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 proteincoding 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.DNA barcoding | fungal biodiversity T he absence of a universally accepted DNA barcode for Fungi, the second most speciose eukaryotic kingdom (1, 2), is a serious limitation for multitaxon ecological and biodiversity studies. DNA barcoding uses standardized 500-to 800-bp sequences to identify species of all eukaryotic kingdoms using primers that are applicable for the broadest possible taxonomic group. Reference barcodes must be derived from expertly identified vouchers deposited in biological collections with online metadata and validated by available online sequence chromatograms. Interspecific variation should exceed intraspecific variation (the barcode gap), and barcoding is optimal when a sequence is constant and unique to one species (3, 4). Ideally, the barcode locus would be the same for all kingdoms. A region of the mitochondrial gene encoding the cytochrome c oxidase subunit 1 (CO1) is the barcode for animals (3, 4) and the default marker adopted by the Consortium for the Barcode of Life for all groups of organisms, including fungi (5). In Oomycota, part of the kingdom Stramenopila historically studied by mycologists, the de facto barcode internal transcribed spacer (ITS) region is suitable for identification, but the default CO1 marker is more reliable in a few clades of closely related species (6)...

The Mucorales (Mucoromycotina) are one of the most ancient groups of fungi comprising ubiquitous, mostly saprotrophic organisms. The first comprehensive molecular studies 11 yr ago revealed the traditional classification scheme, mainly based on morphology, as highly artificial. Since then only single clades have been investigated in detail but a robust classification of the higher levels based on DNA data has not been published yet. Therefore we provide a classification based on a phylogenetic analysis of four molecular markers including the large and the small subunit of the ribosomal DNA, the partial actin gene and the partial gene for the translation elongation factor 1-alpha. The dataset comprises 201 isolates in 103 species and represents about one half of the currently accepted species in this order. Previous family concepts are reviewed and the family structure inferred from the multilocus phylogeny is introduced and discussed. Main differences between the current classification and preceding concepts affects the existing families Lichtheimiaceae and Cunninghamellaceae, as well as the genera Backusella and Lentamyces which recently obtained the status of families along with the Rhizopodaceae comprising Rhizopus, Sporodiniella and Syzygites. Compensatory base change analyses in the Lichtheimiaceae confirmed the lower level classification of Lichtheimia and Rhizomucor while genera such as Circinella or Syncephalastrum completely lacked compensatory base changes.

The zygomycete genus Lichtheimia (syn. Absidia pro parte, Mycocladus) consists of saprotrophic fungi inhabiting soil or dead plant material. Lichtheimia corymbifera (syn. Absidia corymbifera, Mycocladus corymbifer) and Lichtheimia ramosa (syn. Absidia ramosa, Mycocladus ramosus) may cause fulminant infections in patients with impaired immunity. The present study investigated the species boundaries in Lichtheimia using genealogical concordance phylogenetic species recognition (by comparison of the genealogies of the internal transcribed spacer [ITS] sequence, the D1/D2 region of the large subunit [LSU], and actin), biological species recognition by mating tests, as well as morphological and physiological characteristics. The three molecular markers used were selected by evaluating the polymorphisms and paralogies of several loci, including those for ␤-tubulin, translation elongation factor 1␣, the two largest subunits of the RNA polymerase II (RPB1 and RPB2), the mitochondrial cytochrome c oxidase subunit I (COI), and the mitochondrial small-subunit (mtSSU) rDNA, among four strains belonging to different putative species. Comparing the genealogies of the ITS, LSU, and actin genes, we recognized seven phylogenetic species. However, mating tests did not show intrinsic reproductive barriers for two pairs of the phylogenetic species. Therefore, we regard five species in Lichtheima to be confirmed: Lichtheimia corymbifera, L. ornata comb. nov., L. ramosa, L. hyalospora, and L. sphaerocystis sp. nov. Only the first three species seem to have clinical relevance. Lichtheimia blakesleeana is reduced to a synonym of Lichtheimia hyalospora. We provide a detailed description of Lichtheimia sphaerocystis sp. nov. and a key for the identification of all accepted species identified in the present study on the basis of their morphological traits and growth at different temperatures.Mucormycoses, i.e., infections caused by members of the Mucoromycotina subphylum, are uncommon but often dramatic, requiring immediate action on the basis of an accurate diagnosis. The recently observed increase in case reports on mucormycosis (32) can be ascribed to the growing number of patients with risk factors, such as diabetes, neutropenia, bone marrow transplantation, and the long-term use of steroids. Although this trend was already observed prior to the availability of voriconazole in medical applications (17, 21), several studies related the increasing incidence of mucormycoses to voriconazole prophylaxis and treatment of aspergillosis infection in immunocompromised patients (18,37,43). According to Roden et al. (32), approximately 5% of cases of mucormycoses are caused by species of Lichtheimia (syn. Absidia pro parte [p.p.], Mycocladus). These authors reviewed 25 well-documented cases of Lichtheimia (as Absidia) infections that have occurred since 1940. However, the actual incidence of the species may have been underestimated, given the fact that no less than 53 clinical Lichtheimia strains were sent to the CBS Fungal Biodiversity Centre (...

The basal fungal order Mortierellales constitutes one of the largest orders in the basal lineages. This group consists of one family and six genera. Most species are saprobic soil inhabiting fungi with the ability of diverse biotransformations or the accumulation of unsaturated fatty acids, making them attractive for biotechnological applications. Only few studies exist aiming at the revelation of the evolutionary relationships of this interesting fungal group. This study includes the largest dataset of LSU and ITS sequences for more than 400 specimens containing 63 type or reference strains. Based on a LSU phylogram, fungal groups were defined and evaluated using ITS sequences and morphological features. Traditional morphology-based classification schemes were rejected, because the morphology of the Mortierellales seems to depend on culture conditions, a fact, which makes the identification of synapomorphic characters tedious. This study belongs to the most comprehensive molecular phylogenetic analyses for the Mortierellales up to date and reveals unresolved species and species complexes.

No abstract