to the more virulent Bd isolate but lower infection loads and no fatal disease when exposed to the less virulent isolate. Resistant American bullfrogs (R. catesbeiana) had high survival across treatments and rapidly cleared Bd infection or avoided infection entirely. We found widespread upregulation of adaptive immune genes and downregulation of important metabolic and cellular maintenance components in wood frogs after Bd exposure, whereas American bullfrogs showed little gene expression change and no evidence of an adaptive immune response. Wood frog responses suggest that adaptive immune defences may be ineffective against virulent Bd isolates that can cause rapid physiological dysfunction. By contrast, American bullfrogs exhibited robust resistance to Bd that is likely attributable, at least in part, to their continued upkeep of metabolic and skin integrity pathways as well as greater antimicrobial peptide expression compared to wood frogs, regardless of exposure. Greater understanding of these defences will ultimately help conservationists manage chytridiomycosis.
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Affiliation(s)
- Evan A. Eskew
- Graduate Group in Ecology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
- EcoHealth Alliance, 460 West 34th Street – 17th Floor, New York, NY 10001, USA
- Author for correspondence: Evan A. Eskew e-mail:
| | - Barbara C. Shock
- Department of Biology, Lincoln Memorial University, 6965 Cumberland Gap Parkway, Harrogate, TN 37752, USA
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | | | - Kevin Keel
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Michael R. Miller
- Department of Animal Science, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Janet E. Foley
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
| | - Brian D. Todd
- Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, One Shields Avenue, Davis, CA 95616, USA
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7
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Advancing Understanding of Amphibian Evolution, Ecology, Behavior, and Conservation with Massively Parallel Sequencing. POPULATION GENOMICS 2018. [DOI: 10.1007/13836_2018_61] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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8
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Gupta AK, Carviel J, Shear NH. Onychomycosis and Chronic Fungal Disease: Exploiting a Commensal Disguise to Stage a Covert Invasion. J Cutan Med Surg 2017; 22:318-322. [PMID: 29191054 DOI: 10.1177/1203475417745827] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Onychomycosis is a chronic fungal infection that is recalcitrant to treatment and often results in relapse. New evidence suggests that disease prognosis may be linked to pathogens manipulating host immune responses. Therefore, individuals with specific mutations, including those affecting pattern recognition receptors or the interleukin (IL)-17 and IL-22 pathways, may be more susceptible to infection. Moreover, it is recommended that those with a family history of immune mutations or predisposition to fungal disease be treated aggressively for onychomycosis prior to symptom progression. In addition, incorporating genetic testing and new investigational therapy such as IL-33 and interferon-γ may improve treatment outcome.
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Affiliation(s)
- Aditya K Gupta
- 1 Department of Medicine, University of Toronto School of Medicine, Toronto, Ontario, Canada.,2 Mediprobe Research, London, Ontario, Canada
| | | | - Neil H Shear
- 3 Division of Dermatology, Department of Medicine, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada
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9
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Farrer RA, Fisher MC. Describing Genomic and Epigenomic Traits Underpinning Emerging Fungal Pathogens. ADVANCES IN GENETICS 2017; 100:73-140. [PMID: 29153405 DOI: 10.1016/bs.adgen.2017.09.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
An unprecedented number of pathogenic fungi are emerging and causing disease in animals and plants, putting the resilience of wild and managed ecosystems in jeopardy. While the past decades have seen an increase in the number of pathogenic fungi, they have also seen the birth of new big data technologies and analytical approaches to tackle these emerging pathogens. We review how the linked fields of genomics and epigenomics are transforming our ability to address the challenge of emerging fungal pathogens. We explore the methodologies and bioinformatic toolkits that currently exist to rapidly analyze the genomes of unknown fungi, then discuss how these data can be used to address key questions that shed light on their epidemiology. We show how genomic approaches are leading a revolution into our understanding of emerging fungal diseases and speculate on future approaches that will transform our ability to tackle this increasingly important class of emerging pathogens.
