Author
Urmas Kõljalg
Other affiliations: University of Helsinki, American Museum of Natural History
Bio: Urmas Kõljalg is an academic researcher from University of Tartu. The author has contributed to research in topics: Species richness & Tomentella. The author has an hindex of 47, co-authored 111 publications receiving 20682 citations. Previous affiliations of Urmas Kõljalg include University of Helsinki & American Museum of Natural History.
Papers published on a yearly basis
Papers
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Conrad L. Schoch1, Keith A. Seifert, Sabine M. Huhndorf2, Vincent Robert3 +157 more•Institutions (59)
TL;DR: Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation.
Abstract: Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups.
4,116 citations
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University of Tartu1, American Museum of Natural History2, University of Gothenburg3, James Hutton Institute4, University of Aberdeen5, Cooperative Institute for Research in Environmental Sciences6, University of California, Berkeley7, Aberystwyth University8, Estonian University of Life Sciences9, Spanish National Research Council10, Royal Botanic Gardens11, Academy of Sciences of the Czech Republic12, Swedish University of Agricultural Sciences13, University of Tennessee14, University of Helsinki15, Stanford University16, Ludwig Maximilian University of Munich17, University of Toronto18, University of Florida19, University of New Mexico20, University of Tübingen21
TL;DR: All fungal species represented by at least two ITS sequences in the international nucleotide sequence databases are now given a unique, stable name of the accession number type, and the term ‘species hypothesis’ (SH) is introduced for the taxa discovered in clustering on different similarity thresholds.
Abstract: The nuclear ribosomal internal transcribed spacer (ITS) region is the formal fungal barcode and in most cases the marker of choice for the exploration of fungal diversity in environmental samples. Two problems are particularly acute in the pursuit of satisfactory taxonomic assignment of newly generated ITS sequences: (i) the lack of an inclusive, reliable public reference data set and (ii) the lack of means to refer to fungal species, for which no Latin name is available in a standardized stable way. Here, we report on progress in these regards through further development of the UNITE database (http://unite.ut.ee) for molecular identification of fungi. All fungal species represented by at least two ITS sequences in the international nucleotide sequence databases are now given a unique, stable name of the accession number type (e.g. Hymenoscyphus pseudoalbidus|GU586904|SH133781.05FU), and their taxonomic and ecological annotations were corrected as far as possible through a distributed, third-party annotation effort. We introduce the term ‘species hypothesis’ (SH) for the taxa discovered in clustering on different similarity thresholds (97–99%). An automatically or manually designated sequence is chosen to represent each such SH. These reference sequences are released (http://unite.ut.ee/repository.php) for use by the scientific community in, for example, local sequence similarity searches and in the QIIME pipeline. The system and the data will be updated automatically as the number of public fungal ITS sequences grows. We invite everybody in the position to improve the annotation or metadata associated with their particular fungal lineages of expertise to do so through the new Web-based sequence management system in UNITE.
2,605 citations
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American Museum of Natural History1, University of Tartu2, University of Colombo3, Royal Netherlands Academy of Arts and Sciences4, University of Florida5, University of Palermo6, Goethe University Frankfurt7, Hobart Corporation8, Nakhon Phanom University9, University of Bamenda10, University of Gothenburg11, Naturalis12, Swedish University of Agricultural Sciences13, Royal Botanic Gardens14, Universiti Malaysia Sabah15, United States Department of Agriculture16, Forest Research Institute Malaysia17, Humboldt State University18, Chinese Academy of Sciences19, Landcare Research20, University of Western Australia21, Estonian University of Life Sciences22, University of Southern Queensland23, Botanic Garden Meise24, Manchester Metropolitan University25, James Cook University26
TL;DR: Diversity of most fungal groups peaked in tropical ecosystems, but ectomycorrhizal fungi and several fungal classes were most diverse in temperate or boreal ecosystems, and manyfungal groups exhibited distinct preferences for specific edaphic conditions (such as pH, calcium, or phosphorus).
Abstract: Fungi play major roles in ecosystem processes, but the determinants of fungal diversity and biogeographic patterns remain poorly understood. Using DNA metabarcoding data from hundreds of globally distributed soil samples, we demonstrate that fungal richness is decoupled from plant diversity. The plant-to-fungus richness ratio declines exponentially toward the poles. Climatic factors, followed by edaphic and spatial variables, constitute the best predictors of fungal richness and community composition at the global scale. Fungi show similar latitudinal diversity gradients to other organisms, with several notable exceptions. These findings advance our understanding of global fungal diversity patterns and permit integration of fungi into a general macroecological framework.
2,346 citations
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Clark University1, National Institutes of Health2, Louisiana State University3, CABI4, Umeå University5, Field Museum of Natural History6, Duke University7, University of Minnesota8, University of Alabama9, Oregon State University10, Centraalbureau voor Schimmelcultures11, United States Department of Agriculture12, University of Tübingen13, Max Planck Society14, University of Florida15, Pennsylvania State University16, Aberystwyth University17, Complutense University of Madrid18, University of Oslo19, University of Hong Kong20, University of Tartu21, University of Gothenburg22, University of Kansas23, University of Maine24, University of Illinois at Urbana–Champaign25, Royal Ontario Museum26, Georgia State University27, Estonian University of Life Sciences28, Washington State University29, Nova Southeastern University30, Ludwig Maximilian University of Munich31, University of Western Ontario32, Uppsala University33, Brandon University34, Royal Botanic Garden Edinburgh35, State University of New York at Purchase36, Boise State University37, Cornell University38
TL;DR: A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community.
