scholarly journals Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for Fungi

2012 ◽  
Vol 109 (16) ◽  
pp. 6241-6246 ◽  
Author(s):  
C. L. Schoch ◽  
K. A. Seifert ◽  
S. Huhndorf ◽  
V. Robert ◽  
J. L. Spouge ◽  
...  
PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253772
Author(s):  
Rosa E. Prahl ◽  
Shahjahan Khan ◽  
Ravinesh C. Deo

Many fungi require specific growth conditions before they can be identified. Direct environmental DNA sequencing is advantageous, although for some taxa, specific primers need to be used for successful amplification of molecular markers. The internal transcribed spacer region is the preferred DNA barcode for fungi. However, inter- and intra-specific distances in ITS sequences highly vary among some fungal groups; consequently, it is not a solely reliable tool for species delineation. Ampelomyces, mycoparasites of the fungal phytopathogen order Erysiphales, can have ITS genetic differences up to 15%; this may lead to misidentification with other closely related unknown fungi. Indeed, Ampelomyces were initially misidentified as other pycnidial mycoparasites, but subsequent research showed that they differ in pycnidia morphology and culture characteristics. We investigated whether the ITS2 nucleotide content and secondary structure was different between Ampelomyces ITS2 sequences and those unrelated to this genus. To this end, we retrieved all ITS sequences referred to as Ampelomyces from the GenBank database. This analysis revealed that fungal ITS environmental DNA sequences are still being deposited in the database under the name Ampelomyces, but they do not belong to this genus. We also detected variations in the conserved hybridization model of the ITS2 proximal 5.8S and 28S stem from two Ampelomyces strains. Moreover, we suggested for the first time that pseudogenes form in the ITS region of this mycoparasite. A phylogenetic analysis based on ITS2 sequences-structures grouped the environmental sequences of putative Ampelomyces into a different clade from the Ampelomyces-containing clades. Indeed, when conducting ITS2 analysis, resolution of genetic distances between Ampelomyces and those putative Ampelomyces improved. Each clade represented a distinct consensus ITS2 S2, which suggested that different pre-ribosomal RNA (pre-rRNA) processes occur across different lineages. This study recommends the use of ITS2 S2s as an important tool to analyse environmental sequencing and unveiling the underlying evolutionary processes.


Author(s):  
Nurrahmi Dewi Fajarningsih

Despite the fact that fungi are important sources of both bioactive compounds and mycotoxins, and that they are very ubiquitous in our environment, their species identification is hampered by incomplete and often unclear literature. Fungi identification is primarily based on their phenotypic and physiological characteristics. Nowadays, many molecular methods to identify fungal species have been developed. One of the methods considered as a new concept to rapidly and accurately identify unknown fungal sample is DNA Barcoding. This literature review will outline the use of DNA barcoding approach to rapidly identify fungal species and the use of ITS region that recently has been designated as primary DNA barcode for fungal kingdom. “DNA barcode” is a short, highly variable and standardized DNA region with approximately 700 nucleotides in length, which is used as a unique pattern to identify living things. Internal Transcribed Spacer (ITS) region of nuclear DNA (rDNA) has become the most sequenced region to identify fungal taxonomy at species level, and even within species. ITS region is a highly polymorphic non-coding region with enough taxonomic units. Therefore, it is able to separate sequences into species level. Even though ribosomal ITS as a universal barcode marker for fungi is still hampered by few limitations, the ITS will remain as the key choice for fungal identification. The search for alternative regions as DNA marker to improve fungal identification, especially in specific heredities, has already started. 


PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7307
Author(s):  
Siyu Wang ◽  
Hongbo Guo ◽  
JiaJia Li ◽  
Wei Li ◽  
Qin Wang ◽  
...  

Background Distinguishing among species in the genus Lepista is difficult because of their similar morphologies. Methods To identify a suitable DNA barcode for identification of Lepista species, we assessed the following five regions: internal transcribed spacer (ITS), the intergenic spacer (IGS), nuclear ribosomal RNA subunit, mitochondrial small subunit rDNA, and tef1. A total of 134 sequences from 34 samples belong to eight Lepista species were analyzed. The utility of each region as a DNA barcode was assessed based on the success rates of its PCR amplification and sequencing, and on its intra- and inter-specific variations. Results The results indicated that the ITS region could distinguish all species tested. We therefore propose that the ITS region can be used as a DNA barcode for the genus Lepista. In addition, a phylogenetic tree based on the ITS region showed that the tested eight Lepista species, including two unrecognized species, formed eight separate and well-supported clades.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 125
Author(s):  
Monier M. Abd El-Ghani ◽  
Ashraf S. A. El-Sayed ◽  
Ahmed Moubarak ◽  
Rabab Rashad ◽  
Hala Nosier ◽  
...  

