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Haghani NB, Lampe RH, Samuel BS, Chalasani SH, Matty MA. Identification and characterization of a skin microbiome on Caenorhabditis elegans suggests environmental microbes confer cuticle protection. Microbiol Spectr 2024:e0016924. [PMID: 38980017 DOI: 10.1128/spectrum.00169-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 06/10/2024] [Indexed: 07/10/2024] Open
Abstract
In the wild, C. elegans are emersed in environments teeming with a veritable menagerie of microorganisms. The C. elegans cuticular surface serves as a barrier and first point of contact with their microbial environments. In this study, we identify microbes from C. elegans natural habitats that associate with its cuticle, constituting a simple "skin microbiome." We rear our animals on a modified CeMbio, mCeMbio, a consortium of ecologically relevant microbes. We first combine standard microbiological methods with an adapted micro skin-swabbing tool to describe the skin-resident bacteria on the C. elegans surface. Furthermore, we conduct 16S rRNA gene sequencing studies to identify relative shifts in the proportion of mCeMbio bacteria upon surface-sterilization, implying distinct skin- and gut-microbiomes. We find that some strains of bacteria, including Enterobacter sp. JUb101, are primarily found on the nematode skin, while others like Stenotrophomonas indicatrix JUb19 and Ochrobactrum vermis MYb71 are predominantly found in the animal's gut. Finally, we show that this skin microbiome promotes host cuticle integrity in harsh environments. Together, we identify a skin microbiome for the well-studied nematode model and propose its value in conferring host fitness advantages in naturalized contexts. IMPORTANCE The genetic model organism C. elegans has recently emerged as a tool for understanding host-microbiome interactions. Nearly all of these studies either focus on pathogenic or gut-resident microbes. Little is known about the existence of native, nonpathogenic skin microbes or their function. We demonstrate that members of a modified C. elegans model microbiome, mCeMbio, can adhere to the animal's cuticle and confer protection from noxious environments. We combine a novel micro-swab tool, the first 16S microbial sequencing data from relatively unperturbed C. elegans, and physiological assays to demonstrate microbially mediated protection of the skin. This work serves as a foundation to explore wild C. elegans skin microbiomes and use C. elegans as a model for skin research.
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Affiliation(s)
- Nadia B Haghani
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California, USA
- University of California San Diego, La Jolla, California, USA
| | - Robert H Lampe
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California, USA
- Integrative Oceanography Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
| | - Buck S Samuel
- Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA
| | - Sreekanth H Chalasani
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California, USA
- University of California San Diego, La Jolla, California, USA
| | - Molly A Matty
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California, USA
- Biology, University of Portland, Portland, Oregon, USA
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Wan B, Chen G, Poon ESK, Fung HS, Lau A, Sin SYW. Environmental factors and host sex influence the skin microbiota structure of Hong Kong newt (Paramesotriton hongkongensis) in a coldspot of chytridiomycosis in subtropical East Asia. Integr Zool 2024. [PMID: 38872359 DOI: 10.1111/1749-4877.12855] [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: 06/15/2024]
Abstract
Chytridiomycosis, an infectious skin disease caused by the chytrid fungi, Batrachochytrium dendrobatidis and B. salamandrivorans, poses a significant threat to amphibian biodiversity worldwide. Antifungal bacteria found on the skin of chytrid-resistant amphibians could potentially provide defense against chytridiomycosis and lower mortality rates among resistant individuals. The Hong Kong newt (Paramesotriton hongkongensis) is native to East Asia, a region suspected to be the origin of chytrids, and has exhibited asymptomatic infection, suggesting a long-term coexistence with the chytrids. Therefore, the skin microbiota of this resistant species warrant investigation, along with other factors that can affect the microbiota. Among the 149 newts sampled in their natural habitats in Hong Kong, China, putative antifungal bacteria were found in all individuals. There were 314 amplicon sequence variants distributed over 25 genera of putative antifungal bacteria; abundant ones included Acinetobacter, Flavobacterium, and Novosphingobium spp. The skin microbiota compositions were strongly influenced by the inter-site geographical distances. Despite inter-site differences, we identified some core skin microbes across sites that could be vital to P. hongkongensis. The dominant cores included the family Comamonadaceae, family Chitinophagaceae, and class Betaproteobacteria. Moreover, habitat elevation and host sex also exhibited significant effects on skin microbiota compositions. The antifungal bacteria found on these newts offer an important resource for conservation against chytridiomycosis, such as developing probiotic treatments for susceptible species.