2,096 citations
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TL;DR: UNITE is a web-based database and sequence management environment for the molecular identification of fungi that targets the formal fungal barcode—the nuclear ribosomal internal transcribed spacer region—and offers all public fungal ITS sequences for reference.
Abstract: Alfred P. Sloan Foundation [G-2015-14062]; Swedish Research Council of Environment, Agricultural Sciences, and Spatial Planning [FORMAS, 215-2011-498]; European Regional Development Fund (Centre of Excellence EcolChange) [TK131]; Estonian Research Council [IUT20-30]. Funding for open access charge: Swedish Research Council of Environment, Agricultural Sciences and Spatial Planning.
1,674 citations
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TL;DR: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols used xiii 1.
Abstract: Preface to the Princeton Landmarks in Biology Edition vii Preface xi Symbols Used xiii 1. The Importance of Islands 3 2. Area and Number of Speicies 8 3. Further Explanations of the Area-Diversity Pattern 19 4. The Strategy of Colonization 68 5. Invasibility and the Variable Niche 94 6. Stepping Stones and Biotic Exchange 123 7. Evolutionary Changes Following Colonization 145 8. Prospect 181 Glossary 185 References 193 Index 201
14,171 citations
01 Jun 2012
TL;DR: SPAdes as mentioned in this paper is a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler and on popular assemblers Velvet and SoapDeNovo (for multicell data).
Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.
10,124 citations
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TL;DR: Increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease.
Abstract: Long-term dietary intake influences the structure and activity of the trillions of microorganisms residing in the human gut, but it remains unclear how rapidly and reproducibly the human gut microbiome responds to short-term macronutrient change. Here we show that the short-term consumption of diets composed entirely of animal or plant products alters microbial community structure and overwhelms inter-individual differences in microbial gene expression. The animal-based diet increased the abundance of bile-tolerant microorganisms (Alistipes, Bilophila and Bacteroides) and decreased the levels of Firmicutes that metabolize dietary plant polysaccharides (Roseburia, Eubacterium rectale and Ruminococcus bromii). Microbial activity mirrored differences between herbivorous and carnivorous mammals, reflecting trade-offs between carbohydrate and protein fermentation. Foodborne microbes from both diets transiently colonized the gut, including bacteria, fungi and even viruses. Finally, increases in the abundance and activity of Bilophila wadsworthia on the animal-based diet support a link between dietary fat, bile acids and the outgrowth of microorganisms capable of triggering inflammatory bowel disease. In concert, these results demonstrate that the gut microbiome can rapidly respond to altered diet, potentially facilitating the diversity of human dietary lifestyles.
7,032 citations
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TL;DR: The approach to utilizing available RNA-Seq and other data types in the authors' manual curation process for vertebrate, plant, and other species is summarized, and a new direction for prokaryotic genomes and protein name management is described.
Abstract: The RefSeq project at the National Center for Biotechnology Information (NCBI) maintains and curates a publicly available database of annotated genomic, transcript, and protein sequence records (http://www.ncbi.nlm.nih.gov/refseq/). The RefSeq project leverages the data submitted to the International Nucleotide Sequence Database Collaboration (INSDC) against a combination of computation, manual curation, and collaboration to produce a standard set of stable, non-redundant reference sequences. The RefSeq project augments these reference sequences with current knowledge including publications, functional features and informative nomenclature. The database currently represents sequences from more than 55,000 organisms (>4800 viruses, >40,000 prokaryotes and >10,000 eukaryotes; RefSeq release 71), ranging from a single record to complete genomes. This paper summarizes the current status of the viral, prokaryotic, and eukaryotic branches of the RefSeq project, reports on improvements to data access and details efforts to further expand the taxonomic representation of the collection. We also highlight diverse functional curation initiatives that support multiple uses of RefSeq data including taxonomic validation, genome annotation, comparative genomics, and clinical testing. We summarize our approach to utilizing available RNA-Seq and other data types in our manual curation process for vertebrate, plant, and other species, and describe a new direction for prokaryotic genomes and protein name management.
4,104 citations
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TL;DR: Overall, this review shows that soil microbes must be considered as important drivers of plant diversity and productivity in terrestrial ecosystems.
Abstract: Microbes are the unseen majority in soil and comprise a large portion of lifes genetic diversity. Despite their abundance, the impact of soil microbes on ecosystem processes is still poorly understood. Here we explore the various roles that soil microbes play in terrestrial ecosystems with special emphasis on their contribution to plant productivity and diversity. Soil microbes are important regulators of plant productivity, especially in nutrient poor ecosystems where plant symbionts are responsible for the acquisition of limiting nutrients. Mycorrhizal fungi and nitrogenfixing bacteria are responsible for c. 5‐20% (grassland and savannah) to 80% (temperate and boreal forests) of all nitrogen, and up to 75% of phosphorus, that is acquired by plants annually. Free-living microbes also strongly regulate plant productivity, through the mineralization of, and competition for, nutrients that sustain plant productivity. Soil microbes, including microbial pathogens, are also important regulators of plant community dynamics and plant diversity, determining plant abundance and, in some cases, facilitating invasion by exotic plants. Conservative estimates suggest that c. 20 000 plant species are completely dependent on microbial symbionts for growth and survival pointing to the importance of soil microbes as regulators of plant species richness on Earth. Overall, this review shows that soil microbes must be considered as important drivers of plant diversity and productivity in terrestrial ecosystems.
3,673 citations