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1

Electrophoretic karyotype of the ascomycete Podospora anserina  

Microsoft Academic Search

Fractionation of intact chromosomes of the ascomycete Podospora anserina by contour-clamped homogenous electric field (CHEF) gel electrophoresis resulted in the resolution of five distinct chromosomal bands. Two of these bands migrated as doublets. Using chromosomal standards from Schizosaccharomyces pombe we estimated the size of the P. anserina genome to about 33.4 megabases (Mb). By heterologous hybridization of fractionated chromosomes the

Heinz D. Osiewacz; Annette Clairmont; Marion Huth

1990-01-01

2

The genome sequence of the model ascomycete fungus Podospora anserina  

Microsoft Academic Search

Background The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. Results We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed sequence tag collection. Similar to higher eukaryotes, the P. anserina transcription\\/splicing machinery generates numerous

Olivier Lespinet; Fabienne Malagnac; Corinne Da Silva; Olivier Jaillon; Betina M Porcel; Arnaud Couloux; Jean-Marc Aury; Béatrice Ségurens; Julie Poulain; Véronique Anthouard; Sandrine Grossetete; Hamid Khalili; Evelyne Coppin; Michelle Déquard-Chablat; Marguerite Picard; Véronique Contamine; Sylvie Arnaise; Anne Bourdais; Véronique Berteaux-Lecellier; Daniel Gautheret; Ronald P de Vries; Evy Battaglia; Pedro M Coutinho; Etienne GJ Danchin; Bernard Henrissat; Riyad EL Khoury; Annie Sainsard-Chanet; Antoine Boivin; Bérangère Pinan-Lucarré; Carole H Sellem; Robert Debuchy; Patrick Wincker; Jean Weissenbach; Philippe Silar

2008-01-01

3

Evidence for giant linear plasmids in the ascomycete Podospora anserina  

Microsoft Academic Search

In the extrachromosomal mutant AL2 of the ascomycete Podospora anserina longevity is correlated with the presence of the linear mitochondrial plasmid pAL2-1. In addition to this autonomous genetic element, two types of closely related pAL2-1-homologous molecules were detected in the high-molecular-weight mitochondrial DNA (mtDNA). One of these molecules is of linear and the other of circular structure. Both molecules contain

Josef Hermanns; Anita Asseburg; Heinz D. Osiewacz

1995-01-01

4

The genome sequence of the model ascomycete fungus Podospora anserina  

PubMed Central

Background The dung-inhabiting ascomycete fungus Podospora anserina is a model used to study various aspects of eukaryotic and fungal biology, such as ageing, prions and sexual development. Results We present a 10X draft sequence of P. anserina genome, linked to the sequences of a large expressed sequence tag collection. Similar to higher eukaryotes, the P. anserina transcription/splicing machinery generates numerous non-conventional transcripts. Comparison of the P. anserina genome and orthologous gene set with the one of its close relatives, Neurospora crassa, shows that synteny is poorly conserved, the main result of evolution being gene shuffling in the same chromosome. The P. anserina genome contains fewer repeated sequences and has evolved new genes by duplication since its separation from N. crassa, despite the presence of the repeat induced point mutation mechanism that mutates duplicated sequences. We also provide evidence that frequent gene loss took place in the lineages leading to P. anserina and N. crassa. P. anserina contains a large and highly specialized set of genes involved in utilization of natural carbon sources commonly found in its natural biotope. It includes genes potentially involved in lignin degradation and efficient cellulose breakdown. Conclusion The features of the P. anserina genome indicate a highly dynamic evolution since the divergence of P. anserina and N. crassa, leading to the ability of the former to use specific complex carbon sources that match its needs in its natural biotope.

Espagne, Eric; Lespinet, Olivier; Malagnac, Fabienne; Da Silva, Corinne; Jaillon, Olivier; Porcel, Betina M; Couloux, Arnaud; Aury, Jean-Marc; Segurens, Beatrice; Poulain, Julie; Anthouard, Veronique; Grossetete, Sandrine; Khalili, Hamid; Coppin, Evelyne; Dequard-Chablat, Michelle; Picard, Marguerite; Contamine, Veronique; Arnaise, Sylvie; Bourdais, Anne; Berteaux-Lecellier, Veronique; Gautheret, Daniel; de Vries, Ronald P; Battaglia, Evy; Coutinho, Pedro M; Danchin, Etienne GJ; Henrissat, Bernard; Khoury, Riyad EL; Sainsard-Chanet, Annie; Boivin, Antoine; Pinan-Lucarre, Berangere; Sellem, Carole H; Debuchy, Robert; Wincker, Patrick; Weissenbach, Jean; Silar, Philippe

2008-01-01

5

Genes inhibiting senescence in the ascomycete Podospora anserina  

Microsoft Academic Search

Senescence occurs in all wild strains of Podospora anserina after continued growth. This syndrome can be inhibited by a synergistic interaction of two linked genes, incoloris and vivax. Whereas the wild strain starts to become senescent after 26 d and the mutants incoloris and vivax after 42 and 66 d respectively, the double mutant shows no signs of aging after

Karl Esser; Wilhelm Keller

1976-01-01

6

Yeti--a degenerate gypsy-like LTR retrotransposon in the filamentous ascomycete Podospora anserina.  

PubMed

In the filamentous ascomycete Podospora anserina a 6,935-bp retrotransposon, Yeti, has been identified and characterized. It is flanked by a 5-bp target site duplication and contains long terminal repeats (LTRs) 354 bp in length. The LTRs show a high degree of identity to the previously reported repetitive element repa, a sequence suggested to represent a solo-LTR element of an unknown transposon. In the investigated Podospora strains, the number of complete Yeti copies is significantly lower than the number of repa elements, with up to 25 copies. Yeti appears to be inactive: it is highly degenerate and no transcripts of the element have been detected even in Podospora cultures grown under elevated stress conditions. The amino acid sequences deduced from Yeti display significant homology, particularly in the reverse transcriptase region, to those of other fungal retrotransposons, indicating that it is a member of the gypsy family. As suggested by the unusual dinucleotide content, degeneration of Yeti appears to be the result of a molecular mechanism resembling repeat-induced point mutation in Neurospora crassa. PMID:11057446

Hamann, A; Feller, F; Osiewacz, H D

2000-10-01

7

Characterization and cloning of plasmid like DNA of the ascomycete Podospora anserina  

Microsoft Academic Search

The previously reported existence of plasmid-like (pl) DNA in senescent mycelia of Podospora anserina was confirmed using new methodology. Detailed analysis of bulk DNA has further shown a possible relationship between pl DNA and mt DNA.

U. Stahl; U. Kück; P. Tudzynski; K. Esser

1980-01-01

8

Evidence for plasmid like DNA in a filamentous fungus, the ascomycete Podospora anserina  

Microsoft Academic Search

The existece of plasmid like DNA was demonstrated in senescent mycelia of Podospora anserina (strain s) by biophysical and electronmicroscopic methods. According to their contour length of about 1.4 and 2.7 µm respectively the molecular weight for the monomer is in the range of 3·106.

Ulf Stahl; Paul A. Lemke; Paul Tudzynski; Ulrich Kfick; Karl Esser

1978-01-01

9

The phenoloxidases of the ascomycete Podospora anserina : The three forms of the major laccase activity  

Microsoft Academic Search

In Podospora anserina three laccase activities (I, II and III) were identified. Present results show the existence of an additional lacaase (an anodic protein; MW 80,000; Rf 0.07). Laccase IV derived from the dissociation at acid pH (4.5) of a protein which showed identical molecular weight (390,000) and Rf (0.1) to the oligomeric laccase I. The recovery of laccase I

Pascal Durrens

1981-01-01

10

Integrative transformation of the ascomycete Podospora anserina : identification of the mating-type locus on chromosome VII of electrophoretically separated chromosomes  

Microsoft Academic Search

Protoplasts of wild-type strain s and a long-lived extrachromosomal mutant (AL2) of the ascomycete Podospora anserina were transformed using a plasmid (pAN7-1) which contains the hygromycin B phosphotransferase gene (hph) of Escherichia coli under the control of Aspergillus nidulans regulatory sequences. After optimizing the transformation procedure, transformation efficiencies of 15–21 transformants\\/µ plasmid DNA were obtained. Using a second selectable vector

Hienz D. Osiewacz; Adriane Skaletz; Karl Esser

1991-01-01

11

Die Phenoloxydasen des Ascomyceten Podospora anserina  

Microsoft Academic Search

The ascomycete Podospora anserina forms two different phenoloxidases. According to their substrate specifity they can be classified as laccase and tyrosinase, respectively. While laccase is found in freshly prepared extracts in a highly active form, the tyrosinase needs to be activated by cold- or heat-treatment. Further characteristics of the two enzymes are: their different solubilities in ammoniumsulfate solution and their

Karl Esser

1963-01-01

12

The genome sequence of Podospora anserina, a classic model fungus  

PubMed Central

The completed genome sequence of the coprophilous fungus Podospora anserina increases the sampling of fungal genomes. In line with its habitat of herbivore dung, this ascomycete has an exceptionally rich gene set devoted to the catabolism of complex carbohydrates.

Paoletti, Mathieu; Saupe, Sven J

2008-01-01

13

Genome analysis of filamentous fungi: identification and characterization of an unusual GT-rich minisatellite in the ascomycete Podospora anserina  

Microsoft Academic Search

A genomic DNA fragment, PaGT7-5, of Podospora anserina was cloned that contains three different repetitive sequence motifs including a minisatellite with an unusual structure.\\u000a This element, PaMin1, consists of ten copies of a 16 bp repeat unit with five GT dinucleotide repeats. Adjacent to PaMin1, a short poly(GT) stretch and four repeats of a 12 bp sequence were identified. Six

Andrea Hamann; Heinz D. Osiewacz

1998-01-01

14

The Phenoloxidases of the Ascomycete Podospora anserina. Structural Differences between Laccases of High and Low Molecular Weight  

Microsoft Academic Search

In order to investigate the extent of the relationship between the three copper-containing glycoproteins, laccases I, I1 and I11 (MI 70000,80000 and 390000 respectively) of Podospora anserina, the following experiments were carried out on laccases I1 and 111: (a) determination of amino acid composition ; (b) determination of N-terminal and C-terminal amino acid ; (c) determination of sugar composition; (d)

Walter MINUTH; Karl ESSER; Martina KLISCHIES

1978-01-01

15

Mitochondrial DNA from Podospora anserina  

Microsoft Academic Search

Mitochondrial (Mt) DNA from Podospora anserina was isolated and characterized with respect to density in CsCl, contour length and endonuclease restriction enzymes. The density of Mt DNA for four races examined was 1.694 g\\/cm3, compared with 1.712 g\\/cm3 for nuclear DNA. Extraction in the presence of a nuclease inhibitor, aurintricarboxylic acid and isolation in DAPI CsCl gradients allowed us to

Donald J. Cummings; Léon Belcour; Claude Grandchamp

1979-01-01

16

Mitochondrial DNA from Podospora anserina  

Microsoft Academic Search

We have examined the structure of the rRNA genes from the mitochondrial genome of Podospora anserina. Using R-loop analysis, nuclease protection experiments, and Southern blot hybridization analysis we have observed two intervening sequences (IVS) in the large rRNA gene, and none in the small rRNA gene. the IVS sequences are 1.65 kbp and 2.73 kbp long, and the larger of

Richard M. Wright; Donald J. Cummings

1983-01-01

17

Isolation and characterization of a laccase gene from Podospora anserina  

Microsoft Academic Search

The genome of the filamentous ascomycetePodospora anserina contains at least four non-adjacent regions that are homologous to the laccase gene ofNeurospora crassa. One of these regions contains a gene (lac2) encoding a protein that displays 62% identity with theN. crassa laccase. In shaken cultures,lac2 mRNA is present at low basal levels throughout the growth phase but increases at least 20-fold

J. Fernández-Larrea; U. Stahl

1996-01-01

18

Die Phenoloxydasen des Ascomyceten Podospora anserina  

Microsoft Academic Search

Laccase of the wild strain of Podospora anserina was purified by subsequent treatment with protamine sulfate, precipitation with ammonium sulfate and column chromatography on DEAE-Sephadex and hydroxylapatite. The purity was confirmed by sedimentation and electrophoresis (molecular weight about 361 000, isoeletric point at pH 5.1).

K. Esser; S. Dick; W. Gielen

1964-01-01

19

Mutations affecting meiosis in Podospora anserina  

Microsoft Academic Search

Forty mutants affecting meiosis and two affecting caryogamy were isolated in Podospora anserina. Growth and mitosis of these mutants were normal. Eighteen of them were studied by both light and electron microscopy so as to determine precisely how the behaviour of the chromosomes and\\/or the structure of the kinetic apparatus were altered.

J. M. Simonet; D. Zickler

1972-01-01

20

The mitochondrial plasmid of Podospora anserina: A mobile intron of a mitochondrial gene  

Microsoft Academic Search

In the ascomycete Podospora anserina strain ageing (senescence) is caused by a mitochondrial plasmid. In juvenile mycelia it is an integral part of the mtDNA and becomes liberated during ageing. The nucleotide sequence of this plasmid and of its flanking regions was determined. It consists of 2,539 by and contains an un identified reading frame (URF) originating in the adjacent

H. D. Osíewacz; K. Esser

1984-01-01

21

Die Phenoloxydasen des Ascomyceten Podospora anserina  

Microsoft Academic Search

0616 041.By using an improved method for purification of the laccase I of the wild type of Podospora anserina, yield and specific activity of this enzyme have been increased, whereas its stability decreased.2.Freshly prepared laccase I seems to be homogeneous, according to its behavior in hydroxylapatite-chromatography, in sedimentation-analysis and in disc-electrophoresis.3.The catalytic, electrophoretic, spectral and molecular properties and the carbohydrate-composition

H. Peter Molitoris; Karl Esser

1970-01-01

22

Rhythmic mycelial growth in Podospora anserina  

Microsoft Academic Search

0725 091.Inhibition of the tricarboxylic acid cycle by sodium fluoroacetate (NFA) suppresses the rhythmic growth in the mutant zonata (z) of Podospora anserina and enhances its linear growth rate. However, in the wild strain, the only effect of this inhibitor is a reduction of the linear growth rate.2.The z-like growth pattern induced in the wild strain by D-galactose also is

Gernot Lysek

1971-01-01

23

A DNA polymerase activity with characteristics of a reverse transcriptase in Podospora anserina  

Microsoft Academic Search

In the filamentous ascomycete fungus Podospora anserina, senescence is associated with dramatic changes of the juvenile mitochondrial genome. During senescence specific regions of the non-senescent genome are excised, ligated and amplified as a plasmid. In this paper, we report our studies on nuclear-mitochondrial extracts for the presence of RNA-dependent DNA polymerase activity (reverse transcriptase). In so-called middle aged mycelia of

Wolfram Steinhilber; Donald J. Cummings

1986-01-01

24

Molecular control of copper homeostasis in filamentous fungi: increased expression of a metallothionein gene during aging of Podospora anserina  

Microsoft Academic Search

The lifespan of the ascomycete Podospora anserina was previously demonstrated to be significantly increased in a copper-uptake mutant, suggesting that copper is a potential stressor involved in degenerative processes. In order to determine whether changes in copper stress occur in the cells during normal aging of cultures, we cloned and characterized a gene coding for a component of the molecular

N. B. Averbeck; C. Borghouts; A. Hamann; V Specke; H.-D. Osiewacz

2001-01-01

25

Assessing organismal aging in the filamentous fungus Podospora anserina.  

PubMed

Podospora anserina is an extensively studied model organism to unravel the mechanism of organismal aging. This filamentous fungus is short-lived and accessible to experimentation. Aging and lifespan are controlled by genetic and environmental traits and, in this model, have a strong mitochondrial etiology. Here, we describe methods and protocols to manipulate and study the aging process in P. anserina at different levels including biochemistry, cell biology, genetics, and physiology. PMID:23296676

Osiewacz, Heinz D; Hamann, Andrea; Zintel, Sandra

2013-01-01

26

Rapamycin Mimics the Incompatibility Reaction in the Fungus Podospora anserina  

Microsoft Academic Search

In filamentous fungi, a programmed cell death (PCD) reaction occurs when cells of unlike genotype fuse. This reaction is caused by genetic differences at specific loci termed het loci (for heterokaryon incompatibility). Although several het genes have been characterized, the mechanism of this cell death reaction and its relation to PCD in higher eukaryotes remains largely unknown. In Podospora anserina,

Karine Dementhon; Mathieu Paoletti; Berangere Pinan-Lucarre; Nathalie Loubradou-Bourges; Martine Sabourin; Sven J. Saupe; Corinne Clave

2003-01-01

27

Mitochondrial metabolism and aging in the filamentous fungus Podospora anserina  

Microsoft Academic Search

The filamentous fungus Podospora anserina has a limited lifespan. In this organism, aging is systematically associated to mitochondrial DNA instability. We recently provided evidence that the respiratory function is a key determinant of its lifespan. Loss of function of the cytochrome pathway leads to the compensatory induction of an alternative oxidase, to a decreased production of reactive oxygen species and

Séverine Lorin; Eric Dufour; Annie Sainsard-Chanet

2006-01-01

28

Mitochondrial genes in Podospora anserina : Recombination and linkage  

Microsoft Academic Search

Summary A fifth cytoplasmic mutation (capr 1) obtained inPodospora anserina is described. In addition to chloramphenicol resistance it confers a strong deficiency in cytochrome aa3 and impairs the germination of ascospores. Genetic analysis shows: 1) strict maternal inheritance of (capr 1) allele; 2) selection against the (capr 1) allele as well in sexual crosses as during vegetative growth; 3) complete

Léon Belcour; Odile Begel

1977-01-01

29

What is a bona fide mating-type gene? Internuclear complementation of mat mutants in Podospora anserina  

Microsoft Academic Search

In the heterothallic ascomycete Podospora anserina, the mating-type locus is occupied by two mutually exclusive sequences termed mat+ and mat–. The mat+ sequence contains only one gene, FPR1, while the mat– sequence contains three genes: FMR1, SMR1 and SMR2. Previous studies have demonstrated that FPR1 and FMR1 are required for fertilization. Further analyses have led to the hypothesis that mat+

S. Arnaise; R. Debuchy; M. Picard

1997-01-01

30

A novel family of linear plasmids with homology to plasmid pAL2-1 of Podospora anserina  

Microsoft Academic Search

Three recently isolated wild-type strains of the ascomycete Podospora anserina were analyzed for the presence of linear mitochondrial plasmids. In one of these strains, designated Wa6, at least 12 distinct plasmid-like elements were identified. From molecular analyses a minimum number of 78 individual linear molecules with proteins bound to their 5' ends was estimated. In addition, the different members of

Josef Hermanns; Fons Debets; Rolf Hoekstra; Heinz D. Osiewacz

1995-01-01

31

Spore-killing meiotic drive factors in a natural population of the fungus Podospora anserina.  

PubMed Central

In fungi, meiotic drive is observed as spore killing. In the secondarily homothallic ascomycete Podospora anserina it is characterized by the abortion of two of the four spores in the ascus. We have identified seven different types of meiotic drive elements (Spore killers). Among 99 isolates from nature, six of these meiotic drive elements occurred in a local population. Spore killers comprise 23% of the natural population of P. anserina in Wageningen, The Netherlands, sampled from 1991 to 1997. One Spore-killer type was also found in a French strain dating from 1937. All other isolates found so far are sensitive to spore killing. All seven Spore killer types differ in the percentage of asci that show killing and in their mutual interactions. Interactions among Spore killer types showed either mutual resistance or dominant epistasis. Most killer elements could be assigned to linkage group III but are not tightly linked to the centromere.

van der Gaag, M; Debets, A J; Oosterhof, J; Slakhorst, M; Thijssen, J A; Hoekstra, R F

2000-01-01

32

Genetic evidence for ribosomal antisuppressors in Podospora anserina  

Microsoft Academic Search

Antisuppressors were screened for with the help of informational suppressors inPodospora anserina. Four mutations in the AS1locus and two in the AS2locus were isolated, using allele non specific suppressors supposed to be ribosomal ambiguity mutations. Four mutations in the AS3locus and 45 in the AS4locus were obtained, using a nonsense (tRNA like) suppressor. All antisuppressors are partially dominant. Most mutations

Marguerite Picard-Bennoun

1976-01-01

33

Lethal mitochondrial genotypes in Podospora anserina : A model for senescence  

Microsoft Academic Search

Crosses between spg1 and spg2, two mitochondrial mutants of Podospora anserina, yield a new type of strain, called pseudo wild-type (PSW), in addition to wild-type recombinants. PSW strains are characterized by a variable phenotype for germination of ascospores and a variable longevity. By autofecondation, PSW strains yield early lethal strains (which die soon after the germination of the spores and

Léon Belcour; Odile Begel

1978-01-01

34

Aging and mitochondrial dysfunction in the filamentous fungus Podospora anserina  

Microsoft Academic Search

\\u000a In the filamentous fungus Podospora anserina, mitochondria play a paramount role in life span control and aging. During aging, these organelles become damaged as the\\u000a result of an age-dependent increase in the generation of mitochondrial reactive oxygen species (ROS). Remodelling of damaged\\u000a proteins of the respiratory chain is limited to early phases in the life span. Only in these stages,

Heinz D. Osiewacz

35

Dynamics of the mitochondrial genome during Podospora anserina aging  

Microsoft Academic Search

Senescence in Podospora anserina is always correlated with extrachromosomal mitochondrial DNA amplification (senDNA). Here we report a quantitative kinetic analysis of the molecular events that occur in the mitochondrial DNA of several wild-type cultures during aging. For each culture, the amplification of senDNA molecules and the modifications of the mitochondrial chromosome are analyzed at different ages and in relation with

Béatrice Albert; Carole H. Sellem

2002-01-01

36

The phenoloxidases of the ascomycete Podospora anserina  

Microsoft Academic Search

1.Eight mutants were isolated following mutagen treatment which are deficient in laccase formation. Seven of these had a pleiotropic effect and exhibited defects in growth rate and in mycelial and sexual morphology.2.By means of tetrad analysis the mutations were assigned to 6 loci. Three mutations were in the incolora locus, the others were non-allelic. Only two of these loci were

H. Prillinger; K. Esser

1977-01-01

37

Systematic deletion of homeobox genes in Podospora anserina uncovers their roles in shaping the fruiting body.  

PubMed

Higher fungi, which comprise ascomycetes and basidiomycetes, play major roles in the biosphere. Their evolutionary success may be due to the extended dikaryotic stage of their life cycle, which is the basis for their scientific name: the Dikarya. Dikaryosis is maintained by similar structures, the clamp in basidiomycetes and the crozier in ascomycetes. Homeodomain transcription factors are required for clamp formation in all basidiomycetes studied. We identified all the homeobox genes in the filamentous ascomycete fungus Podospora anserina and constructed deletion mutants for each of these genes and for a number of gene combinations. Croziers developed normally in these mutants, including those with up to six deleted homeogenes. However, some mutants had defects in maturation of the fruiting body, an effect that could be rescued by providing wild-type maternal hyphae. Analysis of mutants deficient in multiple homeogenes revealed interactions between the genes, suggesting that they operate as a complex network. Similar to their role in animals and plants, homeodomain transcription factors in ascomycetes are involved in shaping multicellular structures. PMID:22662159

Coppin, Evelyne; Berteaux-Lecellier, Véronique; Bidard, Frédérique; Brun, Sylvain; Ruprich-Robert, Gwenaël; Espagne, Eric; Aït-Benkhali, Jinane; Goarin, Anne; Nesseir, Audrey; Planamente, Sara; Debuchy, Robert; Silar, Philippe

2012-05-25

38

Calorie restriction in the filamentous fungus Podospora anserina.  

PubMed

Calorie restriction (CR) is a regimen of reduced food intake that, although the underlying mechanism is unknown, in many organisms leads to life span extension. Podospora anserina is one of the few known ageing filamentous fungi and the ageing process and concomitant degeneration of mitochondria have been well-studied. CR in P. anserina increases not only life span but also forestalls the ageing-related decline in fertility. Here we review what is known about CR in P. anserina and about possibly involved mechanisms like enhanced mitochondrial stability, reduced production of reactive oxygen species and changes in the OXPHOS machinery. Additionally, we present new microscopic data on mitochondrial dynamics under rich nutritional and CR conditions at different points in life. Lines that have grown under severe CR for more than 50x the normal life span, show no accumulation of age-related damage, though fecundity is reduced in some of these lines. Finally, we discuss the possible role of CR in P. anserina in nature and the effect of CR at different points in life. PMID:20064602

van Diepeningen, Anne D; Slakhorst, S Marijke; Koopmanschap, A Bertha; Ikink, Gerjon J; Debets, Alfons J M; Hoekstra, Rolf F

2010-01-11

39

Modulation of the glyoxalase system in the aging model Podospora anserina: effects on growth and lifespan.  

PubMed

The eukaryotic glyoxalase system consists of two enzymatic components, glyoxalase I (lactoylglutathione lyase) and glyoxalase II (hydroxyacylglutathione hydrolase). These enzymes are dedicated to the removal of toxic ?-oxoaldehydes like methylglyoxal (MG). MG is formed as a by-product of glycolysis and MG toxicity results from its damaging capability leading to modifications of proteins, lipids and nucleic acids. An efficient removal of MG appears to be essential to ensure cellular functionality and viability. Here we study the effects of the genetic modulation of genes encoding the components of the glyoxalase system in the filamentous ascomycete and aging modelPodospora anserina. Overexpression of PaGlo1 leads to a lifespan reduction on glucose rich medium, probably due to depletion of reduced glutathione. Deletion of PaGlo1 leads to hypersensitivity against MG added to the growth medium. A beneficial effect on lifespan is observed when both PaGlo1 and PaGlo2 are overexpressed and the corresponding strains are grown on media containing increased glucose concentrations. Notably, the double mutant has a 'healthy' phenotype without physiological impairments. Moreover, PaGlo1/PaGlo2_OEx strains are not long-lived on media containing standard glucose concentrations suggesting a tight correlation between the efficiency and capacity to remove MG within the cell, the level of available glucose and lifespan. Overall, our results identify the up-regulation of both components of the glyoxalase system as an effective intervention to increase lifespan in P. anserina. PMID:21212464

Scheckhuber, Christian Q; Mack, Sandra J; Strobel, Ingmar; Ricciardi, Filomena; Gispert, Suzana; Osiewacz, Heinz D

2010-12-01

40

The transcriptional response to nonself in the fungus Podospora anserina.  

PubMed

In fungi, heterokaryon incompatibility is a nonself recognition process occurring when filaments of different isolates of the same species fuse. Compatibility is controlled by so-called het loci and fusion of strains of unlike het genotype triggers a complex incompatibility reaction that leads to the death of the fusion cell. Herein, we analyze the transcriptional changes during the incompatibility reaction in Podospora anserina. The incompatibility response was found to be associated with a massive transcriptional reprogramming: 2231 genes were up-regulated by a factor 2 or more during incompatibility. In turn, 2441 genes were down-regulated. HET, NACHT, and HeLo domains previously found to be involved in the control of heterokaryon incompatibility were enriched in the up-regulated gene set. In addition, incompatibility was characterized by an up-regulation of proteolytic and other hydrolytic activities, of secondary metabolism clusters and toxins and effector-like proteins. The up-regulated set was found to be enriched for proteins lacking orthologs in other species and chromosomal distribution of the up-regulated genes was uneven with up-regulated genes residing preferentially in genomic islands and on chromosomes IV and V. There was a significant overlap between regulated genes during incompatibility in P. anserina and Neurospora crassa, indicating similarities in the incompatibility responses in these two species. Globally, this study illustrates that the expression changes occurring during cell fusion incompatibility in P. anserina are in several aspects reminiscent of those described in host-pathogen or symbiotic interactions in other fungal species. PMID:23589521

Bidard, Frédérique; Clavé, Corinne; Saupe, Sven J

2013-06-21

41

The Transcriptional Response to Nonself in the Fungus Podospora anserina  

PubMed Central

In fungi, heterokaryon incompatibility is a nonself recognition process occurring when filaments of different isolates of the same species fuse. Compatibility is controlled by so-called het loci and fusion of strains of unlike het genotype triggers a complex incompatibility reaction that leads to the death of the fusion cell. Herein, we analyze the transcriptional changes during the incompatibility reaction in Podospora anserina. The incompatibility response was found to be associated with a massive transcriptional reprogramming: 2231 genes were up-regulated by a factor 2 or more during incompatibility. In turn, 2441 genes were down-regulated. HET, NACHT, and HeLo domains previously found to be involved in the control of heterokaryon incompatibility were enriched in the up-regulated gene set. In addition, incompatibility was characterized by an up-regulation of proteolytic and other hydrolytic activities, of secondary metabolism clusters and toxins and effector-like proteins. The up-regulated set was found to be enriched for proteins lacking orthologs in other species and chromosomal distribution of the up-regulated genes was uneven with up-regulated genes residing preferentially in genomic islands and on chromosomes IV and V. There was a significant overlap between regulated genes during incompatibility in P. anserina and Neurospora crassa, indicating similarities in the incompatibility responses in these two species. Globally, this study illustrates that the expression changes occurring during cell fusion incompatibility in P. anserina are in several aspects reminiscent of those described in host-pathogen or symbiotic interactions in other fungal species.

Bidard, Frederique; Clave, Corinne; Saupe, Sven J.

2013-01-01

42

Insights into exo- and endoglucanase activities of family 6 glycoside hydrolases from Podospora anserina.  

PubMed

The ascomycete Podospora anserina is a coprophilous fungus that grows at late stages on droppings of herbivores. Its genome encodes a large diversity of carbohydrate-active enzymes. Among them, four genes encode glycoside hydrolases from family 6 (GH6), the members of which comprise putative endoglucanases and exoglucanases, some of them exerting important functions for biomass degradation in fungi. Therefore, this family was selected for functional analysis. Three of the enzymes, P. anserina Cel6A (PaCel6A), PaCel6B, and PaCel6C, were functionally expressed in the yeast Pichia pastoris. All three GH6 enzymes hydrolyzed crystalline and amorphous cellulose but were inactive on hydroxyethyl cellulose, mannan, galactomannan, xyloglucan, arabinoxylan, arabinan, xylan, and pectin. PaCel6A had a catalytic efficiency on cellotetraose comparable to that of Trichoderma reesei Cel6A (TrCel6A), but PaCel6B and PaCel6C were clearly less efficient. PaCel6A was the enzyme with the highest stability at 45°C, while PaCel6C was the least stable enzyme, losing more than 50% of its activity after incubation at temperatures above 30°C for 24 h. In contrast to TrCel6A, all three studied P. anserina GH6 cellulases were stable over a wide range of pHs and conserved high activity at pH values of up to 9. Each enzyme displayed a distinct substrate and product profile, highlighting different modes of action, with PaCel6A being the enzyme most similar to TrCel6A. PaCel6B was the only enzyme with higher specific activity on carboxymethylcellulose (CMC) than on Avicel and showed lower processivity than the others. Structural modeling predicts an open catalytic cleft, suggesting that PaCel6B is an endoglucanase. PMID:23645193

Poidevin, Laetitia; Feliu, Julia; Doan, Annick; Berrin, Jean-Guy; Bey, Mathieu; Coutinho, Pedro M; Henrissat, Bernard; Record, Eric; Heiss-Blanquet, Senta

2013-05-03

43

A Network of HMG-box Transcription Factors Regulates Sexual Cycle in the Fungus Podospora anserina.  

PubMed

High-mobility group (HMG) B proteins are eukaryotic DNA-binding proteins characterized by the HMG-box functional motif. These transcription factors play a pivotal role in global genomic functions and in the control of genes involved in specific developmental or metabolic pathways. The filamentous ascomycete Podospora anserina contains 12 HMG-box genes. Of these, four have been previously characterized; three are mating-type genes that control fertilization and development of the fruit-body, whereas the last one encodes a factor involved in mitochondrial DNA stability. Systematic deletion analysis of the eight remaining uncharacterized HMG-box genes indicated that none were essential for viability, but that seven were involved in the sexual cycle. Two HMG-box genes display striking features. PaHMG5, an ortholog of SpSte11 from Schizosaccharomyces pombe, is a pivotal activator of mating-type genes in P. anserina, whereas PaHMG9 is a repressor of several phenomena specific to the stationary phase, most notably hyphal anastomoses. Transcriptional analyses of HMG-box genes in HMG-box deletion strains indicated that PaHMG5 is at the hub of a network of several HMG-box factors that regulate mating-type genes and mating-type target genes. Genetic analyses revealed that this network also controls fertility genes that are not regulated by mating-type transcription factors. This study points to the critical role of HMG-box members in sexual reproduction in fungi, as 11 out of 12 members were involved in the sexual cycle in P. anserina. PaHMG5 and SpSte11 are conserved transcriptional regulators of mating-type genes, although P. anserina and S. pombe diverged 550 million years ago. Two HMG-box genes, SOX9 and its upstream regulator SRY, also play an important role in sex determination in mammals. The P. anserina and S. pombe mating-type genes and their upstream regulatory factor form a module of HMG-box genes analogous to the SRY/SOX9 module, revealing a commonality of sex regulation in animals and fungi. PMID:23935511

Ait Benkhali, Jinane; Coppin, Evelyne; Brun, Sylvain; Peraza-Reyes, Leonardo; Martin, Tom; Dixelius, Christina; Lazar, Noureddine; van Tilbeurgh, Herman; Debuchy, Robert

2013-07-18

44

Mitochondrial recombination increases with age in Podospora anserina.  

PubMed

With uniparental inheritance of mitochondria, there seems little reason for homologous recombination in mitochondria, but the machinery for mitochondrial recombination is quite well-conserved in many eukaryote species. In fungi and yeasts heteroplasmons may be formed when strains fuse and transfer of organelles takes place, making it possible to study mitochondrial recombination when introduced mitochondria contain different markers. A survey of wild-type isolates from a local population of the filamentous fungus Podospora anserina for the presence of seven optional mitochondrial introns indicated that mitochondrial recombination does take place in nature. Moreover the recombination frequency appeared to be correlated with age: the more rapidly ageing fraction of the population had a significantly lower linkage disequilibrium indicating more recombination. Direct confrontation experiments with heterokaryon incompatible strains with different mitochondrial markers at different (relative) age confirmed that mitochondrial recombination increases with age. We propose that with increasing mitochondrial damage over time, mitochondrial recombination - even within a homoplasmic population of mitochondria - is a mechanism that may restore mitochondrial function. PMID:20226205

van Diepeningen, Anne D; Goedbloed, Daniël J; Slakhorst, S Marijke; Koopmanschap, A Bertha; Maas, Marc F P M; Hoekstra, Rolf F; Debets, Alfons J M

2010-03-10

45

Grafting as a method for studying development in the filamentous fungus Podospora anserina.  

PubMed

While grafting and transplant experiments have extensively been used to study development in animals and plants, they have seldom been employed to study fungal development. Here, grafting is used to study the interplay between mycelium and multicellular fruiting bodies during maturation in the model ascomycete Podospora anserina. Data indicate that grafts need a competent mycelium to continue their ripening. Vegetative incompatibility does not prevent transplanted fructifications to undergo development. Grafting onto mutant mycelia confirmed a previous model stating that the NADPH oxidase PaNox1 is required in the developing fruiting bodies, while the MAP kinase cascade PaMpk1 is required in the mycelium. Data also show that the IDC1 protein is required not only in the developing fruiting bodies but also in the mycelium, likely because of its role in anastomosis. Finally, entry inside the grafted fruiting bodies of a ribosomal protein tagged with GFP could be detected, suggesting that cellular components are imported from the underlying mycelium during maturation. PMID:21802060

Silar, Philippe

2011-06-21

46

Genetic and biochemical analysis of cycloheximide resistance in the fungus Podospora anserina  

Microsoft Academic Search

Genetic analysis of cycloheximide-resistant mutants has shown that at least three genes control the resistance to cycloheximide in Podospora anserina and that the antibiotic resistance is recessive to sensitivity. In vitro and in vivo studies of protein synthesis indicated that for two mutants cycloheximide resistance is associated with the ribosomes. For one of these mutants, the elongation step in protein

Marc Crouzet; Michel Perrot; Maria Nogueira; Joël Bégueret

1978-01-01

47

Mitochondrial free radical generation and lifespan control in the fungal aging model Podospora anserina  

Microsoft Academic Search

In the filamentous fungus Podospora anserina a central role of mitochondria in the control of aging has been repeatedly demonstrated. Interestingly, impairments in cytochrome c oxidase (COX) activity induce an enhancement in the expression of the quinol-oxygen alternative oxidoreductase (AOX) correlating with an extension of lifespan. This effect is thought to be determined by a reduction of the free radical

Ricardo Gredilla; Jürgen Grief; Heinz D. Osiewacz

2006-01-01

48

Genetic evidences for a polycistronic unit of transcription in the complex locus “14” in Podospora anserina  

Microsoft Academic Search

Genetic analysis of 61 mutations of the median segment of the complex locus “14” in Podospora anserina is presented. These mutations affecting spore pigmentation have been screened following various mutagenesis (UV, Nitrosoguanidine, ICR-170) and they display several phenotypes. Comparison of complementation and genetic maps shows that this genetic region exhibits the most conspicuous genetic properties of classical operons: polarized complementation,

Marguerite Picard

1971-01-01

49

Mitochondrial DNA Rearrangements of Podospora anserina are under the Control of the Nuclear Gene Grisea  

Microsoft Academic Search

Podospora anserina is a filamentous fungus with a limited life span. Life span is controlled by nuclear and extranuclear genetic traits. Herein we report the nature of four alterations in the nuclear gene grisea that lead to an altered morphology, a defect in the formation of female gametangia, and an increased life span. Three sequence changes are located in the

Corina Borghouts; Erik Kimpel; Heinz D. Osiewacz

1997-01-01

50

Isolation of the two allelic incompatibility genes s and S of the fungus Podospora anserina  

Microsoft Academic Search

The two allelic genes s and S are responsible for heterogenic incompatibility between wild type strains of the fungus Podospora anserina. The s gene has been cloned by SIB selection and expression in a strain containing a neutral allele of this locus. The S gene was isolated from a genomic library using the DNA of the s locus as a

Béatrice Turcq; Muriel Denayrolles; Joël Begueret

1990-01-01

51

Cello-oligosaccharide oxidation reveals differences between two lytic polysaccharide monooxygenases (family GH61) from Podospora anserina.  

PubMed

The genome of the coprophilic ascomycete Podospora anserina encodes 33 different genes encoding copper-dependent lytic polysaccharide monooxygenases (LPMOs) from glycoside hydrolase family 61 (GH61). In this study, two of these enzymes (P. anserina GH61A [PaGH61A] and PaGH61B), which both harbored a family 1 carbohydrate binding module, were successfully produced in Pichia pastoris. Synergistic cooperation between PaGH61A or PaGH61B with the cellobiose dehydrogenase (CDH) of Pycnoporus cinnabarinus on cellulose resulted in the formation of oxidized and nonoxidized cello-oligosaccharides. A striking difference between PaGH61A and PaGH61B was observed through the identification of the products, among which were doubly and triply oxidized cellodextrins, which were released only by the combination of PaGH61B with CDH. The mass spectrometry fragmentation patterns of these oxidized products could be consistent with oxidation at the C-6 position with a geminal diol group. The different properties of PaGH61A and PaGH61B and their effect on the interaction with CDH are discussed in regard to the proposed in vivo function of the CDH/GH61 enzyme system in oxidative cellulose hydrolysis. PMID:23124232

Bey, Mathieu; Zhou, Simeng; Poidevin, Laetitia; Henrissat, Bernard; Coutinho, Pedro M; Berrin, Jean-Guy; Sigoillot, Jean-Claude

2012-11-02

52

Cello-Oligosaccharide Oxidation Reveals Differences between Two Lytic Polysaccharide Monooxygenases (Family GH61) from Podospora anserina  

PubMed Central

The genome of the coprophilic ascomycete Podospora anserina encodes 33 different genes encoding copper-dependent lytic polysaccharide monooxygenases (LPMOs) from glycoside hydrolase family 61 (GH61). In this study, two of these enzymes (P. anserina GH61A [PaGH61A] and PaGH61B), which both harbored a family 1 carbohydrate binding module, were successfully produced in Pichia pastoris. Synergistic cooperation between PaGH61A or PaGH61B with the cellobiose dehydrogenase (CDH) of Pycnoporus cinnabarinus on cellulose resulted in the formation of oxidized and nonoxidized cello-oligosaccharides. A striking difference between PaGH61A and PaGH61B was observed through the identification of the products, among which were doubly and triply oxidized cellodextrins, which were released only by the combination of PaGH61B with CDH. The mass spectrometry fragmentation patterns of these oxidized products could be consistent with oxidation at the C-6 position with a geminal diol group. The different properties of PaGH61A and PaGH61B and their effect on the interaction with CDH are discussed in regard to the proposed in vivo function of the CDH/GH61 enzyme system in oxidative cellulose hydrolysis.

Bey, Mathieu; Zhou, Simeng; Poidevin, Laetitia; Henrissat, Bernard; Coutinho, Pedro M.; Sigoillot, Jean-Claude

2013-01-01

53

Mitochondrial quality control in aging and lifespan control of the fungal aging model Podospora anserina.  

PubMed

Aging of biological systems is a fundamental process controlled by a complex network of molecular pathways. In the filamentous fungus Podospora anserina, a model in which organismal aging can conveniently be analysed, mitochondria play a central role. A wide range of relevant pathways were identified that contribute to the maintenance of a population of functional mitochondria. These pathways act in a hierarchical manner, but all the pathways are limited in capacity. At the end of the life cycle, when the various surveillance pathways are overwhelmed and damage has passed certain thresholds, programmed cell death brings the life of individual P. anserina to an end. PMID:21936839

Osiewacz, Heinz D

2011-10-01

54

Genetic map of mitochondrial DNA in Podospora anserina  

Microsoft Academic Search

In order to develop an eukaryotic vector with the Podospora plasmid, further characterization is required of the mitochondrial DNA into which this plasmid is integrated, a physical map (restriction sites) of the Podospora chondriome (size 95 kb) has been completed. As prerequisite for the establishment of a genetic (functional) map, 70% of the chondriome was cloned in E. coli vectors.

Ulrich Kück; Karl Esser

1982-01-01

55

Assignment of linkage groups to the electrophoretically-separated chromosomes of the fungus Podospora anserina  

Microsoft Academic Search

An electrophoretic karyotype of the filamentous fungus Podospora anserina has been obtained using contour-clamped homogenous electric field gel electrophoresis. Six chromosomal bands were separated with one migrating as a doublet. The size of the chromosomes was estimated to be between 3.8 and 6.0 megabase pairs (mb) using the chromosomes of Schizosaccharomyces pombe as size standards, giving a total genome size

Jean Paul Javerzat; Corinne Jacquier; Christian Barreau

1993-01-01

56

The complete DNA sequence of the mitochondrial genome of Podospora anserina  

Microsoft Academic Search

The complete 94,192 bp sequence of the mitochondrial genome from race s of Podospora anserina is presented (1 kb=103 base pairs). Three regions unique to race A are also presented bringing the size of this genome to 100,314 bp. Race s contains 31 group I introns (33 in race A) and 2 group II introns (3 in race A). Analysis

Donald J. Cummings; Kenneth L. McNally; Joanne M. Domenico; Etsuko T. Matsuura

1990-01-01

57

Regulation of proteolytic enzymes in Podospora anserina : Selection and properties of self-lysing mutant strains  

Microsoft Academic Search

Summary  Previous results showed that cell disintegration in the fungusPodospora anserina occured through the action of two proteases, enzymes whose messengers were normally latent during the extension stage of\\u000a the thallus.\\u000a \\u000a We selected three mutant strains in which the constitutive activity of the protease messengers was expressed by an arrest\\u000a of growth early in development (10 to 30 hours after spore

Yvonne M. Delettre; Jean Bernet

1976-01-01

58

The mating types of Podospora anserina : functional analysis and sequence of the fertilization domains  

Microsoft Academic Search

The two idiomorphic alleles calledmat+ andmat-, which control the mating types inPodospora anserina, have been cloned.Mat+ andmat- encompass 3.8 kb and 4.7 kb respectively, of unrelated DNA sequences flanked by common sequences. Subcloning allowed the identification and localization in each locus of the gene that controls fertilization, probably by determining the mating type. Themat+ gene, calledFPR1, encodes a protein with

Robert Debuchy; Evelyne Coppin

1992-01-01

59

Reversion of a long-living, undifferentiated mutant of Podospora anserina by copper  

Microsoft Academic Search

The Podospora anserina nuclear mutant grisea displays an undifferentiated growth phenotype (diminished production of aerial hyphae), is female sterile (lack of perithecia), has a prolonged life-span compared to the wild-type strain, and lacks detectable phenoloxidase (laccase and tyrosinase) activity. Reversion of all of these characteristics to those of the wild-type phenotype was accomplished by supplementing the growth medium with extra

Karin Marbach; Juan Fernfindez-Larrea; Ulf Stahl

1994-01-01

60

The PaAlr1 magnesium transporter is required for ascospore development in Podospora anserina.  

PubMed

The PaAlr1 gene encoding a putative plasma membrane magnesium (Mg) transporter in Podospora anserina was inactivated. The PaAlr1(?) mutants showed sensitivity to deprivation and excess Mg(2+) and Ca(2+). They also exhibited an autonomous ascospore maturation defect. Mutant ascospores were arrested at an early stage when they contained two nuclei. These data emphasize the role of Mg ions during sexual development in a filamentous fungus. PMID:23063190

Grognet, Pierre; Lalucque, Hervé; Silar, Philippe

2012-08-31

61

Mitochondrial DNA amplification in senescent cultures of Podospora anserina : Variability between the retained, amplified sequences  

Microsoft Academic Search

The non-nuclear DNA of a number of independent senescent cultures of Podospora anserina was extracted and studied. In all cases, a specific repetitive DNA (SEN-DNA) arranged in multimeric sets of circular molecules, was identified. Depending on the senescent culture, the SEN-DNA was found either in a band of about same density as the mitochondrial DNA from young mycelia (1.694 g\\/cm3)

Léon Belcour; Odile Begel; Marie-Odile Mossé; Corinne Vierny

1981-01-01

62

The degenerate DNA transposon Pat and repeat-induced point mutation (RIP) in Podospora anserina  

Microsoft Academic Search

A degenerate DNA transposon, Pat, was identified in the genomes of various wild-type strains of the filamentous fungus Podospora anserina. In these strains, the number (approximately 20–25 copies per genome) and location of Pat sequences appear to be conserved. Two copies of Pat, one complete and one partial, were cloned and characterized. The sequence of the complete element is 1856?bp

A. Hamann; F. Feller; H. D. Osiewacz

2000-01-01

63

Intramolecular cross-overs generate deleted mitochondrial DNA molecules in Podospora anserina  

Microsoft Academic Search

The unavoidable senescence process that limits the vegetative growth of Podospora anserina is always associated with an accumulation of various classes of circular, tandemly arranged, defective mitochondrial DNA\\u000a molecules (senDNAs). The monomers of the senDNAs belonging to the so-called ? class share a common core, but differ in both their length and termini. To understand the mechanism leading to their

Corinne Jamet-Vierny; Jocelyne Boulay; Jean-François Briand

1997-01-01

64

Replication and Expression of a Bacterial-Mitochondrial Hybrid Plasmid in the Fungus Podospora anserina  

Microsoft Academic Search

Hybrid plasmids consisting of the bacterial plasmid pBR322 and plasmid-like DNA (pl DNA) sequences from the fungus Podospora anserina are not only able to replicate in Escherichia coli but also in the fungus. This was proved by both biophysical and biological evidence involving buoyant density profiles, DNA\\\\cdot DNA hybridization, and restriction analysis-all confirming that pl DNA behaves as a true

Ulf Stahl; Paul Tudzynski; Ulrich Kuck; Karl Esser

1982-01-01

65

Plasmid-like DNA is part of mitochondrial DNA in Podospora anserina  

Microsoft Academic Search

As previously reported, a ccc DNA with a contour length of 0.75 µm and molecular weight of 2.4 kb (termed plasmid-like, p1DNA) is the causative agent of senescence in the fungus Podospora anserina. Its postulated location in mtDNA was proved correct by the following experiments:1.Restriction analysis of mtDNA resulted in different molecular weights for both, juvenile (95 kb) and senescent

Ulrich KiJck; Ulf Stahl; Karl Esser

1981-01-01

66

Molecular control of copper homeostasis in filamentous fungi: increased expression of a metallothionein gene during aging of Podospora anserina.  

