Nothing Special in the Specialist? Draft Genome Sequence of Cryomyces antarcticus, the Most Extremophilic Fungus from Antarctica

Abstract The draft genome of the Antarctic endemic fungus Cryomyces antarcticus is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with Neurospora crassa as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes

About -rV ending verbs in the Sakhalin dialect of Ainu

Table S2. Abbreviations of peroxidase gene names used for the peroxidase-catalase superfamily. (XLSX 54 kb

Generacija novih genotipskih i fenotipskih svojstava prirodnih i umjetnih hibrida kvasaca

Evolution and genome stabilization have mostly been studied on the Saccharomyces hybrids isolated from natural and alcoholic fermentation environments. Genetic and phenotypic properties have usually been compared to the laboratory and reference strains, as the true ancestors of the natural hybrid yeasts are unknown. In this way the exact impact of different parental fractions on the genome organization or metabolic activity of the hybrid yeasts is difficult to resolve completely. In the present work the evolution of geno- and phenotypic properties is studied in the interspecies hybrids created by the cross-breeding of S. cerevisiae with S. uvarum or S. kudriavzevii auxotrophic mutants. We hypothesized that the extent of genomic alterations in S. cerevisiae × S. uvarum and S. cerevisiae × S. kudriavzevii should affect the physiology of their F1 offspring in different ways. Our results, obtained by amplified fragment length polymorphism (AFLP) genotyping and karyotyping analyses, showed that both subgenomes of the S. cerevisiae x S. uvarum and of S. cerevisiae × S. kudriavzevii hybrids experienced various modifications. However, the S. cerevisiae × S. kudriavzevii F1 hybrids underwent more severe genomic alterations than the S. cerevisiae × S. uvarum ones. Generation of the new genotypes also influenced the physiological performances of the hybrids and the occurrence of novel phenotypes. Significant differences in carbohydrate utilization and distinct growth dynamics at increasing concentrations of sodium chloride, urea and miconazole were observed within and between the S. cerevisiae × S. uvarum and S. cerevisiae × S. kudriavzevii hybrids. Parental strains also demonstrated different contributions to the final metabolic outcomes of the hybrid yeasts. A comparison of the genotypic properties of the artificial hybrids with several hybrid isolates from the wine-related environments and wastewater demonstrated a greater genetic variability of the S. cerevisiae × S. kudriavzevii hybrids. Saccharomyces cerevisiae × S. uvarum artificial and natural hybrids showed considerable differences in osmolyte tolerance and sensitivity to miconazole, whereas the S. cerevisiae × S. kudriavzevii hybrids exhibited differences also in maltotriose utilization. The results of this study suggest that chromosomal rearrangements and genomic reorganizations as post-hybridization processes may affect the phenotypic properties of the hybrid progeny substantially. Relative to their ancestors, the F1 segregants may generate different phenotypes, indicating novel routes of evolution in response to environmental growth conditions.Evolucija i stabilizacija genoma kvasca uglavnom se proučavaju s pomoću interspecijskih hibrida roda Saccharomyces, izoliranih iz prirodnih staništa ili tijekom alkoholnih fermentacija. Njihova genetska i fenotipska svojstva obično se uspoređuju sa svojstvima laboratorijskih i referentnih sojeva, budući da su izvorni roditeljski sojevi prirodnih hibrida kvasaca nepoznati. Na ovaj je način teško u potpunosti razumjeti utjecaj različitih roditeljskih frakcija na organizaciju genoma ili metaboličku aktivnost hibrida kvasaca. U ovom je radu proučena evolucija genotipskih i fenotipskih svojstava interspecijskih hibrida, nastalih križanjem kvasca S. cerevisiae s auksotrofnim mutantima kvasaca S. uvarum i S. kudriavzevii. Naša je hipoteza bila da bi genomske promjene nastale u hibridima S. cerevisiae × S. uvarum i S. cerevisiae × S. kudriavzevii trebale na različite načine utjecati na fiziologiju njihovih F1 segreganata. Rezultati dobiveni genotipizacijom, tj. analizom polimorfizma duljine umnoženih fragmenata (engl. amplified fragment length polymorphism - AFLP) i kariotipizacijom pokazuju da su oba subgenoma hibrida S. cerevisiae × S. uvarum i S. cerevisiae × S. kudriavzevii izmjenjena. Međutim, promjene genoma segreganata F1 hibrida S. cerevisiae × S. kudriavzevii bile su znatnije od onih segreganata hibrida S. cerevisiae × S. uvarum. Novi su genotipovi utjecali na fiziološke značajke hibrida te nastanak novih fenotipova. Bitna je razlika među hibridima S. cerevisiae × S. uvarum i S. cerevisiae × S. kudriavzevii opažena u potrošnji šećera i različitoj dinamici rasta kod povećanih koncentracija natrijevog klorida, uree i mikonazola. Roditeljski su sojevi različito utjecali na konačnu metaboličku sliku hibrida kvasaca. Usporedbom genotipskih svojstava umjetnih hibrida s nekoliko hibrida izoliranih iz prirodnih staništa (vinograda i otpadnih voda) utvrđena je veća genetska raznolikost hibrida S. cerevisiae × S. kudriavzevii. Umjetni i prirodni hibridi Saccharomyces cerevisiae × S. uvarum bili su različito osjetljivi prema osmolitima i mikonazolu, dok su se hibridi S. cerevisiae × S. kudriavzevii razlikovali i u potrošnji maltotrioze. Iz dobivenih se rezultata može zaključiti da kromosomalna rekombinacija i genomska reorganizacija kao post-hibridizacijski procesi mogu značajno utjecati na fenotipska svojstva hibridnih potomaka. U usporedbi s roditeljskim sojevima, segreganti F1 mogu generirati različite fenotipove, što upućuje na zaključak da su specifični uvjeti rasta kvasaca uzrokovali nastanak novih evolucijskih tokova

