Wallemia sebi
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ABSTRACT:
PROVIDER: PRJNA65013 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Wallemia genome sequencing and assembly of 23 environmental strains
| PRJNA527765 | ENA
Project description:Wallemia mellicola genome sequencing and assembly of 25 environmental strains
| PRJNA527769 | ENA
Project description:One of the most commonly encountered species in the small basidiomycetous sub-phylum Wallemiomycotina is Wallemia mellicola, a xerotolerant fungus with a widespread distribution. To investigate the population characteristics of the species, whole genomes of twenty-five strains were sequenced. Apart from identification of four strains of clonal origin, the distances between the genomes failed to reflect either the isolation habitat of the strains or their geographical origin. Strains from different parts of the world appeared to represent a relatively homogenous and widespread population. The lack of concordance between individual gene phylogenies and the decay of linkage disequilibrium indicated that W. mellicola is at least occasionally recombining. Two versions of a putative mating-type locus have been found in all sequenced genomes, each present in approximately half of the strains. W. mellicola thus appears to be capable of (sexual) recombination and shows no signs of allopatric speciation or specialization to specific habitats.
| S-EPMC6628117 | biostudies-literature
Project description:Wallemia sebi is a xerophilic food- and air-borne fungus. The name has been used for strains that prevail in cold, temperate and tropical climates. In this study, multi-locus phylogenetic analyses, using the internal transcribed spacer (ITS) regions, DNA replication licensing factor (MCM7), pre-rRNA processing protein (TSR1), RNA polymerase II largest subunit (RPB1), RNA polymerase II second largest subunit (RPB2) and a new marker 3´-phosphoadenosine-5´-phosphatase (HAL2), confirmed the previous hypothesis that W. sebi presents a complex of at least four species. Here, we confirm and apply the phylogenetic analyses based species hypotheses from a companion study to guide phenotypic assessment of W. sebi like strains from a wide range of substrates, climates and continents allowed the recognition of W. sebi sensu stricto and three new species described as W. mellicola, W. Canadensis, and W. tropicalis. The species differ in their conidial size, xerotolerance, halotolerance, chaotolerance, growth temperature regimes, extracellular enzyme activity profiles, and secondary metabolite patterns. A key to all currently accepted Wallemia species is provided that allow their identification on the basis of physiological, micromorphological and culture characters.
| S-EPMC4446336 | biostudies-literature
Project description:BackgroundWallemia ichthyophaga is a highly specialized basidiomycetous fungus. It is one of the most halophilic fungi ever described, only able to grow at low water activity. This specialization is thought to explain why it is only rarely isolated from nature.ResultsGenomes of 21 W. ichthyophaga strains were sequenced with PE150 reads on BGISEQ500 platform. The genomes shared high similarity with the reference genome of the species, they were all smaller than 10 Mbp and had a low number of predicted genes. Groups of strains isolated in the same location encompassed clones as well as very divergent strains. There was little concordance between phylogenies of predicted genes. Linkage disequilibrium of pairs of polymorphic loci decayed relatively quickly as a function of distance between the loci (LD decay distance 1270 bp). For the first time a putative mating-type locus was identified in the genomes of W. ichthyophaga.ConclusionBased on the comparison of W. ichthyophaga genomes it appears that some phylogenetic lineages of the species can persist in the same location over at least several years. Apart from this, the differences between the strains do not reflect the isolation habitat or geographic location. Together with results supporting the existence of (sexual) recombination in W. ichthyophaga, the presented results indicate that strains of W. ichthyophaga can form a single recombining population even between different habitats and over large geographical distances.
| S-EPMC6738226 | biostudies-literature
Project description:Genome of saprotrophic basidiomycete
| PRJNA70685 | ENA
Project description:BACKGROUND: The basidomycete Wallemia ichthyophaga from the phylogenetically distinct class Wallemiomycetes is the most halophilic fungus known to date. It requires at least 10% NaCl and thrives in saturated salt solution. To investigate the genomic basis of this exceptional phenotype, we obtained a de-novo genome sequence of the species type-strain and analysed its transcriptomic response to conditions close to the limits of its lower and upper salinity range. RESULTS: The unusually compact genome is 9.6 Mb large and contains 1.67% repetitive sequences. Only 4884 predicted protein coding genes cover almost three quarters of the sequence. Of 639 differentially expressed genes, two thirds are more expressed at lower salinity. Phylogenomic analysis based on the largest dataset used to date (whole proteomes) positions Wallemiomycetes as a 250-million-year-old sister group of Agaricomycotina. Contrary to the closely related species Wallemia sebi, W. ichthyophaga appears to have lost the ability for sexual reproduction. Several protein families are significantly expanded or contracted in the genome. Among these, there are the P-type ATPase cation transporters, but not the sodium/ hydrogen exchanger family. Transcription of all but three cation transporters is not salt dependent. The analysis also reveals a significant enrichment in hydrophobins, which are cell-wall proteins with multiple cellular functions. Half of these are differentially expressed, and most contain an unusually large number of acidic amino acids. This discovery is of particular interest due to the numerous applications of hydrophobines from other fungi in industry, pharmaceutics and medicine. CONCLUSIONS: W. ichthyophaga is an extremophilic specialist that shows only low levels of adaptability and genetic recombination. This is reflected in the characteristics of its genome and its transcriptomic response to salt. No unusual traits were observed in common salt-tolerance mechanisms, such as transport of inorganic ions or synthesis of compatible solutes. Instead, various data indicate a role of the cell wall of W. ichthyophaga in its response to salt. Availability of the genomic sequence is expected to facilitate further research into this unique species, and shed more light on adaptations that allow it to thrive in conditions lethal to most other eukaryotes.
| S-EPMC3849046 | biostudies-literature