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Affiliation(s)
- Bowen Wan
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Guoling Chen
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Emily Shui Kei Poon
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Hon Shing Fung
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Anthony Lau
- Science Unit, Lingnan University, Hong Kong, China
| | - Simon Yung Wa Sin
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
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3
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Risely A, Byrne PG, Hoye BJ, Silla AJ. Dietary carotenoid supplementation has long-term and community-wide effects on the amphibian skin microbiome. Mol Ecol 2024; 33:e17203. [PMID: 37962103 DOI: 10.1111/mec.17203] [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: 04/21/2023] [Revised: 08/24/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023]
Abstract
The amphibian skin microbiome plays a crucial role in host immunity and pathogen defence, yet we know little about the environmental drivers of skin microbial variation across host individuals. Inter-individual variation in the availability of micro-nutrients such as dietary carotenoids, which are involved in amphibian immunity, may be one factor that influences skin microbial assembly across different life history stages. We compared the effect of four carotenoid supplementation regimes during different life stages on the adult skin microbiome using a captive population of the critically endangered southern corroboree frog, Pseudophryne corroboree. We applied 16S rRNA sequencing paired with joint-species distribution models to examine the effect of supplementation on taxon abundances. We found that carotenoid supplementation had subtle yet taxonomically widespread effects on the skin microbiome, even 4.5 years post supplementation. Supplementation during any life-history stage tended to have a positive effect on the number of bacterial taxa detected, although explanatory power was low. Some genera were sensitive to supplementation pre-metamorphosis, but most demonstrated either additive or dominant effects, whereby supplementation during one life history stage had intermediate or similar effects, respectively, to supplementation across life. Carotenoid supplementation increased abundances of taxa belonging to lactic acid bacteria, including Lactococcus and Enterococcus, a group of bacteria that have previously been linked to protection against the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). While the fitness benefits of these microbial shifts require further study, these results suggest a fundamental relationship between nutrition and the amphibian skin microbiome which may be critical to amphibian health and the development of novel conservation strategies.
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Affiliation(s)
- A Risely
- School of Science, Engineering and Environment, Salford University, Manchester, UK
| | - Phillip G Byrne
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Bethany J Hoye
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Aimee J Silla
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
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Hartmann AM, McGrath-Blaser SE, Colón-Piñeiro Z, Longo AV. Ontogeny drives shifts in skin bacterial communities in facultatively paedomorphic salamanders. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001399. [PMID: 37815535 PMCID: PMC10634365 DOI: 10.1099/mic.0.001399] [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: 05/15/2023] [Accepted: 10/02/2023] [Indexed: 10/11/2023]
Abstract
Microbiomes are major determinants of host growth, development and survival. In amphibians, host-associated bacteria in the skin can inhibit pathogen infection, but many processes can influence the structure and composition of the community. Here we quantified the shifts in skin-associated bacteria across developmental stages in the striped newt (Notophthalmus perstriatus), a threatened salamander species with a complex life history and vulnerable to infection by the amphibian chytrid fungus Batrachochytrium dendrobatidis and ranavirus. Our analyses show that pre-metamorphic larval and paedomorphic stages share similar bacterial compositions, and that the changes in the microbiome coincided with physiological restructuring during metamorphosis. Newts undergoing metamorphosis exhibited microbiome compositions that were intermediate between paedomorphic and post-metamorphic stages, further supporting the idea that metamorphosis is a major driver of host-associated microbes in amphibians. We did not find support for infection-related disruption of the microbiome, though infection replicates were small for each respective life stage.
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Affiliation(s)
- Arik M. Hartmann
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | | | | | - Ana V. Longo
- Department of Biology, University of Florida, Gainesville, Florida, USA
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Douglas AJ, Katzenback BA. The wood frog (Rana sylvatica): An emerging comparative model for anuran immunity and host-ranavirus interactions. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 147:104733. [PMID: 37550009 DOI: 10.1016/j.dci.2023.104733] [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: 12/11/2022] [Revised: 05/06/2023] [Accepted: 05/09/2023] [Indexed: 08/09/2023]
Abstract
The wood frog (Rana sylvatica) is widely distributed across North America and is the only amphibian found north of the Arctic Circle due to its remarkable ability to tolerate whole-body freezing. Recent mass mortalities attributable to Ranavirus spp. (family Iridoviridae) in wild juvenile wood frogs, coupled with the apparent high susceptibility of wood frogs to experimental infection with frog virus 3 (FV3), the type species of the Ranavirus genus, or FV3-like isolates underscore the serious threat ranaviruses poses to wood frog populations. Despite the ecological relevance and unique life history of wood frogs, our understanding of the wood frog immune system and antiviral response to ranaviral infections is in its infancy. Here we aim to (1) synthesize the limited knowledge of wood frog immune defences, (2) review recent progress in establishing the wood frog as a study system for ranavirus infection, and (3) highlight the future use of wood frogs as a model anuran to provide insight into the evolution of anuran immune systems and antiviral responses.