Astragalus L. is one of the largest angiosperm complex genera that belongs to the family Fabaceae, subfamily Papilionoideae or Faboideae under the subtribe Astragalinae of the tribe Galegeae. The current study includes the whole plant morphology, DNA barcode (ITS2), and molecular marker (SCoT). Ten taxa representing four species of Astragalus were collected from different localities in Egypt during the period from February 2018 to May 2019. Morphologically, identification and classification of collected Astragalus plants occurred by utilizing the light microscope, regarding the taxonomic revisions of the reference collected Astragalus specimens in other Egyptian Herbaria. For molecular validation, ten SCoT primers were used in this study, producing a unique banding pattern to differentiate between ten samples of Astragalus taxa which generated 212 DNA fragments with an average of 12.2 bands per 10 Astragalus samples, with 8 to 37 fragments per primer. The 212 fragments amplified were distributed as 2 monomorphic bands, 27 polymorphic without unique bands, 183 unique bands (210 Polymorphic with unique bands), and ITS2 gene sequence was showed as the optimal barcode for identifying Astragalus L. using BLAST searched on NCBI database, and afterward, analyzing the chromatogram for ITS region, 10 samples have been identified as two samples representing A. hauarensis, four samples representing A. sieberi, three samples representing A. spinosus and one sample representing A. vogelii. Based on the ITS barcode, A. hauarensis RMG1, A. hauarensis RMG2, A. sieberi RMG1, A. sieberi RMG2, A. sieberi RMG3, A. sieberi RMG4, A. spinosus RMG1, A. spinosus RMG2, A. spinosus RMG3, A. vogelii RMG were deposited into GenBank with accession # MT367587.1, MT367591.1, MT367593.1, MT367585.1, MT367586.1, MT367588.1, MT160347.1, MT367590.1, MT367589.1, MT367592.1, respectively. These results indicated the efficiency of SCoT markers and ITS2 region in identifying and determining genetic relationships between Astragalus species.


Phytotaxa ◽  
2016 ◽  
Vol 266 (2) ◽  
pp. 134 ◽  
Author(s):  
QI ZHAO ◽  
YAN-JIA HAO ◽  
JIAN-KUI LIU ◽  
KEVIN D. HYDE ◽  
YANG-YANG CUI ◽  
...  

Infundibulicybe rufa sp. nov., is described from Jiuzhaigou Biosphere Reserve, southwestern China. It is characterized by the combination of the following characters: umbilicate to slightly infundibuliform, reddish brown pileus; decurrent, cream lamellae; cylindrical stipe concolorous with the pileus surface. Molecular phylogenetic analyses using the nuclear ribosomal internal transcribed spacer (ITS) region indicates that I. rufa is closely related to I. mediterranea and I. bresadolana. A description, line drawings, phylogenetic placement and comparison with allied taxa for the new taxon are presented.


2002 ◽  
Vol 15 (1) ◽  
pp. 49 ◽  
Author(s):  
Dorothy A. Steane ◽  
Dean Nicolle ◽  
Gay E. McKinnon ◽  
René E. Vaillancourt ◽  
Brad M. Potts

This expanded survey of ITS sequences represents the largest analysis of molecular data ever attempted on Eucalyptus. Sequences of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA were included in an analysis of 90 species of Eucalyptus s.s. and 28 species representing eight other genera (Allosyncarpia, Angophora, Arillastrum, Corymbia, Eucalyptopsis, Stockwellia, Lophostemon and Metrosideros). The results of the study indicate that Angophora and Corymbia form a well-supported clade that is highly differentiated from Eucalyptus s.s. Corymbia species are divided between two clades, one of which may be the sister to Angophora. Allosyncarpia, Arillastrum, Eucalyptopsis and ‘Stockwellia’ are also highly differentiated from Eucalyptus s.s. If the genus Eucalyptus is to be expanded to include Angophora and Corymbia(sensu Brooker 2000), ITS data suggest that Allosyncarpia, Eucalyptopsis, ‘Stockwellia’ and potentially Arillastrum should also be included in Eucalyptus s.l. The ITS data suggest that subg. Symphyomyrtus is paraphyletic and that subg. Minutifructus should be included within it. Within subg.Symphyomyrtus, only sect. Maidenaria appears to be monophyletic. Sections Adnataria and Dumaria are probably monophyletic; sections Exsertaria and Latoangulatae are very close and probably should be combined in a single section. Section Bisectae is polyphyletic and is divided into two distinct lineages. The phylogenetic groups depicted by ITS data are consistent with the frequency of natural inter-specific hybridisations as well as data from controlled crosses within subgenus Symphyomyrtus. The ITS data illustrate that subg. Idiogenes and western Australian monocalypts are early evolutionary lines relative to E. diversifolia, E. rubiginosa (monotypic subg. Primitiva) and the eastern monocalypts and that subg. Primitiva should be sunk into subg. Eucalyptus. Subgenus Eudesmia may be monophyletic, grouping with subgenera Idiogenes and Eucalyptus. Further work is required to confirm the phylogenetic positions of the monotypic subgenera Alveolata, Cruciformes, Acerosae and Cuboidea.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Victor Olusegun Oyetayo

Molecular identification of eighteenTermitomycesspecies collected from two states, Ondo and Ekiti in Nigeria was carried out using the internal transcribed spacer (ITS) region. The amplicons obtained from rDNA ofTermitomycesspecies were compared with existing sequences in the NCBI GenBank. The results of the ITS sequence analysis discriminated between all theTermitomycesspecies (obtained from Ondo and Ekiti States) andTermitomycessp. sequences obtained from NCBI GenBank. The degree of similarity of T1 to T18 to gene ofTermitomycessp. obtained from NCBI ranges between 82 and 99 percent.Termitomycesspecies from Garbon with ascension number AF321374 was the closest relative of T1 to T18 except T12 that has T. eurhizus and T. striatus as the closet relative. Phylogenetic tree generated with ITS sequences obtained from NCBI GenBank data revealed that T1 to T18 are more related toTermitomycesspecies indigenous to African countries such as Senegal, Congo, and Gabon.


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