1. |
- Kõljalg, Urmas, et al.
(författare)
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Towards a unified paradigm for sequence-based identification of fungi.
- 2013
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Ingår i: Molecular ecology. - : Wiley. - 1365-294X .- 0962-1083. ; 22:21, s. 5271-7
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Tidskriftsartikel (refereegranskat)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.
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2. |
- Schoch, Conrad L., et al.
(författare)
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Finding needles in haystacks: linking scientific names, reference specimens and molecular data for Fungi
- 2014
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Ingår i: Database: The Journal of Biological Databases and Curation. - : Oxford University Press (OUP). - 1758-0463. ; 2014:bau061, s. 1-21
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Tidskriftsartikel (refereegranskat)abstract
- DNA phylogenetic comparisons have shown that morphology-based species recognition often underestimates fungal diversity. Therefore, the need for accurate DNA sequence data, tied to both correct taxonomic names and clearly annotated specimen data, has never been greater. Furthermore, the growing number of molecular ecology and microbiome projects using high-throughput sequencing require fast and effective methods for en masse species assignments. In this article, we focus on selecting and re-annotating a set of marker reference sequences that represent each currently accepted order of Fungi. The particular focus is on sequences from the internal transcribed spacer region in the nuclear ribosomal cistron, derived from type specimens and/or ex-type cultures. Re-annotated and verified sequences were deposited in a curated public database at the National Center for Biotechnology Information (NCBI), namely the RefSeq Targeted Loci (RTL) database, and will be visible during routine sequence similarity searches with NR_prefixed accession numbers. A set of standards and protocols is proposed to improve the data quality of new sequences, and we suggest how type and other reference sequences can be used to improve identification of Fungi.
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3. |
- Telleria, M. Teresa, et al.
(författare)
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A reevaluation of Hypochnium (Polyporales) based on morphological and molecular characters
- 2010
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Ingår i: Mycologia. - 0027-5514. ; 102:6, s. 1426-1436
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Tidskriftsartikel (refereegranskat)abstract
- Abstract: Hypochnicium is a genus of corticioid, wood-inhabiting fungi in the Polyporales with a worldwide distribution. The genus has been characterized by the nature of the spores: thick-walled, smooth or ornamented, and cyanophilous. Nine new ITS nrDNA sequences from species of this genus were aligned with 32 sequences obtained from GenBank and phylogenetic analyses were performed. The species of Hypochinicum were resolved as monophyletic using two Hyphoderma species as out-group. Four well-supported clades were determined within the genus: one contains taxa with smooth spores and the other three species with ornamented spores. Hypochnicium albostramineum is closely related to H. wakefieldiae, but new evidence shows that the two species are morphologically difficult to distinguish from each other. Hypochnicium versatum must be included in Gloeohypochnicium and the new combination Gloeohypochnicium versatum is proposed. Two new species, Hypochnicium michelii from Spain, and Hypochnicium guineensis, from Equatorial Guinea, are described.
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