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Affiliation(s)
- Alexander J Douglas
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L3G1, Canada
| | - Barbara A Katzenback
- Department of Biology, University of Waterloo, Waterloo, Ontario, N2L3G1, Canada.
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Matthee CA, Bierman A, Krasnov BR, Matthee S, van der Mescht L. Documenting the microbiome diversity and distribution in selected fleas from South Africa with an emphasis on the cat flea, Ctenocephalides f. felis. Parasitology 2023; 150:979-989. [PMID: 37681253 PMCID: PMC10941216 DOI: 10.1017/s0031182023000835] [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: 03/22/2023] [Revised: 08/04/2023] [Accepted: 08/22/2023] [Indexed: 09/09/2023]
Abstract
The factors that influence parasite associated bacterial microbial diversity and the geographic distributions of bacteria are not fully understood. In an effort to gain a deeper understanding of the relationship between the bacterial diversity of Ctenocephalides fleas and host species and the external environment, we conducted a metagenetic analysis of 107 flea samples collected from 8 distinct sampling sites in South Africa. Pooled DNA samples mostly comprising of 2 or 3 individuals sampled from the same host, and belonging to the same genetic cluster, were sequenced using the Ion PGM™ Hi-Q™ Kit and the Ion 316™ Chip v2. Differences were detected in the microbiome compositions between Ctenocephalides felis, Ctenocephalides canis and Ctenocephalides connatus. Although based on a small sample, C. connatus occurring on wildlife harboured a higher bacterial richness when compared to C. felis on domestic animals. Intraspecific differences in the microbial OTU diversity were detected within C. f. felis that occurred on domestic cats and dogs. Different genetic lineages of C. f. felis were similar in microbial compositions but some differences exist in the presence or absence of rare bacteria. Rickettsia and Bartonella OTU's identified in South African cat fleas differ from those identified in the USA and Australia. Intraspecific microbial compositions also differ across geographic sampling sites. Generalized dissimilarity modelling showed that temperature and humidity are potentially important environmental factors explaining the pattern obtained.
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Affiliation(s)
- Conrad A. Matthee
- Department of Botany and Zoology, Evolutionary Genomics Group, Stellenbosch University, Stellenbosch, South Africa
| | - Anandi Bierman
- Department of Conservation Ecology & Entomology, Centre for Invasion Biology, Stellenbosch University, Stellenbosch, South Africa
| | - Boris R. Krasnov
- Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Israel
| | - Sonja Matthee
- Department of Conservation Ecology & Entomology, Stellenbosch University, Stellenbosch, South Africa
| | - Luther van der Mescht
- Department of Botany and Zoology, Evolutionary Genomics Group, Stellenbosch University, Stellenbosch, South Africa
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7
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Jiang Z, Shen Y, Niu Z, Li X. Effects of cadmium and diethylhexyl phthalate on skin microbiota of Rana chinensis tadpoles. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:64285-64299. [PMID: 37067706 DOI: 10.1007/s11356-023-26853-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 04/03/2023] [Indexed: 05/11/2023]
Abstract
Skin microbiotas play a crucial role in the health, homeostasis, and immune function of amphibians. The contaminants in water could affect the structure and composition of microbial communities. The effects of coexisting pollutants on frogs cannot be adequately explained by a single exposure due to the coexistence of Cd and DEHP in the environment. Following exposure to Cd and/or DEHP, we examined the histological characteristics of Rana chensinensis tadpoles. We also used the 16S rRNA gene sequencing technique to assess the relative abundance of skin microbial communities among tadpoles from each treatment group. Our findings indicate that R. chensinensis' skin experienced some degree of injury due to exposure to Cd and DEHP, which led to the imbalance of their skin microbial community homeostasis and thus interfered with the normal trial status of the host. That may eventually lead to the decline of the amphibian population.
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Affiliation(s)
- Zhaoyang Jiang
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, People's Republic of China
| | - Yujia Shen
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, People's Republic of China
| | - Ziyi Niu
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, People's Republic of China
| | - Xinyi Li
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, Shaanxi, People's Republic of China.