PubMed

The lifespan of the ascomycete Podospora anserina was previously demonstrated to be significantly increased in a copper-uptake mutant, suggesting that copper is a potential stressor involved in degenerative processes. In order to determine whether changes in copper stress occur in the cells during normal aging of cultures, we cloned and characterized a gene coding for a component of the molecular machinery involved in the control of copper homeostasis. This gene, PaMt1, is a single-copy gene that encodes a metallothionein of 26 amino acids. The coding sequence of PaMt1 is interrupted by a single intron. The deduced amino acid sequence shows a high degree of sequence identity to metallothioneins of the filamentous ascomycete Neurospora crassa and the basidiomycete Agaricus bisporus, and to the N-terminal portion of mammalian metallothioneins. Levels of PaMt1 transcript increase in response to elevated amounts of copper in the growth medium and during aging of wild-type cultures. In contrast, in the long-lived mutant grisea, transcript levels first increase but then decrease again. The ability of wild-type cultures to respond to exogenous copper stress via the induction of PaMt1 transcription is not affected as they grow older. PMID:11212915

Averbeck, N B; Borghouts, C; Hamann, A; Specke, V; Osiewacz, H D

2001-01-01

67

Carotenoids and carotenogenic genes in Podospora anserina : engineering of the carotenoid composition extends the life span of the mycelium  

Microsoft Academic Search

Carotenoids have been identified in the fungus Podospora anserina and a parallel pathway to neurosporene and ?-carotene was established. Three genes for the ?-carotene branch have been cloned\\u000a and their function elucidated. They correspond to the al-1, al-2 and al-3 genes from Neurospora crassa. They were individually and in combinations over-expressed in P. anserina in order to modify the carotenoid

Ingmar Strobel; Jürgen Breitenbach; Christian Q. Scheckhuber; Heinz D. Osiewacz; Gerhard Sandmann

2009-01-01

68

Mitochondrial pathways governing stress resistance, life, and death in the fungal aging model Podospora anserina.  

PubMed

Work from more than 50 years of research has unraveled a number of molecular pathways that are involved in controlling aging of the fungal model system Podospora anserina. Early research revealed that wild-type strain aging is linked to gross reorganization of the mitochondrial DNA. Later it was shown that aging of P. anserina does also take place, although at a slower pace, when the wild-type specific mitochondrial DNA rearrangements do not occur. Now it is clear that a network of different pathways is involved in the control of aging. Branches of these pathways appear to be connected and constitute a hierarchical system of responses. Although cross talk between the individual pathways seems to be fundamental in the coordination of the overall system, the precise underlying interactions remain to be unraveled. Such a systematic approach aims at a holistic understanding of the process of biological aging, the ultimate goal of modern systems biology. PMID:20536834

Osiewacz, Heinz D; Brust, Diana; Hamann, Andrea; Kunstmann, Birgit; Luce, Karin; Müller-Ohldach, Mathis; Scheckhuber, Christian Q; Servos, Jörg; Strobel, Ingmar

2010-06-01

69

Induction of longevity by cytoplasmic transfer of a linear plasmid in Podospora anserina  

Microsoft Academic Search

InPodospora anserina the longevity inducing linear plasmid pAL2-1 was transferred from the extrachromosomal long-lived mutant AL2 to the shor-tlived wild-type strain A. The resulting strain, AL2-IV, exhibited the long-lived phenotype. In the short-lived progeny of crosses between this strain and wild-type strain A, the plasmid was absent. In contrast, all long-lived progeny contained both the autonomous plasmid as well as

Josef Hermanns; Heinz D. Osiewacz

1996-01-01

70

Two allelic genes responsible for vegetative incompatibility in the fungus Podospora anserina are not essential for cell viability  

Microsoft Academic Search

Vegetative incompatibility is a lethal reaction that destroys the heterokaryotic cells formed by the fusion of hyphae of non-isogenic strains in many fungi. That incompatibility is genetically determined is well known but the function of the genes triggering this rapid cell death is not. The two allelic incompatibility genes, s and S, of the fungus Podospora anserina were characterized. Both

B. Turcq; C. Deleu; M. Denayrolles; J. Bégueret

1991-01-01

71

Ribosomal suppressors and antisuppressors in Podospora anserina: Altered susceptibility to paromomycin and relationships between genetic and phenotypic suppression  

Microsoft Academic Search

Informational suppressors and antisuppressors have been previously isolated in Podospora anserina, and their properties suggest that they could be ribosomal mutants involved in the control of translational fidelity. In this paper we present results concerning relationships between these mutants and paromomycin, an aminoglycoside antibiotic known to stimulate translational errors. The mutants were found to manifest an altered growth sensitivity to

E. Coppin-Raynal

1981-01-01

72

Regulation of Gene Expression During the Vegetative Incompatibility Reaction in Podospora anserina: Characterization of Three Induced Genes  

Microsoft Academic Search

Vegetative incompatibility in fungi limits the formation of viable heterokaryons. It results from the coexpression of incompatible genes in the heterokaryotic cells and leads to a cell death reaction. In Podospora anserina, a modification of gene expression takes place during this reaction, including a strong decrease of total RNA synthesis and the appearance of a new set of proteins. Using

Nathalie Bourges; Alexis Groppi; Christian Barreau; Corinne Clave ´

73

A model to explain senescence in the filamentous fungus Podospora anserina by the action of plasmid like DNA  

Microsoft Academic Search

On the basis of genetic, physiological and biochemical data an attempt is made to explain the syndrome of senescence in Podospora anserina. A covalently closed circular DNA (ccc DNA) found only in aging mycelia is considered as the causative agent. It is assumed that during the juvenile phase this species of DNA is an integrated part of the mitochondrial genome.

Karl Esser; Paul Tudzynski; Ulf Stahl; Ulrich Kiick

1980-01-01

74

Propagation of a Novel Cytoplasmic, Infectious and Deleterious Determinant Is Controlled by Translational Accuracy in Podospora anserina  

Microsoft Academic Search

Some mutant strains of the filamentous fungus Podospora anserina spontaneously present a growth impairment, which has been called Crippled Growth (CG). CG is caused by a cytoplasmic and infectious factor, C. C is efficiently transmitted during mitosis but is not transmitted to the progeny after sexual crosses. C is induced by stationary phase and cured by various means, most of

Philippe Silar; Vicki Haedens; Michele Rossignol

1999-01-01

75

Ribosomal proteins in the fungus Podospora anserina : Evidence for an electrophoretically altered 60S protein in a cycloheximide resistant mutant  

Microsoft Academic Search

Proteins of cytoplasmic ribosomes of the Podospora anserina were analyzed by two dimentional gel electrophoresis. The numbers of proteins were estimated to be 28 in the small subunit and 41 in the large subunit. The L21 protein of the large subunit was found to migrate differently in a cycloheximide resistant mutant.

Joël Begueret; Michel Perrot; Marc Crouzet

1977-01-01

76

Three mitochondrial unassigned open reading frames of Podospora anserina represent remnants of a viral-type RNA polymerase gene  

Microsoft Academic Search

The mitochondrial DNA of Podospora anserina is complex, consisting of a characteristic set of genes with a large number of introns and a substantial amount of sequence of unknown function and origin. In addition, as indicated by various types of reorganization, this genome is highly flexible. Here we report the identification of three unassigned mitochondrial open reading frames (ORF P',

Josef Hermanns; Heinz D. Osiewacz

1994-01-01

77

Cloning the Mating Types of the Heterothallic Fungus Podospora anserina: Developmental Features of Haploid Transformants Carrying Both Mating Types  

Microsoft Academic Search

DNAs that encode the mating-type functions (mat+ and mat-) of the filamentous fungus Podospora anserina were cloned with the use of the mating-type A probe from Neurospora crassa. Cloning the full mat information was ascertained through gene replacement experiments. Molecular and functional analyses of haploid transformants carrying both mating types lead to several striking conclusions. Mat+ mat- strains are dual

Marguerite Picard; Robert Debuchy; Evelyne Coppin

78

Positive screening and transformation of ura5 mutants in the fungus Podospora anserina : characterization of the transformants  

Microsoft Academic Search

To develop a transformation system in the filamentous fungus Podospora anserina we have selected ura5 mutants deficient in orotidylic acid pyrophosphorylase using a positive screening. These mutants could be transformed to prototrophy by an hybrid vector carrying the ura5 gene of this organism. The properties of the transformants have been analysed. In most cases integration of the transforming vector occurred

V. Razanamparany; J. Bégueret

1986-01-01

79

WD-repeat instability and diversification of the Podospora anserina hnwd non-self recognition gene family  

Microsoft Academic Search

BACKGROUND: Genes involved in non-self recognition and host defence are typically capable of rapid diversification and exploit specialized genetic mechanism to that end. Fungi display a non-self recognition phenomenon termed heterokaryon incompatibility that operates when cells of unlike genotype fuse and leads to the cell death of the fusion cell. In the fungus Podospora anserina, three genes controlling this allorecognition

Damien Chevanne; Sven J Saupe; Corinne Clavé; Mathieu Paoletti

2010-01-01

80

Poly(ADP-ribose) polymerase is a substrate recognized by two metacaspases of Podospora anserina.  

PubMed

The two metacaspases MCA1 and MCA2 of the fungal aging model organism Podospora anserina (PaMCA1 and PaMCA2, respectively) have previously been demonstrated to be involved in the control of programmed cell death (PCD) and life span. In order to identify specific pathways and components which are controlled by the activity of these enzymes, we set out to characterize them further. Heterologous overexpression in Escherichia coli of the two metacaspase genes resulted in the production of proteins which aggregate and form inclusion bodies from which the active protein has been recovered via refolding in appropriate buffers. The renaturated proteins are characterized by an arginine-specific activity and are active in caspase-like self-maturation leading to the generation of characteristic small protein fragments. Both activities are dependent on the presence of calcium. Incubation of the two metacaspases with recombinant poly(ADP-ribose) polymerase (PARP), a known substrate of mammalian caspases, led to the identification of PARP as a substrate of the two P. anserina proteases. Using double mutants in which P. anserina Parp (PaParp) is overexpressed and PaMca1 is either overexpressed or deleted, we provide evidence for in vivo degradation of PaPARP by PaMCA1. These results support the idea that the substrate profiles of caspases and metacaspases are at least partially overlapping. Moreover, they link PCD and DNA maintenance in the complex network of molecular pathways involved in aging and life span control. PMID:23584991

Strobel, Ingmar; Osiewacz, Heinz D

2013-04-12

81

DNA sequence analysis of the 24.5 Kilobase pair cytochrome oxidase subunit I mitochondrial gene from Podospora anserina : a gene with sixteen introns  

Microsoft Academic Search

The DNA sequence of a 26.7 Kilobase pair (103 base pairs = 1 Kb) region of the mitochondrial genomes of races s and A from Podospora anserina was determined. Within this region, the 24.5 Kb cytochrome oxidase subunit I gene was located and its exon sequences determined by computer analysis comparisons with other fungal genes. The Podospora COI gene was

Donald J. Cummings; François Michel; Kenneth L. MeNally

1989-01-01

82

Alternative oxidase dependent respiration leads to an increased mitochondrial content in two long-lived mutants of the aging model Podospora anserina.  

PubMed

The retrograde response constitutes an important signalling pathway from mitochondria to the nucleus which induces several genes to allow compensation of mitochondrial impairments. In the filamentous ascomycete Podospora anserina, an example for such a response is the induction of a nuclear-encoded and iron-dependent alternative oxidase (AOX) occurring when cytochrome-c oxidase (COX) dependent respiration is affected. Several long-lived mutants are known which predominantly or exclusively respire via AOX. Here we show that two AOX-utilising mutants, grisea and PaCox17::ble, are able to compensate partially for lowered OXPHOS efficiency resulting from AOX-dependent respiration by increasing mitochondrial content. At the physiological level this is demonstrated by an elevated oxygen consumption and increased heat production. However, in the two mutants, ATP levels do not reach WT levels. Interestingly, mutant PaCox17::ble is characterized by a highly increased release of the reactive oxygen species (ROS) hydrogen peroxide. Both grisea and PaCox17::ble contain elevated levels of mitochondrial proteins involved in quality control, i. e. LON protease and the molecular chaperone HSP60. Taken together, our work demonstrates that AOX-dependent respiration in two mutants of the ageing model P. anserina is linked to a novel mechanism involved in the retrograde response pathway, mitochondrial biogenesis, which might also play an important role for cellular maintenance in other organisms. PMID:21305036

Scheckhuber, Christian Q; Houthoofd, Koen; Weil, Andrea C; Werner, Alexandra; De Vreese, Annemie; Vanfleteren, Jacques R; Osiewacz, Heinz D

2011-01-27

83

Structural and biochemical analyses of glycoside hydrolase families 5 and 26 ?-(1,4)-mannanases from Podospora anserina reveal differences upon manno-oligosaccharide catalysis.  

PubMed

The microbial deconstruction of the plant cell wall is a key biological process that is of increasing importance with the development of a sustainable biofuel industry. The glycoside hydrolase families GH5 (PaMan5A) and GH26 (PaMan26A) endo-?-1,4-mannanases from the coprophilic ascomycete Podospora anserina contribute to the enzymatic degradation of lignocellulosic biomass. In this study, P. anserina mannanases were further subjected to detailed comparative analysis of their substrate specificities, active site organization, and transglycosylation capacity. Although PaMan5A displays a classical mode of action, PaMan26A revealed an atypical hydrolysis pattern with the release of mannotetraose and mannose from mannopentaose resulting from a predominant binding mode involving the -4 subsite. The crystal structures of PaMan5A and PaMan26A were solved at 1.4 and 2.85 ? resolution, respectively. Analysis of the PaMan26A structure supported strong interaction with substrate at the -4 subsite mediated by two aromatic residues Trp-244 and Trp-245. The PaMan26A structure appended to its family 35 carbohydrate binding module revealed a short and proline-rich rigid linker that anchored together the catalytic and the binding modules. PMID:23558681

Couturier, Marie; Roussel, Alain; Rosengren, Anna; Leone, Philippe; Stålbrand, Henrik; Berrin, Jean-Guy

2013-04-04

84

Mitochondrial Group II Introns, Cytochrome c Oxidase, and Senescence in Podospora anserina  

PubMed Central

Podospora anserina is a filamentous fungus with a limited life span. It expresses a degenerative syndrome called senescence, which is always associated with the accumulation of circular molecules (senDNAs) containing specific regions of the mitochondrial chromosome. A mobile group II intron (?) has been thought to play a prominent role in this syndrome. Intron ? is the first intron of the cytochrome c oxidase subunit I gene (COX1). Mitochondrial mutants that escape the senescence process are missing this intron, as well as the first exon of the COX1 gene. We describe here the first mutant of P. anserina that has the ? sequence precisely deleted and whose cytochrome c oxidase activity is identical to that of wild-type cells. The integration site of the intron is slightly modified, and this change prevents efficient homing of intron ?. We show here that this mutant displays a senescence syndrome similar to that of the wild type and that its life span is increased about twofold. The introduction of a related group II intron into the mitochondrial genome of the mutant does not restore the wild-type life span. These data clearly demonstrate that intron ? is not the specific senescence factor but rather an accelerator or amplifier of the senescence process. They emphasize the role that intron ? plays in the instability of the mitochondrial chromosome and the link between this instability and longevity. Our results strongly support the idea that in Podospora, “immortality” can be acquired not by the absence of intron ? but rather by the lack of active cytochrome c oxidase.

Begel, Odile; Boulay, Jocelyne; Albert, Beatrice; Dufour, Eric; Sainsard-Chanet, Annie

1999-01-01

85

The HET-s Prion Protein of the Filamentous Fungus Podospora anserina Aggregates in Vitro into Amyloid-like Fibrils  

Microsoft Academic Search

The HET-s protein of Podospora anserina is a fungal prion. This protein behaves as an infectious cytoplasmic element that is transmitted horizontally from one strain to another. Under the prion form, the HET-s protein forms aggregates in vivo. The specificity of this prion model compared with the yeast prions resides in the fact that under the prion form HET-s causes

Suzana Dos Reis; Vincent Forge; Joel Begueret; Sven J. Saupe; Universitede Bordeaux

2002-01-01

86

The Function of the Coding Sequences for the Putative Pheromone Precursors in Podospora anserina Is Restricted to Fertilization  

Microsoft Academic Search

We cloned the pheromone precursor genes of Podospora anserina in order to elucidate their role in the biology of this fungus. The mfp gene encodes a 24-amino-acid polypeptide finished by the CAAX motif, characteristic of fungal lipopeptide pheromone precursors similar to the a-factor precursor of Saccharomyces cerevisiae. The mfm gene encodes a 221-amino-acid polypeptide, which is related to the S.

Evelyne Coppin; C. de Renty; Robert Debuchy

2005-01-01

87

The onset of senescence is affected by DNA rearrangements of a discontinuous mitochondrial gene in Podospora anserina  

Microsoft Academic Search

Mapping and transcription studies have revealed that in Podospora anserina the causative agent of senescence, a mitochondrial plasmid (p1DNA), is identical with intronl of the discontinuous gene for cytochrome-c-oxidase subunit 1 (COI), which is 2 kpb from the discontinuous gene for cytochrome b (Cytb). A mitochondrial mutant (ex1) devoid of the COI, but not of the Cytb gene provides longevity.

Ulrich Kiick; Heinz D. Osiewacz; Udo Schmidt; Birgit Kappelhoff; Erika Schulte; Ulf Stahl; Karl Esser

1985-01-01

88

Deletion of the mating-type sequences in Podospora anserina abolishes mating without affecting vegetative functions and sexual differentiation  

Microsoft Academic Search

The mating-type locus of Podospora anserina controls fusion of sexual cells as well as subsequent stages of development of the fruiting bodies. The two alleles at the locus are defined by specific DNA regions comprising 3.8 kb for mat+ and 4.7 kb for mat-, which have identical flanking sequences. Here we present the characterization of several mutants that have lost

Evelyne Coppin; Sylvie Arnaise; Véronique Contamine; Marguerite Picard

1993-01-01

89

The mat - allele of Podospora anserina contains three regulatory genes required for the development of fertilized female organs  

Microsoft Academic Search

In the filamentous fungus Podospora anserina, mating type is specified by a single locus with two alternate alleles, termed mat- and mat+. A previous study has shown that the mat+ sequence consists of 3.7 kb and contains a single gene relevant to the sexual cycle. This gene, called FPR1, encodes a protein with a HMG DNA-binding domain and is required

Robert Debuchy; Sylvie Arnaise; Gael Lecellier

1993-01-01

90

The Molecular Mechanism of Protoplasmic Incompatibility and its Relationship to the Formation of Protoperithecia in Podospora anserina  

Microsoft Academic Search

SUMMARY In Podospora anserina, protoplasmic incompatibility due to interactions between non-allelic genes was suppressed by the effect of mutations in two modifier genes, mod-I and mod-2. It is shown that mod-I and mod-2 are involved in the production of three specific proteins, a phenoloxidase and two previously identified proteases (Bdgueret & Bernet, 1973a) which are associated with the phenomenon of

H. BOUCHERIE; J. BEGUERET; J. BERNET

1976-01-01

91

Evidence for a life span-prolonging effect of a linear plasmid in a longevity mutant of Podospora anserina  

Microsoft Academic Search

The linear mitochondrial plasmid pAL2-1 of the long-lived mutant AL2 of Podospora anserina was demonstrated to be able to integrate into the high molecular weight mitochondrial DNA (mtDNA). Hybridization analysis and densitometric evaluation of the mitochondrial genome isolated from cultures of different ages revealed that the mtDNA is highly stable during the whole life span of the mutant. In addition,

J. Hermanns; A. Asseburg; H. D. Osiewacz

1994-01-01

92

Sequence diversity and unusual variability at the het-c locus involved in vegetative incompatibility in the fungus Podospora anserina  

Microsoft Academic Search

The het-c locus of the filamentous fungus Podospora anserina controls heterokaryon formation through genetic interaction with alleles of the unlinked loci het-e and het-d. We have isolated four wild-type and two mutant alleles of the het-c locus. A comparison of the predicted proteins encoded by the different wild-type alleles revealed an unusual high level of amino-acid replacements compared to silent

S. Saupe; B. Turcq; J. Bégueret

1995-01-01

93

Impact of a Disruption of a Pathway Delivering Copper to Mitochondria on Podospora anserina Metabolism and Life Span  

Microsoft Academic Search

A global depletion of cellular copper as the result of a deficiency in high-affinity copper uptake was previously shown to affect the phenotype and life span of the filamentous fungus Podospora anserina. We report here the construction of a strain in which the delivery of copper to complex IV of the mitochondrial respiratory chain is affected. This strain, PaCox17::ble, is

Stefan W. Stumpferl; Oliver Stephan; Heinz D. Osiewacz

2004-01-01

94

Characterization of the genomic organization of the region bordering the centromere of chromosome V of Podospora anserina by direct sequencing  

Microsoft Academic Search

A Podospora anserina BAC library of 4800 clones has been constructed in the vector pBHYG allowing direct selection in fungi. Screening of the BAC collection for centromeric sequences of chromosome V allowed the recovery of clones localized on either sides of the centromere, but no BAC clone was found to contain the centromere. Seven BAC clones containing 322,195 and 156,244bp

Philippe Silar; Christian Barreau; Robert Debuchy; Sébastien Kicka; Béatrice Turcq; Annie Sainsard-Chanet; Carole H Sellem; Alain Billault; Laurence Cattolico; Simone Duprat; Jean Weissenbach

2003-01-01

95

Extrachromosomal mutants from Podospora anserina : Permanent vegetative growth in spite of multiple recombination events in the mitochondrial genome  

Microsoft Academic Search

Two longlife mutants (ex1, ex2) from Podospora anserina have been isolated which, in contrast to all wild-type strains, show indefinite vegetative growth. Genetic analysis has demonstrated that their longevity is extrachromosomally inherited. The mitochondrial (mt) genome differs from the wild-type mtDNA by an almost complete deletion of the COI gene. Included in the deletion is the first intron (plDNA) of

Erika Schulte; Ulrich Kiiek; Karl Esser

1988-01-01

96

PaCATB, a secreted catalase protecting Podospora anserina against exogenous oxidative stress.  

PubMed

A differential mass spectrometry analysis of secreted proteins from juvenile and senescent Podospora anserina cultures revealed age-related differences in protein profiles. Among other proteins with decreased abundance in the secretome of senescent cultures a catalase, termed PaCATB, was identified. Genetic modulation of the abundance of PaCATB identified differential effects on the phenotype of the corresponding strains. Deletion of PaCatB resulted in decreased resistance, over-expression in increased resistance against hydrogen peroxide. While the lifespan of the genetically modified strains was found to be unaffected under standard growth conditions, increased exogenous hydrogen peroxide stress in the growth medium markedly reduced the lifespan of the PaCatB deletion strain but extended the lifespan of PaCatB over-expressors. Overall our data identify a component of the secretome of P. anserina as a new effective factor to cope with environmental stress, stress that under natural conditions is constantly applied on organisms and influences aging processes. PMID:21865610

Zintel, Sandra; Bernhardt, Dominik; Rogowska-Wrzesinska, Adelina; Osiewacz, Heinz D

2011-08-01

97

Cyclophilin D links programmed cell death and organismal aging in Podospora anserina.  

PubMed

Cyclophilin D (CYPD) is a mitochondrial peptidyl prolyl-cis,trans-isomerase involved in opening of the mitochondrial permeability transition pore (mPTP). CYPD abundance increases during aging in mammalian tissues and in the aging model organism Podospora anserina. Here, we show that treatment of the P. anserina wild-type with low concentrations of the cyclophilin inhibitor cyclosporin A (CSA) extends lifespan. Transgenic strains overexpressing PaCypD are characterized by reduced stress tolerance, suffer from pronounced mitochondrial dysfunction and are characterized by accelerated aging and induction of cell death. Treatment with CSA leads to correction of mitochondrial function and lifespan to that of the wild-type. In contrast, PaCypD deletion strains are not affected by CSA within the investigated concentration range and show increased resistance against inducers of oxidative stress and cell death. Our data provide a mechanistic link between programmed cell death (PCD) and organismal aging and bear implications for the potential use of CSA to intervene into biologic aging. PMID:20626725

Brust, Diana; Daum, Bertram; Breunig, Christine; Hamann, Andrea; Kühlbrandt, Werner; Osiewacz, Heinz D

2010-08-15

98

Wood utilization is dependent on catalase activities in the filamentous fungus Podospora anserina.  

PubMed

Catalases are enzymes that play critical roles in protecting cells against the toxic effects of hydrogen peroxide. They are implicated in various physiological and pathological conditions but some of their functions remain unclear. In order to decipher the role(s) of catalases during the life cycle of Podospora anserina, we analyzed the role of the four monofunctional catalases and one bifunctional catalase-peroxidase genes present in its genome. The five genes were deleted and the phenotypes of each single and all multiple mutants were investigated. Intriguingly, although the genes are differently expressed during the life cycle, catalase activity is dispensable during both vegetative growth and sexual reproduction in laboratory conditions. Catalases are also not essential for cellulose or fatty acid assimilation. In contrast, they are strictly required for efficient utilization of more complex biomass like wood shavings by allowing growth in the presence of lignin. The secreted CATB and cytosolic CAT2 are the major catalases implicated in peroxide resistance, while CAT2 is the major player during complex biomass assimilation. Our results suggest that P. anserina produces external H(2)O(2) to assimilate complex biomass and that catalases are necessary to protect the cells during this process. In addition, the phenotypes of strains lacking only one catalase gene suggest that a decrease of catalase activity improves the capacity of the fungus to degrade complex biomass. PMID:22558065

Bourdais, Anne; Bidard, Frederique; Zickler, Denise; Berteaux-Lecellier, Veronique; Silar, Philippe; Espagne, Eric

2012-04-27

99

Characterization of a Glycoside Hydrolase Family 31 ?-Glucosidase Involved in Starch Utilization in Podospora anserina.  

PubMed

For Podospora anserina, several studies of cellulolytic enzymes have been established, but characteristics of amylolytic enzymes are not well understood. When P. anserina grew in starch as carbon source, it accumulated glucose, nigerose, and maltose in the culture supernatant. At the same time, the fungus secreted ?-glucosidase (PAG). PAG was purified from the culture supernatant, and was found to convert soluble starch to nigerose and maltose. The recombinant enzyme with C-terminal His-tag (rPAG) was produced with Pichia pastoris. Most rPAG produced under standard conditions lost its affinity for nickel-chelating resin, but the affinity was improved by the use of a buffered medium (pH 8.0) supplemented with casamino acid and a reduction of the cultivation time. rPAG suffered limited proteolysis at the same site as the original PAG. A site-directed mutagenesis study indicated that proteolysis had no effect on enzyme characteristics. A kinetic study indicated that the PAG possessed significant transglycosylation activity. PMID:24096679

Song, Kyung-Mo; Okuyama, Masayuki; Kobayashi, Kazuyuki; Mori, Haruhide; Kimura, Atsuo

2013-10-07

100

PaCATB, a secreted catalase protecting Podospora anserina against exogenous oxidative stress  

PubMed Central

A differential mass spectrometry analysis of secreted proteins from juvenile and senescent Podospora anserina cultures revealed age-related differences in protein profiles. Among other proteins with decreased abundance in the secretome of senescent cultures a catalase, termed PaCATB, was identified. Genetic modulation of the abundance of PaCATB identified differential effects on the phenotype of the corresponding strains. Deletion of PaCatB resulted in decreased resistance, over-expression in increased resistance against hydrogen peroxide. While the lifespan of the genetically modified strains was found to be unaffected under standard growth conditions, increased exogenous hydrogen peroxide stress in the growth medium markedly reduced the lifespan of the PaCatB deletion strain but extended the lifespan of PaCatB over-expressors. Overall our data identify a component of the secretome of P. anserina as a new effective factor to cope with environmental stress, stress that under natural conditions is constantly applied on organisms and influences aging processes.

Zintel, Sandra; Bernhardt, Dominik; Rogowska-Wrzesinska, Adelina; Osiewacz, Heinz D.

2011-01-01

101

Podospora anserina hemicellulases potentiate the Trichoderma reesei secretome for saccharification of lignocellulosic biomass.  

PubMed

To improve the enzymatic hydrolysis (saccharification) of lignocellulosic biomass by Trichoderma reesei, a set of genes encoding putative polysaccharide-degrading enzymes were selected from the coprophilic fungus Podospora anserina using comparative genomics. Five hemicellulase-encoding genes were successfully cloned and expressed as secreted functional proteins in the yeast Pichia pastoris. These novel fungal CAZymes belonging to different glycoside hydrolase families (PaMan5A and PaMan26A mannanases, PaXyn11A xylanase, and PaAbf51A and PaAbf62A arabinofuranosidases) were able to break down their predicted cognate substrates. Although PaMan5A and PaMan26A displayed similar specificities toward a range of mannan substrates, they differed in their end products, suggesting differences in substrate binding. The N-terminal CBM35 module of PaMan26A displayed dual binding specificity toward xylan and mannan. PaXyn11A harboring a C-terminal CBM1 module efficiently degraded wheat arabinoxylan, releasing mainly xylobiose as end product. PaAbf51A and PaAbf62A arabinose-debranching enzymes exhibited differences in activity toward arabinose-containing substrates. Further investigation of the contribution made by each P. anserina auxiliary enzyme to the saccharification of wheat straw and spruce demonstrated that the endo-acting hemicellulases (PaXyn11A, PaMan5A, and PaMan26A) individually supplemented the secretome of the industrial T. reesei CL847 strain. The most striking effect was obtained with PaMan5A that improved the release of total sugars by 28% and of glucose by 18%, using spruce as lignocellulosic substrate. PMID:21037302

Couturier, Marie; Haon, Mireille; Coutinho, Pedro M; Henrissat, Bernard; Lesage-Meessen, Laurence; Berrin, Jean-Guy

2010-10-29

102

Identification of a hypothetical protein from Podospora anserina as a nitroalkane oxidase.  

PubMed

The flavoprotein nitroalkane oxidase (NAO) from Fusarium oxysporum catalyzes the oxidation of primary and secondary nitroalkanes to their respective aldehydes and ketones. Structurally, the enzyme is a member of the acyl-CoA dehydrogenase superfamily. To date no enzymes other than that from F. oxysporum have been annotated as NAOs. To identify additional potential NAOs, the available database was searched for enzymes in which the active site residues Asp402, Arg409, and Ser276 were conserved. Of the several fungal enzymes identified in this fashion, PODANSg2158 from Podospora anserina was selected for expression and characterization. The recombinant enzyme is a flavoprotein with activity on nitroalkanes comparable to the F. oxysporum NAO, although the substrate specificity is somewhat different. Asp399, Arg406, and Ser273 in PODANSg2158 correspond to the active site triad in F. oxysporum NAO. The k(cat)/K(M)-pH profile with nitroethane shows a pK(a) of 5.9 that is assigned to Asp399 as the active site base. Mutation of Asp399 to asparagine decreases the k(cat)/K(M) value for nitroethane over 2 orders of magnitude. The R406K and S373A mutations decrease this kinetic parameter by 64- and 3-fold, respectively. The structure of PODANSg2158 has been determined at a resolution of 2.0 A, confirming its identification as an NAO. PMID:20481475

Tormos, José R; Taylor, Alexander B; Daubner, S Colette; Hart, P John; Fitzpatrick, Paul F

2010-06-22

103

Purification and characterization of a new laccase from the filamentous fungus Podospora anserina.  

PubMed

A new laccase from the filamentous fungus Podospora anserina has been isolated and identified. The 73 kDa protein containing 4 coppers, truncated from its first 31 amino acids, was successfully overexpressed in Pichia pastoris and purified in one step with a yield of 48% and a specific activity of 644Umg(-1). The kinetic parameters, k(cat) and K(M), determined at 37 °C and optimal pH are 1372 s(-1) and 307 ?M for ABTS and, 1.29 s(-1) and 10.9 ?M, for syringaldazine (SGZ). Unlike other laccases, the new protein displays a better thermostability, with a half life>400 min at 37 °C, is less sensitive to chloride and more stable at pH 7. Even though, the new 566 amino-acid enzyme displays a large homology with Bilirubin oxidase (BOD) from Myrothecium verrucaria (58%) and exhibits the four histidine rich domains consensus sequences of BODs, the new enzyme is not able to oxidize neither conjugated nor unconjugated bilirubin. PMID:23220637

Durand, Fabien; Gounel, Sébastien; Mano, Nicolas

2012-12-06

104

Substrate binding to a GH131 ?-glucanase catalytic domain from Podospora anserina.  

PubMed

?-Glucanases have been utilized widely in industry to treat various carbohydrate-containing materials. Recently, the Podospora anserina ?-glucanase 131A (PaGluc131A) was identified and classified to a new glycoside hydrolases GH131 family. It shows exo-?-1,3/exo-?-1,6 and endo-?-1,4 glucanase activities with a broad substrate specificity for laminarin, curdlan, pachyman, lichenan, pustulan, and cellulosic derivatives. Here we report the crystal structures of the PaGluc131A catalytic domain with or without ligand (cellotriose) at 1.8Å resolution. The cellotriose was clearly observed to occupy the +1 to +3 subsites in substrate binding cleft. The broadened substrate binding groove may explain the diverse substrate specificity. Based on our crystal structures, the GH131 family enzyme is likely to carry out the hydrolysis through an inverting catalytic mechanism, in which E99 and E139 are supposed to serve as the general base and general acid. PMID:23880343

Jiang, Tong; Chan, Hsiu-Chien; Huang, Chun-Hsiang; Ko, Tzu-Ping; Huang, Ting-Yung; Liu, Je-Ruei; Guo, Rey-Ting

2013-07-20

105

Deletion of PaAif2 and PaAmid2, two genes encoding mitochondrial AIF-like oxidoreductases of Podospora anserina, leads to increased stress tolerance and lifespan extension.  

PubMed

Wild-type strains of the ascomycete Podospora anserina are characterized by a limited lifespan. Mitochondria play a central role in this ageing process raising the question of whether apoptosis-like processes, which are also connected to mitochondrial function, are involved in the control of the final stage in the fungal life cycle. While a role of two metacaspases in apoptosis and lifespan control was recently demonstrated in P. anserina, virtually nothing is known about the function of the protein family of apoptosis-inducing factors (AIFs). Here we report data about proteins belonging to this family. We demonstrate that the cytosolic members PaAIF1 and PaAMID1 do not affect lifespan. In contrast, loss of PaAIF2 and PaAMID2, which both were localized to mitochondria, are characterized by a significantly increased ROS tolerance and a prolonged lifespan. In addition, deletion of PaAmid2 severely affects sporogenesis. These data identify components of a caspase-independent molecular pathway to be involved in developmental processes and in the induction of programmed cell death in the senescent stage of P. anserina. PMID:20306265

Brust, Diana; Hamann, Andrea; Osiewacz, Heinz D

2010-03-21

106

Sequence analysis of the gene coding for glyceraldehyde-3-phosphate dehydrogenase ( gpd ) of Podospora anserina : use of homologous regulatory sequences to improve transformation efficiency  

Microsoft Academic Search

The glyceraldehyde-3-phosphate dehydrogenase (gpd) gene of Podospora anserina has been isolated from a genomic library by heterologous hybridization with the corresponding gene of Curvularia lunata. The coding region consists of 1014 nucleotides and is interrupted by a single intron. The amino-acid sequence encoded by the gpd gene shows a high degree of sequence identity with the corresponding gene products of

Riidiger Ridder; Heinz D. Osiewacz

1992-01-01

107

Analysis of class I introns in a mitochondrial plasmid associated with senescence of Podospora anserina reveals extraordinary resemblance to the Tetrahymena ribosomal intron  

Microsoft Academic Search

Recently, the nucleotide sequences for three “mitochondrial plasmids” associated with senescence of Podospora anserina were determined (Cummings et al. 1985). One of these sequences, corresponding to the plasmid termed e senDNA, contains three class I introns, all within a protein coding sequence equivalent to the mammalian “URF1” gene. Here, we present primary and secondary structure analyses for two of these

François Michel; Donald J. Cummings

1985-01-01

108

The mod-A Suppressor of Nonallelic Heterokaryon Incompatibility in Podospora anserina Encodes a Proline-Rich Polypeptide Involved in Female Organ Formation  

Microsoft Academic Search

Vegetative incompatibility in fungi results from the control of heterokaryon formation by the genes present at het loci. Coexpression of antagonistic het genes in the same hyphae leads to a lethal process. In Podospora anserina, self-incompatible strains containing nonallelic incompatible genes in the same nucleus are inviable as the result of a growth arrest and a lytic process. Mutations in

Christian Barreau; Maya Iskandar; Gabriel Loubradou; Veronique Levallois

109

The [Het-s] prion of Podospora anserina and its role in heterokaryon incompatibility.  

PubMed

[Het-s] is a prion from the filamentous fungus Podospora anserina and corresponds to a self-perpetuating amyloid aggregate of the HET-s protein. This prion protein is involved in a fungal self/non-self discrimination process termed heterokaryon incompatibility corresponding to a cell death reaction occurring upon fusion of genetically unlike strains. Two antagonistic allelic variants of this protein exist: HET-s, the prion form of which corresponds to [Het-s] and HET-S, incapable of prion formation. Fusion of a [Het-s] and HET-S strain triggers the incompatibility reaction, so that interaction of HET-S with the [Het-s] prion leads to cell death. HET-s and HET-S are highly homologous two domain proteins with a N-terminal globular domain termed HeLo and a C-terminal unstructured prion forming domain (PFD). The structure of the prion form of the HET-s PFD has been solved by solid state NMR and corresponds to a very well ordered ?-solenoid fold with a triangular hydrophobic core. The ability to form this ?-solenoid fold is retained in a distant homolog of HET-s from another fungal species. A model for the mechanism of [Het-s]/HET-S incompatibility has been proposed. It is believe that when interacting with the [Het-s] prion seed, the HET-S C-terminal region adopts the ?-solenoid fold. This would act as a conformational switch to induce refolding and activation of the HeLo domain which then would exert its toxicity by a yet unknown mechanism. PMID:21334447

Saupe, Sven J

2011-02-18

110

Overexpression of PaParp encoding the poly(ADP-ribose) polymerase of Podospora anserina affects organismal aging.  

PubMed

Poly(ADP-ribose) polymerases (PARPs) are a diverse group of proteins present in all multicellular eukaryotes. They catalyze the NAD(+)-dependent modification of proteins with poly(ADP-ribose). Poly(ADP-ribosyl)ation plays a key role in a plethora of processes including DNA repair, tumor progression and aging. Here we report that PaPARP, the single protein with a PARP catalytic domain, in the fungal aging model Podospora anserina, indeed displays a NAD(+)-dependent poly(ADP-ribose) polymerase activity. While unable to select a PaParp deletion strain, we succeeded in the generation of PaParp overexpressors. Biochemically these strains are characterized by reduced mitochondrial membrane potential and a lowered ATP content. They show an increased sensitivity against different stressors including the DNA damaging agent phleomycin, the reactive oxygen generator paraquat, and the apoptosis inducer farnesol. PaParp overexpressors are impaired in growth, in pigmentation and fertility, and have a shortened lifespan. Our results demonstrate the relevance of poly(ADP-ribose) metabolism for aging and development in P. anserina. With a single PARP this metabolism is less complex than in higher eukaryotes and thus P. anserina appears to be a promising system to connect basic PARP functions with the well established network of pathways relevant for organismal aging. PMID:21145908

Müller-Ohldach, Mathis; Brust, Diana; Hamann, Andrea; Osiewacz, Heinz D

2010-12-09

111

Two nuclear life cycle-regulated genes encode interchangeable subunits c of mitochondrial ATP synthase in Podospora anserina.  

PubMed

An F(1)F(O) ATP synthase in the inner mitochondrial membrane catalyzes the late steps of ATP production via the process of oxidative phosphorylation. A small protein subunit (subunit c or ATP9) of this enzyme shows a substantial genetic diversity, and its gene can be found in both the mitochondrion and/or nucleus. In a representative set of 26 species of fungi for which the genomes have been entirely sequenced, we found five Atp9 gene repartitions. The phylogenetic distribution of nuclear and mitochondrial Atp9 genes suggests that their evolution has included two independent transfers to the nucleus followed by several independent episodes of the loss of the mitochondrial and/or nuclear gene. Interestingly, we found that in Podospora anserina, subunit c is exclusively produced from two nuclear genes (PaAtp9-5 and PaAtp9-7), which display different expression profiles through the life cycle of the fungus. The PaAtp9-5 gene is specifically and strongly expressed in germinating ascospores, whereas PaAtp9-7 is mostly transcribed during sexual reproduction. Consistent with these observations, deletion of PaAtp9-5 is lethal, whereas PaAtp9-7 deletion strongly impairs ascospore production. The P. anserina PaAtp9-5 and PaAtp9-7 genes are therefore nonredundant. By swapping the 5' and 3' flanking regions between genes we demonstrated, however, that the PaAtp9 coding sequences are functionally interchangeable. These findings show that after transfer to the nucleus, the subunit c gene in Podospora became a key target for the modulation of cellular energy metabolism according to the requirements of the life cycle. PMID:21273631

Déquard-Chablat, Michelle; Sellem, Carole H; Golik, Pawel; Bidard, Frédérique; Martos, Alexandre; Bietenhader, Maïlis; di Rago, Jean-Paul; Sainsard-Chanet, Annie; Hermann-Le Denmat, Sylvie; Contamine, Véronique

2011-01-27

112

A gene responsible for vegetative incompatibility in the fungus Podospora anserina encodes a protein with a GTP-binding motif and G? homologous domain  

Microsoft Academic Search

The het-e-1 gene of the fungus Podospora anserina is responsible for vegetative incompatibility through specific interactions with different alleles of the unlinked gene, het-c Coexpression of two incompatible genes triggers a cell death reaction that prevents heterokaryon formation. The het-el allele has been cloned to get information on the function of the locus. It encodes a putative 1356-amino-acid polypeptide that

Sven Saupe; Béatrice Turcq; Joël Bégueret

1995-01-01

113

Copper homeostasis and aging in the fungal model system Podospora anserina: differential expression of PaCtr3 encoding a copper transporter  

Microsoft Academic Search

Lifespan extension of Podospora anserina mutant grisea is caused by a loss-of-function mutation in the nuclear gene Grisea. This gene encodes the copper regulated transcription factor GRISEA recently shown to be involved in the expression of PaSod2 encoding the mitochondrial manganese superoxide dismutase. Here we report the identification and characterization of a second target gene. This gene, PaCtr3, encodes a

Corina Borghouts; Christian Q Scheckhuber; Oliver Stephan; Heinz D Osiewacz

2002-01-01

114

The Protein Product of the Het-s Heterokaryon Incompatibility Gene of the Fungus Podospora anserina Behaves as a Prion Analog  

Microsoft Academic Search

The het-s locus of Podospora anserina is a heterokaryon incompatibility locus. The coexpression of the antagonistic het-s and het-S alleles triggers a lethal reaction that prevents the formation of viable heterokaryons. Strains that contain the het-s allele can display two different phenotypes, [Het-s] or [Het-s*], according to their reactivity in incompatibility. The detection in these phenotypically distinct strains of a

Virginie Coustou; Carol Deleu; Sven Saupe; Joel Begueret

1997-01-01

115

HET-E and HET-D Belong to a New Subfamily of WD40 Proteins Involved in Vegetative Incompatibility Specificity in the Fungus Podospora anserina  

Microsoft Academic Search

Vegetative incompatibility, which is very common in filamentous fungi, prevents a viable heterokaryotic cell from being formed by the fusion of filaments from two different wild-type strains. Such incompatibility is always the consequence of at least one genetic difference in specific genes (het genes). In Podospora anserina, alleles of the het-e and het-d loci control heterokaryon viability through genetic interactions

Pascale Balhadere; Marie-Louise Penin; Christian Barreau; Beatrice Turcq

2002-01-01

116

GRISEA, a copper-modulated transcription factor from Podospora anserina involved in senescence and morphogenesis, is an ortholog of MAC1 in Saccharomyces cerevisiae  

Microsoft Academic Search

The initial characterization of Grisea suggested that this gene codes for a transcription factor involved in the genetic control of cellular copper homeostasis\\u000a in Podospora anserina. Here we demonstrate that GRISEA activates in vivo gene expression in Saccharomyces cerevisiae and is characterized by a modular organization. The DNA-binding domain was mapped to the first 168 N-terminal amino acids\\u000a and the

C. Borghouts; H. D. Osiewacz

1998-01-01

117

The linear mitochondrial plasmid pAL2-1 of a long-lived Podospora anserina mutant is an invertron encoding a DNA and RNA polymerase  

Microsoft Academic Search

The molecular characterization of an additional DNA species (pAL2-1) which was identified previously in a long-lived extrachromosomal mutant (AL2) of Podospora anserina revealed that this element is a mitochondrial linear plasmid. pAL2-1 is absent from the corresponding wild-type strain, has a size of 8395 bp and contains perfect long terminal inverted repeats (TIRs) of 975 bp. Exonuclease digestion experiments indicated

Josef Hermanns; Heinz D. Osiewacz

1992-01-01

118

Identification and characterization of a gene encoding a subtilisin-like serine protease induced during the vegetative incompatibility reaction in Podospora anserina  

Microsoft Academic Search

In the filamentous fungi, cell fusion between unlike individuals generally triggers a cell-death reaction known as vegetative incompatibility. In Podospora anserina, it was shown that, during this cell-death reaction, there is a strong increase in proteolytic activity. Here, we report the purification of a 36-kDa protease that is induced during the incompatibility reaction. An internal peptide of this protein displayed

Mathieu Paoletti; Michel Castroviejo; Joël Bégueret; Corinne Clavé

2001-01-01

119

Deletion of the mitochondrial NADH kinase increases mitochondrial DNA stability and life span in the filamentous fungus Podospora anserina.  

