| 1. |
- Nilsson, R. Henrik, 1976, et al.
(author)
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How, not if, is the question mycologists should be asking about DNA-based typification
- 2023
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In: MycoKeys. - : Pensoft Publishers. - 1314-4057 .- 1314-4049. ; :96, s. 143-157
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Journal article (peer-reviewed)abstract
- Fungal metabarcoding of substrates such as soil, wood, and water is uncovering an unprecedented number of fungal species that do not seem to produce tangible morphological structures and that defy our best attempts at cultivation, thus falling outside the scope of the International Code of Nomenclature for algae, fungi, and plants. The present study uses the new, ninth release of the species hypotheses of the UNITE database to show that species discovery through environmental sequencing vastly outpaces traditional, Sanger sequencing-based efforts in a strongly increasing trend over the last five years. Our findings chal-lenge the present stance of some in the mycological community - that the current situation is satisfactory and that no change is needed to "the code" - and suggest that we should be discussing not whether to allow DNA-based descriptions (typifications) of species and by extension higher ranks of fungi, but what the precise requirements for such DNA-based typifications should be. We submit a tentative list of such criteria for further discussion. The present authors hope for a revitalized and deepened discussion on DNA-based typification, because to us it seems harmful and counter-productive to intentionally deny the overwhelming majority of extant fungi a formal standing under the International Code of Nomenclature for algae, fungi, and plants.
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| 2. |
- Anslan, Sten, et al.
(author)
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Great differences in performance and outcome of high-throughput sequencing data analysis platforms for fungal metabarcoding
- 2018
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In: MycoKeys. - : Pensoft Publishers. - 1314-4057 .- 1314-4049. ; 39, s. 29-40
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Journal article (peer-reviewed)abstract
- Along with recent developments in high-throughput sequencing (HTS) technologies and thus fast accumulation of HTS data, there has been a growing need and interest for developing tools for HTS data processing and communication. In particular, a number of bioinformatics tools have been designed for analysing metabarcoding data, each with specific features, assumptions and outputs. To evaluate the potential effect of the application of different bioinformatics workflow on the results, we compared the performance of different analysis platforms on two contrasting high-throughput sequencing data sets. Our analysis revealed that the computation time, quality of error filtering and hence output of specific bioinformatics process largely depends on the platform used. Our results show that none of the bioinformatics workflows appears to perfectly filter out the accumulated errors and generate Operational Taxonomic Units, although PipeCraft, LotuS and PIPITS perform better than QIIME2 and Galaxy for the tested fungal amplicon dataset. We conclude that the output of each platform requires manual validation of the OTUs by examining the taxonomy assignment values.
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| 3. |
- Anslan, Sten, et al.
(author)
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PipeCraft : Flexible open-source toolkit for bioinformatics analysis of custom high-throughput amplicon sequencing data
- 2017
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In: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 17:6, s. e234-e240
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Journal article (peer-reviewed)abstract
- High-throughput sequencing methods have become a routine analysis tool in environmental sciences as well as in public and private sector. These methods provide vast amount of data, which need to be analysed in several steps. Although the bioinformatics may be applied using several public tools, many analytical pipelines allow too few options for the optimal analysis for more complicated or customized designs. Here, we introduce PipeCraft, a flexible and handy bioinformatics pipeline with a user-friendly graphical interface that links several public tools for analysing amplicon sequencing data. Users are able to customize the pipeline by selecting the most suitable tools and options to process raw sequences from Illumina, Pacific Biosciences, Ion Torrent and Roche 454 sequencing platforms. We described the design and options of PipeCraft and evaluated its performance by analysing the data sets from three different sequencing platforms. We demonstrated that PipeCraft is able to process large data sets within 24hr. The graphical user interface and the automated links between various bioinformatics tools enable easy customization of the workflow. All analytical steps and options are recorded in log files and are easily traceable.
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| 4. |
- Anslan, Sten, et al.