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10
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Scheele BC, Skerratt LF, Hunter DA, Banks SC, Pierson JC, Driscoll DA, Byrne PG, Berger L. Disease-associated change in an amphibian life-history trait. Oecologia 2017; 184:825-833. [DOI: 10.1007/s00442-017-3911-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 07/06/2017] [Indexed: 11/30/2022]
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11
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Revisiting Adaptive Potential, Population Size, and Conservation. Trends Ecol Evol 2017; 32:506-517. [PMID: 28476215 DOI: 10.1016/j.tree.2017.03.012] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/28/2017] [Accepted: 03/31/2017] [Indexed: 11/24/2022]
Abstract
Additive genetic variance (VA) reflects the potential for evolutionary shifts and can be low for some traits or populations. High VA is critical for the conservation of threatened species under selection to facilitate adaptation. Theory predicts tight associations between population size and VA, but data from some experimental models, and managed and natural populations do not always support this prediction. However, VA comparisons often have low statistical power, are undertaken in highly controlled environments distinct from natural habitats, and focus on traits with limited ecological relevance. Moreover, investigations of VA typically fail to consider rare alleles, genetic load, or linkage disequilibrium, resulting in deleterious effects associated with favored alleles in small populations. Large population size remains essential for ensuring adaptation.
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12
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Shultz AJ, Baker AJ, Hill GE, Nolan PM, Edwards SV. SNPs across time and space: population genomic signatures of founder events and epizootics in the House Finch ( Haemorhous mexicanus). Ecol Evol 2016; 6:7475-7489. [PMID: 28725414 PMCID: PMC5513257 DOI: 10.1002/ece3.2444] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/11/2016] [Indexed: 12/27/2022] Open
Abstract
Identifying genomic signatures of natural selection can be challenging against a background of demographic changes such as bottlenecks and population expansions. Here, we disentangle the effects of demography from selection in the House Finch (Haemorhous mexicanus) using samples collected before and after a pathogen‐induced selection event. Using ddRADseq, we genotyped over 18,000 SNPs across the genome in native pre‐epizootic western US birds, introduced birds from Hawaii and the eastern United States, post‐epizootic eastern birds, and western birds sampled across a similar time span. We found 14% and 7% reductions in nucleotide diversity, respectively, in Hawaiian and pre‐epizootic eastern birds relative to pre‐epizootic western birds, as well as elevated levels of linkage disequilibrium and other signatures of founder events. Despite finding numerous significant frequency shifts (outlier loci) between pre‐epizootic native and introduced populations, we found no signal of reduced genetic diversity, elevated linkage disequilibrium, or outlier loci as a result of the epizootic. Simulations demonstrate that the proportion of outliers associated with founder events could be explained by genetic drift. This rare view of genetic evolution across time in an invasive species provides direct evidence that demographic shifts like founder events have genetic consequences more widespread across the genome than natural selection.
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Affiliation(s)
- Allison J Shultz
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology Harvard University Cambridge MA USA
| | - Allan J Baker
- Department of Natural History, Royal Ontario Museum Department of Ecology and Evolutionary Biology University of Toronto Toronto ON Canada
| | - Geoffrey E Hill
- Department of Biological Sciences Auburn University Auburn AL USA
| | - Paul M Nolan
- Department of Biology The Citadel Charleston SC USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology and Museum of Comparative Zoology Harvard University Cambridge MA USA
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13
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Palomar G, Bosch J, Cano JM. Heritability of Batrachochytrium dendrobatidis burden and its genetic correlation with development time in a population of Common toad (Bufo spinosus). Evolution 2016; 70:2346-2356. [PMID: 27480345 DOI: 10.1111/evo.13029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 07/15/2016] [Accepted: 07/20/2016] [Indexed: 11/26/2022]
Abstract
Despite the important threat that emerging pathogens pose for the conservation of biodiversity as well as human health, very little is known about the adaptive potential of host species to withstand infections. We studied the quantitative genetic architecture responsible for the burden of the fungal pathogen Batrachochytrium dendrobatidis in a population of common toads in conjunction with other life-history traits (i.e., body size and development rate) that may be affected by common selective pressures. We found a significant heritable component that is associated with fungal burden, which may allow for local adaptation to this pathogen to proceed. In addition, the high genetic correlation found between fungal burden and development time suggests that both traits have to be taken into account in order to assess the adaptive response of host populations to this emerging pathogen.