PubMed

In the filamentous fungus Podospora anserina, aging is systematically associated with mitochondrial DNA (mtDNA) instability. A causal link between deficiency of the cytochrome respiratory pathway and lifespan extension has been demonstrated. Knock out of the cytochrome respiratory pathway induces the expression of an alternative oxidase and is associated with a reduction in free radical production. The question of the links between mtDNA stability, ROS generation and lifespan is therefore clearly raised in this organism. NADPH lies at the heart of many anti-oxidant defenses of the cell. In Saccharomyces cerevisiae, the mitochondrial NADPH is largely provided by the Pos5 NADH kinase. We show here that disruption of PaNdk1 encoding the potential mitochondrial NADH kinase of P. anserina leads to severe somatic and sexual defects and to hypersensitivity to hydrogen peroxide and paraquat. Surprisingly, it also leads to a spectacular increase of mtDNA stability and lifespan. We propose that an adaptative metabolic change including the induction of the alternative oxidase can account for these results. PMID:20096769

El-Khoury, Riyad; Sainsard-Chanet, Annie

2010-01-22

120

WD-repeat instability and diversification of the Podospora anserina hnwd non-self recognition gene family  

PubMed Central

Background Genes involved in non-self recognition and host defence are typically capable of rapid diversification and exploit specialized genetic mechanism to that end. Fungi display a non-self recognition phenomenon termed heterokaryon incompatibility that operates when cells of unlike genotype fuse and leads to the cell death of the fusion cell. In the fungus Podospora anserina, three genes controlling this allorecognition process het-d, het-e and het-r are paralogs belonging to the same hnwd gene family. HNWD proteins are STAND proteins (signal transduction NTPase with multiple domains) that display a WD-repeat domain controlling recognition specificity. Based on genomic sequence analysis of different P. anserina isolates, it was established that repeat regions of all members of the gene family are extremely polymorphic and undergoing concerted evolution arguing for frequent recombination within and between family members. Results Herein, we directly analyzed the genetic instability and diversification of this allorecognition gene family. We have constituted a collection of 143 spontaneous mutants of the het-R (HNWD2) and het-E (hnwd5) genes with altered recognition specificities. The vast majority of the mutants present rearrangements in the repeat arrays with deletions, duplications and other modifications as well as creation of novel repeat unit variants. Conclusions We investigate the extreme genetic instability of these genes and provide a direct illustration of the diversification strategy of this eukaryotic allorecognition gene family.

2010-01-01

121

A general framework for optimization of probes for gene expression microarray and its application to the fungus Podospora anserina  

PubMed Central

Background The development of new microarray technologies makes custom long oligonucleotide arrays affordable for many experimental applications, notably gene expression analyses. Reliable results depend on probe design quality and selection. Probe design strategy should cope with the limited accuracy of de novo gene prediction programs, and annotation up-dating. We present a novel in silico procedure which addresses these issues and includes experimental screening, as an empirical approach is the best strategy to identify optimal probes in the in silico outcome. Findings We used four criteria for in silico probe selection: cross-hybridization, hairpin stability, probe location relative to coding sequence end and intron position. This latter criterion is critical when exon-intron gene structure predictions for intron-rich genes are inaccurate. For each coding sequence (CDS), we selected a sub-set of four probes. These probes were included in a test microarray, which was used to evaluate the hybridization behavior of each probe. The best probe for each CDS was selected according to three experimental criteria: signal-to-noise ratio, signal reproducibility, and representative signal intensities. This procedure was applied for the development of a gene expression Agilent platform for the filamentous fungus Podospora anserina and the selection of a single 60-mer probe for each of the 10,556 P. anserina CDS. Conclusions A reliable gene expression microarray version based on the Agilent 44K platform was developed with four spot replicates of each probe to increase statistical significance of analysis.

2010-01-01

122

Identification and characterization of PaMTH1, a putative O-methyltransferase accumulating during senescence of Podospora anserina cultures.  

PubMed

A differential protein display screen resulted in the identification of a 27-kDa protein which strongly accumulates during the senescence of Podospora anserina cultures grown under standard conditions. After partial determination of the amino-acid sequence by mass-spectrometry analysis of trypsin-generated fragments, pairs of degenerated primers were deduced and used to amplify parts of the sequence coding for the protein. These PCR products were utilized to select specific cDNA and genomic clones from DNA libraries of P. anserina. A subsequent DNA-sequence analysis revealed that the 27-kDa protein is encoded by a discontinuous gene, PaMth1, capable of coding for 240 amino acids. The first three amino-terminal residues appear to be removed post-translationally. The deduced amino-acid sequence shows significant homology to S-adenosylmethionine (SAM)-dependent methyltransferases. We hypothesize that the 27-kDa protein, PaMTH1, is involved in age-related methylation reactions protecting aging cultures against increasing oxidative stress. PMID:10794178

Averbeck, N B; Jensen, O N; Mann, M; Schägger, H; Osiewacz, H D

2000-03-01

123

A non-Mendelian MAPK-generated hereditary unit controlled by a second MAPK pathway in Podospora anserina.  

PubMed

The Podospora anserina PaMpk1 MAP kinase (MAPK) signaling pathway can generate a cytoplasmic and infectious element resembling prions. When present in the cells, this C element causes the crippled growth (CG) cell degeneration. CG results from the inappropriate autocatalytic activation of the PaMpk1 MAPK pathway during growth, whereas this cascade normally signals stationary phase. Little is known about the control of such prion-like hereditary units involved in regulatory inheritance. Here, we show that another MAPK pathway, PaMpk2, is crucial at every stage of the fungus life cycle, in particular those controlled by PaMpk1 during stationary phase, which includes the generation of C. Inactivation of the third P. anserina MAPK pathway, PaMpk3, has no effect on the development of the fungus. Mutants of MAPK, MAPK kinase, and MAPK kinase kinase of the PaMpk2 pathway are unable to present CG. This inability likely relies upon an incorrect activation of PaMpk1, although this MAPK is normally phosphorylated in the mutants. In PaMpk2 null mutants, hyphae are abnormal and PaMpk1 is mislocalized. Correspondingly, stationary phase differentiations controlled by PaMpk1 are defective in the mutants of the PaMpk2 cascade. Constitutive activation of the PaMpk2 pathway mimics in many ways its inactivation, including an effect on PaMpk1 localization. Analysis of double and triple mutants inactivated for two or all three MAPK genes undercover new growth and differentiation phenotypes, suggesting overlapping roles. Our data underscore the complex regulation of a prion-like element in a model organism. PMID:22426880

Lalucque, Hervé; Malagnac, Fabienne; Brun, Sylvain; Kicka, Sébastien; Silar, Philippe

2012-03-16

124

Mutations in mating-type genes of the heterothallic fungus Podospora anserina lead to self-fertility.  

PubMed Central

The heterothallic fungus Podospora anserina has two mating-type alleles termed mat+ and mat-. The mat+ sequence contains one gene, FPR1, while mat- contains three genes: FMR1, SMR1, and SMR2. FPR1 and FMR1 are required for fertilization, which is followed by mitotic divisions of the two parental nuclei inside the female organ. This leads to the formation of plurinucleate cells containing a mixture of parental mat+ and mat- nuclei. Further development requires a recognition between mat+ and mat- nuclei before migration of the mat+/mat- pairs into specialized hyphae in which karyogamy, meiosis, and ascospore formation take place. FPR1, FMR1, and SMR2 control this internuclear recognition step. Initial development of the dikaryotic stage is supposed to require SMR1; disruption of SMR1 results in barren perithecia. In a systematic search for suppressors restoring fertility, we isolated 15 suppressors-all of them mutations in the mating-type genes. These fmr1, smr2, and fpr1 mutants, as well as the strains disrupted for FMR1, SMR2, and FPR1, are weakly self-fertile. They are able to act as the male partner on a strain of the same mating type and give a mixture of biparental and uniparental progeny when crossed with a wild-type strain of opposite mating type. These observations lead us to propose that SMR2, FMR1, and FPR1 act as activators and repressors of fertilization and internuclear recognition functions.

Arnaise, S; Zickler, D; Le Bilcot, S; Poisier, C; Debuchy, R

2001-01-01

125

Sequence analysis of mitochondrial DNA from Podospora anserina. Pervasiveness of a class I intron in three separate genes.  

PubMed

A 48 kb region of the 95 kb mitochondrial genome of Podospora anserina has been mapped and sequenced (1 kb = 10(3) base-pairs). The DNA sequence of the genes for ND2, 3, 4, ATPase 6 and URFC are presented here. As in Neurospora crassa, the ND2 and 3 genes consist of a unit separated by one TAA stop codon. ND3, 4 and ATPase 6 are interrupted by class I introns. All three introns are remarkably similar in the C-domain of their secondary structure, sufficient enough to designate them as new subgroup, class IC introns. The open reading frames of the ND3 and 4 introns bear a high sequence similarity to the open reading frame of the class IB introns of ATPase 6 from N. crassa and ND1 from Neurospora intermedia Varkud. We also show that the tRNA Met-2 gene is duplicated and is involved in a recombinational event. The 5' region of URFC is also duplicated but no involvement of this gene with recombination or formation of plasmids is known. The evolutionary significance of the similarities of intron secondary structures and open reading frames of the ND3, 4 and ATPase 6 genes is discussed, including the possible separate evolution of structural and coding sequences. PMID:2975708

Cummings, D J; Domenico, J M

1988-12-20

126

Mutations affecting translational fidelity in the eucaryote Podospora anserina: Characterization of two ribosomal restrictive mutations  

Microsoft Academic Search

Fifty-nine mutations that restrict suppressor efficiency were selected in the fungus Podospra anserina using four different screening methods. Previous genetic analysis has shown that these antisuppressors lie in six loci and that they could be similar to ribosomal restrictive mutations known in Escherichia coli. The present study deals with the response of two of them, AS1-1 and AS6-1, to paromomycin

Marguerite Picard-Bennoun

1981-01-01

127

Reactivity in vegetative incompatibility of the HE?TE protein of the fungus Podospora anserina is dependent on GTP-binding activity and a WD40 repeated domain  

Microsoft Academic Search

The het-e gene of the filamentous fungus Podospora anserina is involved in vegetative incompatibility. Co-expression of antagonistic alleles of the unlinked loci het-e and het-c triggers a cell death reaction that prevents the formation of viable heterokaryons between strains that contain incompatible\\u000a combinations of het-c and het-e alleles. The het-e1\\u000a A gene encodes a polypeptide that contains a putative GTP-binding

P. Balhadère; J. Bégueret; B. Turcq

1997-01-01

128

The transcriptional response to the inactivation of the PaMpk1 and PaMpk2 MAP kinase pathways in Podospora anserina.  

PubMed

Transcription pattern during mycelium growth of Podospora anserina was assayed by microarray analysis in wild type and in mutants affected in the MAP kinase genes PaMpk1 and PaMpk2 and in the NADPH oxidase gene PaNox1. 15% of the genes have their expression modified by a factor two or more as growth proceeds in wild type. The genes whose expression is modified during growth in P. anserina are either not conserved or differently regulated in Neurospora crassa and Aspergillus niger, two fungi for which transcriptome data during growth are available. The P. anserina mutants display a similar alteration of their transcriptome profile, with nearly 1000 genes affected similarly in the three mutants, accounting for their similar growth phenotypes. Yet, each mutant has its specific set of modified transcripts, in line with particular phenotypes exhibited by each mutant. Again, there is limited conservation during evolution of the genes regulated at the transcription level by MAP kinases, as indicated by the comparison the P. anserina data, with those of Aspergillus fumigatus and N. crassa, two fungi for which gene expression data are available for mutants of the MAPK pathways. Among the genes regulated in wild type and affected in the mutants, those involved in carbohydrate and secondary metabolisms appear prominent. The vast majority of the genes differentially expressed are of unknown function. Availability of their transcription profile at various stages of development should help to decipher their role in fungal physiology and development. PMID:22721649

Bidard, Frédérique; Coppin, Evelyne; Silar, Philippe

2012-06-19

129

The mitochondrial tyrosyl-tRNA synthetase of Podospora anserina is a bifunctional enzyme active in protein synthesis and RNA splicing.  

PubMed Central

The Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (mt tyrRS), which is encoded by the nuclear gene cyt-18, functions not only in aminoacylation but also in the splicing of group I introns. Here, we isolated the cognate Podospora anserina mt tyrRS gene, designated yts1, by using the N. crassa cyt-18 gene as a hybridization probe. DNA sequencing of the P. anserina gene revealed an open reading frame (ORF) of 641 amino acids which has significant similarity to other tyrRSs. The yts1 ORF is interrupted by two introns, one near its N terminus at the same position as the single intron in the cyt-18 gene and the other downstream in a region corresponding to the nucleotide-binding fold. The P. anserina yts1+ gene transformed the N. crassa cyt-18-2 mutant at a high frequency and rescued both the splicing and protein synthesis defects. Furthermore, the YTS1 protein synthesized in Escherichia coli was capable of splicing the N. crassa mt large rRNA intron in vitro. Together, these results indicate that YTS1 is a bifunctional protein active in both splicing and protein synthesis. The P. anserina YTS1 and N. crassa CYT-18 proteins share three blocks of amino acids that are not conserved in bacterial or yeast mt tyrRSs which do not function in splicing. One of these blocks corresponds to the idiosyncratic N-terminal domain shown previously to be required for splicing activity of the CYT-18 protein. The other two are located in the putative tRNA-binding domain toward the C terminus of the protein and also appear to be required for splicing. Since the E. coli and yeast mt tyrRSs do not function in splicing, the adaptation of the Neurospora and Podospora spp. mt tyrRSs to function in splicing most likely occurred after the divergence of their common ancestor from yeast. Images

Kamper, U; Kuck, U; Cherniack, A D; Lambowitz, A M

1992-01-01

130

Inhibitors of mitochondrial function prevent senescence in the ascomycete Podospora anserina  

Microsoft Academic Search

Summary The onset of senescence, i.e. decrease of growth rate followed by cellular death, is prevented when inhibitors of mitochondrial function (ethidiumbromide, streptomycin, tiamulin) are present in the culture medium. If mycelia are transferred to a medium not containing one of these substances, senescence occurs after the usual time interval (30 d at 26° C). Inhibitors of cytoplasmic protein synthesis

Paul Tudzynski; Karl Esser

1977-01-01

131

Prevention of senescence in the ascomycete Podospora anserina by the antibiotic tiamulin  

Microsoft Academic Search

THE syndrome of senescence or aging is common to all living material. In many fungi the peripheral hyphae become senescent after prolonged vegetative growth, that is, their growth rate decreases and they eventually die. In some fungi, senescence is caused by transmissible elements, of temporarily if their metabolism is drastically reduced1,5, but anastomosis. The onset of senescence is influenced by

K. Esser; P. Tudzynski

1977-01-01

132

Biological roles of the Podospora anserina mitochondrial Lon protease and the importance of its N-domain.  

PubMed

Mitochondria have their own ATP-dependent proteases that maintain the functional state of the organelle. All multicellular eukaryotes, including filamentous fungi, possess the same set of mitochondrial proteases, unlike in unicellular yeasts, where ClpXP, one of the two matricial proteases, is absent. Despite the presence of ClpXP in the filamentous fungus Podospora anserina, deletion of the gene encoding the other matricial protease, PaLon1, leads to lethality at high and low temperatures, indicating that PaLON1 plays a main role in protein quality control. Under normal physiological conditions, the PaLon1 deletion is viable but decreases life span. PaLon1 deletion also leads to defects in two steps during development, ascospore germination and sexual reproduction, which suggests that PaLON1 ensures important regulatory functions during fungal development. Mitochondrial Lon proteases are composed of a central ATPase domain flanked by a large non-catalytic N-domain and a C-terminal protease domain. We found that three mutations in the N-domain of PaLON1 affected fungal life cycle, PaLON1 protein expression and mitochondrial proteolytic activity, which reveals the functional importance of the N-domain of the mitochondrial Lon protease. All PaLon1 mutations affected the C-terminal part of the N-domain. Considering that the C-terminal part is predicted to have an ? helical arrangement in which the number, length and position of the helices are conserved with the solved structure of its bacterial homologs, we propose that this all-helical structure participates in Lon substrate interaction. PMID:22693589

Adam, Céline; Picard, Marguerite; Déquard-Chablat, Michelle; Sellem, Carole H; Hermann-Le Denmat, Sylvie; Contamine, Véronique

2012-05-31

133

The importomer peroxins are differentially required for peroxisome assembly and meiotic development in Podospora anserina: insights into a new peroxisome import pathway.  

PubMed

Peroxisome biogenesis relies on two known peroxisome matrix protein import pathways that are mediated by the receptors PEX5 and PEX7. These pathways converge at the importomer, a peroxisome-membrane complex that is required for protein translocation into peroxisomes and consists of docking and RING-finger subcomplexes. In the fungus Podospora anserina, the RING-finger peroxins are crucial for meiocyte formation, while PEX5, PEX7 or the docking peroxin PEX14 are not. Here we show that PEX14 and the PEX14-related protein PEX14/17 are differentially involved in peroxisome import during development. PEX14/17 activity does not compensate for loss of PEX14 function, and elimination of both proteins has no effect on meiocyte differentiation. In contrast, the docking peroxin PEX13, and the peroxins implicated in peroxisome membrane biogenesis PEX3 and PEX19, are required for meiocyte formation. Remarkably, the PTS2 coreceptor PEX20 is also essential for meiocyte differentiation and this function does not require PEX5 or PEX7. This finding suggests that PEX20 can mediate the import receptor activity of specific peroxisome matrix proteins. Our results suggest a new pathway for peroxisome import, which relies on PEX20 as import receptor and which seems critically required for specific developmental processes, like meiocyte differentiation in P.?anserina. PMID:21895788

Peraza-Reyes, Leonardo; Arnaise, Sylvie; Zickler, Denise; Coppin, Evelyne; Debuchy, Robert; Berteaux-Lecellier, Véronique

2011-09-12

134

Two Copies of mthmg1, Encoding a Novel Mitochondrial HMG-Like Protein, Delay Accumulation of Mitochondrial DNA Deletions in Podospora anserina  

PubMed Central

In the filamentous fungus Podospora anserina, two degenerative processes which result in growth arrest are associated with mitochondrial genome (mitochondrial DNA [mtDNA]) instability. Senescence is correlated with mtDNA rearrangements and amplification of specific regions (senDNAs). Premature death syndrome is characterized by the accumulation of specific mtDNA deletions. This accumulation is due to indirect effects of the AS1-4 mutation, which alters a cytosolic ribosomal protein gene. The mthmg1 gene has been identified as a double-copy suppressor of premature death. It greatly delays premature death and the accumulation of deletions when it is present in two copies in an AS1-4 context. The duplication of mthmg1 has no significant effect on the wild-type life span or on senDNA patterns. In an AS1+ context, deletion of the mthmg1 gene alters germination, growth, and fertility and reduces the life span. The ?mthmg1 senescent strains display a particular senDNA pattern. This deletion is lethal in an AS1-4 context. According to its physical properties (very basic protein with putative mitochondrial targeting sequence and HMG-type DNA-binding domains) and the cellular localization of an mtHMG1-green fluorescent protein fusion, mtHMG1 appears to be a mitochondrial protein possibly associated with mtDNA. It is noteworthy that it is the first example of a protein combining the two DNA-binding domains, AT-hook motif and HMG-1 boxes. It may be involved in the stability and/or transmission of the mitochondrial genome. To date, no structural homologues have been found in other organisms. However, mtHMG1 displays functional similarities with the Saccharomyces cerevisiae mitochondrial HMG-box protein Abf2.

Dequard-Chablat, Michelle; Alland, Cynthia

2002-01-01

135

Plasticity of the mitochondrial genome in Podospora. Polymorphism for 15 optional sequences: group-I, group-II introns, intronic ORFs and an intergenic region  

Microsoft Academic Search

The mitochondrial chromosome of 15 Podo-spora anserina and one Podospora comata wild-type strains have been extensively examined for the presence of optional elements and for sequence divergence. Among\\u000a the P. anserina strains, nine optional sequences were found. By comparing P. anserina with the closely related and weakly interfertile P. comata species, six additional optional sequences were detected. These optional elements

Léon Belcour; Michèle Rossignol; France Koll; Carole H. Sellem; Catherine Oldani

1997-01-01

136

Occurrence of a major protein associated with fruiting body development in Neurospora and related Ascomycetes.  

PubMed Central

Electrophoretic and immunological analysis of fruiting body (perithecial) extracts demonstrates the occurrence of a major phase-specific perithecial protein in all Neurospora species and in the closely related Gelasinospora cerealis and Sordariafimicola. The perithecial proteins from these different species fall into a number of groups with different electrophoretic mobilities. They appear to be immunologically closely related but not identical to one another even within the same genus, with only partial identity exhibited between the heterothallic and pseudohomothallic Neurospora on the one hand and the homothallic Neurospora on the other hand. In immunological analysis of fruiting body extracts of the other Ascomycetes, Podospora anserina, Cochliobolus maydis, and Aspergillus nidulans, and of ascus extracts of Saccharomyces cerevisiae, no crossreaction with the Neurospora perithecial protein was found. Images

Nasrallah, J B; Srb, A M

1977-01-01

137

Mating-Type Genes from the Homothallic Fungus Sordaria Macrospora Are Functionally Expressed in a Heterothallic Ascomycete  

PubMed Central

Homokaryons from the homothallic ascomycte Sordaria macrospora are able to enter the sexual pathway and to form fertile fruiting bodies. To analyze the molecular basis of homothallism and to elucidate the role of mating-products during fruiting body development, we cloned and sequenced the entire S. macrospora mating-type locus. Comparison of the Sordaria mating-type locus with mating-type idiomorphs from the heterothallic ascomycetes Neurospora crassa and Podospora anserina revealed that sequences from both idiomorphs (A/a and mat-/mat+, respectively) are contiguous in S. macrospora. DNA sequencing of the S. macrospora mating-type region allowed the identification of four open reading frames (ORFs), which were termed Smt-a1, SmtA-1, SmtA-2 and SmtA-3. While Smt-a1, SmtA-1, and SmtA-2 show strong sequence similarities with the corresponding N. crassa mating-type ORFs, SmtA-3 has a chimeric character. It comprises sequences that are similar to the A and a mating-type idiomorph from N. crassa. To determine functionality of the S. macrospora mating-type genes, we show that all ORFs are transcriptionally expressed. Furthermore, we transformed the S. macrospora mating-type genes into mat- and mat+ strains of the closely related heterothallic fungus P. anserina. The transformation experiments show that mating-type genes from S. macrospora induce fruiting body formation in P. anserina.

Poggeler, S.; Risch, S.; Kuck, U.; Osiewacz, H. D.

1997-01-01

138

Mating types and sexual development in filamentous ascomycetes.  

PubMed Central

The progress made in the molecular characterization of the mating types in several filamentous ascomycetes has allowed us to better understand their role in sexual development and has brought to light interesting biological problems. The mating types of Neurospora crassa, Podospora anserina, and Cochliobolus heterostrophus consist of unrelated and unique sequences containing one or several genes with multiple functions, related to sexuality or not, such as vegetative incompatibility in N. crassa. The presence of putative DNA binding domains in the proteins encoded by the mating-type (mat) genes suggests that they may be transcriptional factors. The mat genes play a role in cell-cell recognition at fertilization, probably by activating the genes responsible for the hormonal signal whose occurrence was previously demonstrated by physiological experiments. They also control recognition between nuclei at a later stage, when reproductive nuclei of each mating type which have divided in the common cytoplasm pair within the ascogenous hyphae. How self is distinguished from nonself at the nuclear level is not known. The finding that homothallic species, able to mate in the absence of a partner, contain both mating types in the same haploid genome has raised more issues than it has resolved. The instability of the mating type, in particular in Sclerotinia trifolorium and Botrytinia fuckeliana, is also unexplained. This diversity of mating systems, still more apparent if the yeasts and the basidiomycetes are taken into account, clearly shows that no single species can serve as a universal mating-type model.

Coppin, E; Debuchy, R; Arnaise, S; Picard, M

1997-01-01

139

Aging in fungi: role of mitochondria in Podospora anserina  

Microsoft Academic Search

In experimental gerontology, there is a long tradition in the use of both unicellular and filamentous species of fungi. In the last three decades, biochemical, genetic and molecular approaches have proved very fruitful in elucidating different aspects of ageing. It was shown that various genes and molecular pathways are involved in life span control. The oxygenic energy metabolism plays a

Heinz D Osiewacz

2002-01-01

140

Prions in Saccharomyces and Podospora spp.: Protein-Based Inheritance  

PubMed Central

Genetic evidence showed two non-Mendelian genetic elements of Saccharomyces cerevisiae, called [URE3] and [PSI], to be prions of Ure2p and Sup35p, respectively. [URE3] makes cells derepressed for nitrogen catabolism, while [PSI] elevates the efficiency of weak suppressor tRNAs. The same approach led to identification of the non-Mendelian element [Het-s] of the filamentous fungus Podospora anserina, as a prion of the het-s protein. The prion form of the het-s protein is required for heterokaryon incompatibility, a normal fungal function, suggesting that other normal cellular functions may be controlled by prions. [URE3] and [PSI] involve a self-propagating aggregation of Ure2p and Sup35p, respectively. In vitro, Ure2p and Sup35p form amyloid, a filamentous protein structure, high in ?-sheet with a characteristic green birefringent staining by the dye Congo Red. Amyloid deposits are a cardinal feature of Alzheimer’s disease, non-insulin-dependent diabetes mellitus, the transmissible spongiform encephalopathies, and many other diseases. The prion domain of Ure2p consists of Asn-rich residues 1 to 80, but two nonoverlapping fragments of the molecule can, when overproduced, induce the de nova appearance of [URE3]. The prion domain of Sup35 consists of residues 1 to 114, also rich in Asn and Gln residues. While runs of Asn and Gln are important for [URE3] and [PSI], no such structures are found in PrP or the Het-s protein. Either elevated or depressed levels of the chaperone Hsp104 interfere with propagation of [PSI]. Both [URE3] and [PSI] are cured by growth of cells in millimolar guanidine HCl. [URE3] is also cured by overexpression of fragments of Ure2p or fusion proteins including parts of Ure2p.

Wickner, Reed B.; Taylor, Kimberly L.; Edskes, Herman K.; Maddelein, Marie-Lise; Moriyama, Hiromitsu; Roberts, B. Tibor

1999-01-01

141

Rab-GDI Complex Dissociation Factor Expressed through Translational Frameshifting in Filamentous Ascomycetes.  

PubMed

In the model fungus Podospora anserina, the PaYIP3 gene encoding the orthologue of the Saccharomyces cerevisiae YIP3 Rab-GDI complex dissociation factor expresses two polypeptides, one of which, the long form, is produced through a programmed translation frameshift. Inactivation of PaYIP3 results in slightly delayed growth associated with modification in repartition of fruiting body on the thallus, along with reduced ascospore production on wood. Long and short forms of PaYIP3 are expressed in the mycelium, while only the short form appears expressed in the maturing fruiting body (perithecium). The frameshift has been conserved over the evolution of the Pezizomycotina, lasting for over 400 million years, suggesting that it has an important role in the wild. PMID:24069231

Malagnac, Fabienne; Fabret, Céline; Prigent, Magali; Rousset, Jean-Pierre; Namy, Olivier; Silar, Philippe

2013-09-19

142

Rab-GDI Complex Dissociation Factor Expressed through Translational Frameshifting in Filamentous Ascomycetes  

PubMed Central

In the model fungus Podospora anserina, the PaYIP3 gene encoding the orthologue of the Saccharomyces cerevisiae YIP3 Rab-GDI complex dissociation factor expresses two polypeptides, one of which, the long form, is produced through a programmed translation frameshift. Inactivation of PaYIP3 results in slightly delayed growth associated with modification in repartition of fruiting body on the thallus, along with reduced ascospore production on wood. Long and short forms of PaYIP3 are expressed in the mycelium, while only the short form appears expressed in the maturing fruiting body (perithecium). The frameshift has been conserved over the evolution of the Pezizomycotina, lasting for over 400 million years, suggesting that it has an important role in the wild.

Prigent, Magali; Rousset, Jean-Pierre; Namy, Olivier; Silar, Philippe

2013-01-01

143

Protoplasmic incompatibility and female organ formation in Podospora anserina : Properties of mutations abolishing both processes  

Microsoft Academic Search

A genetic block, effective only with the addition of mutations in two genes, suppresses both the incompatibility process in strain confrontation (“barrage”) and the formation of female organs. Investigations on this block lead us to propose that it operates at the ribosomal level and prevents the translation of the messenger of a proteolytic enzyme, a postulated early protein in protoperithecia

Hélian Boucherie; Jean Bernet

1974-01-01

144

Alternative splicing in ascomycetes.  

PubMed

Alternative splicing is a complex and regulated process, which results in mRNA with different coding capacities from a single gene. Extend and types of alternative splicing vary greatly among eukaryotes. In this review, I focus on alternative splicing in ascomycetes, which in general have significant lower extend of alternative splicing than mammals. Yeast-like species have low numbers of introns and consequently alternative splicing is lower compared to filamentous fungi. Several examples from single studies as well as from genomic scale analysis are presented, including a survey of alternative splicing in Neurospora crassa. Another focus is regulation by riboswitch RNA and alternative splicing in a heterologous system, along with putative protein factors involved in regulation. PMID:23515838

Kempken, Frank

2013-03-21

145

Unmasking a temperature-dependent effect of the P. anserina i-AAA protease on aging and development.  

PubMed

Different molecular pathways involved in maintaining mitochondrial function are of fundamental importance to control cellular homeostasis. Mitochondrial i-AAA protease is part of such a surveillance system and PaIAP is the putative ortholog in the fungal aging model Podospora anserina. Here we investigated the role of PaIAP in aging and development. Deletion of the gene encoding PaIAP resulted in a specific phenotype. When incubated at 27°C, spore germination and fruiting body formation are not different from that of the corresponding wild-type strain. Unexpectedly, the lifespan of the deletion strain is strongly increased. In contrast, cultivation at an elevated temperature of 37°C leads to impairments in spore germination and fruiting body formation, and to a reduced lifespan. The higher PaIAP abundance in wild-type strains of the fungus grown at elevated temperature and the phenotype of the deletion strain unmasks a temperature-related role of the protein. The protease appears to be part of a molecular system that has evolved to allow survival under changing temperatures as they characteristically occur in nature. PMID:22134244

Weil, Andrea; Luce, Karin; Dröse, Stefan; Wittig, Ilka; Brandt, Ulrich; Osiewacz, Heinz D

2011-12-15

146

Unmasking a temperature-dependent effect of the P. anserina i-AAA protease on aging and development  

PubMed Central

Different molecular pathways involved in maintaining mitochondrial function are of fundamental importance to control cellular homeostasis. Mitochondrial i-AAA protease is part of such a surveillance system, and PaIAP is the putative ortholog in the fungal aging model Podospora anserina. Here, we investigate the role of PaIAP in aging and development. Deletion of the gene encoding PaIAP resulted in a specific phenotype. When incubated at 27°C, spore germination and fruiting body formation are not different from that of the corresponding wild-type strain. Unexpectedly, the lifespan of the deletion strain is strongly increased. In contrast, cultivation at an elevated temperature of 37°C leads to impairments in spore germination and fruiting body formation and to a reduced lifespan. The higher PaIAP abundance in wild-type strains of the fungus grown at elevated temperature and the phenotype of the deletion strain unmasks a temperature-related role of the protein. The protease appears to be part of a molecular system that has evolved to allow survival under changing temperatures, as they characteristically occur in nature.

Weil, Andrea; Luce, Karin; Drose, Stefan; Wittig, Ilka; Brandt, Ulrich

2011-01-01

147

Two NADPH oxidase isoforms are required for sexual reproduction and ascospore germination in the filamentous fungus Podospora anserina  

Microsoft Academic Search

NADPH oxidases are enzymes that produce reactive oxygen species (ROS) using electrons derived from intracellular NADPH. In plants and mammals, ROS have been proposed to be second messengers that signal defence responses or cell proliferation. By inactivating PaNox1 and PaNox2, two genes encoding NADPH oxidases, we demonstrate the crucial role of these enzymes in the control of two key steps

Fabienne Malagnac; Hervé Lalucque; Gersende Lepère; Philippe Silar

2004-01-01

148

A general framework for optimization of probes for gene expression microarray and its application to the fungus Podospora anserina  

Microsoft Academic Search

BACKGROUND: The development of new microarray technologies makes custom long oligonucleotide arrays affordable for many experimental applications, notably gene expression analyses. Reliable results depend on probe design quality and selection. Probe design strategy should cope with the limited accuracy of de novo gene prediction programs, and annotation up-dating. We present a novel in silico procedure which addresses these issues and

Frédérique Bidard; Sandrine Imbeaud; Nancie Reymond; Olivier Lespinet; Philippe Silar; Corinne Clavé; Hervé Delacroix; Véronique Berteaux-Lecellier; Robert Debuchy

2010-01-01

149

PRP8 inteins in species of the genus Botrytis and other ascomycetes.  

PubMed

The mobile elements termed inteins have a sporadic distribution in microorganisms. It is unclear how these elements are maintained. Inteins are intervening protein sequences that autocatalytically excise themselves from a precursor. Excision is a post-translational process referred to as 'protein splicing' in which the sequences flanking the intein are ligated, reforming the mature host protein. Some inteins contain a homing endonuclease domain (HEG) that is proposed to facilitate propagation of the intein element within a gene pool. We have previously demonstrated that the HEG of the PRP8 intein is highly active during meiosis in Botrytis cinerea. Here we analysed the Prp8 gene status in 21 additional Botrytis species to obtain insight into the mode of intein inheritance within the Botrytis lineage. Of the 21 species, 15 contained a PRP8 intein whereas six did not. The analysis was extended to closely related (Sclerotiniaceae) and distantly related (Ascomycota) taxa, focussing on evolutionary diversification of the PRP8 intein, including their possible acquisition by horizontal transfer and loss by deletion. Evidence was obtained for the occurrence of genetic footprints of previous intein occupation. There is no compelling evidence of horizontal transfer among species. Three distinct states of the Prp8 allele were identified, distributed over different orders within the Ascomycota: an occupied allele; an empty allele that was never occupied; an empty allele that was presumably previously occupied, from which the intein was precisely deleted. The presence of the genetic footprint identifies 20 species (including Neurospora crassa, Magnaporthe oryzae and Fusarium oxysporum) that previously contained the intein but have lost it entirely, while only 18 species (including Podospora anserina and Fusarium graminearum) appear never to have contained a PRP8 intein. The analysis indicates that inteins may be maintained in an equilibrium state. PMID:22285471

Bokor, Annika A M; Kohn, Linda M; Poulter, Russell T M; van Kan, Jan A L

2012-01-20

150

Phylogenetics of Saccharomycetales, the ascomycete yeasts  

Microsoft Academic Search

Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial

Sung-Oui Suh; Meredith Blackwell; Cletus P. Kurtzman; M.-A. Lachance

2006-01-01

151

Mating-type genes for classical strain improvements of ascomycetes  

Microsoft Academic Search

The ability to mate fungi in the laboratory is a valuable tool for genetic analysis and for classical strain improvement. In ascomycetous fungi, mating typically occurs between morphologically identical partners that are distinguished by their mating type. In most cases, the single mating-type locus conferring mating behavior consists of dissimilar DNA sequences (idiomorphs) in the mating partners. All ascomycete mating-type

S. Pöggeler

2001-01-01

152

Phylogenetics of Saccharomycetales, the ascomycete yeasts.  

PubMed

Ascomycete yeasts (phylum Ascomycota: subphylum Saccharomycotina: class Saccharomycetes: order Saccharomycetales) comprise a monophyletic lineage with a single order of about 1000 known species. These yeasts live as saprobes, often in association with plants, animals and their interfaces. A few species account for most human mycotic infections, and fewer than 10 species are plant pathogens. Yeasts are responsible for important industrial and biotechnological processes, including baking, brewing and synthesis of recombinant proteins. Species such as Saccharomyces cerevisiae are model organisms in research, some of which led to a Nobel Prize. Yeasts usually reproduce asexually by budding, and their sexual states are not enclosed in a fruiting body. The group also is well defined by synapomorphies visible at the ultrastructural level. Yeast identification and classification changed dramatically with the availability of DNA sequencing. Species identification now benefits from a constantly updated sequence database and no longer relies on ambiguous growth tests. A phylogeny based on single gene analyses has shown the order to be remarkably divergent despite morphological similarities among members. The limits of many previously described genera are not supported by sequence comparisons, and multigene phylogenetic studies are under way to provide a stable circumscription of genera, families and orders. One recent multigene study has resolved species of the Saccharomycetaceae into genera that differ markedly from those defined by analysis of morphology and growth responses, and similar changes are likely to occur in other branches of the yeast tree as additional sequences become available. PMID:17486976

Suh, Sung-Oui; Blackwell, Meredith; Kurtzman, Cletus P; Lachance, Marc-André

153

MOD-D, a Ga Subunit of the Fungus Podospora anserina, Is Involved in Both Regulation of Development and Vegetative Incompatibility  

Microsoft Academic Search

Cell death via vegetative incompatibility is widespread in fungi but molecular mechanism and biological function of the process are poorly understood. One way to investigate this phenomenon was to study genes named mod that modified incompatibility reaction. In this study, we cloned the mod-D gene that encodes a Ga protein. The mod-D mutant strains present developmental defects. Previously, we showed

Gabriel Loubradou; Beatrice Turcq

1999-01-01

154

Inactivation of the Podospora anserina Vegetative Incompatibility Locus het-c, Whose Product Resembles a Glycolipid Transfer Protein, Drastically Impairs Ascospore Production  

Microsoft Academic Search

The het-c locus contains different alleles that elicit nonallelic vegetative incompatibility through specific interactions with alleles of the unlinked loci het-e and het-d. The het-c2 allele has been cloned. It encodes a 208-amino acid polypeptide that is similar to a glycolipid transfer protein purified from pig brain. Disruption of this gene drastically impairs ascospore production in homozygous crosses, and some

Sven Saupe; Cecile Descamps; Beatrice Turcq; Joel Begueret

1994-01-01

155

ASYMMETRY IN SEXUAL PHEROMONES IS NOT REQUIRED FOR ASCOMYCETE MATING  

PubMed Central

SUMMARY Background We investigated the determinants of sexual identity in the budding yeast, Saccharomyces cerevisiae. The higher fungi are divided into the Ascomycetes and the Basidiomycetes. Most Ascomycetes have two mating types: one (called ? in yeasts and MAT1-1 in filamentous fungi) produces a small, unmodified, peptide pheromone, and the other (a in yeasts and MAT1-2 in filamentous fungi) produces a peptide pheromone conjugated to a C terminal farnesyl group that makes it very hydrophobic. In the Basidiomycetes, all pheromones are lipid-modified, and this difference is a distinguishing feature between the phyla. We asked whether the asymmetry in pheromone modification is required for successful mating in Ascomycetes. Results We cloned receptor and pheromone genes from a filamentous Ascomycete and a Basidiomycete and expressed these in the budding yeast, Saccharomyces cerevisiae, to generate novel, alternative mating pairs. We find that two yeast cells can mate even when both cells secrete a-like or ?-like peptides. Importantly, this is true regardless of whether the cells express the a- or ?-mating type loci, which control the expression of other, sex-specific genes, in addition to the pheromones and pheromone receptors. Conclusions We demonstrate that the asymmetric pheromone modification is not required for successful mating of ascomycete fungi and confirm that, in budding yeast, the primary determinants of mating are the specificity of the receptors and their corresponding pheromones.

Goncalves-Sa, Joana; Murray, Andrew

2011-01-01

156

Flavan-3-ols and flavonoids from Potentilla anserina.  

PubMed

Roots/rhizomes and aerial parts of Potentilla anserina L. (Rosaceae) contain two flavan-3-ols: (+)-catechin and (+)-gallocatechin. The flavonol glycosides and glucuronides isolated from the herb were kaempferol 3- O-beta- D-glucoside, kaempferol 3- O-beta- D-(6''- O-( E)- P-coumaroyl)glucopyranoside, quercetin 3- O-beta- D-glucoside, quercetin 3- O-beta- D-xyloside, quercetin 3- O-alpha- L-rhamnoside, quercetin 3- O-beta- D-sambubioside, quercetin 3- O-beta- D-glucuronide, isorhamnetin 3- O-beta- D-glucuronide, myricetin 3- O-alpha- L-rhamnoside, and myricetin 3- O-beta- D-glucuronide. Herbacetin 8-methyl ether-3- O-beta- D-sophoroside (8-methoxykaempferol 3-sophoroside) was identified in the flowers. The 6''-methyl ester of quercetin 3- O-beta- D-galacturonide, which may be an artifact, was isolated from the herb. The total flavonoid content calculated as quercetin-3- O-beta- D-glucuronide was 1% in the lyophilized herb used in this study and 0.5% in a commercial drug, meeting DAC standards. PMID:17238103

Kombal, R; Glasl, H

1995-10-01

157

A complete inventory of fungal kinesins in representative filamentous ascomycetes  

Microsoft Academic Search

Complete inventories of kinesins from three pathogenic filamentous ascomycetes, Botryotinia fuckeliana, Cochliobolus heterostrophus, and Gibberella moniliformis, are described. These protein sequences were compared with those of the filamentous saprophyte, Neurospora crassa and the two yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe. Data mining and phylogenetic analysis of the motor domain yielded a constant set of 10 kinesins in the filamentous fungal

Conrad L. Schoch; James R. Aist; Olen C. Yoder; B. Gillian Turgeona

2003-01-01

158

Enzymology of the thermophilic ascomycetous fungus Thermoascus aurantiacus  

Microsoft Academic Search

Different strains of the thermophilic ascomycetous fungus Thermoascus aurantiacus have been reported in the literature to produce high levels of a variety of industrial interest enzymes (i.e. amylases, cellulases, pectinases and xylanases), which have been shown to be remarkably stable over a wide range of temperatures and appear to have tremendous commercial potential. Most studies on enzyme production by T.

Michel Brienzo; Valdeir Arantes; Adriane M.F. Milagres

2008-01-01

159

Catalytic Properties and Classification of Cellobiose Dehydrogenases from Ascomycetes? †  

PubMed Central

Putative cellobiose dehydrogenase (CDH) genes are frequently discovered in various fungi by genome sequencing projects. The expression of CDH, an extracellular flavocytochrome, is well studied in white rot basidiomycetes and is attributed to extracellular lignocellulose degradation. CDH has also been reported for plant-pathogenic or saprotrophic ascomycetes, but the molecular and catalytic properties of these enzymes are currently less investigated. This study links various ascomycetous cdh genes with the molecular and catalytic characteristics of the mature proteins and suggests a differentiation of ascomycete class II CDHs into two subclasses, namely, class IIA and class IIB, in addition to the recently introduced class III of hypothetical ascomycete CDHs. This new classification is based on sequence and biochemical data obtained from sequenced fungal genomes and a screening of 40 ascomycetes. Thirteen strains showed CDH activity when they were grown on cellulose-based media, and Chaetomium atrobrunneum, Corynascus thermophilus, Dichomera saubinetii, Hypoxylon haematostroma, Neurospora crassa, and Stachybotrys bisbyi were selected for detailed studies. In these strains, one or two cdh-encoding genes were found that stem either from class IIA and contain a C-terminal carbohydrate-binding module or from class IIB without such a module. In several strains, both genes were found. Regarding substrate specificity, class IIB CDHs show a less pronounced substrate specificity for cellobiose than class IIA enzymes. A pH-dependent pattern of the intramolecular electron transfer was also observed, and the CDHs were classified into three groups featuring acidic, intermediate, or alkaline pH optima. The pH optimum, however, does not correlate with the CDH subclasses and is most likely a species-dependent adaptation to different habitats.

Harreither, Wolfgang; Sygmund, Christoph; Augustin, Manfred; Narciso, Melanie; Rabinovich, Mikhail L.; Gorton, Lo; Haltrich, Dietmar; Ludwig, Roland

2011-01-01

160

Relation between phylogeny and physiology in some ascomycetous yeasts  

Microsoft Academic Search

The question of whether yeasts with similar physiological properties are closely related has been examined using recently\\u000a published phylogenetic analyses of 26S domain D1\\/D2 rDNA nucleotide sequences from all currently recognized ascomycetous yeasts.\\u000a When apparently unique metabolic pathways are examined, some relationships between physiology and rDNA phylogeny are evident.\\u000a Most Candida and Pichia species that are able to assimilate methanol

Wouter J. Middelhoven; Cletus P. Kurtzman

2003-01-01

161

Relative Incidence of Ascomycetous Yeasts in Arctic Coastal Environments  

Microsoft Academic Search

Previous studies of fungi in polar environments have revealed a prevalence of basidiomycetous yeasts in soil and in subglacial\\u000a environments of polythermal glaciers. Ascomycetous yeasts have rarely been reported from extremely cold natural environments,\\u000a even though they are known contaminants of frozen foods. Using media with low water activity, we have isolated various yeast\\u000a species from the subglacial ice of

Lorena Butinar; Tadeja Strmole; Nina Gunde-Cimerman

2011-01-01

162

Mitochondrial Intronic Open Reading Frames in Podospora: Mobility and Consecutive Exonic Sequence Variations  

PubMed Central

The mitochondrial genome of 23 wild-type strains belonging to three different species of the filamentous fungus Podospora was examined. Among the 15 optional sequences identified are two intronic reading frames, nad1-i4-orf1 and cox1-i7-orf2. We show that the presence of these sequences was strictly correlated with tightly clustered nucleotide substitutions in the adjacent exon. This correlation applies to the presence or absence of closely related open reading frames (ORFs), found at the same genetic locations, in all the Pyrenomycete genera examined. The recent gain of these optional ORFs in the evolution of the genus Podospora probably account for such sequence differences. In the homoplasmic progeny from heteroplasmons constructed between Podospora strains differing by the presence of these optional ORFs, nad1-i4-orf1 and cox1-i7-orf2 appeared highly invasive. Sequence comparisons in the nad1-i4 intron of various strains of the Pyrenomycete family led us to propose a scenario of its evolution that includes several events of loss and gain of intronic ORFs. These results strongly reinforce the idea that group I intronic ORFs are mobile elements and that their transfer, and comcomitant modification of the adjacent exon, could participate in the modular evolution of mitochondrial genomes.

Sellem, C. H.; d'Aubenton-Carafa, Y.; Rossignol, M.; Belcour, L.

1996-01-01

163

Evolution of the frequency (frq) clock locus in Ascomycete fungi.  

PubMed

The frequency (frq) locus of Neurospora crassa plays a key role in the organization of circadian rhythms. Similar timing systems have been found in nearly all eukaryotes as well as some prokaryotes; thus, frq may be an excellent gene with which to conduct evolutionary studies. To investigate, we used the cloned frq locus from ascomycete fungi representing two classical taxonomic classes and three orders to examine two open questions in ascomycete evolution. Class Pyrenomycetidae is represented by several species of Neurospora, Sordaria fimicola, and Chromocrea spinulosa; class Loculoascomycetidae is represented by the marine fungus Leptosphaeria australiensis. Generation of detailed restriction maps of homologs from the Neurospora species allows analysis of evolutionary relationships among these closely related species. A maximum-parsimony tree based on these restriction data suggests that Neurospora tetrasperma groups more closely with Neurospora sitophila than with Neurospora crassa using the homothallic species Neurospora galapagosensis as an outgroup. A maximum-parsimony tree derived using amino acid sequences from Neurospora crassa, Sordaria fimicola, Chromocrea spinulosa, and Leptosphaeria australiensis surprisingly suggests that Leptosphaeria austral should be classified within Pyrenomycetes rather than in a separate class. This suggestion is based on the observations that Leptosphaeria groups with Chromocrea on an evolutionary tree, is more closely related to Neurospora and Sordaria than is Chromocrea, and shares a conserved intron with Chromocrea. Together, these data show that frq is a useful gene with which to conduct evolutionary studies. PMID:8896376

Lewis, M T; Feldman, J F

1996-11-01

164

Genomics of alternative sulfur utilization in ascomycetous yeasts.  

PubMed

Thirteen ascomycetous yeast strains with sequenced genomes were assayed for their ability to grow on chemically defined medium with 16 different sulfur compounds as the only significant source of sulfur. These compounds included sulfoxides, sulfones, sulfonates, sulfamates and sulfate esters. Broad utilization of alternative sulfur sources was observed in Komagataella pastoris (syn. Pichia pastoris), Lodderomyces elongisporus, Millerozyma farinosa (syn. Pichia sorbitophila), Pachysolen tannophilus, Scheffersomyces stipitis (syn. Pichia stipitis), Spathaspora passalidarum, Yamadazyma tenuis (syn. Candida tenuis) and Yarrowia lipolytica. Kluyveromyces lactis, Saccharomyces cerevisiae and Zygosaccharomyces rouxii were mainly able to utilize sulfonates and sulfate esters, while Lachancea thermotolerans and Schizosaccharomyces pombe were limited to aromatic sulfate esters. Genome analysis identified several candidate genes with bacterial homologues that had been previously shown to be involved in the utilization of alternative sulfur sources. Analysis of candidate gene promoter sequences revealed a significant overrepresentation of DNA motifs that have been shown to regulate sulfur metabolism in Sacc. cerevisiae. PMID:22790398

Linder, Tomas

2012-07-12

165

Relation between phylogeny and physiology in some ascomycetous yeasts.  