(author)
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Seasonal and annual variation in fungal communities associated with epigeic springtails (Collembola spp.) in boreal forests
- 2018
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In: Soil Biology and Biochemistry. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0038-0717 .- 1879-3428. ; 116, s. 245-252
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Journal article (peer-reviewed)abstract
- Soil fauna mediate nutrient cycling through engineering physical properties and altering microbial commtmities in soil. Collembola is one of the most abundant groups of soil fauna, which regulates microbial communities by consumption and dispersal. The spatial structure of associations between Collembola and soil microbes have been described in several studies, but temporal variation of these associations remains unclear. Using high throughput sequencing, we studied the fungal communities on Collembola (Entomobiya nivalis, Orchesella flavescens, Pogonognathellus longicornis) body surface, gut and their immediate habitat (topsoil samples) in four seasons across three years. The soil samples were characterized by fairly uniform relative abundance of saprotrophic and mycorrhizal fungi, whereas collembolans were associated mostly with saprotrophs. The structure of fungal communities from all substrate types exhibited comparable patterns of temporal distance decay of shnilarity. Unlike in soil, fungal richness and composition in Collembola body and gut samples exhibited seasonal and annual variation, with a significant interaction term, indicating low predictability. These results reflect spatial and temporal plasticity of the fungal communities associated with epigeic Collembola, indicating the high adaptability of collembolans to available conditions. We found that the Collembola associations with fungi (including diet) did not vary among the studied epigeic Collembola species. The detected high diversity of fungi associated with Collembola suggests that dispersal by arthropod vectors may represent a powerful alternative to aerial dispersal of fungal propagules.
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| 5. |
- Anslan, Sten, et al.
(author)
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Temporal changes in fungal communities associated with guts and appendages of Collembola as based on culturing and high-throughput sequencing
- 2016
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In: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717 .- 1879-3428. ; 96, s. 152-159
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Journal article (peer-reviewed)abstract
- Due to high abundance and feeding habits, invertebrates are of great importance for shaping microbial communities at the fine scale. Springtails (Collembola) that feed on fungal spores and mycelia may contribute to dispersal through carrying fungal propagules in their guts or on their appendages. The Collembola–fungal associations are mainly investigated by microscopy or culturing techniques, which allow identify only fungi that have distinctive morphological characteristics or that can be cultured in vitro. Here we identified the Collembola-associated fungi on the body surface and in the gut content using both culturing and high-throughput sequencing (HTS) methods. We studied three epigeic Collembola species found on the Norway spruce dominated forest stands throughout the vegetation period – Entomobrya nivalis, Orchesella flavescens andPogonognathellus longicornis. We discovered over 1200 fungal operational taxonomic units (OTUs), i.e. the proxies for species, based on 97% sequence similarity of the ITS2 subregion of ribosomal DNA. Most of the fungi were saprotrophs, but we detected also mycorrhizal, parasitic and lichenized fungi. Season was the most important factor affecting fungal richness and composition, especially on body surface. Although the data matrix revealed significant effect of substrate, we were unable to detect the significant fungal community differences between body surface and gut samples of conspecifics. There were no significant differences among studied epigeic Collembola species in the preference for fungal diet. Our study demonstrates that collembolans associate with a broader range of fungi than previously observed and thus potentially play an important role in enhancing fungal colonization through dispersal activities.
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| 6. |
- Bahram, Mohammad, et al.
(author)
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Newly designed 16S rRNA metabarcoding primers amplify diverse and novel archaeal taxa from the environment
- 2019
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In: Environmental Microbiology Reports. - : WILEY. - 1758-2229 .- 1758-2229. ; 11:4, s. 487-494
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Journal article (peer-reviewed)abstract
- High-throughput studies of microbial communities suggest that Archaea are a widespread component of microbial diversity in various ecosystems. However, proper quantification of archaeal diversity and community ecology remains limited, as sequence coverage of Archaea is usually low owing to the inability of available prokaryotic primers to efficiently amplify archaeal compared to bacterial rRNA genes. To improve identification and quantification of Archaea, we designed and validated the utility of several primer pairs to efficiently amplify archaeal 16S rRNA genes based on up-to-date reference genes. We demonstrate that several of these primer pairs amplify phylogenetically diverse Archaea with high sequencing coverage, outperforming commonly used primers. Based on comparing the resulting long 16S rRNA gene fragments with public databases from all habitats, we found several novel family- to phylum-level archaeal taxa from topsoil and surface water. Our results suggest that archaeal diversity has been largely overlooked due to the limitations of available primers, and that improved primer pairs enable to estimate archaeal diversity more accurately.
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| 7. |
- Bahram, Mohammad, et al.
