Ana V Longo, Jaiber J Solano-Iguaran, Andrés Valenzuela-Sánchez, Mario Alvarado-Rybak, Claudio Azat, Leonardo D Bacigalupe
{"title":"Blurred Lines Between Determinism and Stochasticity in an Amphibian Phylosymbiosis Under Pathogen Infection.","authors":"Ana V Longo, Jaiber J Solano-Iguaran, Andrés Valenzuela-Sánchez, Mario Alvarado-Rybak, Claudio Azat, Leonardo D Bacigalupe","doi":"10.1111/mec.17741","DOIUrl":null,"url":null,"abstract":"<p><p>Selection, dispersal and drift jointly contribute to generating variation in microbial composition within and between hosts, habitats and ecosystems. However, we have limited examples of how these processes interact as hosts and their microbes turn over across latitudinal gradients of biodiversity and climate. To bridge this gap, we assembled an extensive dataset of 580 skin bacteriomes from 22 amphibian species distributed across a 10° latitudinal range in Chile. Amphibians are susceptible to the fungal pathogen Batrachochytrium dendrobatidis (Bd), which infects their skin, potentially leading to changes in the normal skin microbiome (i.e., dysbiosis). Using comparative methods, accounting for pathogen infection and implementing resampling schemes, we found evidence of phylosymbiosis, characterised by more similar bacterial communities in closely related amphibian species. We also compared how neutral processes affected the assembly of skin bacteria by focusing on two widespread species from our dataset: the Chilean four-eyed frog (Pleurodema thaul) and Darwin's frog (Rhinoderma darwinii). Neutral models revealed that dispersal and chance largely facilitated the occurrence of ~90% of skin bacteria in both species. Deterministic processes (e.g., phylosymbiosis, active recruitment of microbes, microbe-microbe interactions) explained the remaining fraction of the bacteriomes. Amphibian species accounted for 21%-32% of the variance found in non-neutral bacterial taxa, whereas the interaction with Bd carried a weaker but still significant effect. Our findings provide evidence from ectotherms that most of their skin bacteria are subject to dispersal and chance, yet contemporary and historical contingencies leave strong signatures in their microbiomes even at large geographical scales.</p>","PeriodicalId":210,"journal":{"name":"Molecular Ecology","volume":" ","pages":"e17741"},"PeriodicalIF":4.5000,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Ecology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1111/mec.17741","RegionNum":1,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Selection, dispersal and drift jointly contribute to generating variation in microbial composition within and between hosts, habitats and ecosystems. However, we have limited examples of how these processes interact as hosts and their microbes turn over across latitudinal gradients of biodiversity and climate. To bridge this gap, we assembled an extensive dataset of 580 skin bacteriomes from 22 amphibian species distributed across a 10° latitudinal range in Chile. Amphibians are susceptible to the fungal pathogen Batrachochytrium dendrobatidis (Bd), which infects their skin, potentially leading to changes in the normal skin microbiome (i.e., dysbiosis). Using comparative methods, accounting for pathogen infection and implementing resampling schemes, we found evidence of phylosymbiosis, characterised by more similar bacterial communities in closely related amphibian species. We also compared how neutral processes affected the assembly of skin bacteria by focusing on two widespread species from our dataset: the Chilean four-eyed frog (Pleurodema thaul) and Darwin's frog (Rhinoderma darwinii). Neutral models revealed that dispersal and chance largely facilitated the occurrence of ~90% of skin bacteria in both species. Deterministic processes (e.g., phylosymbiosis, active recruitment of microbes, microbe-microbe interactions) explained the remaining fraction of the bacteriomes. Amphibian species accounted for 21%-32% of the variance found in non-neutral bacterial taxa, whereas the interaction with Bd carried a weaker but still significant effect. Our findings provide evidence from ectotherms that most of their skin bacteria are subject to dispersal and chance, yet contemporary and historical contingencies leave strong signatures in their microbiomes even at large geographical scales.
期刊介绍:
Molecular Ecology publishes papers that utilize molecular genetic techniques to address consequential questions in ecology, evolution, behaviour and conservation. Studies may employ neutral markers for inference about ecological and evolutionary processes or examine ecologically important genes and their products directly. We discourage papers that are primarily descriptive and are relevant only to the taxon being studied. Papers reporting on molecular marker development, molecular diagnostics, barcoding, or DNA taxonomy, or technical methods should be re-directed to our sister journal, Molecular Ecology Resources. Likewise, papers with a strongly applied focus should be submitted to Evolutionary Applications. Research areas of interest to Molecular Ecology include:
* population structure and phylogeography
* reproductive strategies
* relatedness and kin selection
* sex allocation
* population genetic theory
* analytical methods development
* conservation genetics
* speciation genetics
* microbial biodiversity
* evolutionary dynamics of QTLs
* ecological interactions
* molecular adaptation and environmental genomics
* impact of genetically modified organisms