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8
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Lastochkina OV, Allagulova CR. The Mechanisms of the Growth Promotion and Protective Effects of Endophytic PGP Bacteria in Wheat Plants Under the Impact of Drought (Review). APPL BIOCHEM MICRO+ 2023; 59:14-32. [DOI: 10.1134/s0003683823010039] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/26/2022] [Accepted: 09/02/2022] [Indexed: 06/23/2023]
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Fieschi-Méric L, Van Leeuwen P, Hopkins K, Bournonville M, Denoël M, Lesbarrères D. Strong restructuration of skin microbiota during captivity challenges ex-situ conservation of amphibians. Front Microbiol 2023; 14:1111018. [PMID: 36891392 PMCID: PMC9986596 DOI: 10.3389/fmicb.2023.1111018] [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: 11/29/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023] Open
Abstract
In response to the current worldwide amphibian extinction crisis, conservation instances have encouraged the establishment of ex-situ collections for endangered species. The resulting assurance populations are managed under strict biosecure protocols, often involving artificial cycles of temperature and humidity to induce active and overwintering phases, which likely affect the bacterial symbionts living on the amphibian skin. However, the skin microbiota is an important first line of defense against pathogens that can cause amphibian declines, such as the chytrid Batrachochytrium dendrobatidis (Bd). Determining whether current husbandry practices for assurance populations might deplete amphibians from their symbionts is therefore essential to conservation success. Here, we characterize the effect of the transitions from the wild to captivity, and between aquatic and overwintering phases, on the skin microbiota of two newt species. While our results confirm differential selectivity of skin microbiota between species, they underscore that captivity and phase-shifts similarly affect their community structure. More specifically, the translocation ex-situ is associated with rapid impoverishment, decrease in alpha diversity and strong species turnover of bacterial communities. Shifts between active and overwintering phases also cause changes in the diversity and composition of the microbiota, and on the prevalence of Bd-inhibitory phylotypes. Altogether, our results suggest that current husbandry practices strongly restructure the amphibian skin microbiota. Although it remains to be determined whether these changes are reversible or have deleterious effects on their hosts, we discuss methods to limit microbial diversity loss ex-situ and emphasize the importance of integrating bacterial communities to applied amphibian conservation.
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Affiliation(s)
- Léa Fieschi-Méric
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), Université de Liège, Liège, Belgium.,Biology Department, Laurentian University, Sudbury, ON, Canada
| | | | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London (ZSL), London, United Kingdom
| | - Marie Bournonville
- Aquarium-Muséum de l'Université de Liège, Freshwater and OCeanic science Unit of reSearch (FOCUS), Liège, Belgium
| | - Mathieu Denoël
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), Université de Liège, Liège, Belgium
| | - David Lesbarrères
- Biology Department, Laurentian University, Sudbury, ON, Canada.,Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
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Goodwin KB, Hutchinson JD, Gompert Z. Spatiotemporal and ontogenetic variation, microbial selection, and predicted Bd-inhibitory function in the skin-associated microbiome of a Rocky Mountain amphibian. Front Microbiol 2022; 13:1020329. [PMID: 36583053 PMCID: PMC9792605 DOI: 10.3389/fmicb.2022.1020329] [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: 08/16/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Host-associated microbiomes play important roles in host health and pathogen defense. In amphibians, the skin-associated microbiota can contribute to innate immunity with potential implications for disease management. Few studies have examined season-long temporal variation in the amphibian skin-associated microbiome, and the interactions between bacteria and fungi on amphibian skin remain poorly understood. We characterize season-long temporal variation in the skin-associated microbiome of the western tiger salamander (Ambystoma mavortium) for both bacteria and fungi between sites and across salamander life stages. Two hundred seven skin-associated microbiome samples were collected from salamanders at two Rocky Mountain lakes throughout the summer and fall of 2018, and 127 additional microbiome samples were collected from lake water and lake substrate. We used 16S rRNA and ITS amplicon sequencing with Bayesian Dirichlet-multinomial regression to estimate the relative abundances of bacterial and fungal taxa, test for differential abundance, examine microbial selection, and derive alpha diversity. We predicted the ability of bacterial communities to inhibit the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen, using stochastic character mapping and a database of Bd-inhibitory bacterial isolates. For both bacteria and fungi, we observed variation in community composition through time, between sites, and with salamander age and life stage. We further found that temporal trends in community composition were specific to each combination of salamander age, life stage, and lake. We found salamander skin to be selective for microbes, with many taxa disproportionately represented relative to the environment. Salamander skin appeared to select for predicted Bd-inhibitory bacteria, and we found a negative relationship between the relative abundances of predicted Bd-inhibitory bacteria and Bd. We hope these findings will assist in the conservation of amphibian species threatened by chytridiomycosis and other emerging diseases.