PubMed

The question of whether yeasts with similar physiological properties are closely related has been examined using recently published phylogenetic analyses of 26S domain D1/D2 rDNA nucleotide sequences from all currently recognized ascomycetous yeasts. When apparently unique metabolic pathways are examined, some relationships between physiology and rDNA phylogeny are evident. Most Candida and Pichia species that are able to assimilate methanol as the sole carbon source are in a clade delimited by C. nanospora and C. boidinii. Exceptions are P. capsulata and P. pastoris which are phylogenetically separated from the other methanol-assimilating yeasts. Yeasts subject to the petite mutation, resulting in respiratory deficiency, belong to three different clades, viz, a Saccharomyces clade delimited by S. cerevisiae and S. rosinii, the Dekkera/Brettanomyces clade, and some Schizosaccharomyces species ('Archiascomycete' clade). However, petite mutants were also found in Zygosaccharomyces fermentati and some other more distantly related species. Yeasts able to assimilate n-hexadecane, uric acid or amines as sole carbon source are broadly distributed over the ascomycetous phylogenetic tree. However, species that assimilate adenine as sole carbon source are closely related. Most of these species also assimilated glycine, uric acid, n-hexadecane, putrescine and branched-chain aliphatic compounds such as isobutanol, leucine and isoleucine. Among the Saccharomycetales, species utilizing all or the great majority of these eight compounds are in the Stephanoascus/Arxula/Blastobotrys clade. Candida blankii, which is distantly related to this clade, proved to be an exception and assimilated six of eight of these compounds. PMID:12755482

Middelhoven, Wouter J; Kurtzman, Cletus P

2003-01-01

166

Deletion of the RING-finger peroxin 2 gene in Aspergillus nidulans does not affect meiotic development.  

PubMed

Peroxins are required for protein import into peroxisomes as well as for peroxisome biogenesis and proliferation. Loss-of-function mutations in genes for the RING-finger peroxins Pex2, Pex10 and Pex12 lead to a specific block in meiosis in the ascomycete Podospora anserina. However, loss of protein import into peroxisomes does not result in this meiotic defect. Therefore, it has been suggested that these peroxins have a specific function required for meiosis. To determine whether this role is conserved in other filamentous fungi, we have deleted the gene encoding Pex2 in Aspergillus nidulans. The phenotypes resulting from this deletion are no different from those of previously isolated pex mutants affected in peroxisomal protein import, and viable ascospores are produced in selfed crosses. Therefore, the role of the RING-finger peroxins in meiosis is not conserved in filamentous ascomycetes. PMID:20236327

Hynes, Michael J; Murray, Sandra L; Kahn, Freya K

2010-02-22

167

Ascomycete fungal communities associated with early decaying leaves of Spartina spp. from central California estuaries  

Microsoft Academic Search

Ascomycetous fungi play an important role in the early stages of decomposition of Spartina alterniflora, but their role in the decomposition of other Spartina species has not been investigated. Here we use fingerprint (terminal restriction fragment length polymorphism) and phylogenetic\\u000a analyses of the 18S to 28S internal transcribed spacer region to compare the composition of the ascomycete fungal communities\\u000a on

Justine I. Lyons; Merryl Alber; James T. Hollibaugh

2010-01-01

168

Ascomycete fungal communities associated with early decaying leaves of Spartina spp. from central California estuaries.  

PubMed

Ascomycetous fungi play an important role in the early stages of decomposition of Spartina alterniflora, but their role in the decomposition of other Spartina species has not been investigated. Here we use fingerprint (terminal restriction fragment length polymorphism) and phylogenetic analyses of the 18S to 28S internal transcribed spacer region to compare the composition of the ascomycete fungal communities on early decay blades of Spartina species (Spartina alterniflora, Spartina densiflora, Spartina foliosa, and a hybrid (S. alterniflora x S. foliosa)) collected from three salt marshes in San Francisco Bay and one in Tomales Bay, California, USA. Phaeosphaeria spartinicola was found on all samples collected and was often dominant. Two other ascomycetes, Phaeosphaeria halima and Mycosphaerella sp. strain 2, were also common. These three species are the same ascomycetes previously identified as the dominant fungal decomposers on S. alterniflora on the east coast. Ascomycetes appeared to exhibit varying degrees of host specificity, demonstrated by grouping patterns on phylogenetic trees. Neither the exotic S. alterniflora nor the hybrid supported fungal flora different from that of the native S. foliosa. However, S. densiflora had a significantly different fungal community than the other species, and hosted at least two unique ascomycetes. Significant differences in the fungal decomposer communities were also detected within species (two clones of S. foliosa), but these were minor and may be due to morphological differences among the plants. PMID:19777266

Lyons, Justine I; Alber, Merryl; Hollibaugh, James T

2009-09-24

169

Selenylation modification can enhance antioxidant activity of Potentilla anserina L. polysaccharide.  

PubMed

Potentilla anserina L. polysaccharide had been selenizingly modified by nitric acid-selenious acid method with microwave-assistant. The optimal reaction parameters on selenylation modification were time 116 min, temperature 63°C, microwave power 190 W and the actual value of selenium content was 2690.1±7.2 ?g/g. The scavenging ability of DPPH, OH and superoxide radicals, the metal chelating ability and reducing power in vitro were compared by antioxidant assay taking the non-modified PAP as a control. The results showed that selenylation modification could significantly enhance the antioxidant activity of SePAP and SePAP could be used as a potential antioxidant. PMID:23624168

Zhao, Baotang; Zhang, Ji; Yao, Jian; Song, Shen; Yin, Zhenxiong; Gao, Qingya

2013-04-24

170

A novel class of peptide pheromone precursors in ascomycetous fungi.  

PubMed

Recently, sexual development in the heterothallic ascomycete Trichoderma reesei (anamorph of Hypocrea jecorina) has been achieved and thus initiated attempts to elucidate regulation and determinants of this process. While the ?-type pheromone of this fungus fits the consensus known from other fungi, the assumed a-type peptide pheromone precursor shows remarkably unusual characteristics: it comprises three copies of the motif (LI)GC(TS)VM thus constituting a CAAX domain at the C-terminus and two Kex2-protease sites. This structure shares characteristics of both a- and ?-type peptide pheromone precursors. Presence of hybrid-type peptide pheromone precursor 1 (hpp1) is essential for male fertility, thus indicating its functionality as a peptide pheromone precursor, while its phosphorylation site is not relevant for this process. However, sexual development in a female fertile background is not perturbed in the absence of hpp1, which rules out a higher order function in this process. Open reading frames encoding proteins with similar characteristics to HPP1 were also found in Fusarium spp., of which Fusarium solani still retains a putative a-factor-like protein, but so far in no other fungal genome available. We therefore propose the novel class of h-type (hybrid) peptide pheromone precursors with H. jecorina HPP1 as the first member of this class. PMID:20735770

Schmoll, Monika; Seibel, Christian; Tisch, Doris; Dorrer, Marcel; Kubicek, Christian P

2010-09-01

171

A novel class of peptide pheromone precursors in ascomycetous fungi  

PubMed Central

Recently, sexual development in the heterothallic ascomycete Trichoderma reesei (anamorph of Hypocrea jecorina) has been achieved and thus initiated attempts to elucidate regulation and determinants of this process. While the ?-type pheromone of this fungus fits the consensus known from other fungi, the assumed a-type peptide pheromone precursor shows remarkably unusual characteristics: it comprises three copies of the motif (LI)GC(TS)VM thus constituting a CAAX domain at the C-terminus and two Kex2-protease sites. This structure shares characteristics of both a- and ?-type peptide pheromone precursors. Presence of hybrid-type peptide pheromone precursor 1 (hpp1) is essential for male fertility, thus indicating its functionality as a peptide pheromone precursor, while its phosphorylation site is not relevant for this process. However, sexual development in a female fertile background is not perturbed in the absence of hpp1, which rules out a higher order function in this process. Open reading frames encoding proteins with similar characteristics to HPP1 were also found in Fusarium spp., of which Fusarium solani still retains a putative a-factor-like protein, but so far in no other fungal genome available. We therefore propose the novel class of h-type (hybrid) peptide pheromone precursors with H. jecorina HPP1 as the first member of this class.

Schmoll, Monika; Seibel, Christian; Tisch, Doris; Dorrer, Marcel; Kubicek, Christian P

2010-01-01

172

Common amino acid domain among endopolygalacturonases of ascomycete fungi.  

PubMed Central

The endopolygalacturonase (EC 3.2.1.15) enzymes produced in vitro by three ascomycete fungi, Aspergillus niger, Sclerotinia sclerotiorum, and Colletotrichum lindemuthianum were studied by using thin-layer isoelectric focusing and activity stain overlay techniques. The polygalacturonases from A. niger and S. sclerotiorum consisted of numerous isoforms, whereas the endopolygalacturonase from C. lindemuthianum consisted of a single protein species. The most abundant endopolygalacturonase isoform produced by each of these organisms was purified and characterized. Biochemical parameters, including molecular weight, isoelectric point, kinetic parameters, temperature and pH optima, and thermal stability, were determined. Considerable differences in physical and chemical properties were demonstrated among these fungal polygalacturonases. Antibodies raised against individual proteins exhibited little cross-reaction, suggesting that these enzymes differ structurally as well as biochemically. In contrast, the analysis of the N-terminal amino acid sequences of the three proteins showed extensive homology, particularly in a region labeled domain 1 in which 84% of the amino acids were conserved. Images

Keon, J P; Waksman, G

1990-01-01

173

Biotechnology of non-Saccharomyces yeasts--the ascomycetes.  

PubMed

Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described. PMID:23184219

Johnson, Eric A

2012-11-27

174

Origin and distribution of epipolythiodioxopiperazine (ETP) gene clusters in filamentous ascomycetes  

PubMed Central

Background Genes responsible for biosynthesis of fungal secondary metabolites are usually tightly clustered in the genome and co-regulated with metabolite production. Epipolythiodioxopiperazines (ETPs) are a class of secondary metabolite toxins produced by disparate ascomycete fungi and implicated in several animal and plant diseases. Gene clusters responsible for their production have previously been defined in only two fungi. Fungal genome sequence data have been surveyed for the presence of putative ETP clusters and cluster data have been generated from several fungal taxa where genome sequences are not available. Phylogenetic analysis of cluster genes has been used to investigate the assembly and heredity of these gene clusters. Results Putative ETP gene clusters are present in 14 ascomycete taxa, but absent in numerous other ascomycetes examined. These clusters are discontinuously distributed in ascomycete lineages. Gene content is not absolutely fixed, however, common genes are identified and phylogenies of six of these are separately inferred. In each phylogeny almost all cluster genes form monophyletic clades with non-cluster fungal paralogues being the nearest outgroups. This relatedness of cluster genes suggests that a progenitor ETP gene cluster assembled within an ancestral taxon. Within each of the cluster clades, the cluster genes group together in consistent subclades, however, these relationships do not always reflect the phylogeny of ascomycetes. Micro-synteny of several of the genes within the clusters provides further support for these subclades. Conclusion ETP gene clusters appear to have a single origin and have been inherited relatively intact rather than assembling independently in the different ascomycete lineages. This progenitor cluster has given rise to a small number of distinct phylogenetic classes of clusters that are represented in a discontinuous pattern throughout ascomycetes. The disjunct heredity of these clusters is discussed with consideration to multiple instances of independent cluster loss and lateral transfer of gene clusters between lineages.

Patron, Nicola J; Waller, Ross F; Cozijnsen, Anton J; Straney, David C; Gardiner, Donald M; Nierman, William C; Howlett, Barbara J

2007-01-01

175

Exploring laccase-like multicopper oxidase genes from the ascomycete Trichoderma reesei: a functional, phylogenetic and evolutionary study  

Microsoft Academic Search

BACKGROUND: The diversity and function of ligninolytic genes in soil-inhabiting ascomycetes has not yet been elucidated, despite their possible role in plant litter decay processes. Among ascomycetes, Trichoderma reesei is a model organism of cellulose and hemicellulose degradation, used for its unique secretion ability especially for cellulase production. T. reesei has only been reported as a cellulolytic and hemicellulolytic organism

Anthony Levasseur; Markku Saloheimo; David Navarro; Martina Andberg; Pierre Pontarotti; Kristiina Kruus; Eric Record

2010-01-01

176

Purification and properties of a lectin from ascomycete mushroom, Ciborinia camelliae.  

PubMed

A lectin was isolated from an ascomycete mushroom, Ciborinia camelliae which was specific to N-acetyl-D-galactosamine. On SDS-polyacrylamide gel electrophoresis; this lectin gave a single band of approximately 17-kDa in the presence of 2-mercaptoethanol, but formed dimers, trimers and tetramers in its absence. Amino acid analysis revealed the lectin contained two cysteines and no methionine. The N-terminal sequence was determined up to residue 21, and no homologous proteins including other ascomycete lectins were found. PMID:12009312

Otta, Yumi; Amano, Koh; Nishiyama, Kano; Ando, Akikazu; Ogawa, Shigeru; Nagata, Yoshiho

2002-05-01

177

Intronic GIY-YIG endonuclease gene in the mitochondrial genome of Podospora curvicolla: evidence for mobility.  

PubMed

Endonuclease genes encoded in invasive introns are themselves supposed to be mobile elements which, during evolution, have colonized pre-existing introns converting them into invasive elements. This hypothesis is supported by numerous data concerning the LAGLI-DADG subclass of intronic endonucleases. Less is known about the GIY-YIG ORFs which constitute another family of endonucleases. In this paper we describe the presence of one optional GIY-YIG ORF in the second intron of the mitochondrial cytochrome b gene in the fungus Podospora curvicolla. We show that this GIY-YIG ORF is efficiently transferred from an ORF-containing intron to an ORF-less allele. We also show that the products of both the GIY-YIG ORF and the non-canonical LAGLI-DADG-GIY-YIG ORF, which is generated by its integration, have endonuclease activities which recognize and cut the insertion site of the optional sequence. This constitutes the first direct evidence for potential mobility of an intronic GIY-YIG endonuclease. We discuss the role that such a mobile sequence could have played during evolution. PMID:10684923

Saguez, C; Lecellier, G; Koll, F

2000-03-15

178

Sterol composition of mycelia of the plant pathogenic ascomycete Leptosphaeria maculans  

Microsoft Academic Search

Analysis of sterols in mycelia of the ascomycete, Leptosphaeria maculans by gas chromatography–mass spectrometry revealed that ergosterol comprised 95% of the total sterols, with eight other sterols comprising the remaining 5%. Six of these latter sterols were putative precursors of ergosterol and their presence suggested a pathway for ergosterol biosynthesis in this fungus. Ergosterol biosynthesis in fungi is inhibited by

K. M Griffiths; A Bacic; B. J Howlett

2003-01-01

179

Soil Ecology of the Entomopathogenic Ascomycetes: A Critical Examination of What We (Think) We Know  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter provides an in-depth review of what is and is not known about the soil ecology of the entomopathogenic Ascomycetes, particularly the fungi Beauveria bassiana and Metarhizium anisopliae. The efficacy of entomopathogenic fungi in soil is subject to a matrix of interlocking abiotic and bi...

180

Origin and distribution of epipolythiodioxopiperazine (ETP) gene clusters in filamentous ascomycetes  

Microsoft Academic Search

BACKGROUND: Genes responsible for biosynthesis of fungal secondary metabolites are usually tightly clustered in the genome and co-regulated with metabolite production. Epipolythiodioxopiperazines (ETPs) are a class of secondary metabolite toxins produced by disparate ascomycete fungi and implicated in several animal and plant diseases. Gene clusters responsible for their production have previously been defined in only two fungi. Fungal genome sequence

Nicola J Patron; Ross F Waller; Anton J Cozijnsen; David C Straney; Donald M Gardiner; William C Nierman; Barbara J Howlett

2007-01-01

181

Geographical Races of Certain Species of Ascomycetous Yeasts in the Moscow and Novosibirsk Regions  

Microsoft Academic Search

Strains of three species of the ascomycetous yeasts Hanseniaspora guilliermondii, Torulaspora delbrueckii, and Debaryomyces hansenii, isolated from the above-ground parts of plants in similar biocenoses of distant geographic regions (Moscow and Novosibirsk regions), have been investigated. The strains in each species were indistinguishable with respect to phenotypic features and general DNA characteristics as determined by restriction analysis. However, comparison of

A. M. Yurkov; I. Yu. Chernov

2005-01-01

182

From the Cover: Explosively launched spores of ascomycete fungi have drag-minimizing shapes  

Microsoft Academic Search

The forcibly launched spores of ascomycete fungi must eject through several millimeters of nearly still air surrounding fruiting bodies to reach dispersive air flows. Because of their microscopic size, spores experience great fluid drag, and although this drag can aid transport by slowing sedimentation out of dispersive air flows, it also causes spores to decelerate rapidly after launch. We hypothesize

Marcus Roper; Rachel E. Pepper; Michael P. Brenner; Anne Pringle

2008-01-01

183

Characterization of Azo Reduction Activity in a Novel Ascomycete Yeast Strain  

Microsoft Academic Search

Several model azo dyes are reductively cleaved by growing cultures of an ascomycete yeast species, Issatch- enkia occidentalis. In liquid media containing 0.2 mM dye and 2% glucose in a mineral salts base, more than 80% of the dyes are removed in 15 h, essentially under microaerophilic conditions. Under anoxic conditions, decolorization does not occur, even in the presence of

Patrícia A. Ramalho; M. Helena Cardoso; A. Cavaco-Paulo; M. Teresa Ramalho

2004-01-01

184

A new pullulan and a branched (1?3)-, (1?6)-linked ?-glucan from the lichenised ascomycete Teloschistes flavicans  

Microsoft Academic Search

The polysaccharides formed on hot alkaline extraction of the ascomycetous lichen Teloschistes flavicans were fractionated to give two glucans, which were characterised by methylation analysis and 1D and 2D NMR spectroscopy. One was a branched ?-glucan containing (1?3) and (1?6) linkages, a structure which is more typical of basidiomycetes rather than ascomycetes, which have linear glucans. The other was an

Rodrigo A Reis; Cesar A Tischer; Philip A. J Gorin; Marcello Iacomini

2002-01-01

185

Phylogenetic origins of the asexual mycorrhizal symbiont Cenococcum geophilum Fr. and other mycorrhizal fungi among the ascomycetes.  

PubMed

The phylogenetic relationship of the asexual mycorrhizal fungus Cenococcum geophilam Fr. among sexual ascomycetes was examined by phylogenetic analysis of nucleotide sequence data from the nuclear small subunit (18S) ribosomal RNA genie region. A specific focus of this study was to test the hypothesis that the genus Elaphomyces is the closest sexual relative of C. geophilum. Thus nucleotide sequence data of five C. geophilum isolates, three Elaphomyces species, and 44 additional genera of ascomycetes were included in the phylogenetic analyses. The percentage of similarity among the 18S rDNA sequences of the C. geophilum isolates examined was 99.8 to 100%, indicating that C. geophilum is monophyletic. Percent similarity of nucleotide sequence among the three Elaphomyces species was also high and ranged from 99.4 to 99.5%. DNA parsimony and distance analysis of the sequence data separated these 2 genera on distant clades when sequence from 44 additional genera of ascomycetes was included. Parsimony and distance analyses positioned C. geophilum as a basal, intermediate lineage between the two Loculoascomycete orders, the Pleosporales and the Dothidiales, and strongly supported Elaphomyces to be of Plectomycete origin. Among the sexual Ascomycetes examined, which included representative taxa from four classes of filamentous Ascomycetes (Plectomycetes, Pyrenomycetes, Discomycetes, and Loculoascomycetes), no close sexual relative to C. geophilum was identified. At least four independent lineages of mycorrhizal fungi were identified among the ascomycetes examined. PMID:8899729

LoBuglio, K F; Berbee, M L; Taylor, J W

1996-10-01

186

Molecular and enzymatic characterisation of extra- and intracellular laccases from the acidophilic ascomycete Hortaea acidophila  

Microsoft Academic Search

The pigmented ascomycete Hortaea acidophila is able to grow at a pH as low as 0.6 and produces laccases that are involved in melanin synthesis. We now present data on an extracellular and an intracellular laccase which exhibit a high stability at low pH. Furthermore, the optimum for enzyme acitivity is extraordinarily low with pH 1.5 for the intracellular laccase with

Larissa Tetsch; Jutta Bend; Udo Hölker

2006-01-01

187

Intracellular Siderophores Are Essential for Ascomycete Sexual Development in Heterothallic Cochliobolus heterostrophus and Homothallic Gibberella zeae? †  

PubMed Central

Connections between fungal development and secondary metabolism have been reported previously, but as yet, no comprehensive analysis of a family of secondary metabolites and their possible role in fungal development has been reported. In the present study, mutant strains of the heterothallic ascomycete Cochliobolus heterostrophus, each lacking one of 12 genes (NPS1 to NPS12) encoding a nonribosomal peptide synthetase (NRPS), were examined for a role in sexual development. One type of strain (?nps2) was defective in ascus/ascospore development in homozygous ?nps2 crosses. Homozygous crosses of the remaining 11 ?nps strains showed wild-type (WT) fertility. Phylogenetic, expression, and biochemical analyses demonstrated that the NRPS encoded by NPS2 is responsible for the biosynthesis of ferricrocin, the intracellular siderophore of C. heterostrophus. Functional conservation of NPS2 in both heterothallic C. heterostrophus and the unrelated homothallic ascomycete Gibberella zeae was demonstrated. G. zeae ?nps2 strains are concomitantly defective in intracellular siderophore (ferricrocin) biosynthesis and sexual development. Exogenous application of iron partially restored fertility to C. heterostrophus and G. zeae ?nps2 strains, demonstrating that abnormal sexual development of ?nps2 strains is at least partly due to their iron deficiency. Exogenous application of the natural siderophore ferricrocin to C. heterostrophus and G. zeae ?nps2 strains restored WT fertility. NPS1, a G. zeae NPS gene that groups phylogenetically with NPS2, does not play a role in sexual development. Overall, these data demonstrate that iron and intracellular siderophores are essential for successful sexual development of the heterothallic ascomycete C. heterostrophus and the homothallic ascomycete G. zeae.

Oide, Shinichi; Krasnoff, Stuart B.; Gibson, Donna M.; Turgeon, B. Gillian

2007-01-01

188

A new trihydroxy fatty acid from the ascomycete, Chinese truffle Tuber indicum  

Microsoft Academic Search

From the chloroform\\/methanol extract of the fruiting bodies of the ascomycete Chinese truffle Tuber indicum Cooke et Massee, a new trihydroxylated monounsaturated fatty acid (1) has been isolated. The structure of this new linoleic acid-derived metabolite was established as 9,10,11-trihydroxy-(12Z)-12-octadecenoic\\u000a acid by means of spectroscopic and chemical methods. The fatty acid composition of the chloroform-soluble fraction of this\\u000a fungus was

Jin-Ming Gao; Chen-Ying Wang; An-Ling Zhang; Ji-Kai Liu

2001-01-01

189

Ascomycetous yeast communities of marine invertebrates in a southeast Brazilian mangrove ecosystem.  

PubMed

The ascomycetous yeast communities associated with 3 bivalve mollusk, and 4 crab species were studied in the mangrove at Coroa Grande on Sepetiba Bay in Rio de Janeiro, Brazil. These were made up mostly of diverse but sparse and apparently allochtonous yeast populations. The striking exception was a prevalent population of the species Kluyveromyces aestuarii, which predominated the yeast communities of 2 detritus feeding crabs, Sesarma rectum and Uca spp., and the shipworm Neoteredo reynei. However, K. aestuarii was absent from the omnivorous crabs Aratus pisonii and Goniopsis cruentata, and the clam Anomalocardia brasiliana, and was rare in the clam Tagelus plebeius from mostly submerged more sandy sediments. Pichia membranaefaciens, Candida valida-like, Candida krusei, Candida sorbosa, Candida colliculosa-like, Candida famata-like, Kloeckera spp., Candida guilliermondii, Candida albicans, Candida silvae, Geotrichum spp., Rhodotorula spp., Cryptococcus spp., and the methylotrophic yeast Candida boidinii were frequently isolated. The 322 ascomycetous yeast cultures representing 252 isolates from crabs and mollusks were classified as 40 species that fit standard descriptions, and 44 putative new species. The ascomycetous yeast communities of the mangrove ecosystem include many new biotypes that require better taxonomic definition. PMID:8546456

de Araujo, F V; Soares, C A; Hagler, A N; Mendonça-Hagler, L C

1995-08-01

190

The Potential for pathogenicity was present in the ancestor of the Ascomycete subphylum Pezizomycotina  

PubMed Central

Background Previous studies in Ascomycetes have shown that the function of gene families of which the size is considerably larger in extant pathogens than in non-pathogens could be related to pathogenicity traits. However, by only comparing gene inventories in extant species, no insights can be gained into the evolutionary process that gave rise to these larger family sizes in pathogens. Moreover, most studies which consider gene families in extant species only tend to explain observed differences in gene family sizes by gains rather than by losses, hereby largely underestimating the impact of gene loss during genome evolution. Results In our study we used a selection of recently published genomes of Ascomycetes to analyze how gene family gains, duplications and losses have affected the origin of pathogenic traits. By analyzing the evolutionary history of gene families we found that most gene families with an enlarged size in pathogens were present in an ancestor common to both pathogens and non-pathogens. The majority of these families were selectively maintained in pathogenic lineages, but disappeared in non-pathogens. Non-pathogen-specific losses largely outnumbered pathogen-specific losses. Conclusions We conclude that most of the proteins for pathogenicity were already present in the ancestor of the Ascomycete lineages we used in our study. Species that did not develop pathogenicity seemed to have reduced their genetic complexity compared to their ancestors. We further show that expansion of gained or already existing families in a species-specific way is important to fine-tune the specificities of the pathogenic host-fungus interaction.

2010-01-01

191

A MADS Box Protein Interacts with a Mating-Type Protein and Is Required for Fruiting Body Development in the Homothallic Ascomycete Sordaria macrospora  

Microsoft Academic Search

MADS box transcription factors control diverse developmental processes in plants, metazoans, and fungi. To analyze the involvement of MADS box proteins in fruiting body development of filamentous ascomycetes, we isolated the mcm1 gene from the homothallic ascomycete Sordaria macrospora, which encodes a putative homologue of the Saccharomyces cerevisiae MADS box protein Mcm1p. Deletion of the S. macrospora mcm1 gene resulted

Nicole Nolting; Stefanie Poggeler

2006-01-01

192

Agrobacterium -mediated gene transfer and enhanced green fluorescent protein visualization in the mycorrhizal ascomycete Tuber borchii : a first step towards truffle genetics  

Microsoft Academic Search

Mycorrhizal ascomycetes are ecologically and commercially important fungi that have proved impervious to genetic transformation so far. We report here on the successful transient transformation of Tuber borchii, an ectomycorrhizal ascomycete that colonizes a variety of trees and produces highly prized hypogeous fruitbodies known as “truffles”. A hypervirulent Agrobacterium tumefaciens strain bearing the binary plasmid pBGgHg was used for transformation.

Benedetto Grimaldi; Michiel A. de Raaf; Patrizia Filetici; Simone Ottonello; Paola Ballario

2005-01-01

193

Sterol composition of mycelia of the plant pathogenic ascomycete Leptosphaeria maculans.  

PubMed

Analysis of sterols in mycelia of the ascomycete, Leptosphaeria maculans by gas chromatography-mass spectrometry revealed that ergosterol comprised 95% of the total sterols, with eight other sterols comprising the remaining 5%. Six of these latter sterols were putative precursors of ergosterol and their presence suggested a pathway for ergosterol biosynthesis in this fungus. Ergosterol biosynthesis in fungi is inhibited by the triazole antifungal agent flutriafol. When L. maculans was grown in the presence of flutriafol, ergosterol content decreased while two 14 alpha-methylated sterols, 24-methylene dihydrolanosterol and obtusifoliol, accumulated. PMID:12482449

Griffiths, K M; Bacic, A; Howlett, B J

2003-01-01

194

Two new for science species of genus Cordyceps fr. (Ascomycetes) from Indian Himalaya.  

PubMed

Two new species for science, Cordyceps kurijimeaensis and C. nirtolii (Clavicipitaceae, Ascomycetes), collected from the forests of the Munsyari Region of the Himalayan hills (Uttarakhand State, India) are described and illustrated. C. kurijimeaensis has the same host, larvae of Hepialus armoricanus, as does Cordyceps (=Ophiocordyceps) sinensis, and C. nirtolii was found on Melanotus communis. Morphology and other diagnostic characteristics show a close relationship between C. kurijimeaensis and C. nirtolii. ITS sequences show a close phylogenetic relationship with members of Clavicipitaceae clade C, strongly supporting the classification of these as new species. PMID:23510219

Negi, Prem Singh; Singh, Ranjit; Koranga, Prithviraj Singh; Ahmed, Zakwan

2012-01-01

195

A study on volatile organic compounds (VOCs) produced by tropical ascomycetous yeasts.  

PubMed

As a part of a program aiming at the selection of strains which might be of interest as sources of natural flavouring molecules, the production of volatile organic compounds (VOCs) by 98 ascomycetous yeast strains (representative of 40 species belonging to 12 genera) isolated from tropical environments was investigated. Volatiles produced were sampled by means of headspace solid-phase microextraction (SPME) and the compounds were analysed and identified by gas chromatography-mass spectroscopy (GC-MS). The VOCs produced were found to be alcohols (amyl alcohol and isoamyl alcohol), aldehydes (2-methyl-2-hexenal and 2-isopropyl-5-methyl-2-hexenal) and esters (ethyl isobutyrate, isobutyl acetate, isoamyl acetate, 2-methylbutyl acetate, ethyl isovalerate, isoamyl propionate and phenylmethyl acetate). Differences in VOC profiles were used to cluster the yeast strains into 25 VOC phenotypes. The different frequency of VOC phenotypes in three specific habitats was correlated to the divergent environmental conditions, possibly affecting the selection of specific yeasts. From a biotechnological viewpoint, this study reveals the potentiality of ascomycetous yeasts isolated from tropical environments as a promising source of VOCs relevant in food and fragrance industry. PMID:14574107

Buzzini, Pietro; Martini, Alessandro; Cappelli, Francesco; Pagnoni, Ugo Maria; Davoli, Paolo

2003-01-01

196

A novel mode of chromosomal evolution peculiar to filamentous Ascomycete fungi  

PubMed Central

Background Gene loss, inversions, translocations, and other chromosomal rearrangements vary among species, resulting in different rates of structural genome evolution. Major chromosomal rearrangements are rare in most eukaryotes, giving large regions with the same genes in the same order and orientation across species. These regions of macrosynteny have been very useful for locating homologous genes in different species and to guide the assembly of genome sequences. Previous analyses in the fungi have indicated that macrosynteny is rare; instead, comparisons across species show no synteny or only microsyntenic regions encompassing usually five or fewer genes. To test the hypothesis that chromosomal evolution is different in the fungi compared to other eukaryotes, synteny was compared between species of the major fungal taxa. Results These analyses identified a novel form of evolution in which genes are conserved within homologous chromosomes, but with randomized orders and orientations. This mode of evolution is designated mesosynteny, to differentiate it from micro- and macrosynteny seen in other organisms. Mesosynteny is an alternative evolutionary pathway very different from macrosyntenic conservation. Surprisingly, mesosynteny was not found in all fungal groups. Instead, mesosynteny appears to be restricted to filamentous Ascomycetes and was most striking between species in the Dothideomycetes. Conclusions The existence of mesosynteny between relatively distantly related Ascomycetes could be explained by a high frequency of chromosomal inversions, but translocations must be extremely rare. The mechanism for this phenomenon is not known, but presumably involves generation of frequent inversions during meiosis.

2011-01-01

197

Explosively launched spores of ascomycete fungi have drag-minimizing shapes  

PubMed Central

The forcibly launched spores of ascomycete fungi must eject through several millimeters of nearly still air surrounding fruiting bodies to reach dispersive air flows. Because of their microscopic size, spores experience great fluid drag, and although this drag can aid transport by slowing sedimentation out of dispersive air flows, it also causes spores to decelerate rapidly after launch. We hypothesize that spores are shaped to maximize their range in the nearly still air surrounding fruiting bodies. To test this hypothesis we numerically calculate optimal spore shapes—shapes of minimum drag for prescribed volumes—and compare these shapes with real spore shapes taken from a phylogeny of >100 species. Our analysis shows that spores are constrained to remain within 1% of the minimum possible drag for their size. From the spore shapes we predict the speed of spore launch, and confirm this prediction through high-speed imaging of ejection in Neurospora tetrasperma. By reconstructing the evolutionary history of spore shapes within a single ascomycete family we measure the relative contributions of drag minimization and other shape determinants to spore shape evolution. Our study uses biomechanical optimization as an organizing principle for explaining shape in a mega-diverse group of species and provides a framework for future measurements of the forces of selection toward physical optima.

Roper, Marcus; Pepper, Rachel E.; Brenner, Michael P.; Pringle, Anne

2008-01-01

198

Identification and phylogeny of ascomycetous yeasts from analysis of nuclear large subunit (26S) ribosomal DNA partial sequences  

Microsoft Academic Search

Approximately 500 species of ascomycetous yeasts, including members of Candida and other anamorphic genera, were analyzed for extent of divergence in the variable D1\\/D2 domain of large subunit (26S) ribosomal DNA. Divergence in this domain is generally sufficient to resolve individual species, resulting in the prediction that 55 currently recognized taxa are synonyms of earlier described species. Phylogenetic relationships among

Cletus P. Kurtzman; Christie J. Robnett

1998-01-01

199

Candida tartarivorans sp. nov., an anamorphic ascomycetous yeast with the capacity to degrade L(+)- and meso-tartaric acid  

Microsoft Academic Search

An undescribed anamorphic yeast species of ascomycetous affinity, for which the name Candida tartarivorans is proposed, was isolated from dried wine lees in Portugal using a selective medium with L(M)-tartaric acid as the sole source of carbon and energy. The single isolate (IGC 4854T) showed the following characteristics : sympodial holoblastic conidiogenesis, absence of asci with ascospores, a negative colour

A. Fonseca; Fell J. W; C. P. Kurtzman; Isabel Spencer-Martins

2000-01-01

200

Molecular and enzymatic characterisation of extra- and intracellular laccases from the acidophilic ascomycete Hortaea acidophila.  

PubMed

The pigmented ascomycete Hortaea acidophila is able to grow at a pH as low as 0.6 and produces laccases that are involved in melanin synthesis. We now present data on an extracellular and an intracellular laccase which exhibit a high stability at low pH. Furthermore, the optimum for enzyme acitivity is extraordinarily low with pH 1.5 for the intracellular laccase with 2,6-dimethoxyphenol (DMOP) as substrate. Two complete laccase gene sequences of H. acidophila were amplified by inverse polymerase chain reaction (PCR). Whereas the deduced protein laccase I contains an predicted N-terminal signal sequence for protein export, laccase II does not and thus may represent the intracellular laccase. The acidophilic character of both laccases seems to be reflected in their primary structure. PMID:16871425

Tetsch, Larissa; Bend, Jutta; Hölker, Udo

2006-07-27

201

Bioconversion of (+)-valencene in submerged cultures of the ascomycete Chaetomium globosum.  

PubMed

Submerged cultures of the ascomycete Chaetomium globosum oxidised the exogenous sesquiterpene (+)-valencene to nootkatone via the stereoselective generation of alpha-nootkatol. Inhibition experiments suggested that the first introduction of oxygen, the rate-limiting step of the bioconversion, may have been catalysed by a cytochrome-P450-monooxygenase. However, nootkatone was not the final metabolite: further flavour-active and inactive, non-volatile oxidation products were identified. (+)-Valencene and the flavour-active mono-oxyfunctionalised transformation products, alpha-nootkatol, nootkatone, and valencene-11,12-epoxide accumulated preferably inside the fungal cells. Di- and poly-oxygenated products, such as nootkatone-11,12-epoxide, were found solely in the culture medium, indicating an active transport of these metabolites into the extracellular compartment during (+)-valencene detoxification. These metabolic properties may have contributed to the high tolerance of the fungus towards the exogenous hydrocarbon. PMID:15602686

Kaspera, Rüdiger; Krings, Ulrich; Nanzad, Tsevegsuren; Berger, Ralf G

2004-12-16

202

Identification, distribution and occurrence of the ascomycete Metschnikowia typographi in the great spruce bark beetle, Dendroctonus micans  

Microsoft Academic Search

This is the first report on the ascomycete Metschnikowia typographi from the adults and larvae of the great spruce bark beetle Dendroctonus micans in Turkey. In total, 910 of 1928 adults and 44 of 149 larvae investigated during the two years were infected by the pathogen.\\u000a In a fresh smear the asci of the pathogen measure 18.5 ± 2.05 ?m

M. Yaman; R. Radek

2008-01-01

203

Evolution of host–parasite relationships of Golovinomyces (Ascomycete: Erysiphaceae) inferred from nuclear rDNA sequences  

Microsoft Academic Search

To understand the evolution of host–parasite relationships in the genus Golovinomyces (Ascomycete: Erysiphaceae), which are obligate parasitic fungi of plants, we investigated the phylogenetic relationships of the genus based on 60 internal transcribed spacer (ITS) and 41 28S rDNA sequences. Five major groups, each represented by isolates from a single tribe of the Asteraceae, were identified in the taxa analyzed

S. Matsuda; S. Takamatsu

2003-01-01

204

12 Evolution of Mating-Type Loci and Mating-Type Chromosomes in Model Species of Filamentous Ascomycetes  

Microsoft Academic Search

\\u000a Sexual reproduction in fungi is regulated by relatively small genomic regions containing the mating-type loci. In this chapter\\u000a we describe the genomic traits and evolutionary features of the mating-type loci and the mating-type chromosomes in model\\u000a systems of filamentous ascomycetes. The main focus of the chapter lies in the recent scientific advances from studies in Neurospora, particularly N. tetrasperma. The

Carrie A. Whittle; Hanna Johannesson

205

Phylogenetic Origins of the Asexual Mycorrhizal Symbiont Cenococcum geophilumFr. and Other Mycorrhizal Fungi among the Ascomycetes  

Microsoft Academic Search

The phylogenetic relationship of the asexual mycorrhizal fungusCenococcum geophilumFr. among sexual ascomycetes was examined by phylogenetic analysis of nucleotide sequence data from the nuclear small subunit (18S) ribosomal RNA genic region. A specific focus of this study was to test the hypothesis that the genusElaphomycesis the closest sexual relative ofC. geophilum.Thus nucleotide sequence data of fiveC. geophilumisolates, threeElaphomycesspecies, and 44

Katherine F. LoBuglio; Mary L. Berbee; John W. Taylor

1996-01-01

206

Comparative degradation of oomycete, ascomycete, and basidiomycete cell walls by mycoparasitic and biocontrol fungi.  

PubMed

Fourteen fungi (primarily representing mycoparasitic and biocontrol fungi) were tested for their ability to grow on and degrade cell walls (CWs) of an oomycete (Pythium ultimum), ascomycete (Fusarium equisetii), and basidiomycete (Rhizoctonia solani), and their hydrolytic enzymes were characterized. Protein was detected in the cultural medium of eleven of the test isolates, and these fungi significantly degraded CWs over the 14-day duration of the experiment. In general, a greater level of CW degradation occurred for F. equisetii and P. ultimum than for R. solani. Fungi that degraded F. equisetii CWs were Coniothyrium minitans, Gliocladium roseum, Myrothecium verrucaria, Talaromyces flavus, and Trichoderma harzianum. Taxa degrading P ultimum CWs included Chaetomium globosum, Coniothyrium minitans, M. verrucaria, Seimatosporium sp., Talaromyces flavus, Trichoderma hamatum, Trichoderma harzianum, and Trichoderma viride. Production of extracellular protein was highly correlated with CW degradation. Considerable variation in the molecular weights of CW-degrading enzymes were detected among the test fungi and the CW substrates in zymogram electrophoresis. Multivariate analysis between CW degradation and hydrolysis of barley beta-glucan (beta1,3- and beta1,4-glucanases), laminarin (beta1,3- and beta1,6-glucanases), carboxymethyl cellulose (endo-beta1,4-glucanases), colloidal chitin (chitinases), and chitosan (chitosanases) was conducted. For F. equisetii CWs, the regression model accounted for 80% of the variability, and carboxymethyl cellulases acting together with beta-glucanases contributed an R2 of 0.52, whereas chitinases and beta-glucanases alone contributed an R2 of 0.11 and 0.12, respectively. Only 61% of the variability observed in the degradation of P. ultimum CWs was explained by the enzyme classes tested, and primarily beta-glucanases (R2 of 0.53) and carboxymethyl cellulases (R2 of 0.08) alone contributed to CW break down. Too few of the test fungi degraded R. solani CWs to perform multivariate analysis effectively. This study identified several fungi that degraded ascomyceteous and oomyceteous, and to a lesser extent, basidiomycetous CWs. An array of enzymes were implicated in CW degradation. PMID:11888164

Inglis, G D; Kawchuk, L M

2002-01-01

207

Candida hyderabadensis sp. nov., a novel ascomycetous yeast isolated from wine grapes.  

PubMed

Three ascomycetous yeast strains were isolated from decaying green wine grapes, collected from Hyderabad city in India. Two strains, YS9 and YS21, were identified as Kodamaea ohmeri and Candida fermentati, respectively. The third strain, YS12(T), differs from Candida parapsilosis, Candida orthopsilosis and Candida metapsilosis, the nearest phylogenetic neighbours, by 1.6-1.9% with respect to the nucleotide sequence of the D1/D2 domain of the 26S rRNA gene and by 1.4-9.2% with respect to the nucleotide sequence of the internal transcribed spacer 1 (ITS1)-5.8S rRNA gene-ITS2 region. YS12(T) also differs from C. parapsilosis, C. metapsilosis and C. orthopsilosis by some phenotypic characteristics. Thus, based on the phenotypic differences and phylogenetic analysis, strain YS12(T) is assigned the status of a new species of Candida, for which the name C. hyderabadensis sp. nov. is proposed. The type strain is YS12(T) (NRRL Y-27953(T)=CBS10444(T)=IAM15334(T)). PMID:17253980

Rao, Ravella Sreenivas; Bhadra, Bhaskar; Kumar, Neradugomma Naveen; Shivaji, Sisinthy

2007-01-24

208

A Putative Transcription Factor MYT2 Regulates Perithecium Size in the Ascomycete Gibberella zeae  

PubMed Central

The homothallic ascomycete fungus Gibberella zeae is a plant pathogen that is found worldwide, causing Fusarium head blight (FHB) in cereal crops and ear rot of maize. Ascospores formed in fruiting bodies (i.e., perithecia) are hypothesized to be the primary inocula for FHB disease. Perithecium development is a complex cellular differentiation process controlled by many developmentally regulated genes. In this study, we selected a previously reported putative transcription factor containing the Myb DNA-binding domain MYT2 for an in-depth study on sexual development. The deletion of MYT2 resulted in a larger perithecium, while its overexpression resulted in a smaller perithecium when compared to the wild-type strain. These data suggest that MYT2 regulates perithecium size differentiation. MYT2 overexpression affected pleiotropic phenotypes including vegetative growth, conidia production, virulence, and mycotoxin production. Nuclear localization of the MYT2 protein supports its role as a transcriptional regulator. Transcriptional analyses of trichothecene synthetic genes suggest that MYT2 additionally functions as a suppressor for trichothecene production. This is the first study characterizing a transcription factor required for perithecium size differentiation in G. zeae, and it provides a novel angle for understanding sexual development in filamentous fungi.

Lin, Yang; Son, Hokyoung; Min, Kyunghun; Lee, Jungkwan; Choi, Gyung Ja; Kim, Jin-Cheol; Lee, Yin-Won

2012-01-01

209

Induction of apoptosis against cancer cell lines by four ascomycetes (endophytes) from Malaysian rainforest.  

PubMed

Endophytic fungi have been shown to be a promising source of biologically active natural products. In the present study, extracts of four endophytic fungi isolated from plants of the National Park, Pahang were evaluated for their cytotoxic activity and the nature of their active compounds determined. Those extracts exhibiting activity with IC(50) values less than 17 ?g/ml against HCT116, MCF-7 and K562 cell lines were shown to induce apoptosis in these cell lines. Molecular analysis, based on sequences of the rDNA internal transcribed spacers ITS1 and ITS4, revealed all four endophytic fungi to be ascomycetes: three sordariomycetes and a dothideomycete. Six known compounds, cytochalasin J, dechlorogriseofulvin, demethylharzianic-acid, griseofulvin, harzianic acid and 2-hexylidene-3-methyl-succinic acid were identified from a rapid dereplication technique for fungal metabolites using an in-house UV library. The results from the present study suggest the potential of endophytic fungi as cytotoxic agents, and there is an indication that the isolates contain bioactive compounds that mainly kill cancer cells by apoptosis. PMID:22397996

Hazalin, Nurul Aqmar Mohamad Nor; Ramasamy, Kalavathy; Lim, Siong Meng; Cole, Anthony L J; Majeed, Abu Bakar Abdul

2012-03-06

210

Conserved and essential transcription factors for cellulase gene expression in ascomycete fungi  

PubMed Central

Rational engineering of filamentous fungi for improved cellulase production is hampered by our incomplete knowledge of transcriptional regulatory networks. We therefore used the model filamentous fungus Neurospora crassa to search for uncharacterized transcription factors associated with cellulose deconstruction. A screen of a N. crassa transcription factor deletion collection identified two uncharacterized zinc binuclear cluster transcription factors (clr-1 and clr-2) that were required for growth and enzymatic activity on cellulose, but were not required for growth or hemicellulase activity on xylan. Transcriptional profiling with next-generation sequencing methods refined our understanding of the N. crassa transcriptional response to cellulose and demonstrated that clr-1 and clr-2 were required for the bulk of that response, including induction of all major cellulase and some major hemicellulase genes. Functional CLR-1 was necessary for expression of clr-2 and efficient cellobiose utilization. Phylogenetic analyses showed that CLR-1 and CLR-2 are conserved in the genomes of most filamentous ascomycete fungi capable of degrading cellulose. In Aspergillus nidulans, a strain carrying a deletion of the clr-2 homolog (clrB) failed to induce cellulase gene expression and lacked cellulolytic activity on Avicel. Further manipulation of this control system in industrial production strains may significantly improve yields of cellulases for cellulosic biofuel production.

Coradetti, Samuel T.; Craig, James P.; Xiong, Yi; Shock, Teresa; Tian, Chaoguang; Glass, N. Louise

2012-01-01

211

Interactions of sterile-cultured lichen-forming ascomycetes with asbestos fibres.  

PubMed

Sterile cultured isolates of lichen-forming ascomycetes have not yet been used to investigate mycobiont-mineral substrate interactions under controlled conditions. In this study Candelariella vitellina, Xanthoparmelia tinctina and Lecanora rupicola mycobionts were isolated and inoculated with chrysotile fibres in the laboratory, in order to verify whether physical and chemical weathering processes, which were already described in the field, may be reproduced in vitro. Tight adhesion of hyphae to chrysotile fibres was observed in all species. The adhering hyphae affected the chemical composition of asbestos fibres, with the selective depletion of magnesium being a prominent feature, as is the case in field conditions. Oxalic acid and pulvinic acid, mycobiont-derived metabolites of X. tinctina and C. vitellina, were involved in the weathering action. Time and environmental factors and the absence of biological synergisms strongly limited the chemical weathering in vitro compared with what was observed in the field. Nevertheless, the results show that in vitro incubation of sterile-cultured lichen-forming fungi with minerals is a practicable experimental system to investigate the weathering effects of different mycobionts and fungal compounds under controlled conditions. PMID:17512715

Favero-Longo, Sergio Enrico; Girlanda, Mariangela; Honegger, Rosmarie; Fubini, Bice; Piervittori, Rosanna

2007-01-26

212

A putative mitochondrial fission gene from the ectomycorrhizal ascomycete Tuber borchii Vittad.: cloning, characterisation and phylogeny.  