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Affiliation(s)
- Gemma Palomar
- Research Unit of Biodiversity (UO-CSIC-PA), Edificio de Investigación, Gonzalo Gutiérrez Quirós s/n, 33600, Mieres, Spain. .,Department of Biology of Organisms and Systems, University of Oviedo, Catedrático Rodrigo Uría s/n, 33006, Oviedo, Spain.
| | - Jaime Bosch
- Museo Nacional de Ciencias Naturales, CSIC, José Gutiérrez Abascal, 2, 28006, Madrid, Spain.,Centro de Investigación, Seguimiento y Evaluación, Parque Nacional de la Sierra de Guadarrama, Cta. M-604, Km. 27.6, 28740, Rascafría, Spain
| | - José Manuel Cano
- Research Unit of Biodiversity (UO-CSIC-PA), Edificio de Investigación, Gonzalo Gutiérrez Quirós s/n, 33600, Mieres, Spain.,Department of Biology of Organisms and Systems, University of Oviedo, Catedrático Rodrigo Uría s/n, 33006, Oviedo, Spain
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14
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Bradley PW, Gervasi SS, Hua J, Cothran RD, Relyea RA, Olson DH, Blaustein AR. Differences in sensitivity to the fungal pathogen Batrachochytrium dendrobatidis among amphibian populations. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2015; 29:1347-1356. [PMID: 26219571 DOI: 10.1111/cobi.12566] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 01/27/2015] [Accepted: 02/22/2015] [Indexed: 05/22/2023]
Abstract
Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies. We experimentally investigated intraspecific differences in host sensitivity to Bd across 10 populations of wood frogs (Lithobates sylvaticus) raised from eggs to metamorphosis. We exposed the post-metamorphic wood frogs to Bd and monitored survival for 30 days under controlled laboratory conditions. Populations differed in overall survival and mortality rate. Infection load also differed among populations but was not correlated with population differences in risk of mortality. Such population-level variation in sensitivity to Bd may result in reservoir populations that may be a source for the transmission of Bd to other sensitive populations or species. Alternatively, remnant populations that are less sensitive to Bd could serve as sources for recolonization after epidemic events.
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Affiliation(s)
- Paul W Bradley
- Environmental Sciences Graduate Program, Oregon State University, 104 Wilkinson Hall, Corvallis, OR, 97331, U.S.A
| | - Stephanie S Gervasi
- Department of Integrative Biology, University of South Florida, 4202 E Fowler Avenue, Tampa, FL, 33620, U.S.A
| | - Jessica Hua
- Department of Forestry and Natural Resources, Purdue University, 715 West State Street, West Lafayette, IN, 47907, U.S.A
| | - Rickey D Cothran
- Department of Biological Sciences, Southwestern Oklahoma University, 100 Campus Drive, Weatherford, OK, 73096, U.S.A
| | - Rick A Relyea
- Department of Biological Sciences, BT2115, Rensselaer Polytechnic Institute, Troy, NY, 12180, U.S.A
| | - Deanna H Olson
- USDA Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way, Corvallis, OR, 97331, U.S.A
| | - Andrew R Blaustein
- Environmental Sciences Graduate Program, Oregon State University, 104 Wilkinson Hall, Corvallis, OR, 97331, U.S.A
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, 97331, U.S.A
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15
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Ruggeri J, Longo AV, Gaiarsa MP, Alencar LRV, Lambertini C, Leite DS, Carvalho-e-Silva SP, Zamudio KR, Toledo LF, Martins M. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest. PLoS One 2015; 10:e0130554. [PMID: 26161777 PMCID: PMC4498819 DOI: 10.1371/journal.pone.0130554] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 05/22/2015] [Indexed: 11/18/2022] Open
Abstract
Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation.