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Affiliation(s)
- Kenen B. Goodwin
- Department of Watershed Sciences, Utah State University, Logan, UT, United States,Department of Wildland Resources, Utah State University, Logan, UT, United States,*Correspondence: Kenen B. Goodwin,
| | - Jaren D. Hutchinson
- Department of Wildland Resources, Utah State University, Logan, UT, United States
| | - Zachariah Gompert
- Department of Biology, Utah State University, Logan, UT, United States
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Martínez-Ugalde E, Ávila-Akerberg V, González Martínez TM, Vázquez Trejo M, Zavala Hernández D, Anaya-Morales SL, Rebollar EA. The skin microbiota of the axolotl Ambystoma altamirani is highly influenced by metamorphosis and seasonality but not by pathogen infection. Anim Microbiome 2022; 4:63. [PMID: 36503640 PMCID: PMC9743558 DOI: 10.1186/s42523-022-00215-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/16/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Microbiomes have been increasingly recognized as major contributors to host health and survival. In amphibians, bacterial members of the skin microbiota protect their hosts by inhibiting the growth of the fungal pathogen Batrachochytrium dendrobatidis (Bd). Even though several studies describe the influence of biotic and abiotic factors over the skin microbiota, it remains unclear how these symbiotic bacterial communities vary across time and development. This is particularly relevant for species that undergo metamorphosis as it has been shown that host physiology and ecology drastically influence diversity of the skin microbiome. RESULTS We found that the skin bacterial communities of the axolotl A. altamirani are largely influenced by the metamorphic status of the host and by seasonal variation of abiotic factors such as temperature, pH, dissolved oxygen and conductivity. Despite high Bd prevalence in these samples, the bacterial diversity of the skin microbiota did not differ between infected and non-infected axolotls, although relative abundance of particular bacteria were correlated with Bd infection intensity. CONCLUSIONS Our work shows that metamorphosis is a crucial process that shapes skin bacterial communities and that axolotls under different developmental stages respond differently to environmental seasonal variations. Moreover, this study greatly contributes to a better understanding of the factors that shape amphibian skin microbiota, especially in a largely underexplored group like axolotls (Mexican Ambystoma species).
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Affiliation(s)
- Emanuel Martínez-Ugalde
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Víctor Ávila-Akerberg
- grid.412872.a0000 0001 2174 6731Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Tanya M. González Martínez
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Montserrat Vázquez Trejo
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Dalia Zavala Hernández
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sara Lucia Anaya-Morales
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico ,grid.251313.70000 0001 2169 2489 Department of Biology, University of Mississippi, Oxford, MS USA
| | - Eria A. Rebollar
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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Bunker ME, Arnold AE, Weiss SL. Wild microbiomes of striped plateau lizards vary with reproductive season, sex, and body size. Sci Rep 2022; 12:20643. [PMID: 36450782 PMCID: PMC9712514 DOI: 10.1038/s41598-022-24518-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 11/16/2022] [Indexed: 12/05/2022] Open
Abstract
Long-term studies of animal microbiomes under natural conditions are valuable for understanding the effects of host demographics and environmental factors on host-associated microbial communities, and how those effects interact and shift over time. We examined how the cloacal microbiome of wild Sceloporus virgatus (the striped plateau lizard) varies under natural conditions in a multi-year study. Cloacal swabs were collected from wild-caught lizards across their entire active season and over three years in southeastern Arizona, USA. Analyses of 16S rRNA data generated on the Illumina platform revealed that cloacal microbiomes of S. virgatus vary as a function of season, sex, body size, and reproductive state, and do so independently of one another. Briefly, microbial diversity was lowest in both sexes during the reproductive season, was higher in females than in males, and was lowest in females when they were vitellogenic, and microbiome composition varied across seasons, sexes, and sizes. The pattern of decreased diversity during reproductive periods with increased sociality is surprising, as studies in other systems often suggest that microbial diversity generally increases with sociality. The cloacal microbiome was not affected significantly by hibernation and was relatively stable from year to year. This study highlights the importance of long term, wide-scale microbiome studies for capturing accurate perspectives on microbiome diversity and composition in animals. It also serves as a warning for comparisons of microbiomes across species, as each may be under a different suite of selective pressures or exhibit short-term variation from external or innate factors, which may differ in a species-specific manner.
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Affiliation(s)
- Marie E. Bunker
- grid.267047.00000 0001 2105 7936Department of Biology, University of Puget Sound, Tacoma, WA USA
| | - A. Elizabeth Arnold
- grid.134563.60000 0001 2168 186XSchool of Plant Sciences and Department of Ecology and Evolutionary Biology, The University of Arizona, Tucson, AZ USA
| | - Stacey L. Weiss
- grid.267047.00000 0001 2105 7936Department of Biology, University of Puget Sound, Tacoma, WA USA
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Busck MM, Lund MB, Bird TL, Bechsgaard JS, Bilde T, Schramm A. Temporal and spatial microbiome dynamics across natural populations of the social spider Stegodyphus dumicola. FEMS Microbiol Ecol 2022; 98:6526868. [PMID: 35147190 DOI: 10.1093/femsec/fiac015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/07/2022] [Accepted: 02/09/2022] [Indexed: 11/13/2022] Open
Abstract
Host symbiont interactions may form obligatory or facultative associations that are context dependent. Long-term studies on microbiome composition from wild populations should assess the temporal and spatial dynamics of host-microbe associations. We characterized the temporal and spatial variation in the bacterial microbiome composition in six populations of the social spider Stegodyphus dumicola for 2.5 years, using 16S rRNA gene amplicon sequencing of whole spiders. Individuals within a nest exhibit highly similar microbiomes, which remain stable over several generations and are not predictably affected by seasonal variation in temperature or humidity. This stability in nest microbiome is likely due to social transmission, whereas drift-like processes during new nest foundations explain variation in host microbiomes between nests. This is supported by the lack of obligate symbionts (i.e. no symbionts are present in all spider individuals). Quantitative PCR analyses showed that the bacterial load of individual spiders is stable in healthy nests but can increase dramatically in perishing nests. These increases are not driven by specific bacterial taxa but likely caused by loss of host immune control under deteriorating conditions. Spider nests show an annual survival rate of approximately 45%, but nest death is not correlated to microbiome composition, and the bacteria found in S. dumicola are not considered to be high virulence pathogens.