PubMed

Mitochondrial binary division is a complex process occurring in multiple steps, mediated by several proteins. In Saccharomyces cerevisiae, a mitochondrial membrane protein, Fis1p, is required for the proper assembly of the mitochondrial division apparatus. In this study, we report the cloning, characterisation and phylogenetic analysis of Tbfis1, a gene from the ectomycorrhizal ascomycetous truffle Tuber borchii, encoding for an orthologue of S. cerevisiae Fis1p. The Tbfis1 coding region consists of a 468-nucleotide open reading frame interrupted by four introns, which encodes for a polypeptide of 155 amino acids, having a predicted transmembrane domain structure typical of the Fis1p Family. Southern blot analysis revealed that Tbfis1 is a single-copy gene in the T. borchii genome. Tbfis1 is highly expressed during the first stages of T. borchii fruit body ripening, while its expression decreases during T. borchii mycelium ageing. Also, Virtual Northern blot analysis revealed Tbfis1 expression in the symbiotic phase of the fungus life cycle. Phylogenetic analysis allowed the identification of Tbfis1 orthologues in filamentous fungi, yeasts, plants, worms, flies and mammals, indicating that the function of the protein coded by this gene has been conserved during evolution. PMID:12910371

Guidi, C; Zeppa, S; Barbieri, E; Zambonelli, A; Polidori, E; Potenza, L; Stocchi, V

2003-08-09

213

Specific, non-nutritional association between an ascomycete fungus and Allomerus plant-ants.  

PubMed

Ant-fungus associations are well known from attine ants, whose nutrition is based on a symbiosis with basidiomycete fungi. Otherwise, only a few non-nutritional ant-fungus associations have been recorded to date. Here we focus on one of these associations involving Allomerus plant-ants that build galleried structures on their myrmecophytic hosts in order to ambush prey. We show that this association is not opportunistic because the ants select from a monophyletic group of closely related fungal haplotypes of an ascomycete species from the order Chaetothyriales that consistently grows on and has been isolated from the galleries. Both the ants' behaviour and an analysis of the genetic population structure of the ants and the fungus argue for host specificity in this interaction. The ants' behaviour reveals a major investment in manipulating, growing and cleaning the fungus. A molecular analysis of the fungus demonstrates the widespread occurrence of one haplotype and many other haplotypes with a lower occurrence, as well as significant variation in the presence of these fungal haplotypes between areas and ant species. Altogether, these results suggest that such an interaction might represent an as-yet undescribed type of specific association between ants and fungus in which the ants cultivate fungal mycelia to strengthen their hunting galleries. PMID:21084334

Ruiz-González, Mario X; Malé, Pierre-Jean G; Leroy, Céline; Dejean, Alain; Gryta, Hervé; Jargeat, Patricia; Quilichini, Angélique; Orivel, Jérôme

2010-11-17

214

Efficient Cloning of Ascomycete Mating Type Genes by PCR Amplification of the Conserved MAT HMG Box  

PubMed

Cloning of mating type (MAT) genes from ascomycetes has been hampered by low conservation among them. One of the pair of MAT genes, represented by MAT-2 of Cochliobolus heterostrophus (a loculoascomycete) and mt a of Neurospora crassa (a pyrenomycete), encodes a protein with a conserved DNA binding motif called the high mobility group (HMG) box. PCR with primer pairs corresponding to the borders of the C. heterostrophus and the N. crassa HMG boxes generated an approximately 0.3-kb product from genomic DNAs of MAT-2 and mt a strains, respectively, but not from MAT-1 and mt A strains. The C. heterostrophus primers amplified approximately 0.3-kb products from DNA of most loculoascomycete genera tested but not from DNA of pyrenomycete genera; this specificity was reversed with the N. crassa primers. The validity of the PCR procedure was documented by near sequence identity between the C. heterostrophus MAT-2 HMG box and PCR products from several Cochliobolus spp. and by cosegregation of the PCR product with mating type in progeny of Setosphaeria turcica and of Cryphonectria parasitica. Regions of the MAT locus flanking the HMG box were readily cloned using the TAIL-PCR procedure with a combination of random and specific primers. PMID:9073486

Christiansen; Yoder; Turgeon

1997-02-01

215

Efficient cloning of ascomycete mating type genes by PCR amplification of the conserved MAT HMG Box.  

PubMed

Cloning of mating type (MAT) genes from ascomycetes has been hampered by low conservation among them. One of the pair of MAT genes, represented by MAT-2 of Cochliobolus heterostrophus (a loculoascomycete) and mt a of Neurospora crassa (a pyrenomycete), encodes a protein with a conserved DNA binding motif called the high mobility group (HMG) box. PCR with primer pairs corresponding to the borders of the C. heterostrophus and the N. crassa HMG boxes generated an approximately 0.3-kb product from genomic DNAs of MAT-2 and mt a strains, respectively, but not from MAT-1 and mt A strains. The C. heterostrophus primers amplified approximately 0.3-kb products from DNA of most loculoascomycete genera tested but not from DNA of pyrenomycete genera; this specificity was reversed with the N. crassa primers. The validity of the PCR procedure was documented by near sequence identity between the C. heterostrophus MAT-2 HMG box and PCR products from several Cochliobolus spp. and by cosegregation of the PCR product with mating type in progeny of Setosphaeria turcica and of Cryphonectria parasitica. Regions of the MAT locus flanking the HMG box were readily cloned using the TAIL-PCR procedure with a combination of random and specific primers. PMID:9126621

Arie, T; Christiansen, S K; Yoder, O C; Turgeon, B G

1997-02-01

216

Molecular Genetics of Mating Recognition in Basidiomycete Fungi  

PubMed Central

The recognition of compatible mating partners in the basidiomycete fungi requires the coordinated activities of two gene complexes defined as the mating-type genes. One complex encodes members of the homeobox family of transcription factors, which heterodimerize on mating to generate an active transcription regulator. The other complex encodes peptide pheromones and 7-transmembrane receptors that permit intercellular signalling. Remarkably, a single species may have many thousands of cross-compatible mating types because the mating-type genes are multiallelic. Different alleles of both sets of genes are necessary for mating compatibility, and they trigger the initial stages of sexual development—the formation of a specialized filamentous mycelium termed the dikaryon, in which the haploid nuclei remain closely associated in each cell but do not fuse. Three species have been taken as models to describe the molecular structure and organization of the mating-type loci and the genes sequestered within them: the pathogenic smut fungus Ustilago maydis and the mushrooms Coprinus cinereus and Schizophyllum commune. Topics addressed in this review are the roles of the mating-type gene products in regulating sexual development, the molecular basis for multiple mating types, and the molecular interactions that permit different allelic products of the mating type genes to be discriminated. Attention is drawn to the remarkable conservation in the mechanisms that regulate sexual development in basidiomycetes and unicellular ascomycete yeasts, Saccharomyces cerevisiae and Schizosaccharomyces pombe, a theme which is developed in the general conclusion to include the filamentous ascomycetes Neurospora crassa and Podospora anserina.

Casselton, Lorna A.; Olesnicky, Natalie S.

1998-01-01

217

Ascomycete communities in the rhizosphere of field-grown wheat are not affected by introductions of genetically modified Pseudomonas putida WCS358r.  

PubMed

A long-term field experiment (1999-2002) was conducted to monitor effects on the indigenous microflora of Pseudomonas putida WCS358r and two transgenic derivatives constitutively producing phenazine-1-carboxylic acid (PCA) or 2,4-diacetylphloroglucinol (DAPG). The strains were introduced as seed coating on wheat into the same field plots each year. Rhizosphere populations of ascomycetes were analysed using denaturing gradient gel electrophoresis (DGGE). To evaluate the significance of changes caused by the genetically modified microorganisms (GMMs), they were compared with effects caused by a crop rotation from wheat to potato. In the first year, only the combination of both GMMs caused a significant shift in the ascomycete community. After the repeated introductions this effect was no longer evident. However, cropping potato significantly affected the ascomycete community. This effect persisted into the next year when wheat was grown. Clone libraries were constructed from samples taken in 1999 and 2000, and sequence analysis indicated ascomycetes of common genera to be present. Most species occurred in low frequencies, distributed almost evenly in all treatments. However, in 1999 Microdochium occurred in relatively high frequencies, whereas in the following year no Microdochium species were detected. On the other hand, Fusarium-like organisms were low in 1999, and increased in 2000. Both the DGGE and the sequence analysis revealed that repeated introduction of P. putida WCS358r had no major effects on the ascomycete community in the wheat rhizosphere, but demonstrated a persistent difference between the rhizospheres of potato and wheat. PMID:16232292

Viebahn, Mareike; Doornbos, Rogier; Wernars, Karel; van Loon, Leendert C; Smit, Eric; Bakker, Peter A H M

2005-11-01

218

Mn(II) Oxidation by an Ascomycete Fungus is Linked to Superoxide Production During Asexual Reproduction  

SciTech Connect

Manganese (Mn) oxides are among the most reactive minerals within the environment, where they control the bioavailability of carbon, nutrients, and numerous metals. Although the ability of microorganisms to oxidize Mn(II) to Mn(III/IV) oxides is scattered throughout the bacterial and fungal domains of life, the mechanism and physiological basis for Mn(II) oxidation remains an enigma. Here, we use a combination of compound-speci?c chemical assays, microspectroscopy, and electron microscopy to show that a common Ascomycete ?lamentous fungus, Stilbella aciculosa, oxidizes Mn(II) to Mn oxides by producing extracellular superoxide during cell differentiation. The reactive Mn oxide phase birnessite and the reactive oxygen species superoxide and hydrogen peroxide are colocalized at the base of asexual reproductive structures. Mn oxide formation is not observed in the presence of superoxide scavengers (e.g., Cu) and inhibitors of NADPH oxidases (e.g., diphenylene iodonium chloride), enzymes responsible for superoxide production and cell differentiation in fungi. Considering the recent identi?cation of Mn(II) oxidation by NADH oxidase-based superoxide production by a common marine bacterium (Roseobacter sp.), these results introduce a surprising homology between some prokaryotic and eukaryotic organisms in the mechanisms responsible for Mn(II) oxidation, where oxidation appears to be a side reaction of extracellular superoxide production. Given the versatility of superoxide as a redox reactant and the widespread ability of fungi to produce superoxide, this microbial extracellular superoxide production may play a central role in the cycling and bioavailability of metals (e.g., Hg, Fe, Mn) and carbon in natural systems.

Hansel, Colleen M.; Zeiner, Carolyn A.; Santelli, Cara M.; Webb, Samuel M.

2012-07-16

219

Functional properties and differential mode of regulation of the nitrate transporter from a plant symbiotic ascomycete  

PubMed Central

Nitrogen assimilation by plant symbiotic fungi plays a central role in the mutualistic interaction established by these organisms, as well as in nitrogen flux in a variety of soils. In the present study, we report on the functional properties, structural organization and distinctive mode of regulation of TbNrt2 (Tuber borchii NRT2 family transporter), the nitrate transporter of the mycorrhizal ascomycete T. borchii. As revealed by experiments conducted in a nitrate-uptake-defective mutant of the yeast Hansenula polymorpha, TbNrt2 is a high-affinity transporter (Km=4.7 ?M nitrate) that is bispecific for nitrate and nitrite. It is expressed in free-living mycelia and in mycorrhizae, where it preferentially accumulates in the plasma membrane of root-contacting hyphae. The TbNrt2 mRNA, which is transcribed from a single-copy gene clustered with the nitrate reductase gene in the T. borchii genome, was specifically up-regulated following transfer of mycelia to nitrate- (or nitrite)-containing medium. However, at variance with the strict nitrate-dependent induction commonly observed in other organisms, TbNrt2 was also up-regulated (at both the mRNA and the protein level) following transfer to a nitrogen-free medium. This unusual mode of regulation differs from that of the adjacent nitrate reductase gene, which was expressed at basal levels under nitrogen deprivation conditions and required nitrate for induction. The functional and expression properties, described in the present study, delineate TbNrt2 as a versatile transporter that may be especially suited to cope with the fluctuating (and often low) mineral nitrogen concentrations found in most natural, especially forest, soils.

Montanini, Barbara; Viscomi, Arturo R.; Bolchi, Angelo; Martin, Yuse; Siverio, Jose M.; Balestrini, Raffaella; Bonfante, Paola; Ottonello, Simone

2005-01-01

220

Cryptosphaerolide: A Cytotoxic Mcl-1 Inhibitor from a Marine-Derived Ascomycete Related to the Genus Cryptosphaeria  

PubMed Central

Examination of the saline fermentation products from the marine-derived ascomycete fungal strain CNL-523 (Cryptosphaeria sp.), resulted in the isolation of cryptosphaerolide (1). The new compound is an ester-substituted sesquiterpenoid related to the eremophilane class. The structure of the new compound was assigned by spectroscopic and chemical methods. Cryptosphaerolide was found to be an inhibitor of the protein Mcl-1, a cancer drug target involved in apoptosis. It also showed significant cytotoxicity against an HCT-116 human colon carcinoma cell line indicating that the compound may be of value in exploring the Mcl-1 pathway as a target for cancer chemotherapy.

Oh, Hyuncheol; Jensen, Paul R.; Murphy, Brian T.; Fiorilla, Catherine; Sullivan, John F.; Ramsey, Timothy; Fenical, William

2010-01-01

221

Cryptosphaerolide, a cytotoxic Mcl-1 inhibitor from a marine-derived ascomycete related to the genus Cryptosphaeria.  

PubMed

Examination of the saline fermentation products from the marine-derived ascomycete fungal strain CNL-523 (Cryptosphaeria sp.) resulted in the isolation of cryptosphaerolide (1). The new compound is an ester-substituted sesquiterpenoid related to the eremophilane class. The structure of the new compound was assigned by spectroscopic and chemical methods. Cryptosphaerolide was found to be an inhibitor of the protein Mcl-1, a cancer drug target involved in apoptosis. It also showed significant cytotoxicity against an HCT-116 human colon carcinoma cell line, indicating that the compound may be of value in exploring the Mcl-1 pathway as a target for cancer chemotherapy. PMID:20462271

Oh, Hyuncheol; Jensen, Paul R; Murphy, Brian T; Fiorilla, Catherine; Sullivan, John F; Ramsey, Timothy; Fenical, William

2010-05-28

222

Candida tartarivorans sp. nov., an anamorphic ascomycetous yeast with the capacity to degrade L(+)- and meso-tartaric acid.  

PubMed

An undescribed anamorphic yeast species of ascomycetous affinity, for which the name Candida tartarivorans is proposed, was isolated from dried wine lees in Portugal using a selective medium with L(+)-tartaric acid as the sole source of carbon and energy. The single isolate (IGC 4854T) showed the following characteristics: sympodial holoblastic conidiogenesis, absence of asci with ascospores, a negative colour reaction with Diazonium Blue B, production of elaborate pseudomycelium and ability to grow with inositol as sole source of carbon. Analysis of the physiological data pointed to a close relationship with other inositol-assimilating taxa, namely the genera Arxula, Stephanoascus, Sympodiomyces, Zygoascus and selected Candida species. Comparative analysis of the D1/D2 variable domain of the 26S rRNA gene of all available sequences for ascomycetous yeasts showed that strain IGC 4854T did not match with any other species in the database. The closest relative was Candida auringiensis Santa Maria, but the two species differed in 24 nucleotide positions. A description of the new species is given. PMID:10826827

Fonseca, A; Fell, J W; Kurtzman, C P; Spencer-Martins, I

2000-01-01

223

Phylogenetic Relationships among Members of the Ascomycetous Yeast Genera Brettanomyces, Debaryomyces, Dekkera, and Kluyveromyces Deduced by Small-Subunit rRNA Gene Sequences  

Microsoft Academic Search

A molecular systematic investigation of members of the ascomycetous yeast genera Brettanomyces, Debaryo- myces, Dekkera, and Kluyveromyces was performed by using 18s rRNA gene sequence analysis. Our comparative sequence analysis revealed that Brettanomyces anomalus and Brettanomyces bruxellensis were closely related to one another and also to their teleomorphs, Dekkera anomala and Dekkera bruxellensis, respectively. Together with Dekkera custersiana and Dekkera

JUNPENG CAI; IAN N. ROBERTS; MATTHEW D. COLLINS

224

In Vitro Testing of Susceptibilities of Filamentous Ascomycetes to Voriconazole, Itraconazole, and Amphotericin B, with Consideration of Phylogenetic Implications  

PubMed Central

The in vitro susceptibilities of three hundred eighty-one isolates representing two classes, five orders, nine families, 30 genera, and 51 species of ascomycetous fungi to voriconazole, itraconazole, and amphotericin B were tested by using a modification of the National Committee for Clinical Laboratory Standards M27-A reference method. For those fungi of known phylogenetic relatedness, drug MICs were consistently low for isolates among all clades, except for members of the family Microascaceae. The highest MICs of all drugs tested were consistently for the Microascaceae, supporting the observation of fungal phylogeny and corresponding susceptibility to antifungal drugs. Itraconazole and voriconazole have a broad range of activity against phylogenetically similar agents of hyalohyphomycosis, phaeohyphomycosis, chromoblastomycosis, and mycetoma.

McGinnis, Michael R.; Pasarell, Lester

1998-01-01

225

Production of the Alkaloid Swainsonine by a Fungal Endosymbiont of the Ascomycete Order Chaetothyriales in the Host Ipomoea carnea.  

PubMed

Some plant species within the Convolvulaceae (morning glory family) from South America, Africa, and Australia cause a neurologic disease in grazing livestock caused by swainsonine. These convolvulaceous species including Ipomoea carnea contain the indolizidine alkaloid swainsonine, an inhibitor of ?-mannosidase and mannosidase II, and polyhydroxy nortropane alkaloids, the calystegines which are glycosidase inhibitors. Swainsonine has been shown to be produced by a fungal endosymbiont in legumes of the Astragalus and Oxytropis genera, where it causes a similar neurologic disease in grazing livestock called locoism. Here we demonstrate that I. carnea plants are infected with a fungal endosymbiont that was cultured from its seeds and which produced swainsonine in pure culture but not the calystegines. The same fungal endosymbiont was detected by PCR and by culturing in I. carnea plants containing swainsonine. The fungal endosymbiont belongs to the Ascomycete order Chaetothyriales. Plants derived from fungicide-treated seeds lacked swainsonine, but calystegine concentrations were unaltered. PMID:23547913

Cook, Daniel; Beaulieu, Wesley T; Mott, Ivan W; Riet-Correa, Franklin; Gardner, Dale R; Grum, Daniel; Pfister, James A; Clay, Keith; Marcolongo-Pereira, Clairton

2013-04-12

226

Molecular and ultrastructural characterization of two ascomycetes found on sunken wood off Vanuatu islands in the deep Pacific ocean.  

PubMed

A new genus of a deep-sea ascomycete with one new species, Alisea longicolla, is described based on analyses of 18S and 28S rDNA sequences and morphological characters. A. longicolla was found together with Oceanitis scuticella, on small twigs and sugar cane debris trawled from the bottom of the Pacific Ocean off Vanuatu Islands. Molecular and morphological characters indicate that both fungi are members of Halosphaeriaceae. Within this family, O. scuticella is phylogenetically related to Ascosalsum and shares similar ascospore morphology and appendage ontogeny. The genus Ascosalsum is considered congeneric with Oceanitis and Ascosalsum cincinnatulum, Ascosalsum unicaudatum and Ascosalsum viscidulum are transferred to Oceanitis, an earlier generic name. PMID:19737615

Dupont, Joëlle; Magnin, Sandrine; Rousseau, Florence; Zbinden, Magali; Frebourg, Ghislaine; Samadi, Sarah; de Forges, Bertrand Richer; Jones, E B Gareth

2009-09-06

227

Exploring laccase-like multicopper oxidase genes from the ascomycete Trichoderma reesei: a functional, phylogenetic and evolutionary study  

PubMed Central

Background The diversity and function of ligninolytic genes in soil-inhabiting ascomycetes has not yet been elucidated, despite their possible role in plant litter decay processes. Among ascomycetes, Trichoderma reesei is a model organism of cellulose and hemicellulose degradation, used for its unique secretion ability especially for cellulase production. T. reesei has only been reported as a cellulolytic and hemicellulolytic organism although genome annotation revealed 6 laccase-like multicopper oxidase (LMCO) genes. The purpose of this work was i) to validate the function of a candidate LMCO gene from T. reesei, and ii) to reconstruct LMCO phylogeny and perform evolutionary analysis testing for positive selection. Results After homologous overproduction of a candidate LMCO gene, extracellular laccase activity was detected when ABTS or SRG were used as substrates, and the recombinant protein was purified to homogeneity followed by biochemical characterization. The recombinant protein, called TrLAC1, has a molecular mass of 104 kDa. Optimal temperature and pH were respectively 40-45°C and 4, by using ABTS as substrate. TrLAC1 showed broad pH stability range of 3 to 7. Temperature stability revealed that TrLAC1 is not a thermostable enzyme, which was also confirmed by unfolding studies monitored by circular dichroism. Evolutionary studies were performed to shed light on the LMCO family, and the phylogenetic tree was reconstructed using maximum-likelihood method. LMCO and classical laccases were clearly divided into two distinct groups. Finally, Darwinian selection was tested, and the results showed that positive selection drove the evolution of sequences leading to well-known laccases involved in ligninolysis. Positively-selected sites were observed that could be used as targets for mutagenesis and functional studies between classical laccases and LMCO from T. reesei. Conclusions Homologous production and evolutionary studies of the first LMCO from the biomass-degrading fungus T. reesei gives new insights into the physicochemical parameters and biodiversity in this family.

2010-01-01

228

The nucleotide sequences of the 5 S rRNAs of seven molds and a yeast and their use in studying ascomycete phylogeny.  

PubMed Central

The sequences of the 5 S rRNAs isolated from 8 ascomycete species belonging to the genera Aspergillus, Penicillium, Acremonium and Candida are reported. Two of the examined strains each yielded a mixture of 3 slightly different 5 S RNAs, which were individually sequenced after fractionation. A previously published sequence for Aspergillus nidulans 5 S RNA was found to contain errors. Reconstruction of an evolutionary tree based on 5 S RNA sequences showed that the 16 presently examined ascomycetes form three clusters. The same threefold partition can be observed in the secondary structure pattern, each cluster showing a slightly different variant of the general 5-helix model for 5 S rRNA (De Wachter, Chen and Vandenberghe (1982) Biochimie 64, 311-329), and different sets of secondary structure equilibrium forms in helices C and E of the aforementioned model. Images

Chen, M W; Anne, J; Volckaert, G; Huysmans, E; Vandenberghe, A; De Wachter, R

1984-01-01

229

A new pullulan and a branched (1-->3)-, (1-->6)-linked beta-glucan from the lichenised ascomycete Teloschistes flavicans.  

PubMed

The polysaccharides formed on hot alkaline extraction of the ascomycetous lichen Teloschistes flavicans were fractionated to give two glucans, which were characterised by methylation analysis and 1D and 2D NMR spectroscopy. One was a branched beta-glucan containing (1-->3) and (1-->6) linkages, a structure which is more typical of basidiomycetes rather than ascomycetes, which have linear glucans. The other was an alpha-glucan with alternating (1-->4) and (1-->6) linkages, found for the first time in Nature. This structure can be classified as a pullulan, which has been isolated from the fungi Aureobasidium pullulans, Tremella mesenterica, and Cyttaria harioti, but has different ratios of the component glycosidic linkages. The significance of the presence of the isolated alpha- and beta-glucans is discussed. PMID:12023070

Reis, Rodrigo A; Tischer, Cesar A; Gorin, Philip A J; Iacomini, Marcello

2002-04-23

230

Infections with the ascomycete fungus Metschnikowia typographi sp.nov. in the bark beetles Ips typographus and Ips amitinus ( Coleoptera, Scolytidae )  

Microsoft Academic Search

The ascomycete fungusMetschnikowia typographi sp.nov. is described. It infects the spruce bark beetlesIps typographus L. andIps amitinus\\u000a Eichl. Masses of vegetative cells and navicular asci (I. typographus 13–17 × 2 µm;I. amitinus 17–22 × 2 µm) were found in cells of the midgut epithelium and in the body cavity of infected beetles. Each ascus contains\\u000a two needle-shaped ascospores flattened in

J. Weiser; R. Wegensteiner; U. Händel; Z. Žižka

2003-01-01

231

Degradation of some phenols and hydroxybenzoates by the imperfect ascomycetous yeasts Candida parapsilosis and Arxula adeninivorans : evidence for an operative gentisate pathway  

Microsoft Academic Search

The imperfect ascomycetous yeastsCandida parapsilosis andArxula adeninivorans degraded 3-hydroxybenzoic acid via gentisate which was the cleavage substrate. 4-Hydroxybenzoic acid was metabolized via protocatechuate. No cleavage enzyme for the latter was detected. In stead of this NADH- and NADPH-dependent monooxygenases were present. In cells grown at the expense of hydroquinone and 4-hydroxygenzoic acid, enzymes of the hydroxyhydroquinone variant of the 3-oxoadipate

Wouter J. Middelhoven; Alex Coenen; Bart Kraakman; Maarten D. Sollewijn Gelpke

1992-01-01

232

Phylogenetic analysis identifies the 'megabacterium' of birds as a novel anamorphic ascomycetous yeast, Macrorhabdus ornithogaster gen. nov., sp. nov.  

PubMed

An organism commonly referred to as 'megabacterium' colonizes the gastric isthmus of many species of birds. It is weakly gram-positive and periodic acid-Schiff-positive and stains with silver stains. Previous studies have shown that it has a nucleus and a cell wall similar to those seen in fungi. Calcofluor white M2R staining suggests that the cell wall contains chitin, a eukaryote-specific substance, and rRNA in situ hybridization demonstrates that it is a eukaryote. To characterize this organism phylogenetically, DNA was extracted from purified cells. rDNA was readily amplified by PCR with pan-fungal DNA primer sets and primer sets derived from the newly determined sequence, but not with bacteria-specific primer sets. Specific primer sets amplified rDNA from isthmus scrapings from an infected bird, but not from a non-infected bird or other control DNA. The sequence was confirmed to derive from the purified organism by in situ rRNA hybridization using a specific probe. Phylogenetic analysis of sequences of the 18S rDNA and domain D1/D2 of 26S rDNA showed the organism to be a previously undescribed anamorphic ascomycetous yeast representing a new genus. The name Macrorhabdus ornithogaster gen. nov., sp. nov. is proposed for this organism. The type material is CBS 9251T (= NRRL Y-27487T). PMID:12892150

Tomaszewski, Elizabeth K; Logan, Kathleen S; Snowden, Karen F; Kurtzman, Cletus P; Phalen, David N

2003-07-01

233

High-Coverage ITS Primers for the DNA-Based Identification of Ascomycetes and Basidiomycetes in Environmental Samples  

PubMed Central

The kingdom Fungi is estimated to include 1.5 million or more species, playing key roles as decomposers, mutualists, and parasites in every biome on the earth. To comprehensively understand the diversity and ecology of this huge kingdom, DNA barcoding targeting the internal transcribed spacer (ITS) region of the nuclear ribosomal repeat has been regarded as a prerequisite procedure. By extensively surveying ITS sequences in public databases, we designed new ITS primers with improved coverage across diverse taxonomic groups of fungi compared to existing primers. An in silico analysis based on public sequence databases indicated that the newly designed primers matched 99% of ascomycete and basidiomycete ITS taxa (species, subspecies or varieties), causing little taxonomic bias toward either fungal group. Two of the newly designed primers could inhibit the amplification of plant sequences and would enable the selective investigation of fungal communities in mycorrhizal associations, soil, and other types of environmental samples. Optimal PCR conditions for the primers were explored in an in vitro investigation. The new primers developed in this study will provide a basis for ecological studies on the diversity and community structures of fungi in the era of massive DNA sequencing.

Yamamoto, Satoshi; Sato, Hirotoshi

2012-01-01

234

Heterologous expression and biochemical characterization of novel pyranose 2-oxidases from the ascomycetes Aspergillus nidulans and Aspergillus oryzae.  

PubMed

A gene encoding a pyranose 2-oxidase (POx; pyranose/oxygen 2-oxidoreductase; glucose 2-oxidase; EC 1.1.3.10) was identified in the genome of the ascomycete Aspergillus nidulans. Attempts to isolate POx directly from A. nidulans cultures or to homologously overexpress the native POx (under control of the constitutive gpdA promoter) in A. nidulans were unsuccessful. cDNA encoding POx was synthesized from mRNA and expressed in Escherichia coli, and the enzyme was subsequently purified and characterized. A putative pyranose 2-oxidase-encoding gene was also identified in the genome of Aspergillus oryzae. The coding sequence was synthetically produced and was also expressed in E. coli. Both purified enzymes were shown to be flavoproteins consisting of subunits of 65 kDa. The A. nidulans enzyme was biochemically similar to POx reported in literature. From all substrates, the highest catalytic efficiency was found with D-glucose. In addition, the enzyme catalyzes the two-electron reduction of 1,4-benzoquinone, several substituted benzoquinones and 2,6-dichloroindophenol. As judged by the catalytic efficiencies (k (cat)/k(m)), some of these quinone electron acceptors are better substrates for pyranose oxidase than oxygen. The enzyme from A. oryzae was physically similar but showed lower kinetic constants compared to the enzyme from A. nidulans. Distinct differences in the stability of the two enzymes may be attributed to a deletion and an insertion in the sequence, respectively. PMID:21968652

Pisanelli, Ines; Wührer, Petra; Reyes-Dominguez, Yazmid; Spadiut, Oliver; Haltrich, Dietmar; Peterbauer, Clemens

2011-10-04

235

Removal of chlorophenolic derivatives by soil isolated ascomycete of Paraconiothyrium variabile and studying the role of its extracellular laccase.  

PubMed

The ability of Paraconiothyrium variabile, a laccase producing ascomycete recently isolated from soil, was studied to eliminate chlorophenol derivatives in submerged culture medium. Among the tested compounds, ?-chlorophenol (?-CP) and pentachlorophenol (PCP) were found to have minimum and maximum toxic effects, respectively, on the growth of the microorganism and at the same time high and low bioelimination percentages. The fungal strain was able to remove 86% of ?-CP (with initial concentration of 40 mg l(-1)) and 56% of 2,4-dichlorophenol (2,4-DCP; with same concentration as ?-CP) after 9 days of incubation while no elimination was observed in the presence of 2,4,6-trichlorophenol (2,4,6-TCP) and PCP. Monitoring of laccase production level in the fermentation broth together with pollutant removal confirmed the key role of this copper-containing oxidase in chlorophenol derivatives elimination. The type of laccase inducer (guaiacol) and its final concentration (250 ?M) and also initial pH of the fermentation broth (pH=5.5) in the elimination of ?-CP increased the final removal yield from 86% to 94.3%. PMID:22277342

Forootanfar, Hamid; Movahednia, Mohammad Mehdi; Yaghmaei, Soheila; Tabatabaei-Sameni, Minoosadat; Rastegar, Hossein; Sadighi, Armin; Faramarzi, Mohammad Ali

2012-01-11

236

Xylogone ganodermophthora sp. nov., an ascomycetous pathogen causing yellow rot on cultivated mushroom Ganoderma lucidum in Korea.  

PubMed

Yellow rot, caused by an ascomycetous fungus having a distinctive arthroconidial anamorph, is the most destructive disease of cultivated Ganoderma lucidum in Korea, but the identity of the yellow rot pathogen (YRP) remains uncertain. Isolates have been identified as Xylogone sphaerospora (with putative anamorph Sporendonema purpurascens) or as Arthrographis cuboidea. Therefore we used morphological features, pathogenicity tests and phylogenetic analyses of DNA sequences from the nuclear ribosomal genes, including partial small subunit and internal transcribed spacer regions, and from the gene encoding RNA polymerase second largest subunit to evaluate the relationship between YRP isolates and these species. YRP isolates formed a distinct subgroup within a clade that included X. sphaerospora, A. cuboidea and Scytalidium lignicola, the type species of Scytalidium, but the disposition of the clade within the Leotiomycetes was uncertain. We describe Xylogone ganodermophthora sp. nov. and Scytalidium ganodermophthorum sp. nov. for the teleomorph and anamorph of YRP respectively. Arthrographis cuboidea is reclassified as Scytalidium cuboideum comb. nov., and the anamorph of X. sphaerospora is named Scytalidium sphaerosporum sp. nov. In pathogenicity tests only X. ganodermophthora caused disease in Ganoderma lucidum. Amplified fragment length polymorphism analyses showed that X. ganodermophthora populations from diseased fruiting bodies or from oak wood in Korea consisted of two clonal groups. PMID:20943517

Kang, Hyo-Jung; Sigler, Lynne; Lee, Jungkwan; Gibas, Connie Fe C; Yun, Sung-Hwan; Lee, Yin-Won

237

Molecular evidence that the asexual industrial fungus Trichoderma reesei is a clonal derivative of the ascomycete Hypocrea jecorina.  

PubMed Central

The relationship of the important cellulase producing asexual fungus Trichoderma reesei to its putative teleomorphic (sexual) ancestor Hypocrea jecorina and other species of the Trichoderma sect. Longibrachiatum was studied by PCR-fingerprinting and sequence analyses of the nuclear ribosomal DNA region containing the internal transcribed spacers (ITS-1 and ITS-2) and the 5.8S rRNA gene. The differences in the corresponding ITS sequences allowed a grouping of anamorphic (asexual) species of Trichoderma sect. Longibrachiatum into Trichoderma longibrachiatum, Trichoderma pseudokoningii, and Trichoderma reesei. The sexual species Hypocrea schweinitzii and H. jecorina were also clearly separated from each other. H. jecorina and T. reesei exhibited identical sequences, suggesting close relatedness or even species identity. Intraspecific and interspecific variation in the PCR-fingerprinting patterns supported the differentiation of species based on ITS sequences, the grouping of the strains, and the assignment of these strains to individual species. The variations between T. reesei and H. jecorina were at the same order of magnitude as found between all strains of H. jecorina, but much lower than the observed interspecific variations. Identical ITS sequences and the high similarity of PCR-fingerprinting patterns indicate a very close relationship between T. reesei and H. jecorina, whereas differences of the ITS sequences and the PCR-fingerprinting patterns show a clear phylogenetic distance between T. reesei/H. jecorina and T. longibrachiatum. T. reesei is considered to be an asexual, clonal line derived from a population of the tropical ascomycete H. jecorina. Images Fig. 2

Kuhls, K; Lieckfeldt, E; Samuels, G J; Kovacs, W; Meyer, W; Petrini, O; Gams, W; Borner, T; Kubicek, C P

1996-01-01

238

Crystal structure of an ascomycete fungal laccase from Thielavia arenaria--common structural features of asco-laccases.  

PubMed

Laccases are copper-containing enzymes used in various applications, such as textile bleaching. Several crystal structures of laccases from fungi and bacteria are available, but ascomycete types of fungal laccases (asco-laccases) have been rather unexplored, and to date only the crystal structure of Melanocarpus albomyces laccase (MaL) has been published. We have now solved the crystal structure of another asco-laccase, from Thielavia arenaria (TaLcc1), at 2.5 Å resolution. The loops near the T1 copper, forming the substrate-binding pockets of the two asco-laccases, differ to some extent, and include the amino acid thought to be responsible for catalytic proton transfer, which is Asp in TaLcc1, and Glu in MaL. In addition, the crystal structure of TaLcc1 does not have a chloride attached to the T2 copper, as observed in the crystal structure of MaL. The unique feature of TaLcc1 and MaL as compared with other laccases structures is that, in both structures, the processed C-terminus blocks the T3 solvent channel leading towards the trinuclear centre, suggesting a common functional role for this conserved 'C-terminal plug'. We propose that the asco-laccases utilize the C-terminal carboxylic group in proton transfer processes, as has been suggested for Glu498 in the CotA laccase from Bacillus subtilis. The crystal structure of TaLcc1 also shows the formation of a similar weak homodimer, as observed for MaL, that may determine the properties of these asco-laccases at high protein concentrations. PMID:21535408

Kallio, Juha P; Gasparetti, Chiara; Andberg, Martina; Boer, Harry; Koivula, Anu; Kruus, Kristiina; Rouvinen, Juha; Hakulinen, Nina

2011-05-25

239

Large-Scale Introgression Shapes the Evolution of the Mating-Type Chromosomes of the Filamentous Ascomycete Neurospora tetrasperma  

PubMed Central

The significance of introgression as an evolutionary force shaping natural populations is well established, especially in animal and plant systems. However, the abundance and size of introgression tracts, and to what degree interspecific gene flow is the result of adaptive processes, are largely unknown. In this study, we present medium coverage genomic data from species of the filamentous ascomycete Neurospora, and we use comparative genomics to investigate the introgression landscape at the genomic level in this model genus. We revealed one large introgression tract in each of the three investigated phylogenetic lineages of Neurospora tetrasperma (sizes of 5.6 Mbp, 5.2 Mbp, and 4.1 Mbp, respectively). The tract is located on the chromosome containing the locus conferring sexual identity, the mating-type (mat) chromosome. The region of introgression is confined to the region of suppressed recombination and is found on one of the two mat chromosomes (mat a). We used Bayesian concordance analyses to exclude incomplete lineage sorting as the cause for the observed pattern, and multilocus genealogies from additional species of Neurospora show that the introgression likely originates from two closely related, freely recombining, heterothallic species (N. hispaniola and N. crassa/N. perkinsii). Finally, we investigated patterns of molecular evolution of the mat chromosome in Neurospora, and we show that introgression is correlated with reduced level of molecular degeneration, consistent with a shorter time of recombination suppression. The chromosome specific (mat) and allele specific (mat a) introgression reported herein comprise the largest introgression tracts reported to date from natural populations. Furthermore, our data contradicts theoretical predictions that introgression should be less likely on sex-determining chromosomes. Taken together, the data presented herein advance our general understanding of introgression as a force shaping eukaryotic genomes.

Menkis, Audrius; Whittle, Carrie A.; Andersson, Siv G. E.; Johannesson, Hanna

2012-01-01

240

Degradation of some phenols and hydroxybenzoates by the imperfect ascomycetous yeasts Candida parapsilosis and Arxula adeninivorans: evidence for an operative gentisate pathway.  

PubMed

The imperfect ascomycetous yeasts Candida parapsilosis and Arxula adeninivorans degraded 3-hydroxybenzoic acid via gentisate which was the cleavage substrate. 4-Hydroxybenzoic acid was metabolized via protocatechuate. No cleavage enzyme for the latter was detected. In stead of this NADH- and NADPH-dependent monooxygenases were present. In cells grown at the expense of hydroquinone and 4-hydroxybenzoic acid, enzymes of the hydroxyhydroquinone variant of the 3-oxoadipate pathway were demonstrated, which also took part in the degradation of 2,4-dihydroxybenzoic acid by C. parapsilosis. PMID:1416914

Middelhoven, W J; Coenen, A; Kraakman, B; Sollewijn Gelpke, M D

1992-10-01

241

Purifying Selection and Birth-and-Death Evolution in the Class II Hydrophobin Gene Families of the Ascomycete Trichoderma/Hypocrea  

SciTech Connect

Hydrophobins are proteins containing eight conserved cysteine residues that occur uniquely in mycelial fungi, where their main function is to confer hydrophobicity to fungal surfaces in contact with air and during attachment of hyphae to hydrophobic surfaces of hosts, symbiotic partners or of themselves resulting in morphogenetic signals. Based on their hydropathy patterns and their solubility characteristics, they are classified in class I and class II hydrophobins, the latter being found only in ascomycetes. Here we have investigated the mechanisms driving the evolution of the class II hydrophobins in nine species of the mycoparasitic ascomycetous genus Trichoderma/Hypocrea, using three fully sequenced genomes (H. jecorina=T. reesei, H. atroviridis=T. atroviride; H. virens=T. virens) and a total of 14.000 ESTs of six others (T. asperellum, H. lixii=T. harzianum, T. aggressivum var. europeae, T. longibrachiatum, T. cf. viride). The former three contained six, ten and nine members, which is the highest number found in any other ascomycete so far. They all showed the conserved four beta-strands/one helix structure, which is stabilized by four disulfide bonds. In addition, a small number of these HFBs contained an extended N-terminus rich in either praline and aspartate, or glycine-asparagine. Phylogenetic analysis reveals a mosaic of terminal clades contain duplicated genes and shows only three reasonably supported clades. Calculation of the ratio of differences in synonymous vs. non-synonymous nucleotide substitutions provides evidence for strong purifying selection (KS/Ka >> 1). A genome database search for class II HFBs from other ascomycetes retrieved a much smaller number of hydrophobins (2-4) from each species, and most of them were from Pyrenomycetes. A combined phylogeny of these sequences with those of Trichoderma showed that the Trichoderma HFBs mostly formed their own clades, whereas those of other pyrenomycetes occured in shared clades. Our study shows that the genus Trichoderma/Hypocrea has a proliferated arsenal of class II hydrophobins which arose by purifying selection and birth-and-death evolution.

kubicek, Christian P.; Baker, Scott E.; Gamauf, Christian; Kenerley, Chuck; Druzhinina, Irina S.

2008-01-10

242

Functional Characterization of MAT1-1-Specific Mating-Type Genes in the Homothallic Ascomycete Sordaria macrospora Provides New Insights into Essential and Nonessential Sexual Regulators?†  

PubMed Central

Mating-type genes in fungi encode regulators of mating and sexual development. Heterothallic ascomycete species require different sets of mating-type genes to control nonself-recognition and mating of compatible partners of different mating types. Homothallic (self-fertile) species also carry mating-type genes in their genome that are essential for sexual development. To analyze the molecular basis of homothallism and the role of mating-type genes during fruiting-body development, we deleted each of the three genes, SmtA-1 (MAT1-1-1), SmtA-2 (MAT1-1-2), and SmtA-3 (MAT1-1-3), contained in the MAT1-1 part of the mating-type locus of the homothallic ascomycete species Sordaria macrospora. Phenotypic analysis of deletion mutants revealed that the PPF domain protein-encoding gene SmtA-2 is essential for sexual reproduction, whereas the ? domain protein-encoding genes SmtA-1 and SmtA-3 play no role in fruiting-body development. By means of cross-species microarray analysis using Neurospora crassa oligonucleotide microarrays hybridized with S. macrospora targets and quantitative real-time PCR, we identified genes expressed under the control of SmtA-1 and SmtA-2. Both genes are involved in the regulation of gene expression, including that of pheromone genes.

Klix, V.; Nowrousian, M.; Ringelberg, C.; Loros, J. J.; Dunlap, J. C.; Poggeler, S.

2010-01-01

243

Characterization of mycobionts of photomorph pairs in the peltigerineae (lichenized ascomycetes) based on internal transcribed spacer sequences of the nuclear ribosomal DNA.  

PubMed

The "one fungus-two photomorphs" hypothesis suggests that certain lichenized fungi can establish a symbiotic relationship with either a eukaryotic or a prokaryotic photobiont. Such pairs of photomorphs are well know from cephalodiate Peltigerineae. Using an ascomycete-specific primer we amplified the internal transcribed spacer region of the nrDNA repeat of the mycobiont from total "lichen DNA" extracts of Peltigera malacea, photomorphs of P. aphthosa, P. britannica, and P. leucophlebia, Nephroma expallidum, and photomorphs of N. arcticum. Comparisons of 5.8S sequences suggest that the sequences obtained belong to the mycobiont and thus, that the ascomycete-specific primer is adequate for amplifying fungal DNA from total lichen-DNA extracts. The strict identity of nucleotide sequences of the internal transcribed spacer region of the nrDNA repeat between joined-photomorphs supports the one fungus-two photomorphs hypothesis. Photomorph may thus primarily reflect phenotypic plasticity of photomorphic fungi in response to changing environmental conditions. The cyanomorph recently reported for P. leucophlebia is shown to be based on a misidentified specimen of P. aphthosa. Comparisons of the ITS sequences further supports recognizing P. aphthosa, P. britannica, and P. leucophlebia at the species rather than the infraspecific level. PMID:9228791

Goffinet, B; Bayer, R J

1997-04-01

244

Phylogenetic relationships among members of the ascomycetous yeast genera Brettanomyces, Debaryomyces, Dekkera, and Kluyveromyces deduced by small-subunit rRNA gene sequences.  

PubMed

A molecular systematic investigation of members of the ascomycetous yeast genera Brettanomyces, Debaryomyces, Dekkera, and Kluyveromyces was performed by using 18S rRNA gene sequence analysis. Our comparative sequence analysis revealed that Brettanomyces anomalus and Brettanomyces bruxellensis were closely related to one another and also to their teleomorphs, Dekkera anomala and Dekkera bruxellensis, respectively. Together with Dekkera custersiana and Dekkera naardenensis, these four species formed a stable and distinct phylogenetic group. The three representative species of the genus Debaryomyces examined (viz., Debaryomyces castellii, Debaryomyces hansenii, and Debaryomyces udenii) were found to be genealogically highly related to each other and exhibited a specific phylogenetic affinity (level of sequence similarity, approximately 99.2%) with Candida guilliermondii (teleomorph, Pichia guilliermondii). Debaryomyces species and C. guilliermondii formed a distinct phylogenetic group, which displayed a significant association with a phylogenetically coherent cluster encompassing Lodderomyces elongisporus, Candida albicans, and four other Candida species. In contrast to the situation with the genera Brettanomyces and Debaryomyces, the genus Kluyveromyces displayed very marked phylogenetic heterogeneity. Kluyveromyces polysporus, the type species of the genus Kluyveromyces, and six other Kluyveromyces species (viz., Kluyveromyces africanus, Kluyveromyces delphensis, Kluyveromyces lodderae, Kluyveromyces thermotolerans, Kluyveromyces waltii, and Kluyveromyces yarrowii) were phylogenetically intermixed with species of the genera Zygosaccharomyces, Saccharomyces, and Torulaspora. In contrast, Kluyveromyces aestuarii, Kluyveromyces dobzhanskii, Kluyveromyces lactis, Kluyveromyces wickerhamii, and three Kluyveromyces marxianus varieties, along with their anamorph, Candida kefyr, formed a highly stable monophyletic group worthy of separate generic status. Kluyveromyces blattae and Kluyveromyces phaffii formed two distinct phylogenetic lines that did not exhibit particularly close affinity with each other or other ascomycetous yeast genera. Our phylogenetic findings are discussed in the context of the results of other genotypic and phenotypic studies. PMID:8934908

Cai, J; Roberts, I N; Collins, M D

1996-04-01

245

Crystal structure of the GalNAc/Gal-specific agglutinin from the phytopathogenic ascomycete Sclerotinia sclerotiorum reveals novel adaptation of a ?-trefoil domain  

PubMed Central

A lectin from the phytopathogenic ascomycete Sclerotina sclerotiorum that shares only weak sequence similarity with characterized fungal lectins has recently been identified. Sclerotina sclerotiorum agglutinin (SSA) is a homodimeric protein consisting of two identical subunits of ?17 kDa and displays specificity primarily towards Gal/GalNAc. Glycan array screening indicates that SSA readily interacts with Gal/GalNAc-bearing glycan chains. The crystal structures of SSA in the ligand-free form and in complex with the Gal-?1,3-GalNAc (T-antigen) disaccharide have been determined at 1.6 and 1.97 Å resolution, respectively. SSA adopts a ?-trefoil domain as previously identified for other carbohydrate-binding proteins of the ricin B-like lectin superfamily and accommodates terminal non-reducing galactosyl and N-acetylgalactosaminyl glycans. Unlike other structurally related lectins, SSA contains a single carbohydrate-binding site at site ?. SSA reveals a novel dimeric assembly markedly dissimilar to those described earlier for ricin-type lectins. The present structure exemplifies the adaptability of the ?-trefoil domain in the evolution of fungal lectins.