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Affiliation(s)
- Joice Ruggeri
- Instituto de Biologia, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, Brazil
| | - Ana V. Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America
| | - Marília P. Gaiarsa
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Laura R. V. Alencar
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Domingos S. Leite
- Laboratório de Antígenos Bacterianos, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | | | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Marcio Martins
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
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Durmuş S, Çakır T, Özgür A, Guthke R. A review on computational systems biology of pathogen-host interactions. Front Microbiol 2015; 6:235. [PMID: 25914674 PMCID: PMC4391036 DOI: 10.3389/fmicb.2015.00235] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 03/10/2015] [Indexed: 12/27/2022] Open
Abstract
Pathogens manipulate the cellular mechanisms of host organisms via pathogen-host interactions (PHIs) in order to take advantage of the capabilities of host cells, leading to infections. The crucial role of these interspecies molecular interactions in initiating and sustaining infections necessitates a thorough understanding of the corresponding mechanisms. Unlike the traditional approach of considering the host or pathogen separately, a systems-level approach, considering the PHI system as a whole is indispensable to elucidate the mechanisms of infection. Following the technological advances in the post-genomic era, PHI data have been produced in large-scale within the last decade. Systems biology-based methods for the inference and analysis of PHI regulatory, metabolic, and protein-protein networks to shed light on infection mechanisms are gaining increasing demand thanks to the availability of omics data. The knowledge derived from the PHIs may largely contribute to the identification of new and more efficient therapeutics to prevent or cure infections. There are recent efforts for the detailed documentation of these experimentally verified PHI data through Web-based databases. Despite these advances in data archiving, there are still large amounts of PHI data in the biomedical literature yet to be discovered, and novel text mining methods are in development to unearth such hidden data. Here, we review a collection of recent studies on computational systems biology of PHIs with a special focus on the methods for the inference and analysis of PHI networks, covering also the Web-based databases and text-mining efforts to unravel the data hidden in the literature.
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Affiliation(s)
- Saliha Durmuş
- Computational Systems Biology Group, Department of Bioengineering, Gebze Technical University, KocaeliTurkey
| | - Tunahan Çakır
- Computational Systems Biology Group, Department of Bioengineering, Gebze Technical University, KocaeliTurkey
| | - Arzucan Özgür
- Department of Computer Engineering, Boǧaziçi University, IstanbulTurkey
| | - Reinhard Guthke
- Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knoell-Institute, JenaGermany
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Downs CJ, Adelman JS, Demas GE. Mechanisms and methods in ecoimmunology: integrating within-organism and between-organism processes. Integr Comp Biol 2014; 54:340-52. [PMID: 24944113 DOI: 10.1093/icb/icu082] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Ecoimmunology utilizes techniques from traditionally laboratory-based disciplines--for example, immunology, genomics, proteomics, neuroendocrinology, and cell biology--to reveal how the immune systems of wild organisms both shape and respond to ecological and evolutionary pressures. Immunological phenotypes are embedded within a mechanistic pathway leading from genotype through physiology to shape higher-order biological phenomena. As such, "mechanisms" in ecoimmunology can refer to both the within-host processes that shape immunological phenotypes, or it can refer the ways in which different immunological phenotypes alter between-organism processes at ecological and evolutionary scales. The mechanistic questions ecoimmunologists can ask, both within-organisms and between-organisms, however, often have been limited by techniques that do not easily transfer to wild, non-model systems. Thus, a major focus in ecoimmunology has been developing and refining the available toolkit. Recently, this toolkit has been expanding at an unprecedented rate, bringing new challenges to choosing techniques and standardizing protocols across studies. By confronting these challenges, we will be able to enhance ecoimmunological inquiries into the physiological basis of life-history trade-offs; the development of low-cost biomarkers for susceptibility to disease; and the investigation of the ecophysiological underpinnings of disease ecology, behavior, and the coevolution of host-parasite systems. The technical advances in, and crossover technologies from, disciplines associated with ecoimmunology and how these advances can help us understand the mechanistic basis of immunological variability in wild species were the focus of the symposium, Methods and Mechanisms in Ecoimmunology.
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Affiliation(s)
- C J Downs
- *Department of Natural Resources and Environmental Sciences, University of Nevada, 1664 North Virginia Street, MS 168, Reno, NV 89557, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Department of Biology, Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - J S Adelman
- *Department of Natural Resources and Environmental Sciences, University of Nevada, 1664 North Virginia Street, MS 168, Reno, NV 89557, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Department of Biology, Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
| | - G E Demas
- *Department of Natural Resources and Environmental Sciences, University of Nevada, 1664 North Virginia Street, MS 168, Reno, NV 89557, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Department of Biology, Center for the Integrative Study of Animal Behavior, Indiana University, Bloomington, IN 47405, USA
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