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Affiliation(s)
- Mette M Busck
- Section for Microbiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Marie B Lund
- Section for Microbiology, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Tharina L Bird
- Department of Biological Sciences and Biotechnology, Botswana International University of Science and Technology (BIUST), Botswana.,Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Aarhus, Denmark.,General Entomology, Ditsong National Museum of Natural History, Pretoria, South Africa.,Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Jesper S Bechsgaard
- Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Trine Bilde
- Section for Genetics, Ecology and Evolution, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Andreas Schramm
- Section for Microbiology, Department of Biology, Aarhus University, Aarhus, Denmark
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14
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Basanta MD, Rebollar EA, García-Castillo MG, Rosenblum EB, Byrne AQ, Piovia-Scott J, Parra-Olea G. Genetic variation of Batrachochytrium dendrobatidis is linked to skin bacterial diversity in the Pacific treefrog Hyliola regilla (hypochondriaca). Environ Microbiol 2021; 24:494-506. [PMID: 34959256 DOI: 10.1111/1462-2920.15861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 11/22/2021] [Accepted: 11/27/2021] [Indexed: 11/29/2022]
Abstract
Symbiotic bacterial communities are crucial to combating infections and contribute to host health. The amphibian skin microbiome plays an important role in protecting their hosts against pathogens such as Batrachochytrium dendrobatidis (Bd), one of the causative agents of chytridiomycosis, which is responsible for dramatic amphibian population declines worldwide. Although symbiotic skin bacteria are known to inhibit Bd growth, an understanding of the relationship between Bd genetic variability, environmental conditions, and skin bacterial communities is limited. Therefore, we examined the associations between Bd infection load, Bd genetic diversity and skin bacterial communities in five populations of Hyliola regilla (hypochondriaca) from environmentally contrasting sites in Baja California, Mexico. We observed differences in Bd genetics and infection load among sites and environments. Genetic analysis of Bd isolates revealed patterns of spatial structure corresponding to the five sites sampled. Amphibian skin bacterial diversity and community structure differed among environments and sites. Bacterial community composition was correlated with Bd genetic differences and infection load, with specific bacterial taxa enriched on infected and un-infected frogs. Our results indicate that skin-associated bacteria and Bd strains likely interact on the host skin, with consequences for microbial community structure and Bd infection intensity.
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Affiliation(s)
- María Delia Basanta
- Instituto de Biología, Universidad Nacional Autónoma de México, Mexico.,Posgrado en Ciencias Biológicas, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, AP 70-153, C.P. 04510, Mexico.,Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Eria A Rebollar
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Mirna G García-Castillo
- Universidad Politécnica de Huatusco, Huatusco, Veracruz, Mexico.,Universidad Veracruzana, Facultad de Ciencias Biológicas y Agropecuarias Región: Orizaba-Córdoba, Amatlán de los Reyes, Veracruz, Mexico
| | - Erica Bree Rosenblum
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA.,Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Allison Q Byrne
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, USA.,Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Jonah Piovia-Scott
- School of Biological Sciences, Washington State University, Vancouver, WA, USA
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15
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Weitzman CL, Rostama B, Thomason CA, May M, Belden LK, Hawley DM. Experimental test of microbiome protection across pathogen doses reveals importance of resident microbiome composition. FEMS Microbiol Ecol 2021; 97:6385755. [PMID: 34626186 DOI: 10.1093/femsec/fiab141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/07/2021] [Indexed: 01/04/2023] Open
Abstract
The commensal microbes inhabiting a host tissue can interact with invading pathogens and host physiology in ways that alter pathogen growth and disease manifestation. Prior work in house finches (Haemorhous mexicanus) found that resident ocular microbiomes were protective against conjunctival infection and disease caused by a relatively high dose of Mycoplasma gallisepticum. Here, we used wild-caught house finches to experimentally examine whether protective effects of the resident ocular microbiome vary with the dose of invading pathogen. We hypothesized that commensal protection would be strongest at low M. gallisepticum inoculation doses because the resident microbiome would be less disrupted by invading pathogen. Our five M. gallisepticum dose treatments were fully factorial with an antibiotic treatment to perturb resident microbes just prior to M. gallisepticum inoculation. Unexpectedly, we found no indication of protective effects of the resident microbiome at any pathogen inoculation dose, which was inconsistent with the prior work. The ocular bacterial communities at the beginning of our experiment differed significantly from those previously reported in local wild-caught house finches, likely causing this discrepancy. These variable results underscore that microbiome-based protection in natural systems can be context dependent, and natural variation in community composition may alter the function of resident microbiomes in free-living animals.