Sulzenbacher, Gerlind; Roig-Zamboni, Veronique; Peumans, Willy J.; Rouge, Pierre; Van Damme, Els J.M.; Bourne, Yves

2010-01-01

246

NPS6, Encoding a Nonribosomal Peptide Synthetase Involved in Siderophore-Mediated Iron Metabolism, Is a Conserved Virulence Determinant of Plant Pathogenic Ascomycetes[W  

PubMed Central

NPS6, encoding a nonribosomal peptide synthetase, is a virulence determinant in the maize (Zea mays) pathogen Cochliobolus heterostrophus and is involved in tolerance to H2O2. Deletion of NPS6 orthologs in the rice (Oryza sativa) pathogen, Cochliobolus miyabeanus, the wheat (Triticum aestivum) pathogen, Fusarium graminearum, and the Arabidopsis thaliana pathogen, Alternaria brassicicola, resulted in reduced virulence and hypersensitivity to H2O2. Introduction of the NPS6 ortholog from the saprobe Neurospora crassa to the ?nps6 strain of C. heterostrophus restored wild-type virulence to maize and tolerance to H2O2, demonstrating functional conservation in filamentous ascomycete phytopathogens and saprobes. Increased sensitivity to iron depletion was identified as a conserved phenotype of ?nps6 strains. Exogenous application of iron enhanced the virulence of ?nps6 strains of C. heterostrophus, C. miyabeanus, F. graminearum, and A. brassicicola to each host. NPS6 is responsible for the biosynthesis of extracellular siderophores by C. heterostrophus, F. graminearum, and A. brassicicola. Application of the extracellular siderophore of A. brassicicola restored wild-type virulence of the ?Abnps6 strain to Arabidopsis. It is proposed that the role of extracellular siderophores in fungal virulence to plants is to supply an essential nutrient, iron, to their producers in planta and not to act as phytotoxins, depriving their hosts of iron.

Oide, Shinichi; Moeder, Wolfgang; Krasnoff, Stuart; Gibson, Donna; Haas, Hubertus; Yoshioka, Keiko; Turgeon, B. Gillian

2006-01-01

247

Evolutionary relationships of vertebrate NACHT domain-containing proteins  

Microsoft Academic Search

Phylogenetic analyses of conserved [neuronal apoptosis inhibitory protein (NAIP), MHC class II transcription activator (CIITA), incompatibility locus protein from Podospora anserina (HET-E), and telomerase-associated protein (TP1)] (NACHT) domains were used to reconstruct the evolutionary history of vertebrate NACHT-containing proteins. The results supported the hypothesis that NOD3 is basal to the other NACHT-containing proteins found in tetrapods. The latter formed two

Austin L. Hughes

2006-01-01

248

Development of a genetic transformation system for Histoplasma capsulatum : Complementation of uracil auxotrophy  

Microsoft Academic Search

We have developed a simple and efficient transformation system for the dimorphic fungus Histoplasma capsulatum. Mutants of H. capsulatum defective in orotidine-5'-monophosphate pyrophosphorylase were transformed to prototrophy by the cloned URA5 gene of the filamentous fungus Podospora anserina. Abortive and mitotically stable transformants were obtained. The stable transformants had integrated copies of the plasmid, some in tandem head-to-tail orientation. Free

Patricia L. Worsham; William E. Goldman

1990-01-01

249

Accelerated Cell Death in Podospora Autophagy Mutants  

Microsoft Academic Search

Although autophagy is characteristic of type II programmed cell death (PCD), its role in cell death is currently debated. Both cell death-promoting and prosurvival roles of autophagy have been reported depending on the organism and the cell type. In filamentous fungi, a cell death reaction known as an incompatibility reaction occurs when cells of unlike genotype fuse. Cell death by

Berangere Pinan-Lucarre; Axelle Balguerie; Corinne Clave ´

2005-01-01

250

Horizontal transfer of a large and highly toxic secondary metabolic gene cluster between fungi.  

PubMed

Genes involved in intermediary and secondary metabolism in fungi are frequently physically linked or clustered. For example, in Aspergillus nidulans the entire pathway for the production of sterigmatocystin (ST), a highly toxic secondary metabolite and a precursor to the aflatoxins (AF), is located in a ?54 kb, 23 gene cluster. We discovered that a complete ST gene cluster in Podospora anserina was horizontally transferred from Aspergillus. Phylogenetic analysis shows that most Podospora cluster genes are adjacent to or nested within Aspergillus cluster genes, although the two genera belong to different taxonomic classes. Furthermore, the Podospora cluster is highly conserved in content, sequence, and microsynteny with the Aspergillus ST/AF clusters and its intergenic regions contain 14 putative binding sites for AflR, the transcription factor required for activation of the ST/AF biosynthetic genes. Examination of ?52,000 Podospora expressed sequence tags identified transcripts for 14 genes in the cluster, with several expressed at multiple life cycle stages. The presence of putative AflR-binding sites and the expression evidence for several cluster genes, coupled with the recent independent discovery of ST production in Podospora [1], suggest that this HGT event probably resulted in a functional cluster. Given the abundance of metabolic gene clusters in fungi, our finding that one of the largest known metabolic gene clusters moved intact between species suggests that such transfers might have significantly contributed to fungal metabolic diversity. PAPERFLICK: PMID:21194949

Slot, Jason C; Rokas, Antonis

2010-12-30

251

Growth and cultural-morphological characteristics of vegetative mycelia of medicinal caterpillar fungus Ophiocordyceps sinensis G.H. Sung et al. (Ascomycetes) isolates from Tibetan plateau (P.R.China).  

PubMed

The morphological and cultural characteristics of vegetative mycelia of 29 Tibetan strains of medicinal caterpillar fungus Ophiocordyceps sinensis (= Cordyceps sinensis) were studied. Data on mycelial growth of the above-mentioned fungi strains on different types of nutrients, the macro- and micromorphological description of colonies grown on different agar media, and anamorph stage identification are provided. It was shown that strains of O. sinensis demonstrated moderately slow growth on selected nutrients compared with other ascomycetous fungi. The highest growth rate value from all analyzed strains is O. sinenis N14-2.7 mm/day was completed with a mycelial run on potato-dextrose agar (pH = 6.0) in 15 d. Most of the examined strains preferred Sabouraun?s dextrose agar; some of the strains preferred potato-dextrose agar as the medium for optimal development. The least favorable nutrient for all strains was Czapek solution agar. Analyses of morphological and microstructural peculiarities on different types of nutrients were conducted and detailed descriptions and illustrations were provided. Based on macro- and micromorphological characteristics, the investigated strains were identified as Hirsutella sinensis and Tolypocladium sinensis species, which were identified as the anamorphs of Ophiocordyceps sinensis. PMID:22181845

Barseghyan, Gayane S; Holliday, John C; Price, Thomas C; Madison, Leah M; Wasser, Solomon P

2011-01-01

252

REVEALING UNDISCOVERED LINEAGES IN THE ASCOMYCETES  

Technology Transfer Automated Retrieval System (TEKTRAN)

With the increased use of molecular tools to determine biological diversity, ecologists are demonstrating the ubiquitous and diverse presence of fungi in terrestrial habitats. Two recent ecological studies using sequences to identify fungi present numerous fungal lineages that do not match any of ...

253

Localization of HET-S to the cell periphery, not to [Het-s] aggregates, is associated with [Het-s]-HET-S toxicity.  

PubMed

Prion diseases are associated with accumulation of the amyloid form of the prion protein, but the mechanisms of toxicity are unknown. Amyloid toxicity is also associated with fungal prions. In Podospora anserina, the simultaneous presence of [Het-s] prion and its allelic protein HET-S causes cell death in a self-/nonself-discrimination process. Here, using the prion form of a fragment of HET-s ([PrD(157)(+)]), we show that [Het-s]-HET-S toxicity can be faithfully recapitulated in yeast. Overexpression of Hsp40 chaperone, Sis1, rescues this toxicity by curing cells of [PrD(157)(+)]. We find no evidence for toxic [PrD(157)(+)] conformers in the presence of HET-S. Instead, [PrD(157)(+)] appears to seed HET-S to accumulate at the cell periphery and to form aggregates distinct from visible [PrD(157)(+)] aggregates. Furthermore, HET-S mutants that cause HET-S to be sequestered into [PrD(157)(+)] prion aggregates are not toxic. The localization of HET-S at the cell periphery and its association with cell death was also observed in the native host Podospora anserina. Thus, upon interaction with [Het-s], HET-S localizes to the cell periphery, and this relocalization, rather than the formation of mixed HET-s/HET-S aggregates, is associated with toxicity. PMID:22037764

Mathur, Vidhu; Seuring, Carolin; Riek, Roland; Saupe, Sven J; Liebman, Susan W

2011-10-28

254

Functional amyloidogenesis and cytotoxicity-insights into biology and pathology.  

PubMed

Prions are self-templating protein structures that can be transferred from organism to organism. The [Het-s] prion propagates as a functional amyloid aggregate in the filamentous fungi Podospora anserina, and is involved in mediating heterokaryon incompatibility. Fusion of a P. anserina strain harboring the [Het-s] prion with another strain expressing the soluble Het-S protein results in cell death. The mechanism of Het-s/Het-S-mediated cell death has now been revealed in a paper just published in PLOS Biology. The study shows that Het-s and Het-S C-terminal domain co-amyloidogenesis induces a profound conformational rearrangement in the N-terminal Het-S HeLo domain, resulting in the exposure of a nascent transmembrane helix. Oligomerization of these helices leads to pore formation, leakage of the cytosolic contents, and subsequent cell death. Thus, Het-s amyloid plays a major role in the life cycle of P. anserina by orchestrating a complex conformational change in the Het-S protein, resulting in cytotoxicity by compromising membrane integrity. This ability of Het-s functional amyloid to initiate programmed cytotoxicity by mediating a conformational change in another protein significantly expands the functional repertoire of amyloid. Moreover, the mechanism of Het-S cell killing may be similar to the mechanism by which some pathological amyloid proteins lead to the demise of post-mitotic tissue. PMID:23300381

Fowler, Douglas M; Kelly, Jeffery W

2012-12-27

255

Functional Amyloidogenesis and Cytotoxicity--Insights into Biology and Pathology  

PubMed Central

Prions are self-templating protein structures that can be transferred from organism to organism. The [Het-s] prion propagates as a functional amyloid aggregate in the filamentous fungi Podospora anserina, and is involved in mediating heterokaryon incompatibility. Fusion of a P. anserina strain harboring the [Het-s] prion with another strain expressing the soluble Het-S protein results in cell death. The mechanism of Het-s/Het-S-mediated cell death has now been revealed in a paper just published in PLOS Biology. The study shows that Het-s and Het-S C-terminal domain co-amyloidogenesis induces a profound conformational rearrangement in the N-terminal Het-S HeLo domain, resulting in the exposure of a nascent transmembrane helix. Oligomerization of these helices leads to pore formation, leakage of the cytosolic contents, and subsequent cell death. Thus, Het-s amyloid plays a major role in the life cycle of P. anserina by orchestrating a complex conformational change in the Het-S protein, resulting in cytotoxicity by compromising membrane integrity. This ability of Het-s functional amyloid to initiate programmed cytotoxicity by mediating a conformational change in another protein significantly expands the functional repertoire of amyloid. Moreover, the mechanism of Het-S cell killing may be similar to the mechanism by which some pathological amyloid proteins lead to the demise of post-mitotic tissue.

Fowler, Douglas M.; Kelly, Jeffery W.

2012-01-01

256

Human CLPP reverts the longevity phenotype of a fungal ClpP deletion strain  

PubMed Central

Mitochondrial maintenance crucially depends on the quality control of proteins by various chaperones, proteases and repair enzymes. While most of the involved components have been studied in some detail, little is known on the biological role of the CLPXP protease complex located in the mitochondrial matrix. Here we show that deletion of PaClpP, encoding the CLP protease proteolytic subunit CLPP, leads to an unexpected healthy phenotype and increased lifespan of the fungal ageing model organism Podospora anserina. This phenotype can be reverted by expression of human ClpP in the fungal deletion background, demonstrating functional conservation of human and fungal CLPP. Our results show that the biological role of eukaryotic CLP proteases can be studied in an experimentally accessible model organism.

Fischer, Fabian; Weil, Andrea; Hamann, Andrea; Osiewacz, Heinz D.

2013-01-01

257

Human CLPP reverts the longevity phenotype of a fungal ClpP deletion strain.  

PubMed

Mitochondrial maintenance crucially depends on the quality control of proteins by various chaperones, proteases and repair enzymes. While most of the involved components have been studied in some detail, little is known on the biological role of the CLPXP protease complex located in the mitochondrial matrix. Here we show that deletion of PaClpP, encoding the CLP protease proteolytic subunit CLPP, leads to an unexpected healthy phenotype and increased lifespan of the fungal ageing model organism Podospora anserina. This phenotype can be reverted by expression of human ClpP in the fungal deletion background, demonstrating functional conservation of human and fungal CLPP. Our results show that the biological role of eukaryotic CLP proteases can be studied in an experimentally accessible model organism. PMID:23360988

Fischer, Fabian; Weil, Andrea; Hamann, Andrea; Osiewacz, Heinz D

2013-01-01

258

Structural similarity between the prion domain of HET-s and a homologue can explain amyloid cross-seeding in spite of limited sequence identity.  

PubMed

We describe a distant homologue of the fungal HET-s prion, which is found in the fungus Fusarium graminearum. The domain FgHET-s(218-289), which corresponds to the prion domain in HET-s from Podospora anserina, forms amyloid fibrils in vitro and is able to efficiently cross-seed HET-s(218-289) prion formation. We structurally characterize FgHET-s(218-289), which displays 38% sequence identity with HET-s(218-289). Solid-state NMR and hydrogen/deuterium exchange detected by NMR show that the fold and a number of structural details are very similar for the prion domains of the two proteins. This structural similarity readily explains why cross-seeding occurs here in spite of the sequence divergence. PMID:20600104

Wasmer, Christian; Zimmer, Agnes; Sabaté, Raimon; Soragni, Alice; Saupe, Sven J; Ritter, Christiane; Meier, Beat H

2010-07-01

259

Age-dependent dissociation of ATP synthase dimers and loss of inner-membrane cristae in mitochondria.  

PubMed

Aging is one of the most fundamental, yet least understood biological processes that affect all forms of eukaryotic life. Mitochondria are intimately involved in aging, but the underlying molecular mechanisms are largely unknown. Electron cryotomography of whole mitochondria from the aging model organism Podospora anserina revealed profound age-dependent changes in membrane architecture. With increasing age, the typical cristae disappear and the inner membrane vesiculates. The ATP synthase dimers that form rows at the cristae tips dissociate into monomers in inner-membrane vesicles, and the membrane curvature at the ATP synthase inverts. Dissociation of the ATP synthase dimer may involve the peptidyl prolyl isomerase cyclophilin D. Finally, the outer membrane ruptures near large contact-site complexes, releasing apoptogens into the cytoplasm. Inner-membrane vesiculation and dissociation of ATP synthase dimers would impair the ability of mitochondria to supply the cell with sufficient ATP to maintain essential cellular functions. PMID:24006361

Daum, Bertram; Walter, Andreas; Horst, Angelika; Osiewacz, Heinz D; Kühlbrandt, Werner

2013-09-04

260

Age-dependent dissociation of ATP synthase dimers and loss of inner-membrane cristae in mitochondria  

PubMed Central

Aging is one of the most fundamental, yet least understood biological processes that affect all forms of eukaryotic life. Mitochondria are intimately involved in aging, but the underlying molecular mechanisms are largely unknown. Electron cryotomography of whole mitochondria from the aging model organism Podospora anserina revealed profound age-dependent changes in membrane architecture. With increasing age, the typical cristae disappear and the inner membrane vesiculates. The ATP synthase dimers that form rows at the cristae tips dissociate into monomers in inner-membrane vesicles, and the membrane curvature at the ATP synthase inverts. Dissociation of the ATP synthase dimer may involve the peptidyl prolyl isomerase cyclophilin D. Finally, the outer membrane ruptures near large contact-site complexes, releasing apoptogens into the cytoplasm. Inner-membrane vesiculation and dissociation of ATP synthase dimers would impair the ability of mitochondria to supply the cell with sufficient ATP to maintain essential cellular functions.

Daum, Bertram; Walter, Andreas; Horst, Angelika; Osiewacz, Heinz D.; Kuhlbrandt, Werner

2013-01-01

261

The natural history of yeast prions.  

PubMed

Although prions were first discovered through their link to severe brain degenerative diseases in animals, the emergence of prions as regulators of the phenotype of the yeast Saccharomyces cerevisiae and the filamentous fungus Podospora anserina has revealed a new facet of prion biology. In most cases, fungal prions are carried without apparent detriment to the host cell, representing a novel form of epigenetic inheritance. This raises the question of whether or not yeast prions are beneficial survival factors or actually gives rise to a "disease state" that is selected against in nature. To date, most studies on the impact of fungal prions have focused on laboratory-cultivated "domesticated" strains of S. cerevisiae. At least eight prions have now been described in this species, each with the potential to impact on a wide range of cellular processes. The discovery of prions in nondomesticated strains of S. cerevisiae and P. anserina has confirmed that prions are not simply an artifact of "domestication" of this species. In this review, I describe what we currently know about the phenotypic impact of fungal prions. I then describe how the interplay between host genotype and the prion-mediated changes can generate a wide array of phenotypic diversity. How such prion-generated diversity may be of benefit to the host in survival in a fluctuating, often hazardous environment is then outlined. Prion research has now entered a new phase in which we must now consider their biological function and evolutionary significance in the natural world. PMID:23763759

Tuite, Mick F

2013-01-01

262

Experimental Relocation of the Mitochondrial ATP9 Gene to the Nucleus Reveals Forces Underlying Mitochondrial Genome Evolution  

PubMed Central

Only a few genes remain in the mitochondrial genome retained by every eukaryotic organism that carry out essential functions and are implicated in severe diseases. Experimentally relocating these few genes to the nucleus therefore has both therapeutic and evolutionary implications. Numerous unproductive attempts have been made to do so, with a total of only 5 successes across all organisms. We have taken a novel approach to relocating mitochondrial genes that utilizes naturally nuclear versions from other organisms. We demonstrate this approach on subunit 9/c of ATP synthase, successfully relocating this gene for the first time in any organism by expressing the ATP9 genes from Podospora anserina in Saccharomyces cerevisiae. This study substantiates the role of protein structure in mitochondrial gene transfer: expression of chimeric constructs reveals that the P. anserina proteins can be correctly imported into mitochondria due to reduced hydrophobicity of the first transmembrane segment. Nuclear expression of ATP9, while permitting almost fully functional oxidative phosphorylation, perturbs many cellular properties, including cellular morphology, and activates the heat shock response. Altogether, our study establishes a novel strategy for allotopic expression of mitochondrial genes, demonstrates the complex adaptations required to relocate ATP9, and indicates a reason that this gene was only transferred to the nucleus during the evolution of multicellular organisms.

Sellem, Carole H.; Kucharczyk, Roza; Clauder-Munster, Sandra; Giraud, Marie-France; Godard, Francois; Salin, Benedicte; Sagot, Isabelle; Gagneur, Julien; Dequard-Chablat, Michelle; Contamine, Veronique; Denmat, Sylvie Hermann-Le; Sainsard-Chanet, Annie; Steinmetz, Lars M.; di Rago, Jean-Paul

2012-01-01

263

Discovery of novel inhibitors of amyloid ?-peptide 1-42 aggregation.  

PubMed

Alzheimer's disease, characterized by deposits of amyloid ?-peptide (A?), is the most common neurodegenerative disease, but it still lacks a specific treatment. We have discovered five chemically unrelated inhibitors of the in vitro aggregation of the A?17-40 peptide by screening two commercial chemical libraries. Four of them (1-4) exhibit relatively low MCCs toward HeLa cells (17-184 ?M). The usefulness of compounds 1-4 to inhibit the in vivo aggregation of A?1-42 has been demonstrated using two fungi models, Saccharomyces cerevisiae and Podospora anserina, previously transformed to express A?1-42. Estimated IC(50)s are around 1-2 ?M. Interestingly, addition of any of the four compounds to sonicated preformed P. anserina aggregates completely inhibited the appearance of SDS-resistant oligomers. This combination of HTP in vitro screening with validation in fungi models provides an efficient way to identify novel inhibitory compounds of A?1-42 aggregation for subsequent testing in animal models. PMID:23009151

López, Laura C; Dos-Reis, Suzana; Espargaró, Alba; Carrodeguas, José A; Maddelein, Marie-Lise; Ventura, Salvador; Sancho, Javier

2012-10-22

264

Experimental relocation of the mitochondrial ATP9 gene to the nucleus reveals forces underlying mitochondrial genome evolution.  

PubMed

Only a few genes remain in the mitochondrial genome retained by every eukaryotic organism that carry out essential functions and are implicated in severe diseases. Experimentally relocating these few genes to the nucleus therefore has both therapeutic and evolutionary implications. Numerous unproductive attempts have been made to do so, with a total of only 5 successes across all organisms. We have taken a novel approach to relocating mitochondrial genes that utilizes naturally nuclear versions from other organisms. We demonstrate this approach on subunit 9/c of ATP synthase, successfully relocating this gene for the first time in any organism by expressing the ATP9 genes from Podospora anserina in Saccharomyces cerevisiae. This study substantiates the role of protein structure in mitochondrial gene transfer: expression of chimeric constructs reveals that the P. anserina proteins can be correctly imported into mitochondria due to reduced hydrophobicity of the first transmembrane segment. Nuclear expression of ATP9, while permitting almost fully functional oxidative phosphorylation, perturbs many cellular properties, including cellular morphology, and activates the heat shock response. Altogether, our study establishes a novel strategy for allotopic expression of mitochondrial genes, demonstrates the complex adaptations required to relocate ATP9, and indicates a reason that this gene was only transferred to the nucleus during the evolution of multicellular organisms. PMID:22916027

Bietenhader, Maïlis; Martos, Alexandre; Tetaud, Emmanuel; Aiyar, Raeka S; Sellem, Carole H; Kucharczyk, Roza; Clauder-Münster, Sandra; Giraud, Marie-France; Godard, François; Salin, Bénédicte; Sagot, Isabelle; Gagneur, Julien; Déquard-Chablat, Michelle; Contamine, Véronique; Hermann-Le Denmat, Sylvie; Sainsard-Chanet, Annie; Steinmetz, Lars M; di Rago, Jean-Paul

2012-08-16

265

A mitochondrial mutator plasmid that causes senescence under dietary restricted conditions  

PubMed Central

Background Calorie or dietary restriction extends life span in a wide range of organisms including the filamentous fungus Podospora anserina. Under dietary restricted conditions, P. anserina isolates are several-fold longer lived. This is however not the case in isolates that carry one of the pAL2-1 homologous mitochondrial plasmids. Results We show that the pAL2-1 homologues act as 'insertional mutators' of the mitochondrial genome, which may explain their negative effect on life span extension. Sequencing revealed at least fourteen unique plasmid integration sites, of which twelve were located within the mitochondrial genome and two within copies of the plasmid itself. The plasmids were able to integrate in their entirety, via a non-homologous mode of recombination. Some of the integrated plasmid copies were truncated, which probably resulted from secondary, post-integrative, recombination processes. Integration sites were predominantly located within and surrounding the region containing the mitochondrial rDNA loci. Conclusion We propose a model for the mechanism of integration, based on innate modes of mtDNA recombination, and discuss its possible link with the plasmid's negative effect on dietary restriction mediated life span extension.

Maas, Marc FPM; Hoekstra, Rolf F; Debets, Alfons JM

2007-01-01

266

LIPIDS STIMULATE SPORE GERMINATION IN THE ENTOMOPATHOGENIC ASCOMYCETE ASCOSPHAERA AGGREGATA  

Technology Transfer Automated Retrieval System (TEKTRAN)

The alfalfa leafcutting bee (Megachile rotundata (Fabr.)) is a solitary bee that is managed on a large scale for pollination of alfalfa seed crops. The bees nest in holes drilled in wood or polystyrene blocks, and their larvae are highly prone to a fungal disease called chalkbrood. The most preval...

267

Ampullosine, a new isoquinoline alkaloid from Sepedonium ampullosporum (Ascomycetes).  

PubMed

A new isoquinoline alkaloid, ampullosine (3-methyl-isoquinoline-6-carboxylic acid, 1), was isolated from Sepedonium ampullosporum and characterized by spectroscopic analysis and chemical reactions. This compound is responsible for the deep yellow color of the culture fluid of this species. Moreover, the known compounds sepedonin (2) and anhydrosepedonin (3) were detected. Twelve strains belonging to eight species of Sepedonium have been screened for these three metabolites by LC/ESI-SRM (selected reaction monitoring). Ampullosine (1) could be detected in almost all species in Sepedonium, but not in the phylogenetically more distant species S. brunneum and S. tulasneanum. Anhydrosepedonin (3) showed antifungal activity against the phytopathogenic fungus Cladosporium cucumerinum. PMID:20614812

Quang, Dang Ngoc; Schmidt, Jürgen; Porzel, Andrea; Wessjohann, Ludger; Haid, Mark; Arnold, Norbert

2010-06-01

268

Oxylipins and ascospore morphology in the ascomycetous yeast genus Dipodascus  

Microsoft Academic Search

Immunofluorescence microscopy was used to assess members of the yeast genus Dipodascus for the presence of 3-hydroxy oxylipins. Fluorescence was associated with the aggregating ascospores in all species tested,\\u000a thus suggesting the association of 3-hydroxy oxylipins with these cells, especially the surrounding slime sheaths. An ultrastructural\\u000a study of the ascospores revealed sheaths with indentations, probably caused by the close packing

D. P. Smith; J. L. F. Kock; P. W. J. van Wyk; C. H. Pohl; E. van Heerden; P. J. Botes; S. Nigam

2003-01-01

269

Reinforced postmating reproductive isolation barriers in Neurospora, an Ascomycete microfungus.  

PubMed

Maladaptive hybridization promotes reinforcement, selection for stringent reproductive isolation barriers during speciation. Reinforcement is suspected when barriers between sympatric populations are stronger than allopatric barriers, and particularly when stronger barriers evolve in the species and sex suffering the greatest costs of hybridization. Canonically, reinforcement involves premating barriers. Selection for postmating barriers is controversial, but theoretically possible. We examined geographical patterns in reproductive isolation barriers between Neurospora crassa and Neurospora intermedia, fungi with pheromone-mediated mate recognition and maternal care. We find that isolation is stronger between sympatric populations than allopatric populations, and stronger barriers are associated with the species (N. crassa) and mating role (maternal) suffering the greater costs of hybridization. Notably, reinforced isolation involves a postmating barrier, abortion of fruitbodies. We hypothesize that fruitbody abortion is selectively advantageous if it increases the likelihood that maternal Neurospora individuals successfully mate conspecifically after maladaptive hybrid fertilization. PMID:20546092

Turner, E; Jacobson, D J; Taylor, J W

2010-06-07

270

Fatal cerebral mycoses caused by the ascomycete Chaetomium strumarium.  

PubMed Central

Three cases of fatal cerebral mycosis in males with prior histories of intravenous drug use from the United States and Australia are reported. Infection in each case was limited to brain abscess; no other sites of infection were observed. The fungus seen by histopathology and isolated from the brain tissue in each case was identified as Chaetomium strumarium. This is the first report of human infection by this species, and C. strumarium is the second species of Chaetomium known to cause primary brain infection. Chaetomium strumarium is unusual among members of the genus Chaetomium in forming ascocarps covered with pale, thin-walled, flexuous hairs, a feature leading to its original placement in the genus Achaetomium. Presence of pinkish exudate droplets and/or crystals associated with hyphae or ascocarps, sometimes accompanied by a pinkish diffusible pigment; good growth at 42 degrees C; and production of small conidia further distinguish this species. The brain abscess isolates were compared with isolates from prior cases of cerebral infection which had been identified as either Chaetomium atrobrunneum or Chaetomium globosum. With reidentification of one isolate originally identified as C. globosum to C. atrobrunneum, only C. strumarium and C. atrobrunneum have been confirmed to cause infection involving the brain.

Abbott, S P; Sigler, L; McAleer, R; McGough, D A; Rinaldi, M G; Mizell, G

1995-01-01

271

Molecular species of ceramides from the ascomycete truffle Tuber indicum  

Microsoft Academic Search

The ceramide fractions were isolated from the chloroform\\/methanolic extractable of the fruiting bodies of Tuber indicum and separated into three kinds of molecular species TI-1, TI-2, and TI-3 by normal and reverse phase silica gel-column chromatography. By means of 1H NMR and 13C NMR spectroscopy, fast atom bombardment mass spectrometry (FAB–MS), and chemical degradation experiment, their component sphingoid base for

Jin-Ming Gao; An-Ling Zhang; Hui Chen; Ji-Kai Liu

2004-01-01

272

THE MATING TYPE LOCUS, AN EXAMPLE OF SYNTENY AMONG ASCOMYCETES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Both mating type loci of Mycosphaerella graminicola were recently cloned and sequenced. Within the non-idiomorphic sequences high similarity was found with palI, encoding a membrane receptor from Aspergillus nidulans, with apc, a putative component of the anaphase promoting complex from Schizosaccha...

273

A differential genome-wide transcriptome analysis: impact of cellular copper on complex biological processes like aging and development.  

PubMed

The regulation of cellular copper homeostasis is crucial in biology. Impairments lead to severe dysfunctions and are known to affect aging and development. Previously, a loss-of-function mutation in the gene encoding the copper-sensing and copper-regulated transcription factor GRISEA of the filamentous fungus Podospora anserina was reported to lead to cellular copper depletion and a pleiotropic phenotype with hypopigmentation of the mycelium and the ascospores, affected fertility and increased lifespan by approximately 60% when compared to the wild type. This phenotype is linked to a switch from a copper-dependent standard to an alternative respiration leading to both a reduced generation of reactive oxygen species (ROS) and of adenosine triphosphate (ATP). We performed a genome-wide comparative transcriptome analysis of a wild-type strain and the copper-depleted grisea mutant. We unambiguously assigned 9,700 sequences of the transcriptome in both strains to the more than 10,600 predicted and annotated open reading frames of the P. anserina genome indicating 90% coverage of the transcriptome. 4,752 of the transcripts differed significantly in abundance with 1,156 transcripts differing at least 3-fold. Selected genes were investigated by qRT-PCR analyses. Apart from this general characterization we analyzed the data with special emphasis on molecular pathways related to the grisea mutation taking advantage of the available complete genomic sequence of P. anserina. This analysis verified but also corrected conclusions from earlier data obtained by single gene analysis, identified new candidates of factors as part of the cellular copper homeostasis system including target genes of transcription factor GRISEA, and provides a rich reference source of quantitative data for further in detail investigations. Overall, the present study demonstrates the importance of systems biology approaches also in cases were mutations in single genes are analyzed to explain the underlying mechanisms controlling complex biological processes like aging and development. PMID:23152891

Servos, Jörg; Hamann, Andrea; Grimm, Carolin; Osiewacz, Heinz D

2012-11-12

274

Two structurally similar fungal prions efficiently cross-seed in vivo but form distinct polymers when coexpressed.  

PubMed

HET-s is a prion protein of the filamentous fungus Podospora anserina. An orthologue of this protein, called FgHET-s has been identified in Fusarium graminearum. The region of the FgHET-s protein corresponding to the prion forming domain of HET-s, forms amyloid fibrils in vitro. These fibrils seed HET-s(218-289) fibril formation in vitro and vice versa. The amyloid fold of HET-s(218-289) and FgHET-s(218-289) are remarkably similar although they share only 38% identity. The present work corresponds to the functional characterization of the FgHET-s(218-289) region as a prion forming domain in vivo. We show that FgHET-s(218-289) is capable of prion propagation in P. anserina and is able to substitute for the HET-s PFD in the full-length HET-s protein. In accordance with the in vitro cross-seeding experiments, we detect no species barrier between P. anserina and F. graminearum PFDs. We use the yeast Saccharomyces cerevisiae as a host to compare the prion performances of the two orthologous PFDs. We find that FgHET-s(218-289) leads to higher spontaneous prion formation rates and mitotic prion stability than HET-s(218-289). Then we analysed the outcome of HET-s(218-289)/FgHET-s(218-289) coexpression. In spite of the cross-seeding ability of HET-s(218-289) and FgHET-s(218-289), in vivo, homotypic polymerization is favoured over mixed fibril formation. PMID:22050595

Benkemoun, Laura; Ness, Frédérique; Sabaté, Raimon; Ceschin, Johanna; Breton, Annick; Clavé, Corinne; Saupe, Sven J

2011-11-03

275

The NADPH oxidase complexes in Botrytis cinerea: evidence for a close association with the ER and the tetraspanin Pls1.  

PubMed

NADPH oxidases (Nox) are major enzymatic systems that generate reactive-oxygen species (ROS) in multicellular eukaryotes. In several fungi they have been shown to be involved in sexual differentiation and pathogenicity. However, in contrast to the well characterized mammalian systems, basic information on the composition, recruitment, and localization of fungal Nox complexes and on the molecular mechanisms of their cellular effects are still lacking. Here we give a detailed analysis of components of the Nox complexes in the gray mold fungus Botrytis cinerea. It had previously been shown that the two catalytic transmembrane subunits BcNoxA and B are important for development of sclerotia and for full virulence, with BcNoxA being involved in spreading of lesions and BcNoxB in penetration; BcNoxR functions as a regulator of both subunits. Here we present evidence (using for the first time a functional GFP fusion able to complement the ?bcnoxA mutant) that BcNoxA localizes mainly to the ER and at the plasma membrane; BcNoxB shows a similar localization pattern, while the regulator BcNoxR is found in vesicles throughout the hyphae and at the hyphal tip. To identify possible interaction partners, which could be involved in the localization or recruitment of the Nox complexes, we functionally characterized the tetraspanin Pls1, a transmembrane protein, which had been suggested to be a NoxB-interacting partner in the saprophyte Podospora anserina. Knock-out experiments and GFP fusions substantiate a link between BcNoxB and BcPls1 because both deletion mutants have overlapping phenotypes (especially a defect in penetration), and the proteins show a similar localization pattern (ER). However, in contrast to the corresponding protein in P. anserina BcPls1 is important for female fertility, but not for ascospore germination. PMID:23418468

Siegmund, Ulrike; Heller, Jens; van Kan, Jan A L; van Kann, Jan A L; Tudzynski, Paul

2013-02-13

276

The NADPH Oxidase Complexes in Botrytis cinerea: Evidence for a Close Association with the ER and the Tetraspanin Pls1  

PubMed Central

NADPH oxidases (Nox) are major enzymatic systems that generate reactive-oxygen species (ROS) in multicellular eukaryotes. In several fungi they have been shown to be involved in sexual differentiation and pathogenicity. However, in contrast to the well characterized mammalian systems, basic information on the composition, recruitment, and localization of fungal Nox complexes and on the molecular mechanisms of their cellular effects are still lacking. Here we give a detailed analysis of components of the Nox complexes in the gray mold fungus Botrytis cinerea. It had previously been shown that the two catalytic transmembrane subunits BcNoxA and B are important for development of sclerotia and for full virulence, with BcNoxA being involved in spreading of lesions and BcNoxB in penetration; BcNoxR functions as a regulator of both subunits. Here we present evidence (using for the first time a functional GFP fusion able to complement the ?bcnoxA mutant) that BcNoxA localizes mainly to the ER and at the plasma membrane; BcNoxB shows a similar localization pattern, while the regulator BcNoxR is found in vesicles throughout the hyphae and at the hyphal tip. To identify possible interaction partners, which could be involved in the localization or recruitment of the Nox complexes, we functionally characterized the tetraspanin Pls1, a transmembrane protein, which had been suggested to be a NoxB-interacting partner in the saprophyte Podospora anserina. Knock-out experiments and GFP fusions substantiate a link between BcNoxB and BcPls1 because both deletion mutants have overlapping phenotypes (especially a defect in penetration), and the proteins show a similar localization pattern (ER). However, in contrast to the corresponding protein in P. anserina BcPls1 is important for female fertility, but not for ascospore germination.

Siegmund, Ulrike; Heller, Jens; van Kann, Jan A. L.; Tudzynski, Paul

2013-01-01

277

Correlated evolution of senescence and ephemeral substrate use in the Sordariomycetes.  

PubMed

Evolutionary theory predicts that senescence--a decline in reproduction and survival with increasing age--can evolve as a trade-off between investment in reproduction on one side and in somatic maintenance and repair on the other. The ecology of a species is crucial because it provides the external causes of death that determine the statistical limit to a species' lifespan. Filamentous fungi are generally believed to be nonsenescent, and there are indeed spectacular examples of very old fungal individuals in nature. However, some fungi utilize ephemeral resources, and therefore, senescence is expected to have evolved, like in the coprophilic Podospora anserina, the only well-studied filamentous fungus with intrinsic senescence. Here, we hypothesize that rapid senescence is more common in fungi than generally believed and that the phylogenetic distribution of senescence correlates with ecology. We collected lifespan data for a set of Sordariomycetes and constructed phylogenies based on several nuclear sequences. Several of the strains were from the CBS culture collection, originally isolated from various substrates, some of which ephemeral. In addition, we isolated new strains from short-lived substrates. Senescence was observed throughout the phylogeny. Correlation tests support the hypothesis that in the Sordariomycetes, senescence is a trait that has arisen in response to ephemeral substrates, and that it has evolved repeatedly and independently along the phylogeny. PMID:22486972

Geydan, Thomas D; Debets, Alfons J M; Verkley, Gerard J M; van Diepeningen, Anne D

2012-04-09

278

Molecular gene therapy: overexpression of the alternative NADH dehydrogenase NDI1 restores overall physiology in a fungal model of respiratory complex I deficiency.  

PubMed

Defects in oxidative phosphorylation lie at the heart of a wide variety of degenerative disorders, cancer, and aging. Here, we show, using the fungal model Podospora anserina, that the overexpression of the native mitochondrial matrix-faced type II NADH dehydrogenase NDI1, paralogue of the human apoptosis inducing factor AIF1, can fully restore all physiological consequences of respiratory complex I deficiency. We disrupted the 19.3-kDa subunit of the complex I catalytic core, orthologue of the human PSST subunit, leading to a complete absence of the complex without affecting the assembly and/or stability of the rest of the respiratory chain. This disruption caused a several-fold life span extension at the expense of both male and female fertility. The effect was generally similar but markedly milder than that caused by defects in the complex III/IV-dependent pathway and not associated with a clear reduction in the steady-state level of mitochondrial reactive oxygen species. Whereas the native expression of NDI1 was sufficient to overcome lethality, only the artificial, constitutive overexpression of NDI1 could fully remedy this deficiency: The latter strikingly restored both life span and fertility to levels indistinguishable from wild type, thus demonstrating its unique potential in molecular gene therapy. PMID:20398675

Maas, Marc F P M; Sellem, Carole H; Krause, Frank; Dencher, Norbert A; Sainsard-Chanet, Annie

2010-04-14

279

In vivo and in vitro analyses of toxic mutants of HET-s: FTIR antiparallel signature correlates with amyloid toxicity.  

PubMed

The folding and interactions of amyloid proteins are at the heart of the debate as to how these proteins may or may not become toxic to their host. Although little is known about this issue, the structure seems to be clearly involved with effects on molecular events. To understand how an amyloid may be toxic, we previously generated a yeast toxic amyloid (mutant 8) from the nontoxic HET-s((218-289)) prion domain of Podospora anserina. Here, we performed a comprehensive structure-toxicity study by mutating individually each of the 10 mutations found in mutant 8. The study of the library of new mutants generated allowed us to establish a clear link between Fourier transform infrared antiparallel signature and amyloid toxicity. All of the mutants that form parallel ?-sheets are not toxic. Double mutations may be sufficient to shift a parallel structure to antiparallel amyloids, which are toxic to yeast. Our findings also suggest that the toxicity of antiparallel structured mutants may be linked to interaction with membranes. PMID:21782829

Berthelot, Karine; Ta, Ha Phuong; Géan, Julie; Lecomte, Sophie; Cullin, Christophe

2011-07-18

280

A systems biological analysis links ROS metabolism to mitochondrial protein quality control.  

PubMed

The analyses of previously generated Podospora anserina strains in which the mitochondrial superoxide dismutase, PaSOD3, is increased in abundance, revealed unexpected results, which, at first glance, are contradictory to the 'free radical theory of aging' (FRTA). To re-analyze these results, we performed additional experiments and developed a mathematical model consisting of a set of differential equations describing the time course of various ROS (reactive oxygen species), components of the cellular antioxidant system (PaSOD3 and mitochondrial peroxiredoxin, PaPRX1), and PaCLPP, a mitochondrial matrix protease involved in protein quality control. Incorporating these components we could identify a positive feed-back loop and demonstrate that the role of superoxide as the primary ROS responsible for age-related molecular damage is more complicated than originally stated by the FRTA. Our study is a first step towards the integration of the various pathways known to be involved in the control of biological aging. PMID:22449407

Kowald, Axel; Hamann, Andrea; Zintel, Sandra; Ullrich, Sebastian; Klipp, Edda; Osiewacz, Heinz D

2012-03-17

281

Reactive oxygen species target specific tryptophan site in the mitochondrial ATP synthase.  

PubMed

The release of reactive oxygen species (ROS) as side products of aerobic metabolism in the mitochondria is an unavoidable consequence. As the capacity of organisms to deal with this exposure declines with age, accumulation of molecular damage caused by ROS has been defined as one of the central events during the ageing process in biological systems as well as in numerous diseases such as Alzheimer's and Parkinson's Dementia. In the filamentous fungus Podospora anserina, an ageing model with a clear defined mitochondrial etiology of ageing, in addition to the mitochondrial aconitase the ATP synthase alpha subunit was defined recently as a hot spot for oxidative modifications induced by ROS. In this report we show, that this reactivity is not randomly distributed over the ATP Synthase, but is channeled to a single tryptophan residue 503. This residue serves as an intra-molecular quencher for oxidative species and might also be involved in the metabolic perception of oxidative stress or regulation of enzyme activity. A putative metal binding site in the proximity of this tryptophan residue appears to be crucial for the molecular mechanism for the selective targeting of oxidative damage. PMID:22133636

Rexroth, Sascha; Poetsch, Ansgar; Rögner, Matthias; Hamann, Andrea; Werner, Alexandra; Osiewacz, Heinz D; Schäfer, Eva R; Seelert, Holger; Dencher, Norbert A

2011-11-19

282

Amyloids and yeast prion biology.  

PubMed

The prions (infectious proteins) of Saccharomyces cerevisiae are proteins acting as genes, by templating their conformation from one molecule to another in analogy to DNA templating its sequence. Most yeast prions are amyloid forms of normally soluble proteins, and a single protein sequence can have any of several self-propagating forms (called prion strains or variants), analogous to the different possible alleles of a DNA gene. A central issue in prion biology is the structural basis of this conformational templating process. The in-register parallel ? sheet structure found for several infectious yeast prion amyloids naturally suggests an explanation for this conformational templating. While most prions are plainly diseases, the [Het-s] prion of Podospora anserina may be a functional amyloid, with important structural implications. Yeast prions are important models for human amyloid diseases in general, particularly because new evidence is showing infectious aspects of several human amyloidoses not previously classified as prions. We also review studies of the roles of chaperones, aggregate-collecting proteins, and other cellular components using yeast that have led the way in improving the understanding of similar processes that must be operating in many human amyloidoses. PMID:23379365

Wickner, Reed B; Edskes, Herman K; Bateman, David A; Kelly, Amy C; Gorkovskiy, Anton; Dayani, Yaron; Zhou, Albert

2013-02-12

283

Increasing mitochondrial superoxide dismutase abundance leads to impairments in protein quality control and ROS scavenging systems and to lifespan shortening.  

PubMed

The fungal aging model Podospora anserina contains three superoxide dismutases (SODs) in different cellular compartments. While PaSOD1 represents the Cu/Zn isoform located in the cytoplasm and in the mitochondrial inter-membrane space, PaSOD2 localizes to the perinuclear ER. PaSOD3, a protein with a manganese binding domain and a mitochondrial targeting sequence (MTS) is the mitochondrial SOD. Over-expression of PaSod3 leads to lifespan reduction and increased sensitivity against paraquat and hydrogen peroxide. The negative effects of PaSod3 over-expression correlate with a strong reduction in the abundance of mitochondrial peroxiredoxin, PaPRX1, and the matrix protease PaCLPP disclosing impairments of mitochondrial quality control and ROS scavenging pathways in PaSod3 over-expressors. Deletion of PaSod3 leads to increased paraquat sensitivity while hydrogen peroxide sensitivity and lifespan are not significantly changed when compared to the wild-type strain. These latter characteristics are unexpected and challenge the 'mitochondrial free radical theory of aging'. PMID:20080171

Zintel, Sandra; Schwitalla, Denise; Luce, Karin; Hamann, Andrea; Osiewacz, Heinz D

2010-01-18

284

A family 5 ?-mannanase from the thermophilic fungus Thielavia arenaria XZ7 with typical thermophilic enzyme features.  

PubMed

A novel ?-mannanase gene, man5XZ7, was cloned from thermophilic fungus Thielavia arenaria XZ7, and successfully expressed in Pichia pastoris. The gene (1,110 bp) encodes a 369-amino acid polypeptide with a molecular mass of approximately 40.8 kDa. The deduced sequence of Man5XZ7 consists of a putative 17-residue signal peptide and a catalytic module belonging to glycoside hydrolase (GH) family 5, and displays 76 % identity with the experimentally verified GH 5 endo-?-1,4-mannanase from Podospora anserina. Recombinant Man5XZ7 was optimally active at 75 °C and pH?5.0 and exhibited high activity at a wide temperature range (>50.0 % activity at 50-85 °C). Moreover, it had good adaptability to acidic to basic pH (>74.1 % activity at pH?4.0-7.0 and 25.6 % even at pH?9.0) and good stability from pH?3.0 to 10.0. These enzymatic properties showed that Man5XZ7 was a new thermophilic and alkali-tolerant ?-mannanase. Further amino acid composition analysis indicated that Man5XZ7 has several characteristic features of thermophilic enzymes. PMID:23299456

Lu, Haiqiang; Zhang, Huitu; Shi, Pengjun; Luo, Huiying; Wang, Yaru; Yang, Peilong; Yao, Bin

2013-01-09

285

Structural dependence of HET-s amyloid fibril infectivity assessed by cryoelectron microscopy.  