(author)
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Stochastic distribution of small soil eukaryotes resulting from high dispersal and drift in a local environment
- 2016
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In: The ISME Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 10, s. 885-896
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Journal article (peer-reviewed)abstract
- A central challenge in ecology is to understand the relative importance of processes that shape diversity patterns. Compared with aboveground biota, little is known about spatial patterns and processes in soil organisms. Here we examine the spatial structure of communities of small soil eukaryotes to elucidate the underlying stochastic and deterministic processes in the absence of environmental gradients at a local scale. Specifically, we focus on the fine-scale spatial autocorrelation of prominent taxonomic and functional groups of eukaryotic microbes. We collected 123 soil samples in a nested design at distances ranging from 0.01 to 64 m from three boreal forest sites and used 454 pyrosequencing analysis of Internal Transcribed Spacer for detecting Operational Taxonomic Units of major eukaryotic groups simultaneously. Among the main taxonomic groups, we found significant but weak spatial variability only in the communities of Fungi and Rhizaria. Within Fungi, ectomycorrhizas and pathogens exhibited stronger spatial structure compared with saprotrophs and corresponded to vegetation. For the groups with significant spatial structure, autocorrelation occurred at a very fine scale (<2 m). Both dispersal limitation and environmental selection had a weak effect on communities as reflected in negative or null deviation of communities, which was also supported by multivariate analysis, that is, environment, spatial processes and their shared effects explained on average <10% of variance. Taken together, these results indicate a random distribution of soil eukaryotes with respect to space and environment in the absence of environmental gradients at the local scale, reflecting the dominant role of drift and homogenizing dispersal.
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| 8. |
- Mikryukov, Vladimir, et al.
(author)
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Connecting the multiple dimensions of global soil fungal diversity
- 2023
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In: Science advances. - 2375-2548. ; 9:48
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Journal article (peer-reviewed)abstract
- How the multiple facets of soil fungal diversity vary worldwide remains virtually unknown, hindering the management of this essential species-rich group. By sequencing high-resolution DNA markers in over 4000 topsoil samples from natural and human-altered ecosystems across all continents, we illustrate the distributions and drivers of different levels of taxonomic and phylogenetic diversity of fungi and their ecological groups. We show the impact of precipitation and temperature interactions on local fungal species richness (alpha diversity) across different climates. Our findings reveal how temperature drives fungal compositional turnover (beta diversity) and phylogenetic diversity, linking them with regional species richness (gamma diversity). We integrate fungi into the principles of global biodiversity distribution and present detailed maps for biodiversity conservation and modeling of global ecological processes.
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| 9. |
- Nilsson, R. Henrik, 1976, et al.
(author)
-
Mycobiome diversity: high-throughput sequencing and identification of fungi.
- 2019
-
In: Nature reviews. Microbiology. - : Springer Science and Business Media LLC. - 1740-1534 .- 1740-1526. ; 17, s. 95-109
-
Research review (peer-reviewed)abstract
- Fungi are major ecological players in both terrestrial and aquatic environments by cycling organic matter and channelling nutrients across trophic levels. High-throughput sequencing (HTS) studies of fungal communities are redrawing the map of the fungal kingdom by hinting at its enormous - and largely uncharted - taxonomic and functional diversity. However, HTS approaches come with a range of pitfalls and potential biases, cautioning against unwary application and interpretation of HTS technologies and results. In this Review, we provide an overview and practical recommendations for aspects of HTS studies ranging from sampling and laboratory practices to data processing and analysis. We also discuss upcoming trends and techniques in the field and summarize recent and noteworthy results from HTS studies targeting fungal communities and guilds. Our Review highlights the need for reproducibility and public data availability in the study of fungal communities. If the associated challenges and conceptual barriers are overcome, HTS offers immense possibilities in mycology and elsewhere.
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| 10. |
- Saitta, Alessandro, et al.
(author)
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Tree species identity and diversity drive fungal richness and community composition along an elevational gradient in a Mediterranean ecosystem
- 2018
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In: Mycorrhiza. - : Springer Science and Business Media LLC. - 0940-6360 .- 1432-1890. ; 28:1, s. 39-47
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Journal article (peer-reviewed)abstract
- Ecological and taxonomic knowledge is important for conservation and utilization of biodiversity. Biodiversity and ecology of fungi in Mediterranean ecosystems is poorly understood. Here, we examined the diversity and spatial distribution of fungi along an elevational gradient in a Mediterranean ecosystem, using DNA metabarcoding. This study provides novel information about diversity of all ecological and taxonomic groups of fungi along an elevational gradient in a Mediterranean ecosystem. Our analyses revealed that among all biotic and abiotic variables tested, host species identity is the main driver of the fungal richness and fungal community composition. Fungal richness was strongly associated with tree richness and peaked in Quercus-dominated habitats and Cistus-dominated habitats. The highest taxonomic richness of ectomycorrhizal fungi was observed under Quercus ilex, whereas the highest taxonomic richness of saprotrophs was found under Pinus. Our results suggest that the effect of plant diversity on fungal richness and community composition may override that of abiotic variables across environmental gradients.
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