title: Effectiveness of ITS and sub-regions as DNA barcode markers for the identification of Basidiomycota (Fungi).
abstract: BACKGROUND
  Fungi are among the most abundant and diverse organisms on Earth. However, a substantial amount of the species diversity, relationships, habitats, and life strategies of these microorganisms remain to be discovered and characterized. One important factor hindering progress is the difficulty in correctly identifying fungi. Morphological and molecular characteristics have been applied in such tasks. Later, DNA barcoding has emerged as a new method for the rapid and reliable identification of species. The nrITS region is considered the universal barcode of Fungi, and the ITS1 and ITS2 sub-regions have been applied as metabarcoding markers. In this study, we performed a large-scale analysis of all the available Basidiomycota sequences from GenBank. We carried out a rigorous trimming of the initial dataset based in methodological principals of DNA Barcoding. Two different approaches (PCI and barcode gap) were used to determine the performance of the complete ITS region and sub-regions.
  
  
  RESULTS
  For most of the Basidiomycota genera, the three genomic markers performed similarly, i.e., when one was considered a good marker for the identification of a genus, the others were also; the same results were observed when the performance was insufficient. However, based on barcode gap analyses, we identified genomic markers that had a superior identification performance than the others and genomic markers that were not indicated for the identification of some genera. Notably, neither the complete ITS nor the sub-regions were useful in identifying 11 of the 113 Basidiomycota genera. The complex phylogenetic relationships and the presence of cryptic species in some genera are possible explanations of this limitation and are discussed.
  
  
  CONCLUSIONS
  Knowledge regarding the efficiency and limitations of the barcode markers that are currently used for the identification of organisms is crucial because it benefits research in many areas. Our study provides information that may guide researchers in choosing the most suitable genomic markers for identifying Basidiomycota species.
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Departamento de Química, 30.421-169, Belo Horizonte, MG, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Badotti
authors.affiliation: Fundação Oswaldo Cruz (FIOCRUZ), Centro de Pesquisas René Rachou - CPqRR, 30190-002, Belo Horizonte, MG, Brazil.
authors.forename: Francislon Silva
authors.initials: FS
authors.lastname: de Oliveira
authors.affiliation: Centro Federal de Educação Tecnológica de Minas Gerais (CEFET-MG), Departamento de Química, 30.421-169, Belo Horizonte, MG, Brazil.
authors.forename: Cleverson Fernando
authors.initials: CF
authors.lastname: Garcia
authors.affiliation: Universidade Federal de Minas Gerais, Departamento de Microbiologia, Av. Antônio Carlos, Belo Horizonte, 6627, 31270-901, MG, Brazil.|Faculdade de Minas (FAMINAS), 66055-090, Belo Horizonte, MG, Brazil.
authors.forename: Aline Bruna Martins
authors.initials: AB
authors.lastname: Vaz
authors.affiliation: Universidade Federal de Minas Gerais, Departamento de Microbiologia, Av. Antônio Carlos, Belo Horizonte, 6627, 31270-901, MG, Brazil.
authors.forename: Paula Luize Camargos
authors.initials: PL
authors.lastname: Fonseca
authors.affiliation: Fundação Oswaldo Cruz (FIOCRUZ), Centro de Pesquisas René Rachou - CPqRR, 30190-002, Belo Horizonte, MG, Brazil.|Faculdade Promove de Tecnologia, 30140-061, Belo Horizonte, MG, Brazil.
authors.forename: Laila Alves
authors.initials: LA
authors.lastname: Nahum
authors.affiliation: Fundação Oswaldo Cruz (FIOCRUZ), Centro de Pesquisas René Rachou - CPqRR, 30190-002, Belo Horizonte, MG, Brazil.|Instituto Tecnológico Vale, 66055-090, Belém, PA, Brazil.
authors.forename: Guilherme
authors.initials: G
authors.lastname: Oliveira
authors.affiliation: Universidade Federal de Minas Gerais, Departamento de Microbiologia, Av. Antônio Carlos, Belo Horizonte, 6627, 31270-901, MG, Brazil. arigoesneto@icb.ufmg.br.
authors.forename: Aristóteles
authors.identifier: http://orcid.org/0000-0002-7692-6243
authors.initials: A
authors.lastname: Góes-Neto
mesh_terms: D001487:Basidiomycota / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D044822:Biodiversity; D058893:DNA Barcoding, Taxonomic / Q000379:methods*; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D030561:Databases, Nucleic Acid; D005658:Fungi / Q000235:genetics; D005800:Genes, Fungal / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics*; D058889:Molecular Typing / Q000379:methods; D016533:Mycological Typing Techniques / Q000379:methods; D010802:Phylogeny; D012331:RNA, Fungal / Q000235:genetics; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D005819:Genetic Markers; D012331:RNA, Fungal
keywords: Barcode gap; Basidiomycota; ITS; ITS1; ITS2; Probable correct identification