PubMed

HET-s is a prion protein of the fungus Podospora anserina which, in the prion state, is active in a self/nonself recognition process called heterokaryon incompatibility. Its prionogenic properties reside in the C-terminal "prion domain." The HET-s prion domain polymerizes in vitro into amyloid fibrils whose properties depend on the pH of assembly; above pH 3, infectious singlet fibrils are produced, and below pH 3, noninfectious triplet fibrils. To investigate the correlation between structure and infectivity, we performed cryo-EM analyses. Singlet fibrils have a helical pitch of approximately 410 ? and a left-handed twist. Triplet fibrils have three protofibrils whose lateral dimensions (36 × 25 ?) and axial packing (one subunit per 9.4 ?) match those of singlets but differ in their supercoiling. At 8.5-? resolution, the cross-section of the singlet fibril reconstruction is largely consistent with that of a ?-solenoid model previously determined by solid-state NMR. Reconstructions of the triplet fibrils show three protofibrils coiling around a common axis and packed less tightly at pH 3 than at pH 2, eventually peeling off. Taken together with the earlier observation that fragmentation of triplet fibrils by sonication does not increase infectivity, these observations suggest a novel mechanism for self-propagation, whereby daughter fibrils nucleate on the lateral surface of singlet fibrils. In triplets, this surface is occluded, blocking nucleation and thereby explaining their lack of infectivity. PMID:21300906

Mizuno, Naoko; Baxa, Ulrich; Steven, Alasdair C

2011-02-07

286

[Yeast prions as a model of neurodegenerative infectious amyloidoses in humans].  

PubMed

Several neurodegenerative diseases (so-called age-related diseases) in humans are associated with development of protein aggregates--amyloids. Prion diseases--kuru, Kreutzfeldt-Jakob and Gerstmann-Straussler-Sheinker diseases, fatal familial insomnia, etc.--are examples of infectious amyloidoses. A model system for investigation of mechanisms of amyloidogenesis and of its infectious nature had been developed as a result of yeast prion discovery. The existence of a prion network as an interaction of different prions identified in yeast is being confirmed recently as an interaction of different anyloids in humans. The potential danger of amyloidoses is conditioned by the very structure of almost all proteins containing fragments capable to be organized as beta-sheets, which lead to their aggregation being exposed. Meanwhile, there are several well-defined examples of the adaptive value of amyloid aggregates: cytoplasmic incompatibility factor in Podospora anserina, spider silk, cytoplasmic stress granules in mammals, prion form of CPEB protein responsible for the neuron activity in Aplisia, etc. These facts should be taken into consideration when seeking antiamyloid drugs. Discovery of protein inheritance in lower eukaryotes modifies our knowledge of the template principle significance in biology and adds a concept of conformational templates (II order templates) involved in reproduction of the three-dimensional structure of the supramolecular complexes in the cell. PMID:22145302

Inge-Vechtomov, S G

287

Structural dependence of HET-s amyloid fibril infectivity assessed by cryoelectron microscopy  

PubMed Central

HET-s is a prion protein of the fungus Podospora anserina which, in the prion state, is active in a self/nonself recognition process called heterokaryon incompatibility. Its prionogenic properties reside in the C-terminal “prion domain.” The HET-s prion domain polymerizes in vitro into amyloid fibrils whose properties depend on the pH of assembly; above pH 3, infectious singlet fibrils are produced, and below pH 3, noninfectious triplet fibrils. To investigate the correlation between structure and infectivity, we performed cryo-EM analyses. Singlet fibrils have a helical pitch of approximately 410 ? and a left-handed twist. Triplet fibrils have three protofibrils whose lateral dimensions (36 × 25 ?) and axial packing (one subunit per 9.4 ?) match those of singlets but differ in their supercoiling. At 8.5-? resolution, the cross-section of the singlet fibril reconstruction is largely consistent with that of a ?-solenoid model previously determined by solid-state NMR. Reconstructions of the triplet fibrils show three protofibrils coiling around a common axis and packed less tightly at pH 3 than at pH 2, eventually peeling off. Taken together with the earlier observation that fragmentation of triplet fibrils by sonication does not increase infectivity, these observations suggest a novel mechanism for self-propagation, whereby daughter fibrils nucleate on the lateral surface of singlet fibrils. In triplets, this surface is occluded, blocking nucleation and thereby explaining their lack of infectivity.

Mizuno, Naoko; Baxa, Ulrich; Steven, Alasdair C.

2011-01-01

288

Hydration Effects on the HET-s Prion and Amyloid-? Fibrillous Aggregates, Studied with Three-Dimensional Molecular Theory of Solvation  

PubMed Central

We study the thermodynamic properties of the experimental fragments of the amyloid fibril made of the HET-s prion proteins (the infectious element of the filamentous fungus Podospora anserina) and of amyloid-? proteins (the major component of Alzheimer's disease-associated plaques) by using the three-dimensional molecular theory of solvation. The full quantitative picture of hydration effects, including the hydration thermodynamics and hydration structure around the fragments, is presented. For both the complexes, the hydration entropic effects dominate, which results in the entropic part offsetting the unfavorable energetic part of the free energy change upon the association. This is in accord with the fact that the hydrophobic cooperativity plays an essential role in the formation of amyloid fibrils. By calculating the partial molar volume of the proteins, we found that the volume change upon the association in both the systems is large and positive, with the implication that high pressure causes destabilization of the fibril. This observation is in good agreement with the recent experimental results. We also found that both the HET-s and amyloid-? pentamers have loose intermolecular packing with voids. The three-dimensional molecular theory of solvation predicts that water molecules can be locked in the interior cavities along the fibril axis for both the HET-s and amyloid-? proteins. We provide a detailed molecular picture of the structural water localized in the interior of the fibrils. Our results suggest that the interior hydration plays an important role in the structural stability of fibrils.

Yamazaki, Takeshi; Blinov, Nikolay; Wishart, David; Kovalenko, Andriy

2008-01-01

289

Cloning and molecular characterization of the glyceraldehyde-3-phosphate dehydrogenase-encoding gene and cDNA from the plant pathogenic fungus Glomerella cingulata.  

PubMed

The glyceraldehyde-3-phosphate dehydrogenase gene (gpdA) has been identified from a genomic DNA library prepared from the plant pathogenic fungus Glomerella cingulata. Nucleotide sequence data revealed that this gene codes for a putative 338-amino-acid protein encoded by two exons of 129 and 885 bp, separated by an intron 216 bp long. The 5' leader sequence is also spliced by an intron of 156 bp. A cDNA clone was prepared using the polymerase chain reaction, the sequence of which was used to confirm the presence of the intron in the coding sequence and the splicing of the 5' leader sequence. The transcriptional start point (tsp) was mapped at -253 nt from the site of the initiation of translation by primer extension and is adjacent to a 42-bp pyrimidine-rich region. The general structure of the 5' flanking region shows similarities to gpdA from Aspergillus nidulans. The putative protein product is 71-86% identical at the aa level to GPDs from Aspergillus nidulans, Cryphonectria parasitica, Curvularia lunata, Podospora anserina and Ustilago maydis. PMID:1452034

Templeton, M D; Rikkerink, E H; Solon, S L; Crowhurst, R N

1992-12-01

290

Lack of mitochondrial citrate synthase discloses a new meiotic checkpoint in a strict aerobe  

PubMed Central

Mitochondrial citrate synthase (mCS) is the initial enzyme of the tricarboxylic acid (TCA) cycle. Despite the key position of this protein in respiratory metabolism, very few studies have addressed the question of the effects of the absence of mCS in development. Here we report on the characterization of 15 point mutations and a complete deletion of the cit1 gene, which encodes mCS in the filamentous fungus Podospora anserina. This gene was identified genetically through a systematic search for suppressors of the metabolic defect of the peroxisomal pex2 mutants. The cit1 mutant strains exhibit no visible vegetative defects. However, they display an unexpected developmental phenotype: in homozygous crosses, cit1 mutations impair meiosis progression beyond the diffuse stage, a key stage of meiotic prophase. Enzyme assays, immunofluorescence and western blotting experiments show that the presence of the mCS protein is more important for completion of meiosis than its well-known enzyme activity. Combined with observations made in budding yeast, our data suggest that there is a general metabolic checkpoint at the diffuse stage in eukaryotes.

Ruprich-Robert, Gwenael; Zickler, Denise; Berteaux-Lecellier, Veronique; Velot, Christian; Picard, Marguerite

2002-01-01

291

The Homologue of het-c of Neurospora crassa Lacks Vegetative Compatibility Function in Fusarium proliferatum†  

PubMed Central

For two fungal strains to be vegetatively compatible and capable of forming a stable vegetative heterokaryon they must carry matching alleles at a series of loci variously termed het or vic genes. Cloned het/vic genes from Neurospora crassa and Podospora anserina have no obvious functional similarity and have various cellular functions. Our objective was to identify the homologue of the Neurospora het-c gene in Fusarium proliferatum and to determine if this gene has a vegetative compatibility function in this economically important and widely dispersed fungal pathogen. In F. proliferatum and five other closely related Fusarium species we found a few differences in the DNA sequence, but the changes were silent and did not alter the amino acid sequence of the resulting protein. Deleting the gene altered sexual fertility as the female parent, but it did not alter male fertility or existing vegetative compatibility interactions. Replacement of the allele-specific portion of the coding sequence with the sequence of an alternate allele in N. crassa did not result in a vegetative incompatibility response in transformed strains of F. proliferatum. Thus, the fphch gene in Fusarium appears unlikely to have the vegetative compatibility function associated with its homologue in N. crassa. These results suggest that the vegetative compatibility phenotype may result from convergent evolution. Thus, the genes involved in this process may need to be identified at the species level or at the level of a group of species and could prove to be attractive targets for the development of antifungal agents.

Kerenyi, Zoltan; Olah, Brigitta; Jeney, Apor; Hornok, Laszlo; Leslie, John F.

2006-01-01

292

Peroxisomes and sexual development in fungi  

PubMed Central

Peroxisomes are versatile and dynamic organelles that are essential for the development of most eukaryotic organisms. In fungi, many developmental processes, such as sexual development, require the activity of peroxisomes. Sexual reproduction in fungi involves the formation of meiotic-derived sexual spores, often takes place inside multicellular fruiting bodies and requires precise coordination between the differentiation of multiple cell types and the progression of karyogamy and meiosis. Different peroxisomal functions contribute to the orchestration of this complex developmental process. Peroxisomes are required to sustain the formation of fruiting bodies and the maturation and germination of sexual spores. They facilitate the mobilization of reserve compounds via fatty acid ?-oxidation and the glyoxylate cycle, allowing the generation of energy and biosynthetic precursors. Additionally, peroxisomes are implicated in the progression of meiotic development. During meiotic development in Podospora anserina, there is a precise modulation of peroxisome assembly and dynamics. This modulation includes changes in peroxisome size, number and localization, and involves a differential activity of the protein-machinery that drives the import of proteins into peroxisomes. Furthermore, karyogamy, entry into meiosis and sorting of meiotic-derived nuclei into sexual spores all require the activity of peroxisomes. These processes rely on different peroxisomal functions and likely depend on different pathways for peroxisome assembly. Indeed, emerging studies support the existence of distinct import channels for peroxisomal proteins that contribute to different developmental stages.

Peraza-Reyes, Leonardo; Berteaux-Lecellier, Veronique

2013-01-01

293

Candida amazonensis sp. nov., an ascomycetous yeast isolated from rotting wood in the Amazonian forest.  

PubMed

Five strains of a novel yeast species were isolated from rotting wood samples collected in an Amazonian forest site in the state of Roraima, northern Brazil. The sequences of the D1/D2 domains of the large subunit of the rRNA gene showed that this species belongs to the Scheffersomyces clade and is related to Candida coipomoensis, Candida lignicola and Candida queiroziae. The novel species Candida amazonensis sp. nov. is proposed to accommodate these isolates. The type strain of C. amazonensis sp. nov. is UFMG-HMD-26.3(T) ( = CBS 12363(T) = NRRL Y-48762(T)). PMID:21856981

Cadete, Raquel M; Melo, Monaliza A; Lopes, Mariana R; Pereira, Gilmara M D; Zilli, Jerri E; Vital, Marcos J S; Gomes, Fátima C O; Lachance, Marc-André; Rosa, Carlos A

2011-08-19

294

Balticolid: A New 12-Membered Macrolide with Antiviral Activity from an Ascomycetous Fungus of Marine Origin  

PubMed Central

A new 12-membered macrolide, balticolid (1) was isolated from the EtOAc extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany. The structure of balticolid was determined to be (3R,11R), (4E,8E)-3-hydroxy-11-methyloxacyclododeca-4,8-diene-1,7-dione using extensive spectral data as well as the modified Mosher ester method. Balticolid (1) displayed anti-HSV-1 activity with an IC50 value of 0.45 ?M.

Shushni, Muftah A. M.; Singh, Rajinder; Mentel, Renate; Lindequist, Ulrike

2011-01-01

295

Candida ecuadorensis sp. nov., an ascomycetous yeast species found in two separate regions of Ecuador.  

PubMed

In the course of an on-going study aimed at cataloguing the natural yeast biodiversity found in Ecuador, two strains (CLQCA 13-025 and CLQCA 20-004(T)) were isolated from samples of cow manure and rotten wood collected in two separate provinces of the country (Orellana and Bolívar). These strains were found to represent a novel yeast species based on the sequences of their D1/D2 domain of the large-subunit (LSU) rRNA gene and their physiological characteristics. Phylogenetic analysis based on LSU D1/D2 sequences revealed this novel species to belong to the Metschnikowia clade and to be most closely related to Candida suratensis, a species recently discovered in a mangrove forest in Thailand. The species name of Candida ecuadorensis sp. nov. is proposed to accommodate these strains, with strain CLQCA 20-004(T) (=CBS 12653(T) = NCYC 3782(T)) designated as the type strain. PMID:23104360

James, Stephen A; Carvajal Barriga, Enrique Javier; Barahona, Patricia Portero; Cross, Kathryn; Bond, Christopher J; Roberts, Ian N

2012-10-26

296

Intracellular siderophores are essential for ascomycete sexual development in heterothallic Cochliobolus heterostrophus and homothallic Gibberella zeae  

Technology Transfer Automated Retrieval System (TEKTRAN)

Connections between fungal development and secondary metabolism have been reported previously, but as yet, no comprehensive analysis of a family of secondary metabolites and their possible role in fungal development has been reported. In the present study, mutant strains of the heterothallic ascomyc...

297

Interactions of plant-beneficial bacteria with the ascomycete Coniochaeta ligniaria  

Microsoft Academic Search

Aims: To assess the interactions between Coniochaeta ligniaria F\\/TGF15 obtained from torrefied grass fibers (TGF) and selected bacteria from the same substrate. Methods and Results: Upon coinoculation on potato dextrose agar, Pseudomonas putida 15\\/TGE5, Methylobacterium radiotolerans 56\\/TGF10, Serratia plymutica 23\\/TGE5, Pseudomonas corrugata 31\\/TGE5, Leifsonia xyli subsp. xyli 66\\/TGF10, Mycobacterium anthracenicum 70\\/TGF15 and Agromyces aurantiacus 95\\/TGF15 were translocated by C. ligniaria,

R. D. Trifonova; J. Postma; Elsas van J. D

2009-01-01

298

Candida nonsorbophila sp. nov., a new ascomycetous yeast species isolated in Thailand.  

PubMed

Four yeast strains, RS42, SSK10, ST-520 and ST-521, isolated from water in a mangrove forest, bark of a tree and fruit of Ficus sp., respectively, were found to represent a hitherto undescribed anamorphic species. The four strains are related to Candida sinolaborantium in the D1/D2 domain of the large subunit rRNA gene, but differed by eight nucleotide substitutions and two indels, and for this reason are regarded as members of a separate species. Because ascospore formation was not detected, it is described as a new species of Candida, Candida nonsorbophila sp. nov. The type strain is RS42(T) (BCC 25963(T)=NBRC 103860(T)=CBS 10862(T)). This species is distinguished from C. sinolaborantium by the inability to assimilate L-sorbose, L-rhamnose and galactitol, and a higher maximum growth temperature. PMID:19416367

Nakase, Takashi; Jindamorakot, Sasitorn; Am-In, Somjit; Ninomiya, Shinya; Kawasaki, Hiroko; Limtong, Savitree

2009-04-15

299

Annulatascus aquatorba sp. nov., a lignicolous freshwater ascomycete from Sirindhorn Peat Swamp Forest, Narathiwat, Thailand.  

PubMed

As part of a long term study of fungi colonizing submerged wood in freshwater streams a new Annulatascus species, A. aquatorba, is described and illustrated from Erythrophleum teysmannii test blocks from Sirindhorn Peat Swamp Forest, southern Thailand. It differs from other species in the genus in ascospore measurements, thickness of the cell wall, 1-3-septate, fusoid to lunate shape, with central brown cells and subhyaline end cells and without a mucilaginous sheath. Asci are cylindrical, pedicellate, with a distinct, wedge-shaped and non-amyloid apical ring. Phylogenetic relationships of this species, based on the combined partial 18S and 28S rDNA, place it in the same clade as A. velatisporus (type species), A. hongkongensis and A. nilensis. PMID:22223172

Boonyuen, Nattawut; Sri-indrasutdhi, Veera; Suetrong, Satinee; Sivichai, Somsak; Jones, E B Gareth

2012-01-05

300

Muscodor yucatanensis, a new endophytic ascomycete from Mexican chakah, Bursera simaruba  

Technology Transfer Automated Retrieval System (TEKTRAN)

During a study on the fungal endophytic associations with some trees of the secondary forest of El Eden Ecological Reserve located in the northeastern Yucatan Peninsula of Mexico, a new fungal species was isolated as an endophyte of a tree named chakah, chachah or hukúp (Bursera simaruba) by indigen...

301

Identification and characterization of polymorphic minisatellites in the phytopathogenic ascomycete Leptosphaeria maculans  

Microsoft Academic Search

Leptosphaeria maculans causes phoma stem canker, the most serious disease of oilseed rape world-wide. Sexual recombination is important in the pathogen life cycle and increases the risk of plant resistance genes being overcome rapidly. Thus, there is a need to develop easy-to-use molecular markers suitable for large-scale population genetic studies. The minisatellite MinLm1, showing six alleles in natural populations, has

Maria Eckert; Lilian Gout; Thierry Rouxel; Françoise Blaise; Malgorzata Jedryczka; Bruce Fitt; Marie-Hélène Balesdent

2005-01-01

302

Karyotype polymorphism correlates with intraspecific infertility in the homothallic ascomycete Sordaria macrospora  

Microsoft Academic Search

The homothallic fungus Sordaria macrospora produces perithecia with meiot- ically derived ascospores. In most cases, intraspecies crosses between strains from different culture collections generate fertile hybrid perithecia in the contact zone of two mycelia. However, in some of these crosses we observed a significant decrease in the fertility of the hybrid perithecia when strains of different origin were used for

Poggeler; Masloff; U. KUCK

2000-01-01

303

Balticolid: a new 12-membered macrolide with antiviral activity from an ascomycetous fungus of marine origin.  

PubMed

A new 12-membered macrolide, balticolid (1) was isolated from the EtOAc extract of the culture broth of fungal strain 222 belonging to the Ascomycota, which was found on driftwood collected from the coast of the Greifswalder Bodden, Baltic Sea, Germany. The structure of balticolid was determined to be (3R,11R), (4E,8E)-3-hydroxy-11-methyloxacyclododeca-4,8-diene-1,7-dione using extensive spectral data as well as the modified Mosher ester method. Balticolid (1) displayed anti-HSV-1 activity with an IC?? value of 0.45 ?M. PMID:21673893

Shushni, Muftah A M; Singh, Rajinder; Mentel, Renate; Lindequist, Ulrike

2011-05-13

304

The Ascomycete Verticillium longisporum Is a Hybrid and a Plant Pathogen with an Expanded Host Range  

PubMed Central

Hybridization plays a central role in plant evolution, but its overall importance in fungi is unknown. New plant pathogens are thought to arise by hybridization between formerly separated fungal species. Evolution of hybrid plant pathogens from non-pathogenic ancestors in the fungal-like protist Phytophthora has been demonstrated, but in fungi, the most important group of plant pathogens, there are few well-characterized examples of hybrids. We focused our attention on the hybrid and plant pathogen Verticillium longisporum, the causal agent of the Verticillium wilt disease in crucifer crops. In order to address questions related to the evolutionary origin of V. longisporum, we used phylogenetic analyses of seven nuclear loci and a dataset of 203 isolates of V. longisporum, V. dahliae and related species. We confirmed that V. longisporum was diploid, and originated three different times, involving four different lineages and three different parental species. All hybrids shared a common parent, species A1, that hybridized respectively with species D1, V. dahliae lineage D2 and V. dahliae lineage D3, to give rise to three different lineages of V. longisporum. Species A1 and species D1 constituted as yet unknown taxa. Verticillium longisporum likely originated recently, as each V. longisporum lineage was genetically homogenous, and comprised species A1 alleles that were identical across lineages.

Inderbitzin, Patrik; Davis, R. Michael; Bostock, Richard M.; Subbarao, Krishna V.

2011-01-01

305

Mating systems in representatives of Parmeliaceae, Ramalinaceae and Physciaceae (Lecanoromycetes, lichen-forming ascomycetes).  

PubMed

The progeny of meiosis of eight Parmeliaceae, two Ramalinaceae and seven Physciaceae were subjected to fingerprint analysis using RAPD-PCR applied to single spore isolates. The sample set included common and widespread rarely fertile species (Parmelia sulcata, Pseudevernia furfuracea, Physcia tenella), local to common, infrequently fertile species (Melanelixia glabra, Parmelina tiliacea, Xanthoparmelia conspersa, X. stenophylla, Anaptychia runcinata, Diploicia canescen, Physconia distorta), local to rare, infrequently or regularly fertile species with declining distributions (Parmelina carporrhizans, P. quercina, Ramalina fastigiata, R. fraxinea, Anaptychia ciliaris), and local to common, regularly fertile species (Physcia aipolia, P. stellaris). All species turned out to be heterothallic, polymorphisms among RAPD markers ranging from 10-87%. The significance of these findings for population genetics and conservation biology, and potential reasons for infrequent ascoma formation in some of the species are discussed. PMID:17512182

Honegger, Rosmarie; Zippler, Undine

2007-02-23

306

Polyphasic taxonomy of the heat resistant ascomycete genus Byssochlamys and its Paecilomyces anamorphs.  

PubMed

Byssochlamys and related Paecilomyces strains are often heat resistant and may produce mycotoxins in contaminated pasteurised foodstuffs. A comparative study of all Byssochlamys species was carried out using a polyphasic approach to find characters that differentiate species and to establish accurate data on potential mycotoxin production by each species. Phylogenetic analysis of the ITS region, parts of the beta-tubulin and calmodulin genes, macro- and micromorphological examinations and analysis of extrolite profiles were applied. Phylogenetic analyses revealed that the genus Byssochlamys includes nine species, five of which form a teleomorph, i.e. B. fulva, B. lagunculariae, B. nivea, B. spectabilis and B. zollerniae, while four are asexual, namely P. brunneolus, P. divaricatus, P. formosus and P. saturatus. Among these, B. nivea produces the mycotoxins patulin and byssochlamic acid and the immunosuppressant mycophenolic acid. Byssochlamys lagunculariae produces byssochlamic acid and mycophenolic acid and thus chemically resembles B. nivea. Some strains of P. saturatus produce patulin and brefeldin A, while B. spectabilis (anamorph P. variotii s.s.) produces viriditoxin. Some micro- and macromorphological characters are valuable for identification purposes, including the shape and size of conidia and ascospores, presence and ornamentation of chlamydospores, growth rates on MEA and CYA and acid production on CREA. A dichotomous key is provided for species identification based on phenotypical characters. PMID:20198134

Samson, R A; Houbraken, J; Varga, J; Frisvad, J C

2009-02-10

307

Two new pathogenic ascomycetes in Guignardia and Rosenscheldiella on New Zealand's pygmy mistletoes (Korthalsella: Viscaceae)  

PubMed Central

Two new pathogens, Guignardia korthalsellae and Rosenscheldiella korthalsellae, are described from New Zealand's pygmy mistletoes (Korthalsella, Viscaceae). Both form ascomata on living phylloclades with minimal disruption of the tissue. Fungal hyphae within the phylloclade are primarily intercellular. Guignardia korthalsellae disrupts a limited number of epidermal cells immediately around the erumpent ascoma, while the ascomata of Rosenscheldiella korthalsellae develop externally on small patches of stromatic tissue that form above stomatal cavities. Rosenscheldiella is applied in a purely morphological sense. LSU sequences show that R. korthalsellae as well as another New Zealand species, Rosenscheldiella brachyglottidis, are members of the Mycosphaerellaceae sensu stricto. Genetically, Rosenscheldiella, in the sense we are using it, is polyphyletic; LSU and ITS sequences place the two New Zealand species in different clades within the Mycosphaerellaceae. Rosenscheldiella is retained for these fungi until generic relationships within the family are resolved. Whether or not the type species of Rosenscheldiella, R. styracis, is also a member of the Mycosphaerellaceae is not known, but it has a similar morphology and relationship to its host as the two New Zealand species.

Sultan, A.; Johnston, P.R.; Park, D.; Robertson, A.W.

2011-01-01

308

Occurrence of a Major Protein Associated with Fruiting Body Development in Neurospora and Related Ascomycetes  

Microsoft Academic Search

Electrophoretic and immunological analysis of fruiting body (perithecial) extracts demonstrates the occurrence of a major phase-specific perithecial protein in all Neurospora species and in the closely related Gelasinospora cerealis and Sordaria fimicola. The perithecial proteins from these different species fall into a number of groups with different electrophoretic mobilities. They appear to be immunologically closely related but not identical to

June Bowman Nasrallah; Adrian M. Srb

1977-01-01

309

Functional Analyses of Two Acetyl Coenzyme A Synthetases in the Ascomycete Gibberella zeae ? †  

PubMed Central

Acetyl coenzyme A (acetyl-CoA) is a crucial metabolite for energy metabolism and biosynthetic pathways and is produced in various cellular compartments with spatial and temporal precision. Our previous study on ATP citrate lyase (ACL) in Gibberella zeae revealed that ACL-dependent acetyl-CoA production is important for histone acetylation, especially in sexual development, but is not involved in lipid synthesis. In this study, we deleted additional acetyl-CoA synthetic genes, the acetyl-CoA synthetases (ACS genes ACS1 and ACS2), to identify alternative acetyl-CoA production mechanisms for ACL. The ACS1 deletion resulted in a defect in sexual development that was mainly due to a reduction in 1-palmitoyl-2-oleoyl-3-linoleoyl-rac-glycerol production, which is required for perithecium development and maturation. Another ACS coding gene, ACS2, has accessorial functions for ACS1 and has compensatory functions for ACL as a nuclear acetyl-CoA producer. This study showed that acetate is readily generated during the entire life cycle of G. zeae and has a pivotal role in fungal metabolism. Because ACSs are components of the pyruvate-acetaldehyde-acetate pathway, this fermentation process might have crucial roles in various physiological processes for filamentous fungi.

Lee, Seunghoon; Son, Hokyoung; Lee, Jungkwan; Min, Kyunghun; Choi, Gyung Ja; Kim, Jin-Cheol; Lee, Yin-Won

2011-01-01

310

A colour reaction for the differentiation of ascomycetous and hemibasidiomycetous yeasts  

Microsoft Academic Search

Seventy yeast strains, representative of twenty-six ascogenous genera, four saprobic hemibasidiomycetous genera and thirteen genera of the Cryptococcales were tested for their reaction with the stabilized aromatic diazonium compound, Diazonium Blue B salt. An aqueous, buffered solution of this compound gave a characteristic red colouration with the colonies of the hemibasidiomycetous species and those Cryptococcales characterized by the hemibasidiomycetous cell-wall

J. P. Walt; V. K. Hopsu-Havu

1976-01-01

311

Isolation and characterization of MAT genes in the symbiotic ascomycete Tuber melanosporum.  

PubMed

• The genome of Tuber melanosporum has recently been sequenced. Here, we used this information to identify genes involved in the reproductive processes of this edible fungus. The sequenced strain (Mel28) possesses only one of the two master genes required for mating, that is, the gene that codes for the high mobility group (HMG) transcription factor (MAT1-2-1), whereas it lacks the gene that codes for the protein containing the ?-box- domain (MAT1-1-1), suggesting that this fungus is heterothallic. • A PCR-based approach was initially employed to screen truffles for the presence of the MAT1-2-1 gene and amplify the conserved regions flanking the mating type (MAT) locus. The MAT1-1-1 gene was finally identified using primers designed from the conserved regions of strains that lack the MAT1-2-1 gene. • Mating type-specific primer pairs were developed to screen asci and gleba from truffles of different origins and to genotype single ascospores within the asci. These analyses provided definitive evidence that T. melanosporum is a heterothallic species with a MAT locus that is organized similarly to those of ancient fungal lineages. • A greater understanding of the reproductive mechanisms that exist in Tuber spp. allows for optimization of truffle plantation management strategies. PMID:20961294

Rubini, Andrea; Belfiori, Beatrice; Riccioni, Claudia; Tisserant, Emilie; Arcioni, Sergio; Martin, Francis; Paolocci, Francesco

2010-10-20

312

Functional analyses of two acetyl coenzyme A synthetases in the ascomycete Gibberella zeae.  

PubMed

Acetyl coenzyme A (acetyl-CoA) is a crucial metabolite for energy metabolism and biosynthetic pathways and is produced in various cellular compartments with spatial and temporal precision. Our previous study on ATP citrate lyase (ACL) in Gibberella zeae revealed that ACL-dependent acetyl-CoA production is important for histone acetylation, especially in sexual development, but is not involved in lipid synthesis. In this study, we deleted additional acetyl-CoA synthetic genes, the acetyl-CoA synthetases (ACS genes ACS1 and ACS2), to identify alternative acetyl-CoA production mechanisms for ACL. The ACS1 deletion resulted in a defect in sexual development that was mainly due to a reduction in 1-palmitoyl-2-oleoyl-3-linoleoyl-rac-glycerol production, which is required for perithecium development and maturation. Another ACS coding gene, ACS2, has accessorial functions for ACS1 and has compensatory functions for ACL as a nuclear acetyl-CoA producer. This study showed that acetate is readily generated during the entire life cycle of G. zeae and has a pivotal role in fungal metabolism. Because ACSs are components of the pyruvate-acetaldehyde-acetate pathway, this fermentation process might have crucial roles in various physiological processes for filamentous fungi. PMID:21666077

Lee, Seunghoon; Son, Hokyoung; Lee, Jungkwan; Min, Kyunghun; Choi, Gyung Ja; Kim, Jin-Cheol; Lee, Yin-Won

2011-06-10

313

Origins and evolution of the HET-s prion-forming protein: searching for other amyloid-forming solenoids.  

PubMed

The HET-s prion-forming domain from the filamentous fungus Podospora anserina is gaining considerable interest since it yielded the first well-defined atomic structure of a functional amyloid fibril. This structure has been identified as a left-handed beta solenoid with a triangular hydrophobic core. To delineate the origins of the HET-s prion-forming protein and to discover other amyloid-forming proteins, we searched for all homologs of the HET-s protein in a database of protein domains and fungal genomes, using a combined application of HMM, psi-blast and pGenThreader techniques, and performed a comparative evolutionary analysis of the N-terminal alpha-helical domain and the C-terminal prion-forming domain of HET-s. By assessing the tandem evolution of both domains, we observed that the prion-forming domain is restricted to Sordariomycetes, with a marginal additional sequence homolog in Arthroderma otae as a likely case of horizontal transfer. This suggests innovation and rapid evolution of the solenoid fold in the Sordariomycetes clade. In contrast, the N-terminal domain evolves at a slower rate (in Sordariomycetes) and spans many diverse clades of fungi. We performed a full three-dimensional protein threading analysis on all identified HET-s homologs against the HET-s solenoid fold, and present detailed structural annotations for identified structural homologs to the prion-forming domain. An analysis of the physicochemical characteristics in our set of structural models indicates that the HET-s solenoid shape can be readily adopted in these homologs, but that they are all less optimized for fibril formation than the P. anserina HET-s sequence itself, due chiefly to the presence of fewer asparagine ladders and salt bridges. Our combined structural and evolutionary analysis suggests that the HET-s shape has "limited scope" for amyloidosis across the wider protein universe, compared to the 'generic' left-handed beta helix. We discuss the implications of our findings on future identification of amyloid-forming proteins sharing the solenoid fold. PMID:22096554

Gendoo, Deena M A; Harrison, Paul M

2011-11-11

314

Characterization of a broad-specificity ?-glucanase acting on ?-(1,3)-, ?-(1,4)-, and ?-(1,6)-glucans that defines a new glycoside hydrolase family.  

PubMed

Here we report the cloning of the Pa_3_10940 gene from the coprophilic fungus Podospora anserina, which encodes a C-terminal family 1 carbohydrate binding module (CBM1) linked to a domain of unknown function. The function of the gene was investigated by expression of the full-length protein and a truncated derivative without the CBM1 domain in the yeast Pichia pastoris. Using a library of polysaccharides of different origins, we demonstrated that the full-length enzyme displays activity toward a broad range of ?-glucan polysaccharides, including laminarin, curdlan, pachyman, lichenan, pustulan, and cellulosic derivatives. Analysis of the products released from polysaccharides revealed that this ?-glucanase is an exo-acting enzyme on ?-(1,3)- and ?-(1,6)-linked glucan substrates and an endo-acting enzyme on ?-(1,4)-linked glucan substrates. Hydrolysis of short ?-(1,3), ?-(1,4), and ?-(1,3)/?-(1,4) gluco-oligosaccharides confirmed this striking feature and revealed that the enzyme performs in an exo-type mode on the nonreducing end of gluco-oligosaccharides. Excision of the CBM1 domain resulted in an inactive enzyme on all substrates tested. To our knowledge, this is the first report of an enzyme that displays bifunctional exo-?-(1,3)/(1,6) and endo-?-(1,4) activities toward beta-glucans and therefore cannot readily be assigned to existing Enzyme Commission groups. The amino acid sequence has high sequence identity to hypothetical proteins within the fungal taxa and thus defines a new family of glycoside hydrolases, the GH131 family. PMID:23023747

Lafond, Mickael; Navarro, David; Haon, Mireille; Couturier, Marie; Berrin, Jean-Guy

2012-09-28

315

Metabolic engineering of muconic acid production in Saccharomyces cerevisiae.  

PubMed

The dicarboxylic acid muconic acid has garnered significant interest due to its potential use as a platform chemical for the production of several valuable consumer bio-plastics including nylon-6,6 and polyurethane (via an adipic acid intermediate) and polyethylene terephthalate (PET) (via a terephthalic acid intermediate). Many process advantages (including lower pH levels) support the production of this molecule in yeast. Here, we present the first heterologous production of muconic acid in the yeast Saccharomyces cerevisiae. A three-step synthetic, composite pathway comprised of the enzymes dehydroshikimate dehydratase from Podospora anserina, protocatechuic acid decarboxylase from Enterobacter cloacae, and catechol 1,2-dioxygenase from Candida albicans was imported into yeast. Further genetic modifications guided by metabolic modeling and feedback inhibition mitigation were introduced to increase precursor availability. Specifically, the knockout of ARO3 and overexpression of a feedback-resistant mutant of aro4 reduced feedback inhibition in the shikimate pathway, and the zwf1 deletion and over-expression of TKL1 increased flux of necessary precursors into the pathway. Further balancing of the heterologous enzyme levels led to a final titer of nearly 141mg/L muconic acid in a shake-flask culture, a value nearly 24-fold higher than the initial strain. Moreover, this strain has the highest titer and second highest yield of any reported shikimate and aromatic amino acid-based molecule in yeast in a simple batch condition. This work collectively demonstrates that yeast has the potential to be a platform for the bioproduction of muconic acid and suggests an area that is ripe for future metabolic engineering efforts. PMID:23164574

Curran, Kathleen A; Leavitt, John M; Karim, Ashty S; Alper, Hal S

2012-11-17

316

NLRP4 negatively regulates autophagic processes through an association with beclin1.  

PubMed

Although more than 20 putative members have been assigned to the nucleotide-binding and oligomerization domain-like receptor (NLR) family, their physiological and biological roles, with the exception of the inflammasome, are not fully understood. In this article, we show that NLR members, such as NLRC4, NLRP3, NLRP4, and NLRP10 interact with Beclin1, an important regulator of autophagy, through their neuronal apoptosis inhibitory protein, MHC class II transcription activator, incompatibility locus protein from Podospora anserina, and telomerase-associated protein domain. Among such NLRs, NLRP4 had a strong affinity to the Beclin1 evolutionally conserved domain. Compromising NLRP4 via RNA interference resulted in upregulation of the autophagic process under physiological conditions and upon invasive bacterial infections, leading to enhancement of the autophagic bactericidal process of group A streptococcus. NLRP4 recruited to the subplasma membrane phagosomes containing group A streptococcus and transiently dissociated from Beclin1, suggesting that NLRP4 senses bacterial infection and permits the initiation of Beclin1-mediated autophagic responses. In addition to a role as a negative regulator of the autophagic process, NLRP4 physically associates with the class C vacuolar protein-sorting complex, thereby negatively regulating maturation of the autophagosome and endosome. Collectively, these results provide novel evidence that NLRP4, and possibly other members of the NLR family, plays a crucial role in biogenesis of the autophagosome and its maturation by the association with regulatory molecules, such as Beclin1 and the class C vacuolar protein-sorting complex. PMID:21209283

Jounai, Nao; Kobiyama, Kouji; Shiina, Masaaki; Ogata, Kazuhiro; Ishii, Ken J; Takeshita, Fumihiko

2011-01-05

317

Autophagy provides nutrients for nonassimilating fungal structures and is necessary for plant colonization but not for infection in the necrotrophic plant pathogen Fusarium graminearum.  

PubMed

The role of autophagy in necrotrophic fungal physiology and infection biology is poorly understood. We have studied autophagy in the necrotrophic plant pathogen Fusarium graminearum in relation to development of nonassimilating structures and infection. We identified an ATG8 homolog F. graminearum ATG8 whose first 116 amino acids before the predicted ATG4 cleavage site are 100% identical to Podospora anserina ATG8. We generated a ?Fgatg8 mutant by gene replacement and showed that this cannot form autophagic compartments. The strain forms no perithecia, has reduced conidia production and the aerial mycelium collapses after a few days in culture. The collapsing aerial mycelium contains lipid droplets indicative of nitrogen starvation and/or an inability to use storage lipids. The capacity to use carbon/energy stored in lipid droplets after a shift from carbon rich conditions to carbon starvation is severely inhibited in the ?Fgatg8 strain demonstrating autophagy-dependent lipid utilization, lipophagy, in fungi. Radial growth rate of the ?Fgatg8 strain is reduced compared with the wild type and the mutant does not grow over inert plastic surfaces in contrast to the wild type. The ability to infect barley and wheat is normal but the mutant is unable to spread from spikelet to spikelet in wheat. Complementation by inserting the F. graminearum atg8 gene into a region adjacent to the actin gene in ?Fgatg8 fully restores the WT phenotype. The results showed that autophagy plays a pivotal role for supplying nutrients to nonassimilating structures necessary for growth and is important for plant colonization. This also indicates that autophagy is a central mechanism for fungal adaptation to nonoptimal C/N ratios. PMID:22240663

Josefsen, Lone; Droce, Aida; Sondergaard, Teis Esben; Sørensen, Jens Laurids; Bormann, Jörg; Schäfer, Wilhelm; Giese, Henriette; Olsson, Stefan

2012-01-13

318

Conformational folding and stability of the HET-C2 glycolipid transfer protein fold: does a molten globule-like state regulate activity?  

PubMed

The glycolipid transfer protein (GLTP) superfamily is defined by the human GLTP fold that represents a novel motif for lipid binding and transfer and for reversible interaction with membranes, i.e., peripheral amphitropic proteins. Despite limited sequence homology with human GLTP, we recently showed that HET-C2 GLTP of Podospora anserina is organized conformationally as a GLTP fold. Currently, insights into the folding stability and conformational states that regulate GLTP fold activity are almost nonexistent. To gain such insights into the disulfide-less GLTP fold, we investigated the effect of a change in pH on the fungal HET-C2 GLTP fold by taking advantage of its two tryptophans and four tyrosines (compared to three tryptophans and 10 tyrosines in human GLTP). pH-induced conformational alterations were determined by changes in (i) intrinsic tryptophan fluorescence (intensity, emission wavelength maximum, and anisotropy), (ii) circular dichroism over the near-UV and far-UV ranges, including thermal stability profiles of the derivatized molar ellipticity at 222 nm, (iii) fluorescence properties of 1-anilinonaphthalene-8-sulfonic acid, and (iv) glycolipid intermembrane transfer activity monitored by Fo?rster resonance energy transfer. Analyses of our recently determined crystallographic structure of HET-C2 (1.9 Å) allowed identification of side chain electrostatic interactions that contribute to HET-C2 GLTP fold stability and can be altered by a change in pH. Side chain interactions include numerous salt bridges and interchain cation-? interactions, but not intramolecular disulfide bridges. Histidine residues are especially important for stabilizing the local positioning of the two tryptophan residues and the conformation of adjacent chains. Induction of a low-pH-induced, molten globule-like state inhibited glycolipid intermembrane transfer by the HET-C2 GLTP fold. PMID:21553912

Kenoth, Roopa; Kamlekar, Ravi Kanth; Simanshu, Dhirendra K; Gao, Yongguang; Malinina, Lucy; Prendergast, Franklyn G; Molotkovsky, Julian G; Patel, Dinshaw J; Venyaminov, Sergei Y; Brown, Rhoderick E

2011-05-19

319

Analyzing the birth and propagation of two distinct prions, [PSI+] and [Het-s](y), in yeast.  

PubMed

Various proteins, like the infectious yeast prions and the noninfectious human Huntingtin protein (with expanded polyQ), depend on a Gln or Asn (QN)-rich region for amyloid formation. Other prions, e.g., mammalian PrP and the [Het-s] prion of Podospora anserina, although still able to form infectious amyloid aggregates, do not have QN-rich regions. Furthermore, [Het-s] and yeast prions appear to differ dramatically in their amyloid conformation. Despite these differences, a fusion of the Het-s prion domain to GFP (Het-sPrD-GFP) can propagate in yeast as a prion called [Het-s](y). We analyzed the properties of two divergent prions in yeast: [Het-s](y) and the native yeast prion [PSI(+)] (prion form of translational termination factor Sup35). Curiously, the induced appearance and transmission of [PSI(+)] and [Het-s](y) aggregates is remarkably similar. Overexpression of tagged prion protein (Sup35-GFP or Het-sPrD-GFP) in nonprion cells gives rise to peripheral, and later internal, ring/mesh-like aggregates. The cells with these ring-like aggregates give rise to daughters with one (perivacuolar) or two (perivacuolar and juxtanuclear) dot-like aggregates per cell. These line, ring, mesh, and dot aggregates are not really the transmissible prion species and should only be regarded as phenotypic markers of the presence of the prions. Both [PSI(+)] and [Het-s](y) first appear in daughters as numerous tiny dot-like aggregates, and both require the endocytic protein, Sla2, for ring formation, but not propagation. PMID:20219972

Mathur, Vidhu; Taneja, Vibha; Sun, Yidi; Liebman, Susan W

2010-03-10

320

Dual conformation of H2H3 domain of prion protein in mammalian cells.  

PubMed

The concept of prion is applied to protein modules that share the ability to switch between at least two conformational states and transmit one of these through intermolecular interaction and change of conformation. Although much progress has been achieved through the understanding of prions from organisms such as Saccharomyces cerevisiae, Podospora anserina, or Aplysia californica, the criteria that qualify a protein module as a prion are still unclear. In addition, the functionality of known prion domains fails to provide clues to understand the first identified prion, the mammalian infectious prion protein, PrP. To address these issues, we generated mammalian cellular models of expression of the C-terminal two helices of PrP, H2 and H3, which have been hypothesized, among other models, to hold the replication and conversion properties of the infectious PrP. We found that the H2H3 domain is an independent folding unit that undergoes glycosylations and glycosylphosphatidylinositol anchoring similar to full-length PrP. Surprisingly, in some conditions the normally folded H2H3 was able to systematically go through a conversion process and generate insoluble proteinase K-resistant aggregates. This structural switch involves the assembly of amyloid structures that bind thioflavin S and oligomers that are reactive to A11 antibody, which specifically detects protein oligomers from neurological disorders. Overall, we show that H2H3 is a conformational switch in a cellular context and is thus suggested to be a candidate for the conversion domain of PrP. PMID:21911495

Xu, Zhou; Prigent, Stéphanie; Deslys, Jean-Philippe; Rezaei, Human

2011-09-12

321

High natural prevalence of a fungal prion.  

PubMed

Prions are infectious proteins that cause fatal diseases in mammals. Prions have also been found in fungi, but studies on their role in nature are scarce. The proposed biological function of fungal prions is debated and varies from detrimental to benign or even beneficial. [Het-s] is a prion of the fungus Podospora anserina. The het-s locus exists as two antagonistic alleles that constitute an allorecognition system: the het-s allele encoding the protein variant capable of prion formation and the het-S allele encoding a protein variant that cannot form a prion. We document here that het-s alleles, capable of prion formation, are nearly twice as frequent as het-S alleles in a natural population of 112 individuals. Then, we report a 92% prevalence of [Het-s] prion infection among the het-s isolates and find evidence of the role of the [Het-s]/het-S allorecognition system on the incidence of infection by a deleterious senescence plasmid. We explain the het-s/het-S allele ratios by the existence of two selective forces operating at different levels. We propose that during the somatic stage, the role of [Het-s]/HET-S in allorecognition leads to frequency-dependent selection for which an equilibrated frequency would be optimal. However, in the sexual cycle, the [Het-s] prion causes meiotic drive favoring the het-s allele. Our findings indicate that [Het-s] is a selected and, therefore, widespread prion whose activity as selfish genetic element is counteracted by balancing selection for allorecognition polymorphism. PMID:22691498

Debets, Alfons J M; Dalstra, Henk J P; Slakhorst, Marijke; Koopmanschap, Bertha; Hoekstra, Rolf F; Saupe, Sven J

2012-06-12

322

STITCHER: Dynamic assembly of likely amyloid and prion ?-structures from secondary structure predictions.  

PubMed

The supersecondary structure of amyloids and prions, proteins of intense clinical and biological interest, are difficult to determine by standard experimental or computational means. In addition, significant conformational heterogeneity is known or suspected to exist in many amyloid fibrils. Previous work has demonstrated that probability-based prediction of discrete ?-strand pairs can offer insight into these structures. Here, we devise a system of energetic rules that can be used to dynamically assemble these discrete ?-strand pairs into complete amyloid ?-structures. The STITCHER algorithm progressively 'stitches' strand-pairs into full ?-sheets based on a novel free-energy model, incorporating experimentally observed amino-acid side-chain stacking contributions, entropic estimates, and steric restrictions for amyloidal parallel ?-sheet construction. A dynamic program computes the top 50 structures and returns both the highest scoring structure and a consensus structure taken by polling this list for common discrete elements. Putative structural heterogeneity can be inferred from sequence regions that compose poorly. Predictions show agreement with experimental models of Alzheimer's amyloid beta peptide and the Podospora anserina Het-s prion. Predictions of the HET-s homolog HET-S also reflect experimental observations of poor amyloid formation. We put forward predicted structures for the yeast prion Sup35, suggesting N-terminal structural stability enabled by tyrosine ladders, and C-terminal heterogeneity. Predictions for the Rnq1 prion and alpha-synuclein are also given, identifying a similar mix of homogenous and heterogeneous secondary structure elements. STITCHER provides novel insight into the energetic basis of amyloid structure, provides accurate structure predictions, and can help guide future experimental studies. Proteins 2011. © 2011 Wiley Periodicals, Inc. PMID:22095906

Bryan, Allen W; O'Donnell, Charles W; Menke, Matthew; Cowen, Lenore J; Lindquist, Susan; Berger, Bonnie

2011-09-23

323

Conformational folding and stability of HET-C2 glycolipid transfer protein (GLTP)-fold: Does a molten globule-like state regulate activity?†  

PubMed Central

The glycolipid transfer protein (GLTP) superfamily is defined by the human GLTP-fold which represents a novel motif for lipid binding/transfer and for reversible interaction with membranes, i.e. peripheral amphitropic proteins. Despite limited sequence homology with human GLTP, we recently showed that HET-C2 GLTP of Podospora anserina is organized conformationally as a GLTP-fold. Currently, insights into the folding stability and conformational states that regulate GLTP-fold activity are almost nonexistent. To gain such insights into the disulfide-less GLTP-fold, we investigated the effect of changing pH on the fungal HET-C2 GLTP-fold by taking advantage of its two tryptophans and four tyrosines (compared to three tryptophans and ten tyrosines in human GLTP). pH-Induced conformational alterations were determined by changes in: i) intrinsic tryptophan fluorescence (intensity, emission wavelength maximum, anisotropy); ii) circular dichroism over the near-UV and far-UV ranges including thermal stability profiles of the derivatized molar ellipticity at 222 nm; iii) fluorescence properties of 1-anilinonaphthalene-8-sulfonic acid; iv) glycolipid inter-membrane transfer activity monitored by Förster resonance energy transfer. Analyses of our recently solved crystallographic structure of HET-C2 (1.9 Å) enabled identification of side chain electrostatic interactions that contribute to HET-C2 GLTP-fold stability and can be altered by pH change. Side-chain interactions include numerous salt bridges and interchain cation-pi interactions, but not intramolecular disulfide bridges. Histidine residues are especially important for stabilizing the local positioning of the two tryptophan residues and the conformation of adjacent chains. Induction of a low pH-induced, molten globule-like state inhibited glycolipid intermembrane transfer by the HET-C2 GLTP-fold.