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Affiliation(s)
- Chava L Weitzman
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
| | - Bahman Rostama
- Department of Biomedical Sciences, University of New England, Biddeford - 04005, ME, USA
| | - Courtney A Thomason
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA.,Division of Remediation, Tennessee Department of Environment and Conservation, Oak Ridge - 37830, TN, USA
| | - Meghan May
- Department of Biomedical Sciences, University of New England, Biddeford - 04005, ME, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
| | - Dana M Hawley
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24060, USA
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16
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Ellison S, Knapp R, Vredenburg V. Longitudinal patterns in the skin microbiome of wild, individually marked frogs from the Sierra Nevada, California. ISME COMMUNICATIONS 2021; 1:45. [PMID: 37938625 PMCID: PMC9723788 DOI: 10.1038/s43705-021-00047-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 08/04/2021] [Accepted: 08/17/2021] [Indexed: 05/29/2023]
Abstract
The amphibian skin microbiome has been the focus of numerous studies because of the protective effects that some bacteria provide against the pathogenic fungus Batrachochytrium dendrobatidis, which has caused a global panzootic among amphibians. However, the mechanisms driving community structure and function in the amphibian skin microbiome are still poorly understood, and longitudinal analyses of the skin microbiome have not yet been conducted in wild populations. In this study, we investigate longitudinal patterns in the skin microbiome of 19 individually marked adult frogs from two wild populations of the endangered Sierra Nevada yellow-legged frog (Rana sierrae), sampled over the course of 2 years. We found that individuals with low bacterial diversity (dominated by order Burkhorderiales) had significantly more stable bacterial communities than those with higher diversity. Amplicon sequence variants (ASVs) with high relative abundance were significantly less transient than those with low relative abundance, and ASVs with intermediate-level relative abundances experienced the greatest volatility over time. Based on these results, we suggest that efforts to develop probiotic treatments to combat B. dendrobatidis should focus on bacteria that are found at high relative abundances in some members of a population, as these strains are more likely to persist and remain stable in the long term.
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Affiliation(s)
- Silas Ellison
- Department of Biology, San Francisco State University, San Francisco, California, USA.
| | - Roland Knapp
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, CA, USA
| | - Vance Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, California, USA
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17
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Cusick JA, Wellman CL, Demas GE. The call of the wild: using non-model systems to investigate microbiome-behaviour relationships. J Exp Biol 2021; 224:jeb224485. [PMID: 33988717 PMCID: PMC8180253 DOI: 10.1242/jeb.224485] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
On and within most sites across an animal's body live complex communities of microorganisms. These microorganisms perform a variety of important functions for their hosts, including communicating with the brain, immune system and endocrine axes to mediate physiological processes and affect individual behaviour. Microbiome research has primarily focused on the functions of the microbiome within the gastrointestinal tract (gut microbiome) using biomedically relevant laboratory species (i.e. model organisms). These studies have identified important connections between the gut microbiome and host immune, neuroendocrine and nervous systems, as well as how these connections, in turn, influence host behaviour and health. Recently, the field has expanded beyond traditional model systems as it has become apparent that the microbiome can drive differences in behaviour and diet, play a fundamental role in host fitness and influence community-scale dynamics in wild populations. In this Review, we highlight the value of conducting hypothesis-driven research in non-model organisms and the benefits of a comparative approach that assesses patterns across different species or taxa. Using social behaviour as an intellectual framework, we review the bidirectional relationship between the gut microbiome and host behaviour, and identify understudied mechanisms by which these effects may be mediated.