Big Sound and Extreme Fungi—Xerophilic, Halotolerant Aspergilli and Penicillia with Low Optimal Temperature as Invaders of Historic Pipe Organs

Recent investigations have shown that xerophilic fungi may pose a biodeterioration risk by threatening objects of cultural heritage including many types of materials, including wood, paint layers, organic glues or leather and even metal. Historic—and also new built—pipe organs combine all those materials. In this study, halotolerant aspergilli and penicillia with low optimal temperatures were shown to be the most frequent invaders of pipe organs. The fungi form white mycelia on the organic components of the organs with a clear preference for the bolus paint of the wooden pipes, the leather-made hinges of the stop actions and all parts fixed by organic glue. Physiological tests showed that the strains isolated from the instruments all show a halotolerant behavior, although none was halophilic. The optimum growth temperature is below 20 °C, thus the fungi are perfectly adapted to the cool and relatively dry conditions in the churches and organs respectively. The de-novo genome sequences analyses of the strains are currently ongoing and will reveal the genomic basis for the halotolerant behavior of the fungi

Back to the Salt Mines: Genome and Transcriptome Comparisons of the Halophilic Fungus <i>Aspergillus salisburgensis</i> and Its Halotolerant Relative <i>Aspergillus sclerotialis</i>

Salt mines are among the most extreme environments as they combine darkness, low nutrient availability, and hypersaline conditions. Based on comparative genomics and transcriptomics, we describe in this work the adaptive strategies of the true halophilic fungus Aspergillus salisburgensis, found in a salt mine in Austria, and compare this strain to the ex-type halotolerant fungal strain Aspergillus sclerotialis. On a genomic level, A. salisburgensis exhibits a reduced genome size compared to A. sclerotialis, as well as a contraction of genes involved in transport processes. The proteome of A. sclerotialis exhibits an increased proportion of alanine, glycine, and proline compared to the proteome of non-halophilic species. Transcriptome analyses of both strains growing at 5% and 20% NaCl show that A. salisburgensis regulates three-times fewer genes than A. sclerotialis in order to adapt to the higher salt concentration. In A. sclerotialis, the increased osmotic stress impacted processes related to translation, transcription, transport, and energy. In contrast, membrane-related and lignolytic proteins were significantly affected in A. salisburgensis

Nothing Special in the Specialist? Draft Genome Sequence of <i>Cryomyces antarcticus</i>, the Most Extremophilic Fungus from Antarctica

<div><p>The draft genome of the Antarctic endemic fungus <i>Cryomyces antarcticus</i> is presented. This rock inhabiting, microcolonial fungus is extremely stress tolerant and it is a model organism for exobiology and studies on stress resistance in Eukaryots. Since this fungus is a specialist in the most extreme environment of the Earth, the analysis of its genome is of important value for the understanding of fungal genome evolution and stress adaptation. A comparison with <i>Neurospora crassa</i> as well as with other microcolonial fungi shows that the fungus has a genome size of 24 Mbp, which is the average in the fungal kingdom. Although sexual reproduction was never observed in this fungus, 34 mating genes are present with protein homologs in the classes Eurotiomycetes, Sordariomycetes and Dothideomycetes. The first analysis of the draft genome did not reveal any significant deviations of this genome from comparative species and mesophilic hyphomycetes.</p></div