Fungi in the basidiomycete genus
are the most prevalent eukaryotic microbes resident on the skin of human and other warm-blooded animals and have been implicated in skin diseases and systemic ...disorders. Analysis of
genomes revealed that key adaptations to the skin microenvironment have a direct genomic basis, and the identification of mating/meiotic genes suggests a capacity to reproduce sexually, even though no sexual cycle has yet been observed. In contrast to other bipolar or tetrapolar basidiomycetes that have either two linked mating-type-determining (
) loci or two
loci on separate chromosomes, in
species studied thus far the two
loci are arranged in a pseudobipolar configuration (linked on the same chromosome but capable of recombining). By generating additional chromosome-level genome assemblies, and an improved
phylogeny, we infer that the pseudobipolar arrangement was the ancestral state of this group and revealed six independent transitions to tetrapolarity, seemingly driven by centromere fission or translocations in centromere-flanking regions. Additionally, in an approach to uncover a sexual cycle,
strains were engineered to express different
alleles in the same cell. The resulting strains produce hyphae reminiscent of early steps in sexual development and display upregulation of genes associated with sexual development as well as others encoding lipases and a protease potentially relevant for pathogenesis of the fungus. Our study reveals a previously unseen genomic relocation of mating-type loci in fungi and provides insight toward the identification of a sexual cycle in
, with possible implications for pathogenicity.
Detection, identification and classification of yeasts have undergone a major transformation in the last decade and a half following application of gene sequence analyses and genome comparisons. ...Development of a database (barcode) of easily determined DNA sequences from domains 1 and 2 (D1/D2) of the nuclear large subunit rRNA gene and from ITS now permits many laboratories to identify species quickly and accurately, thus replacing the laborious and often inaccurate phenotypic tests previously used. Phylogenetic analysis of gene sequences is leading to a major revision of yeast systematics that will result in redefinition of nearly all genera. This new understanding of species relationships has prompted a change of rules for naming and classifying yeasts and other fungi, and these new rules are presented in the recently implemented International Code of Nomenclature for algae, fungi, and plants (Melbourne Code). The use of molecular methods for species identification and the impact of Code changes on classification will be discussed, as will use of phylogeny for prediction of biotechnological applications.
Next generation sequencing enables improved phylogenetic analysis of yeasts and enables prediction of metabolic properties of different yeast species.
A new species of the yeast genus Blastobotrys was discovered during a worldwide survey of culturable xerophilic fungi in house dust. Several culture‐dependent and independent studies from around the ...world detected the same species from a wide range of substrates including indoor air, cave wall paintings, bats, mummies, and the iconic self‐portrait of Leonardo da Vinci from ca 1512. However, none of these studies identified their strains, clones, or OTUs as Blastobotrys. We introduce the new species as Blastobotrys davincii f.a., sp. nov. (holotype CBS H‐24879) and delineate it from other species using morphological, phylogenetic, and physiological characters. The new species of asexually (anamorphic) budding yeast is classified in Trichomonascaceae and forms a clade along with its associated sexual state genus Trichomonascus. Despite the decade‐old requirement to use a single generic name for fungi, both names are still used. Selection of the preferred name awaits a formal nomenclatural proposal. We present arguments for adopting Blastobotrys over Trichomonascus and introduce four new combinations as Blastobotrys allociferrii (≡ Candida allociferrii), B. fungorum (≡ Sporothrix fungorum), B. mucifer (≡ Candida mucifera), and Blastobotrys vanleenenianus (≡ Trichomonascus vanleenenianus). We provide a nomenclatural review and an accepted species list for the 37 accepted species in the Blastobotrys/Trichomonascus clade. Finally, we discuss the identity of the DNA clones detected on the da Vinci portrait, and the importance of using appropriate media to isolate xerophilic or halophilic fungi.
Several surveys from around the world reported the same yeast species from a wide range of substrates, most notably from the iconic self‐portrait of Leonardo da Vinci. None of these studiesidentified their strains, clones, or OTUs as Blastobotrys. Here we describe this as a new species and name it Blastobotrys davincii.
Take‐away
Blastobotrys davincii is introduced as a new species.
Surveys have detected this species, but could never correctly identify or name it.
The species was found on the da Vinci portrait, mummies and other substrates.
A nomenclature review and an accepted species list for the Blastobotrys/Trichomonascus clade is provided.
Appropriate isolation media are important to allow for growth of specific fungi.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Colonization of apples by ballistoconidium-forming fungi causes a new disorder, here named ‘white haze’. White haze may occur in mild form in the field, but only becomes problematic after ...Ultra-Low Oxygen storage, and, therefore, may be considered as a postharvest disorder. All isolates, obtained using the spore-fall method, were morphologically identified as anamorphs of smut fungi belonging to the genus Tilletiopsis. Sequence analysis of the D1/D2 and the ITS domains of the rDNA revealed nine novel taxa scattered among the Exobasidiomycetidae (Ustilaginomycetes). Field experiments confirmed the erratic incidence of white haze over the years, and the development of the disorder seems to be enhanced at lower temperatures and a high relative humidity. Several scab fungicide treatments showed diminishing effects on the incidence of white haze.