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Affiliation(s)
- Jessica A. Cusick
- Department of Biology, Indiana University, Biology Building 142, 1001 East Third Street, Bloomington, IN 47405, USA
- Animal Behavior Program, Indiana University, 409 N. Park Avenue, Bloomington, IN 47405, USA
| | - Cara L. Wellman
- Animal Behavior Program, Indiana University, 409 N. Park Avenue, Bloomington, IN 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, 1101 E. 10th Street, Bloomington, IN 47405-7007, USA
- Program in Neuroscience, Indiana University, Psychology Building, 1101 E 10th Street Bloomington, IN 47405-2204, USA
| | - Gregory E. Demas
- Department of Biology, Indiana University, Biology Building 142, 1001 East Third Street, Bloomington, IN 47405, USA
- Animal Behavior Program, Indiana University, 409 N. Park Avenue, Bloomington, IN 47405, USA
- Program in Neuroscience, Indiana University, Psychology Building, 1101 E 10th Street Bloomington, IN 47405-2204, USA
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18
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Kavamura VN, Mendes R, Bargaz A, Mauchline TH. Defining the wheat microbiome: Towards microbiome-facilitated crop production. Comput Struct Biotechnol J 2021; 19:1200-1213. [PMID: 33680361 PMCID: PMC7902804 DOI: 10.1016/j.csbj.2021.01.045] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 01/29/2021] [Accepted: 01/30/2021] [Indexed: 12/17/2022] Open
Abstract
Wheat is one of the world's most important crops, but its production relies heavily on agrochemical inputs which can be harmful to the environment when used excessively. It is well known that a multitude of microbes interact with eukaryotic organisms, including plants, and the sum of microbes and their functions associated with a given host is termed the microbiome. Plant-microbe interactions can be beneficial, neutral or harmful to the host plant. Over the last decade, with the development of next generation DNA sequencing technology, our understanding of the plant microbiome structure has dramatically increased. Considering that defining the wheat microbiome is key to leverage crop production in a sustainable way, here we describe how different factors drive microbiome assembly in wheat, including crop management, edaphic-environmental conditions and host selection. In addition, we highlight the benefits to take a multidisciplinary approach to define and explore the wheat core microbiome to generate solutions based on microbial (synthetic) communities or single inoculants. Advances in plant microbiome research will facilitate the development of microbial strategies to guarantee a sustainable intensification of crop production.
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Affiliation(s)
- Vanessa N. Kavamura
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, UK
| | - Rodrigo Mendes
- Laboratory of Environmental Microbiology, Embrapa Environment, Jaguariúna, SP, Brazil
| | - Adnane Bargaz
- Agrobiosciences, Mohammed VI Polytechnic University, Benguerir, Morocco
| | - Tim H. Mauchline
- Sustainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, UK
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19
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Naumann B, Schweiger S, Hammel JU, Müller H. Parallel evolution of direct development in frogs - Skin and thyroid gland development in African Squeaker Frogs (Anura: Arthroleptidae: Arthroleptis). Dev Dyn 2021; 250:584-600. [PMID: 33354814 DOI: 10.1002/dvdy.275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Cases of parallel evolution offer the possibility to identify adaptive traits and to uncover developmental constraints on the evolutionary trajectories of these traits. The independent evolution of direct development from the ancestral biphasic life history in frogs is such a case of parallel evolution. In frogs, aquatic larvae (tadpoles) differ profoundly from their adult forms and exhibit a stunning diversity regarding their habitats, morphology and feeding behaviors. The transition from the tadpole to the adult is a climactic, thyroid hormone (TH)-dependent process of profound and fast morphological rearrangement called metamorphosis. One of the organ systems that experiences the most comprehensive metamorphic rearrangements is the skin. Direct-developing frogs lack a free-swimming tadpole and hatch from terrestrial eggs as fully formed froglets. In the few species examined, development is characterized by the condensed and transient formation of some tadpole-specific features and the early formation of adult-specific features during a "cryptic" metamorphosis. RESULTS We show that skin in direct-developing African squeaker frogs (Arthroleptis) is also repatterned from a tadpole-like to an adult-like histology during a cryptic metamorphosis. This repatterning correlates with histological thyroid gland maturation. A comparison with data from the Puerto Rican coqui (Eleutherodactylus coqui) reveals that the evolution of direct development in these frogs is associated with a comparable heterochronic shift of thyroid gland maturation. CONCLUSION This suggests that the development of many adult features is still dependent on, and possibly constrained by, the ancestral dependency on thyroid hormone signaling.
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Affiliation(s)
| | - Susan Schweiger
- Institut für Zoologie und Evolutionsforschung, Jena, Germany
| | - Jörg U Hammel
- Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung, Außenstelle am DESY, Hamburg, Germany
| | - Hendrik Müller
- Institut für Zoologie und Evolutionsforschung, Jena, Germany.,Zentralmagazin Naturwissenschaftlicher Sammlungen, Martin-Luther-Universität Halle-Wittenberg, Halle (Saale), Germany.,Department of Life Sciences, The Natural History Museum, London, UK
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