ABSTRACT
Malassezia furfur is a yeast species belonging to Malasseziomycetes, Ustilaginomycotina and Basidiomycota that is found on healthy warm-blooded animal skin, but also involved in various skin ...disorders like seborrheic dermatitis/dandruff and pityriasis versicolor. Moreover, Malassezia are associated with bloodstream infections, Crohn's disease and pancreatic carcinoma. Recent advances in Malassezia genomics and genetics have focused on the nuclear genome. In this work, we present the M. furfur mitochondrial (mt) genetic heterogenicity with full analysis of 14 novel and six available M. furfur mt genomes. The mitogenome analysis reveals a mt gene content typical for fungi, including identification of variable mt regions suitable for intra-species discrimination. Three of them, namely the trnK–atp6 and cox3–nad3 intergenic regions and intron 2 of the cob gene, were selected for primer design to identify strain differences. Malassezia furfur strains belonging to known genetic variable clusters, based on AFLP and nuclear loci, were assessed for their mt variation using PCR amplification and sequencing. The results suggest that these mt regions are excellent molecular markers for the typing of M. furfur strains and may provide added value to nuclear regions when assessing evolutionary relationships at the intraspecies level.
A total of 20 M. furfur mt genomes show a highly conserved gene order but vary in intron abundance and intergenic regions, revealing promising multicopy target regions for typing.
The world’s ten most feared fungi Hyde, Kevin D.; Al-Hatmi, Abdullah M. S.; Andersen, Birgitte ...
Fungal diversity,
11/2018, Volume:
93, Issue:
1
Journal Article
Peer reviewed
An account is provided of the world’s ten most feared fungi. Within areas of interest, we have organized the entries in the order of concern. We put four human pathogens first as this is of concern ...to most people. This is followed by fungi producing mycotoxins that are highly harmful for humans;
Aspergillus flavus
, the main producer of aflatoxins, was used as an example. Problems due to indoor air fungi may also directly affect our health and we use
Stachybotrys chartarum
as an example. Not everyone collects and eats edible mushrooms. However, fatalities caused by mushroom intoxications often make news headlines and therefore we include one of the most poisonous of all mushrooms,
Amanita phalloides
, as an example. We then move on to the fungi that damage our dwellings causing serious anxiety by rotting our timber structures and flooring.
Serpula lacrymans
, which causes dry rot is an excellent example. The next example serves to represent all plant and forest pathogens. Here we chose
Austropuccinia psidii
as it is causing devastating effects in Australia and will probably do likewise in New Zealand. Finally, we chose an important amphibian pathogen which is causing serious declines in the numbers of frogs and other amphibians worldwide. Although we target the top ten most feared fungi, numerous others are causing serious concern to human health, plant production, forestry, other animals and our factories and dwellings. By highlighting ten feared fungi as an example, we aim to promote public awareness of the cost and importance of fungi.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
ABSTRACT
Cryptococcus spp. are fungal species belonging to Tremellomycetes, Agaricomycotina, Basidiomycota, and several members are responsible for cryptococcosis, one of the most ubiquitous human ...mycoses. Affecting mainly immunosuppressed patients, but also immunocompetent ones, the members of this genus present a high level of genetic diversity. In this study, two mitochondrial intergenic regions, i.e. nad1-cob and cob-rps3, were tested for the intra- or interspecies discrimination and identification of strains and species of the genus Cryptococcus. Phylogenetic trees were constructed based on individual and concatenated sequences from representative pathogenic strains of the Cryptococcus neoformans/Cryptococcus gattii complex, representing serotypes and AFLP genotypes of all newly introduced species of this complex. Using both intergenic regions, as well as the concatenated dataset, the strains clustered in accordance with the new taxonomy. These results suggest that identification of Cryptococcus strains is possible by employing these mitochondrial intergenic regions using PCR amplification as a quick and effective method to elucidate genotypic and taxonomic differences. Thus, these regions may be applicable to a broad range of clinical studies, leading to a rapid recognition of the clinical profiles of patients.
Cryptococcus spp. are fungal species belonging to Tremellomycetes, Agaricomycotina, Basidiomycota, and several members are responsible for cryptococcosis, one of the most ubiquitous human mycoses. ...Affecting mainly immunosuppressed patients, but also immunocompetent ones, the members of this genus present a high level of genetic diversity. In this study, two mitochondrial intergenic regions, i.e. nadl-cob and cob-rps3, were tested for the intra- or interspecies discrimination and identification of strains and species of the genus Cryptococcus. Phylogenetic trees were constructed based on individual and concatenated sequences from representative pathogenic strains of the Cryptococcus neqfomians/Cryptococcus gattii complex, representing serotypes and AFLP genotypes of all newly introduced species of this complex. Using both intergenic regions, as well as the concatenated dataset, the strains clustered in accordance with the new taxonomy. These results suggest that identification of Cryptococcus strains is possible by employing these mitochondrial intergenic regions using PCR amplification as a quick and effective method to elucidate genotypic and taxonomic differences. Thus, these regions may be applicable to a broad range of clinical studies, leading to a rapid recognition of the clinical profiles of patients.
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