Kenoth, Roopa; Kamlekar, Ravi Kanth; Simanshu, Dhirendra K.; Gao, Yongguang; Malinina, Lucy; Prendergast, Franklyn G.; Molotkovsky, Julian G.; Patel, Dinshaw J.; Venyaminov, Sergei Y.; Brown, Rhoderick E.

2011-01-01

324

Characterization of a Broad-Specificity ?-Glucanase Acting on ?-(1,3)-, ?-(1,4)-, and ?-(1,6)-Glucans That Defines a New Glycoside Hydrolase Family  

PubMed Central

Here we report the cloning of the Pa_3_10940 gene from the coprophilic fungus Podospora anserina, which encodes a C-terminal family 1 carbohydrate binding module (CBM1) linked to a domain of unknown function. The function of the gene was investigated by expression of the full-length protein and a truncated derivative without the CBM1 domain in the yeast Pichia pastoris. Using a library of polysaccharides of different origins, we demonstrated that the full-length enzyme displays activity toward a broad range of ?-glucan polysaccharides, including laminarin, curdlan, pachyman, lichenan, pustulan, and cellulosic derivatives. Analysis of the products released from polysaccharides revealed that this ?-glucanase is an exo-acting enzyme on ?-(1,3)- and ?-(1,6)-linked glucan substrates and an endo-acting enzyme on ?-(1,4)-linked glucan substrates. Hydrolysis of short ?-(1,3), ?-(1,4), and ?-(1,3)/?-(1,4) gluco-oligosaccharides confirmed this striking feature and revealed that the enzyme performs in an exo-type mode on the nonreducing end of gluco-oligosaccharides. Excision of the CBM1 domain resulted in an inactive enzyme on all substrates tested. To our knowledge, this is the first report of an enzyme that displays bifunctional exo-?-(1,3)/(1,6) and endo-?-(1,4) activities toward beta-glucans and therefore cannot readily be assigned to existing Enzyme Commission groups. The amino acid sequence has high sequence identity to hypothetical proteins within the fungal taxa and thus defines a new family of glycoside hydrolases, the GH131 family.

Lafond, Mickael; Navarro, David; Haon, Mireille; Couturier, Marie

2012-01-01

325

Hydration effects on the HET-s prion and amyloid-beta fibrillous aggregates, studied with three-dimensional molecular theory of solvation.  

PubMed

We study the thermodynamic properties of the experimental fragments of the amyloid fibril made of the HET-s prion proteins (the infectious element of the filamentous fungus Podospora anserina) and of amyloid-beta proteins (the major component of Alzheimer's disease-associated plaques) by using the three-dimensional molecular theory of solvation. The full quantitative picture of hydration effects, including the hydration thermodynamics and hydration structure around the fragments, is presented. For both the complexes, the hydration entropic effects dominate, which results in the entropic part offsetting the unfavorable energetic part of the free energy change upon the association. This is in accord with the fact that the hydrophobic cooperativity plays an essential role in the formation of amyloid fibrils. By calculating the partial molar volume of the proteins, we found that the volume change upon the association in both the systems is large and positive, with the implication that high pressure causes destabilization of the fibril. This observation is in good agreement with the recent experimental results. We also found that both the HET-s and amyloid-beta pentamers have loose intermolecular packing with voids. The three-dimensional molecular theory of solvation predicts that water molecules can be locked in the interior cavities along the fibril axis for both the HET-s and amyloid-beta proteins. We provide a detailed molecular picture of the structural water localized in the interior of the fibrils. Our results suggest that the interior hydration plays an important role in the structural stability of fibrils. PMID:18689456

Yamazaki, Takeshi; Blinov, Nikolay; Wishart, David; Kovalenko, Andriy

2008-08-08

326

Analyzing the Birth and Propagation of Two Distinct Prions, [PSI+] and [Het-s]y, in Yeast  

PubMed Central

Various proteins, like the infectious yeast prions and the noninfectious human Huntingtin protein (with expanded polyQ), depend on a Gln or Asn (QN)-rich region for amyloid formation. Other prions, e.g., mammalian PrP and the [Het-s] prion of Podospora anserina, although still able to form infectious amyloid aggregates, do not have QN-rich regions. Furthermore, [Het-s] and yeast prions appear to differ dramatically in their amyloid conformation. Despite these differences, a fusion of the Het-s prion domain to GFP (Het-sPrD-GFP) can propagate in yeast as a prion called [Het-s]y. We analyzed the properties of two divergent prions in yeast: [Het-s]y and the native yeast prion [PSI+] (prion form of translational termination factor Sup35). Curiously, the induced appearance and transmission of [PSI+] and [Het-s]y aggregates is remarkably similar. Overexpression of tagged prion protein (Sup35-GFP or Het-sPrD-GFP) in nonprion cells gives rise to peripheral, and later internal, ring/mesh-like aggregates. The cells with these ring-like aggregates give rise to daughters with one (perivacuolar) or two (perivacuolar and juxtanuclear) dot-like aggregates per cell. These line, ring, mesh, and dot aggregates are not really the transmissible prion species and should only be regarded as phenotypic markers of the presence of the prions. Both [PSI+] and [Het-s]y first appear in daughters as numerous tiny dot-like aggregates, and both require the endocytic protein, Sla2, for ring formation, but not propagation.

Mathur, Vidhu; Taneja, Vibha; Sun, Yidi

2010-01-01

327

Contribución al estudio de los ascomicetes bitunicados de Cataluña. Contribution to the study of Bitunicate Ascomycetes in Catalonia (NE Spain)  

Microsoft Academic Search

El grupo de los Loculoascomicetes reúne aquellos ascomicetes con ascomas ascostromáticos, de ontogenia ascolocular; ascos bitunicados, con dehiscencia fisitunicada y ascósporas casi siempre septadas.\\u000aEl principal objetivo de este trabajo ha consistido en elaborar un catálogo de los Ascomicetes bitunicados no liquenificados ni liquenícolas de Cataluña, destinado a dar a conocer la diversidad florística, sobre todo de zonas áridas o

Dolores Sierra López

2006-01-01

328

A transcriptomic study of grapevine (Vitis vinifera cv. Cabernet-Sauvignon) interaction with the vascular ascomycete fungus Eutypa lata.  

PubMed

Eutypa dieback is a vascular disease that may severely affect vineyards throughout the world. In the present work, microarrays were made in order (i) to improve our knowledge of grapevine (Vitis vinifera cv. Cabernet-Sauvignon) responses to Eutypa lata, the causal agent of Eutypa dieback; and (ii) to identify genes that may prevent symptom development. Qiagen/Operon grapevine microarrays comprising 14,500 probes were used to compare, under three experimental conditions (in vitro, in the greenhouse, and in the vineyard), foliar material of infected symptomatic plants (S(+)R(+)), infected asymptomatic plants (S(-)R(+)), and healthy plants (S(-)R(-)). These plants were characterized by symptom notation after natural (vineyard) or experimental (in vitro and greenhouse) infection, re-isolation of the fungus located in the lignified parts, and the formal identification of E. lata mycelium by PCR. Semi-quantitative real-time PCR experiments were run to confirm the expression of some genes of interest in response to E. lata. Their expression profiles were also studied in response to other grapevine pathogens (Erysiphe necator, Plasmopara viticola, and Botrytis cinerea). (i) Five functional categories of genes, that is those involved in metabolism, defence reactions, interaction with the environment, transport, and transcription, were up-regulated in S(+)R(+) plants compared with S(-)R(-) plants. These genes, which cannot prevent infection and symptom development, are not specific since they were also up-regulated after infection by powdery mildew, downy mildew, and black rot. (ii) Most of the genes that may prevent symptom development are associated with the light phase of photosynthesis. This finding is discussed in the context of previous data on the mode of action of eutypin and the polypeptide fraction secreted by Eutypa. PMID:20190040

Camps, Céline; Kappel, Christian; Lecomte, Pascal; Léon, Céline; Gomès, Eric; Coutos-Thévenot, Pierre; Delrot, Serge

2010-02-26

329

Lachancea lanzarotensis sp. nov., an ascomycetous yeast isolated from grapes and wine fermentation in Lanzarote, Canary Islands.  

PubMed

During the characterization of the microbiota biodiversity associated with grapes and wineries in different bioclimatic conditions of the Canary Islands (Spain), a novel yeast species was isolated from Lanzarote, the driest wine-producing region of the archipelago. Seven strains isolated from grapes, microvinifications and wineries are described. Sequence analysis of the D1/D2 domain of the LSU rDNA gene and 5.8S-ITS regions revealed that the isolates were phylogenetically a member of the genus Lachancea and are closely related to Lachancea meyersii NRRL Y-27269(T) and Lachancea nothofagi NRRL Y-48670(T). On the basis of morphological, biochemical and physiological characterization and phylogenetic analysis, a novel ascosporogenous yeast species, Lachancea lanzarotensis sp. nov., is proposed. The type strain is L2C-15(T) ( = CBS 12615(T) = CECT 13066(T)) which was isolated from grape berries of Vitis vinifera L. cv. Listán Negro red grape variety in Tinajo, Lanzarote. The MycoBank no. is MB 801390. PMID:23125316

González, Sara S; Alcoba-Flórez, Julia; Laich, Federico

2012-11-02

330

Margaretbarromyces dictyosporus gen. sp. nov.: a permineralized corticolous ascomycete from the Eocene of Vancouver Island, British Columbia  

Microsoft Academic Search

A single, permineralized ascoma resembling a pseudothecium assignable to the Pleosporales is described from the Eocene Appian Way fossil locality on Vancouver Island, British Columbia. The ascoma is globose, ostiolate, and erumpent on a fragment of the bark from an unidentified seed plant. Basally arranged asci contain large, multicelled, obovate ascospores within a single cavity or locule enclosed by a

Randal A. Mindell; Ruth A. Stockey; Graham Beard; Randolph S. Currah

2007-01-01

331

Cultivation of medicinal caterpillar fungus, Cordyceps militaris (Ascomycetes), and production of cordycepin using the spent medium from levan fermentation.  

PubMed

A process of tandem cultivation for the production of green and invaluable bioproducts (levan and Cordycepes militaris) useful for medical applications has been successfully developed. The process involves first cultivating Bacillus subtilis strain natto in sucrose medium to produce levan, followed by the subsequent cultivation of C. militaris in liquid- and solid-state cultures using the spent medium from levan fermentation as substrates. The factors affecting the cell growth and production of metabolites of C. militaris were investigated, and the various metabolites produced in the culture filtrate, mycelia, and fruiting body were analyzed. In addition, cordycepin was prepared from the solid waste medium of C. militaris. This is an excellent example in the development of cost effective biorefineries that maximize useful product formation from the available biomass. The preparation of cordycepin from solid waste medium of C. militaris using a method with high extraction efficiency and minimum solvent usage is also environmentally friendly. PMID:23796221

Wu, Fang-Chen; Chen, Yi-Lin; Chang, Shu-Ming; Shih, Ing-Lung

2013-01-01

332

Molecular Evidence that the Asexual Industrial Fungus Trichoderma reesei is a Clonal Derivative of the Ascomycete Hypocrea jecorina  

Microsoft Academic Search

The relationship of the important cellulase producing asexual fungus Trichoderma reesei to its putative teleomorphic (sexual) ancestor Hypocrea jecorina and other species of the Trichoderma sect. Longibrachiatum was studied by PCR-fingerprinting and sequence analyses of the nuclear ribosomal DNA region containing the internal transcribed spacers (ITS-1 and ITS-2) and the 5.8S rRNA gene. The differences in the corresponding ITS sequences

K. Kuhls; E. Lieckfeldt; G. J. Samuels; W. Kovacs; W. Meyer; O. Petrini; W. Gams; T. Borner; C. P. Kubicek

1996-01-01

333

Two novel ascomycetous yeast species, Wickerhamomyces scolytoplatypi sp. nov. and Cyberlindnera xylebori sp. nov., isolated from ambrosia beetle galleries.  

PubMed

Thirteen strains of yeasts were isolated from ambrosia beetle galleries at several sites in Japan. Based on the morphological and biochemical characteristics and phylogenetic analysis of the D1/D2 domain of the large subunit (LSU) rRNA gene of the yeasts, 10 strains were shown to represent a novel species of the genus Wickerhamomyces, described as Wickerhamomyces scolytoplatypi sp. nov. (type strain NBRC 11029(T) = CBS 12186(T)), and were closely related to Wickerhamomyces hampshirensis. The three other strains represented a novel species of the genus Cyberlindnera, described as Cyberlindnera xylebori sp. nov. (type strain NBRC 11048(T) = CBS 12187(T)), and were closely related to Cyberlindnera euphorbiiphila. It is suggested that these species are associated with ambrosia beetles and we consider ambrosia beetle galleries as good sources of novel yeasts. PMID:23667144

Ninomiya, Shinya; Mikata, Kozaburo; Kajimura, Hisashi; Kawasaki, Hiroko

2013-05-10

334

GzSNF1 Is Required for Normal Sexual and Asexual Development in the Ascomycete Gibberella zeae? †  

PubMed Central

The sucrose nonfermenting 1 (SNF1) protein kinase of yeast plays a central role in the transcription of glucose-repressible genes in response to glucose starvation. In this study, we deleted an ortholog of SNF1 from Gibberella zeae to characterize its functions by using a gene replacement strategy. The mycelial growth of deletion mutants (?GzSNF1) was reduced by 21 to 74% on diverse carbon sources. The virulence of ?GzSNF1 mutants on barley decreased, and the expression of genes encoding cell-wall-degrading enzymes was reduced. The most distinct phenotypic changes were in sexual and asexual development. ?GzSNF1 mutants produced 30% fewer perithecia, which matured more slowly, and asci that contained one to eight abnormally shaped ascospores. Mutants in which only the GzSNF1 catalytic domain was deleted had the same phenotype changes as the ?GzSNF1 strains, but the phenotype was less extreme in the mutants with the regulatory domain deleted. In outcrosses between the ?GzSNF1 mutants, each perithecium contained ?70% of the abnormal ascospores, and ?50% of the asci showed unexpected segregation patterns in a single locus tested. The asexual spores of the ?GzSNF1 mutants were shorter and had fewer septa than those of the wild-type strain. The germination and nucleation of both ascospores and conidia were delayed in ?GzSNF1 mutants in comparison with those of the wild-type strain. GzSNF1 expression and localization depended on the developmental stage of the fungus. These results suggest that GzSNF1 is critical for normal sexual and asexual development in addition to virulence and the utilization of alternative carbon sources.

Lee, Seung-Ho; Lee, Jungkwan; Lee, Seunghoon; Park, Eun-Hee; Kim, Ki-Woo; Kim, Myoung-Dong; Yun, Sung-Hwan; Lee, Yin-Won

2009-01-01

335

Production of the alkaloid swainsonine by a fungal endosymbiont of the ascomycete order Chaetothyriales in the host Ipomoea carnea.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Some plant species within the Convolvulaceae (morning glory family) from South America, Africa, and Australia cause a neurologic disease in grazing livestock caused by swainsonine. These convolvulaceous species including Ipomoea carnea contain the indolizidine alkaloid swainsonine, an inhibitor of ...

336

Small, basic antifungal proteins secreted from filamentous ascomycetes: a comparative study regarding expression, structure, function and potential application  

Microsoft Academic Search

Peptides and proteins with antimicrobial activity are produced throughout all kingdoms in nature, from prokaryotes to lower and higher eukaryotes, including fungi, plants, invertebrates and vertebrates. These proteins contribute to an important constitutive or induced defense mechanism of the producer against microorganisms. According to their variety in structure and function, these proteins are classified arbitrarily into groups that are based

F. Marx

2004-01-01

337

First fungal community analyses of endophytic ascomycetes associated with Viscum album ssp. austriacum and its host Pinus sylvestris.  

PubMed

The endophytic fungal communities in the hemi-parasitic epiphyte Viscum album and in its phorophyte Pinus sylvestris were compared to reveal the fungal distribution patterns in their hosts. The ITS nrDNA of 208 multiple-isolated fungal strains was sequenced and a newly designed process was applied for assigning taxon names to the obtained sequences. Furthermore, the isolates were grouped as clusters, by subjecting a sequence similarity matrix to various cluster analyses, the results of which were compared and verified by data from phylogenetic reconstructions. In contrast to a previously reported dominance of Leotiomycetes among Pinus inhabiting fungi, the endophytic communities of the two host plant species studied here were dominated by Xylariaceae (Sordariomycetes). This is in accordance with the finding that host selectivity was only a minor factor in explaining the distribution patterns of the endophytic fungi in Viscum and Pinus. Organ and, probably, tissue selectivity had a more pronounced effect. The composition and condition of the woods in the surrounding, however, are concluded to be the major determinants, due to the following circumstantial evidence: The highest similarities in fungal community compositions were found for the leaves of the two host plant species, especially when considering only the older leaves. The finding that the inhabitants of matured or senescent organs are less host-selective is in accordance with decreasing defence capabilities of ageing host plant tissue and an increased nutrient supply for saprobic taxa. Therefore, the composition of the fungal communities in ageing leaves seems to be predominantly ascribed to contagious spread and to depend on the spectrum of nearby sporulating fungal taxa. We suggest that because a broad range of suitable substrates for Xylariaceae was present in immediate vicinity of the study sites, these fungi also dominated among the recorded endophytic taxa. PMID:20943170

Peršoh, Derek; Melcher, Martina; Flessa, Fabienne; Rambold, Gerhard

2010-05-11

338

Cell polarity and hyphal morphogenesis are controlled by multiple rho-protein modules in the filamentous ascomycete Ashbya gossypii.  

PubMed Central

Polarized cell growth requires a polarized organization of the actin cytoskeleton. Small GTP-binding proteins of the Rho-family have been shown to be involved in the regulation of actin polarization as well as other processes. Hyphal growth in filamentous fungi represents an ideal model to investigate mechanisms involved in generating cell polarity and establishing polarized cell growth. Since a potential role of Rho-proteins has not been studied so far in filamentous fungi we isolated and characterized the Ashbya gossypii homologs of the Saccharomyces cerevisiae CDC42, CDC24, RHO1, and RHO3 genes. The AgCDC42 and AgCDC24 genes can both complement conditional mutations in the S. cerevisiae CDC42 and CDC24 genes and both proteins are required for the establishment of actin polarization in A. gossypii germ cells. Agrho1 mutants show a cell lysis phenotype. Null mutant strains of Agrho3 show periodic swelling of hyphal tips that is overcome by repolarization and polar hyphal growth in a manner resembling the germination pattern of spores. Thus different Rho-protein modules are required for distinct steps during polarized hyphal growth of A. gossypii.

Wendland, J; Philippsen, P

2001-01-01

339

The mechanism of toxicity in HET-S/HET-s prion incompatibility.  

PubMed

The HET-s protein from the filamentous fungus Podospora anserina is a prion involved in a cell death reaction termed heterokaryon incompatibility. This reaction is observed at the point of contact between two genetically distinct strains when one harbors a HET-s prion (in the form of amyloid aggregates) and the other expresses a soluble HET-S protein (96% identical to HET-s). How the HET-s prion interaction with HET-S brings about cell death remains unknown; however, it was recently shown that this interaction leads to a relocalization of HET-S from the cytoplasm to the cell periphery and that this change is associated with cell death. Here, we present detailed insights into this mechanism in which a non-toxic HET-s prion converts a soluble HET-S protein into an integral membrane protein that destabilizes membranes. We observed liposomal membrane defects of approximately 10 up to 60 nm in size in transmission electron microscopy images of freeze-fractured proteoliposomes that were formed in mixtures of HET-S and HET-s amyloids. In liposome leakage assays, HET-S has an innate ability to associate with and disrupt lipid membranes and that this activity is greatly enhanced when HET-S is exposed to HET-s amyloids. Solid-state nuclear magnetic resonance (NMR) analyses revealed that HET-s induces the prion-forming domain of HET-S to adopt the ?-solenoid fold (previously observed in HET-s) and this change disrupts the globular HeLo domain. These data indicate that upon interaction with a HET-s prion, the HET-S HeLo domain partially unfolds, thereby exposing a previously buried ?34-residue N-terminal transmembrane segment. The liberation of this segment targets HET-S to the membrane where it further oligomerizes, leading to a loss of membrane integrity. HET-S thus appears to display features that are reminiscent of pore-forming toxins. PMID:23300377

Seuring, Carolin; Greenwald, Jason; Wasmer, Christian; Wepf, Roger; Saupe, Sven J; Meier, Beat H; Riek, Roland

2012-12-27

340

Transcription of sterol ? 5,6-desaturase and sterol 14?-demethylase is induced in the plant pathogenic ascomycete, Leptosphaeria maculans, during treatment with a triazole fungicide  

Microsoft Academic Search

Two genes whose derived amino acid sequences closely resemble the ergosterol biosynthetic enzymes, sterol ?5,6-desaturase (erg3) and sterol 14?-demethylase (erg11), were cloned from the plant pathogenic fungus Leptosphaeria maculans. Transcript levels of both these genes increased following exposure of L. maculans to the triazole fungicide, flutriafol, which specifically inhibits the ergosterol biosynthetic pathway. This induction may be due to a

Katherine M Griffiths; Barbara J Howlett

2002-01-01

341

Potential of Metarhizium anisopliae (Metsch.) Sorokin (Ascomycetes, hypocreales) in the control of Bonagota salubricola (Meyrick) (Lepidoptera, Tortricidae) and its compatibility with chemical insecticides.  

PubMed

Several insects are harmful to apples grown in Brazil, especially the leafroller Bonagota salubricola (Lepidoptera, Tortricidae), usually controlled with chemical insecticides. The purpose of the present study was to investigate the use of Metarhizium anisopliae strains in the control of the apple leafroller, by assessing their virulence to B. salubricola larvae in bioassays with suspensions of 2 x 10? to 2 x 10? conidia/mL as well as their relationship with protease expression. The most effective strain underwent a compatibility test with chemical insecticides. The M. anisopliae E6 strain showed a good performance, with up to 88% mortality and a LT?? of 1.66 days. The virulence was positively correlated with a higher enzymatic activity. The E6 strain was compatible with tebufenozide, evidencing its potential to control B. salubricola. PMID:21180896

Anhalt, F A; Azevedo, J L; Sugayama, R L; Specht, A; Barros, N M

2010-11-01

342

SPORE-EXPULSION RATES AND EXTENTS OF BLADE OCCUPATION BY ASCOMYCETES OF THE SMOOTH-CORDGRASS STANDING-DECAY SYSTEM. (R825147)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

343

Mitochondrial Carnitine-Dependent Acetyl Coenzyme A Transport Is Required for Normal Sexual and Asexual Development of the Ascomycete Gibberella zeae  

PubMed Central

Fungi have evolved efficient metabolic mechanisms for the exact temporal (developmental stages) and spatial (organelles) production of acetyl coenzyme A (acetyl-CoA). We previously demonstrated mechanistic roles of several acetyl-CoA synthetic enzymes, namely, ATP citrate lyase and acetyl-CoA synthetases (ACSs), in the plant-pathogenic fungus Gibberella zeae. In this study, we characterized two carnitine acetyltransferases (CATs; CAT1 and CAT2) to obtain a better understanding of the metabolic processes occurring in G. zeae. We found that CAT1 functioned as an alternative source of acetyl-CoA required for lipid accumulation in an ACS1 deletion mutant. Moreover, deletion of CAT1 and/or CAT2 resulted in various defects, including changes to vegetative growth, asexual/sexual development, trichothecene production, and virulence. Although CAT1 is associated primarily with peroxisomal CAT function, mislocalization experiments showed that the role of CAT1 in acetyl-CoA transport between the mitochondria and cytosol is important for sexual and asexual development in G. zeae. Taking these data together, we concluded that G. zeae CATs are responsible for facilitating the exchange of acetyl-CoA across intracellular membranes, particularly between the mitochondria and the cytosol, during various developmental stages.

Son, Hokyoung; Min, Kyunghun; Lee, Jungkwan; Choi, Gyung Ja; Kim, Jin-Cheol

2012-01-01

344

DNA sequence characterization and molecular evolution of MAT1 and MAT2 mating-type loci of the self-compatible ascomycete mold Neosartorya fischeri.  

PubMed

Degenerate PCR and chromosome-walking approaches were used to identify mating-type (MAT) genes and flanking regions from the homothallic (sexually self-fertile) euascomycete fungus Neosartorya fischeri, a close relative of the opportunistic human pathogen Aspergillus fumigatus. Both putative alpha- and high-mobility-group-domain MAT genes were found within the same genome, providing a functional explanation for self-fertility. However, unlike those in many homothallic euascomycetes (Pezizomycotina), the genes were not found adjacent to each other and were termed MAT1 and MAT2 to recognize the presence of distinct loci. Complete copies of putative APN1 (DNA lyase) and SLA2 (cytoskeleton assembly control) genes were found bordering the MAT1 locus. Partial copies of APN1 and SLA2 were also found bordering the MAT2 locus, but these copies bore the genetic hallmarks of pseudogenes. Genome comparisons revealed synteny over at least 23,300 bp between the N. fischeri MAT1 region and the A. fumigatus MAT locus region, but no such long-range conservation in the N. fischeri MAT2 region was evident. The sequence upstream of MAT2 contained numerous candidate transposase genes. These results demonstrate a novel means involving the segmental translocation of a chromosomal region by which the ability to undergo self-fertilization may be acquired. The results are also discussed in relation to their significance in indicating that heterothallism may be ancestral within the Aspergillus section Fumigati. PMID:17384199

Rydholm, C; Dyer, P S; Lutzoni, F

2007-03-23

345

DNA Sequence Characterization and Molecular Evolution of MAT1 and MAT2 Mating-Type Loci of the Self-Compatible Ascomycete Mold Neosartorya fischeri?  

PubMed Central

Degenerate PCR and chromosome-walking approaches were used to identify mating-type (MAT) genes and flanking regions from the homothallic (sexually self-fertile) euascomycete fungus Neosartorya fischeri, a close relative of the opportunistic human pathogen Aspergillus fumigatus. Both putative alpha- and high-mobility-group-domain MAT genes were found within the same genome, providing a functional explanation for self-fertility. However, unlike those in many homothallic euascomycetes (Pezizomycotina), the genes were not found adjacent to each other and were termed MAT1 and MAT2 to recognize the presence of distinct loci. Complete copies of putative APN1 (DNA lyase) and SLA2 (cytoskeleton assembly control) genes were found bordering the MAT1 locus. Partial copies of APN1 and SLA2 were also found bordering the MAT2 locus, but these copies bore the genetic hallmarks of pseudogenes. Genome comparisons revealed synteny over at least 23,300 bp between the N. fischeri MAT1 region and the A. fumigatus MAT locus region, but no such long-range conservation in the N. fischeri MAT2 region was evident. The sequence upstream of MAT2 contained numerous candidate transposase genes. These results demonstrate a novel means involving the segmental translocation of a chromosomal region by which the ability to undergo self-fertilization may be acquired. The results are also discussed in relation to their significance in indicating that heterothallism may be ancestral within the Aspergillus section Fumigati.

Rydholm, C.; Dyer, P. S.; Lutzoni, F.

2007-01-01

346

Draft Genome Sequence of the Ascomycete Phaeoacremonium aleophilum Strain UCR-PA7, a Causal Agent of the Esca Disease Complex in Grapevines  

PubMed Central

Grapevine infections by Phaeoacremonium aleophilum in association with other pathogenic fungi cause complex and economically important vascular diseases. Here we present the first draft of the P. aleophilum genome sequence, which comprises 624 scaffolds with a total length of 47.5 Mb (L50, 45; N50, 336 kb) and 8,926 predicted protein-coding genes.

Blanco-Ulate, Barbara; Rolshausen, Philippe

2013-01-01

347

Cch1 and Mid1 Are Functionally Required for Vegetative Growth under Low-Calcium Conditions in the Phytopathogenic Ascomycete Botrytis cinerea  

PubMed Central

In the filamentous phytopathogen Botrytis cinerea, the Ca2+/calcineurin signaling cascade has been shown to play an important role in fungal growth, differentiation, and virulence. This study deals with the functional characterization of two components of this pathway, the putative calcium channel proteins Cch1 and Mid1. The cch1 and mid1 genes were deleted, and single and double knockout mutants were analyzed during different stages of the fungal life cycle. Our data indicate that Cch1 and Mid1 are functionally required for vegetative growth under conditions of low extracellular calcium, since the growth of both deletion mutants is strongly impaired when they are exposed to the Ca2+-chelating agents EGTA and 1,2-bis(o-aminophenoxy)ethane-N,N,N?,N?-tetraacetic acid (BAPTA). The impact of external Ca2+ was investigated by supplementing with CaCl2 and the ionophore A23187, both of which resulted in elevated growth for all mutants. However, deletion of either gene had no impact on germination, sporulation, hyphal morphology, or virulence. By use of the aequorin reporter system to measure intracellular calcium levels, no differences between the mutant strains and the wild type were obtained. Localization studies revealed a subcellular distribution of the Mid1–green fluorescent protein (GFP) fusion protein in network-like filaments, probably the endoplasmic reticulum (ER) membranes, indicating that Mid1 is not a plasma membrane-located calcium channel in B. cinerea.

Harren, Karin

2013-01-01

348

Aqueous extracts of Cordyceps militaris (Ascomycetes) lower the levels of plasma glucose by activating the cholinergic nerve in streptozotocin-induced diabetic rats.  

PubMed

In our previous research, Cordyceps militaris (CM) had a hypoglycemic effect in normal rats. In this study we wanted to elucidate whether CM also had an effect on diabetic rats. Twelve rats with streptozotocin-induced diabetes were separated randomly into 2 groups. First, aqueous extracts of CM 10 mg/kg (CM group) or saline (control group) was fed to the rats; then the plasma glucose levels were assayed. Second, the signaling proteins IRS-1 and GLUT-4 collected from the muscle were detected. Finally, another 2 groups of rats were injected with atropine 0.1 mg/kg intraperitoneally just before the CM/saline feeding, and the assays mentioned above were repeated. Blood glucose decreased 7.2% in the CM group but only 1.5% in the control group (P < 0.05). The IRS-1 signal was 2.9-fold higher than actin in the CM group but only 0.8-fold higher in the control group (P < 0.005). In GLUT-4 signal, the difference was 1.7- vs. 0.6-fold, respectively, compared with actin (P < 0.05). However, atropine injection made CM-induced hypoglycemia or elevation of IRS-1 and GLUT-4 not significant. In conclusion, CM had a hypoglycemic effect in diabetic rats and atropine blocked it. Therefore, the cholinergic activation also was considered to be involved in the hypoglycemic effect of CM in rats with streptozotocin-induced diabetes. PMID:23662615

Cheng, Yu-Wen; Chen, Ying-I; Tzeng, Chung-Yuh; Chang, Chin-Hsien; Lee, Yu-Chen; Chen, Hong-Chen; Tsai, Chin-Chun; Hsu, Tai-Hao; Lai, Yiu-Kay; Chang, Shih-Liang

2013-01-01

349

Purifying selection and birth-and-death evolution in the class II hydrophobin gene families of the ascomycete Trichoderma\\/Hypocrea  

Microsoft Academic Search

BACKGROUND: Hydrophobins are proteins containing eight conserved cysteine residues that occur uniquely in mycelial fungi. Their main function is to confer hydrophobicity to fungal surfaces in contact with air or during attachment of hyphae to hydrophobic surfaces of hosts, symbiotic partners or themselves resulting in morphogenetic signals. Based on their hydropathy patterns and solubility characteristics, hydrophobins are divided into two

Christian P. kubicek; Scott E. Baker; Christian Gamauf; Charles M. Kenerley; Irina S. Druzhinina

2008-01-01

350

The Wood Rot Ascomycete Xylaria polymorpha Produces a Novel GH78 Glycoside Hydrolase That Exhibits ?-l-Rhamnosidase and Feruloyl Esterase Activities and Releases Hydroxycinnamic Acids from Lignocelluloses  

PubMed Central

Soft rot (type II) fungi belonging to the family Xylariaceae are known to substantially degrade hardwood by means of their poorly understood lignocellulolytic system, which comprises various hydrolases, including feruloyl esterases and laccase. In the present study, several members of the Xylariaceae were found to exhibit high feruloyl esterase activity during growth on lignocellulosic materials such as wheat straw (up to 1,675 mU g?1) or beech wood (up to 80 mU g?1). Following the ester-cleaving activity toward methyl ferulate, a hydrolase of Xylaria polymorpha was produced in solid-state culture on wheat straw and purified by different steps of anion-exchange and size-exclusion chromatography to apparent homogeneity (specific activity, 2.2 U mg?1). The peptide sequence of the purified protein deduced from the gene sequence and verified by de novo peptide sequencing shows high similarity to putative ?-l-rhamnosidase sequences belonging to the glycoside hydrolase family 78 (GH78; classified under EC 3.2.1.40). The purified enzyme (98 kDa by SDS-PAGE, 103 kDa by size-exclusion chromatography; pI 3.7) converted diverse glycosides (e.g., ?-l-rhamnopyranoside and ?-l-arabinofuranoside) but also natural and synthetic esters (e.g., chlorogenic acid, hydroxycinnamic acid glycoside esters, veratric acid esters, or p-nitrophenyl acetate) and released free hydroxycinnamic acids (ferulic and coumaric acid) from arabinoxylan and milled wheat straw. These catalytic properties strongly suggest that X. polymorpha GH78 is a multifunctional enzyme. It is the first fungal enzyme that combines glycosyl hydrolase with esterase activities and may help this soft rot fungus to degrade lignocelluloses.

Nghi, Do Huu; Bittner, Britta; Kellner, Harald; Jehmlich, Nico; Ullrich, Rene; Pecyna, Marek J.; Nousiainen, Paula; Sipila, Jussi; Huong, Le Mai; Hofrichter, Martin

2012-01-01

351

Ascomycete communities in the rhizosphere of field-grown wheat are not affected by introductions of genetically modified Pseudomonas putida WCS358r  

Microsoft Academic Search

Summary A long-term field experiment (1999-2002) was con- ducted to monitor effects on the indigenous micro- flora of Pseudomonas putida WCS358r and two transgenic derivatives constitutively producing phenazine-1-carboxylic acid (PCA) or 2,4- diacetylphloroglucinol (DAPG). The strains were intro- duced as seed coating on wheat into the same field plots each year. Rhizosphere populations of asco- mycetes were analysed using denaturing

Mareike Viebahn; Rogier Doornbos; Karel Wernars; Leendert C. van Loon; Eric Smit; Peter A. H. M. Bakker

2005-01-01

352

The Aspergillus nidulans stress response transcription factor StzA is ascomycete-specific and shows species-specific polymorphisms in the C-terminal region.  

PubMed

Orthologues of the Aspergillus nidulans gene stzA were identified and characterised in an additional 19 fungi. These orthologues were restricted to, and found within all the Pezizomycotina subphyla of the Ascomycota, for which data are available, but not the Saccharomycotina or Taphrinomycotina subphyla. Intron analysis indicated that both intron loss and gain have occurred in this gene. The orthologous proteins demonstrate considerable size variation (between 663 and 897 amino acids); with almost all this variability accounted for by a hyper-variable region that is carboxy terminal to the zinc finger region. The Hypocrea jecorina orthologue (ACE1) has the binding site 5'AGGCA. There is evidence of competition, or interaction, between the ACE1/StzA and AreA binding sites in promoters of stzA and its orthologues, as well as genes involved in the metabolism of amino acids. The A. nidulans and A. fumigatus cpcA promoters have seven potential ACE1/StzA binding sites, six of which are highly conserved in position. Two very closely positioned sites are conserved across 14 of the 19 fungi analysed. Potential CpcA binding sites (5'TGAC/GTCA) have been identified between -50 and -170bp of the ATG start in the promoters of 16 of the stzA orthologues. PMID:18678248

Chilton, I J; Delaney, C E; Barham-Morris, J; Fincham, D A; Hooley, P; Whitehead, M P

2008-07-17

353

In vitro antibacterial activities of aqueous extracts from Algerian desert truffles (Terfezia and Tirmania, Ascomycetes) against Pseudomonas aeruginosa and Staphylococcus aureus.  

PubMed

The aim of this study is to evaluate the in vitro effects of aqueous extracts of three species of Algerian desert truffles (Terfezia claveryi, T. leonis, and Tirmania nivea) on the growth of Pseudomonas aeruginosa and Staphylococcus aureus. The antimicrobial activity of the three aqueous extracts was tested using the agar well diffusion and kinetic bacterial growth curves methods. The aqueous extracts of Terfezia claveryi and Tirmania nivea were found to possess a very powerful antibacterial activity against both S. aureus and P. aeruginosa using agar well diffusion. Using 4% and 11% of the aqueous extracts of T. claveryi and T. nivea in the growth medium of S. aureus caused a significant inhibition of S. aureus growth by 86.48% and 99.09%, respectively. The aqueous extracts of T. claveryi and T. nivea were found to cause a significant inhibition of the growth of P. aeruginosa by 71.11% and 100%, respectively. However, the aqueous extract of Terfecia leonis did not show any antibacterial activity. Therefore, T. claveryi and Tirmania nivea can be considered a source of natural therapeutic agents that can be used to treat eye infections caused by resistant bacteria such as P. aeruginosa and S. aureus. PMID:22181843

Gouzi, Hicham; Belyagoubi, Larbi; Abdelali, Khadidja Nesrine; Khelifi, Adila

2011-01-01

354

Structural and functional characterization of the GalNAc/Gal-specific lectin from the phytopathogenic ascomycete Sclerotinia sclerotiorum (Lib.) de Bary.  

PubMed

The lectin found in mycelium and sclerotes of the phytopathogenic fungus Sclerotinia sclerotiorum is a homodimer consisting of two identical non-covalently bound subunits of 16,000 Da. CD spectra analysis revealed that the S. sclerotiorum agglutinin (SSA) contains predominantly beta-sheet structures. SSA exhibits specificity towards GalNAc whereby the hydroxyls at positions 4 and 6 of the pyranose ring play a key role in the interaction with simple sugars. The carbohydrate-binding site of SSA can also accommodate disaccharides. The N-terminal sequence of SSA shares no significant similarity with any other protein except a lectin from the Sclerotiniaceae species Ciborinia camelliae. A comparison of SSA and the lectins from C. camelliae and some previously characterized lectins indicates that the Sclerotiniaceae lectins form a homogeneous family of fungal lectins. This newly identified lectin family, which is structurally unrelated to any other family of fungal lectins, is most probably confined to the Ascomycota. PMID:12901882

Candy, Laure; Van Damme, Els J M; Peumans, Willy J; Menu-Bouaouiche, Laurence; Erard, Monique; Rougé, Pierre

2003-08-22

355

Cch1 and Mid1 are functionally required for vegetative growth under low-calcium conditions in the phytopathogenic ascomycete Botrytis cinerea.  

PubMed

In the filamentous phytopathogen Botrytis cinerea, the Ca(2+)/calcineurin signaling cascade has been shown to play an important role in fungal growth, differentiation, and virulence. This study deals with the functional characterization of two components of this pathway, the putative calcium channel proteins Cch1 and Mid1. The cch1 and mid1 genes were deleted, and single and double knockout mutants were analyzed during different stages of the fungal life cycle. Our data indicate that Cch1 and Mid1 are functionally required for vegetative growth under conditions of low extracellular calcium, since the growth of both deletion mutants is strongly impaired when they are exposed to the Ca(2+)-chelating agents EGTA and 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA). The impact of external Ca(2+) was investigated by supplementing with CaCl(2) and the ionophore A23187, both of which resulted in elevated growth for all mutants. However, deletion of either gene had no impact on germination, sporulation, hyphal morphology, or virulence. By use of the aequorin reporter system to measure intracellular calcium levels, no differences between the mutant strains and the wild type were obtained. Localization studies revealed a subcellular distribution of the Mid1-green fluorescent protein (GFP) fusion protein in network-like filaments, probably the endoplasmic reticulum (ER) membranes, indicating that Mid1 is not a plasma membrane-located calcium channel in B. cinerea. PMID:23475703

Harren, Karin; Tudzynski, Bettina

2013-03-08

356

Mitochondrial carnitine-dependent acetyl coenzyme A transport is required for normal sexual and asexual development of the ascomycete Gibberella zeae.  

PubMed

Fungi have evolved efficient metabolic mechanisms for the exact temporal (developmental stages) and spatial (organelles) production of acetyl coenzyme A (acetyl-CoA). We previously demonstrated mechanistic roles of several acetyl-CoA synthetic enzymes, namely, ATP citrate lyase and acetyl-CoA synthetases (ACSs), in the plant-pathogenic fungus Gibberella zeae. In this study, we characterized two carnitine acetyltransferases (CATs; CAT1 and CAT2) to obtain a better understanding of the metabolic processes occurring in G. zeae. We found that CAT1 functioned as an alternative source of acetyl-CoA required for lipid accumulation in an ACS1 deletion mutant. Moreover, deletion of CAT1 and/or CAT2 resulted in various defects, including changes to vegetative growth, asexual/sexual development, trichothecene production, and virulence. Although CAT1 is associated primarily with peroxisomal CAT function, mislocalization experiments showed that the role of CAT1 in acetyl-CoA transport between the mitochondria and cytosol is important for sexual and asexual development in G. zeae. Taking these data together, we concluded that G. zeae CATs are responsible for facilitating the exchange of acetyl-CoA across intracellular membranes, particularly between the mitochondria and the cytosol, during various developmental stages. PMID:22798392

Son, Hokyoung; Min, Kyunghun; Lee, Jungkwan; Choi, Gyung Ja; Kim, Jin-Cheol; Lee, Yin-Won

2012-07-13

357

Aging as Evolution-Facilitating Program and a Biochemical Approach to Switch It Off  

NASA Astrophysics Data System (ADS)

A concept is presented considering aging of living organisms as a final step of their ontogenetic program. It is assumed that such an aging program was invented by biological evolution to facilitate the evolutionary process. Indications are summarized suggesting that controlled production of toxic forms of oxygen (so called reactive oxygen species) by respiring intracellular organelles (mitochondria) is an obligatory component of the aging program. First results of a research project devoted to an attempt to interrupt aging program by antioxidants specifically addressed to mitochondria have been described. Within the framework of the project, antioxidants of a new type (SkQ) were synthesized. SkQs are composed of (i) plastoquinone (an antioxidant moiety), (ii) a penetrating cation, and (iii) a decane or pentane linker. Using planar bilayer phospholipid membranes, we selected SkQ derivatives of the highest penetrability, namely plastoquinonyl decyl triphenylphosphonium (SkQ1), plastoquinonyl decyl rhodamine 19 (SkQR1), and methylplastoquinonyl decyl triphenylphosphonium (SkQ3). Anti- and prooxidant properties of these substances and also of ubiquinonyl-decyl-triphenylphosphonium (MitoQ) were tested in isolated mitochondria. Micromolar concentrations of cationic quinones are found to be very strong prooxidants, but in the lower (sub-micromolar) concentrations they display antioxidant activity which decreases in the series SkQ1 = SkQR1 > SkQ3 > MitoQ. Thus, the window between the anti- and prooxidant effects is the smallest for MitoQ and the largest for SkQ1 and SkQR1. SkQ1 is rapidly reduced by complex III of the mitochondrial respiratory chain, i.e. it is a rechargeable antioxidant. Extremely low concentrations of SkQ1 and SkQR1 completely arrest the H2O2-induced apoptosis in human fibroblasts and HeLa cells (for SkQ1, C 1/2 = 8 · 10-9M). Higher concentrations of SkQ1 are required to block necrosis initiated by reactive oxygen species (ROS). In mice, SkQ1 decelerates the development of three types of accelerated aging (progeria) and also of normal aging, and this effect is especially demonstrative at early stages of aging. The same pattern is shown in invertebrates (Drosophila and Daphnia), and fungus (Podospora anserina). In mammals, the effect of SkQs on aging is accompanied by inhibition of development of such age-related diseases as osteoporosis, involution of thymus, cataract, retinopathy, etc. SkQ1 manifests a strong therapeutic action on some already pronounced retinopathies, in particular, congenital retinal dysplasia. With drops containing 250 nM SkQ1, vision is recovered in 66 of 96 animals (dogs, cats and horses) who became blind because of retinopathy. SkQ1-containing drops instilled into eyes prevent the loss of sight in rabbits suffering from experimental uveitis and restore vision to animals that had already become blind due to this pathology. A favorable effect is also achieved in experimental glaucoma in rabbits. Moreover, the pretreatment of rats with 0.2 nM SkQ1 significantly decreases the H2O2-induced arrhythmia of the isolated heart. SkQ1 strongly reduces the damaged area in myocardial infarction or stroke and prevents the death of animals from kidney infarction. In p53-/- mice, SkQ1 decreases the ROS level in the spleen cells and inhibits appearance of lymphomas which are the main cause of death of such animals. As a result, the lifespan increases. SkQs look like promising drugs to treat aging and age-related diseases.

Skulachev, Vladimir P.

358

An attempt to prevent senescence: a mitochondrial approach.  

PubMed

Antioxidants specifically addressed to mitochondria have been studied to determine if they can decelerate senescence of organisms. For this purpose, a project has been established with participation of several research groups from Russia and some other countries. This paper summarizes the first results of the project. A new type of compounds (SkQs) comprising plastoquinone (an antioxidant moiety), a penetrating cation, and a decane or pentane linker has been synthesized. Using planar bilayer phospholipid membrane (BLM), we selected SkQ derivatives with the highest permeability, namely plastoquinonyl-decyl-triphenylphosphonium (SkQ1), plastoquinonyl-decyl-rhodamine 19 (SkQR1), and methylplastoquinonyldecyltriphenylphosphonium (SkQ3). Anti- and prooxidant properties of these substances and also of ubiquinonyl-decyl-triphenylphosphonium (MitoQ) were tested in aqueous solution, detergent micelles, liposomes, BLM, isolated mitochondria, and cell cultures. In mitochondria, micromolar cationic quinone derivatives were found to be prooxidants, but at lower (sub-micromolar) concentrations they displayed antioxidant activity that decreases in the series SkQ1=SkQR1>SkQ3>MitoQ. SkQ1 was reduced by mitochondrial respiratory chain, i.e. it is a rechargeable antioxidant. Nanomolar SkQ1 specifically prevented oxidation of mitochondrial cardiolipin. In cell cultures, SkQR1, a fluorescent SkQ derivative, stained only one type of organelles, namely mitochondria. Extremely low concentrations of SkQ1 or SkQR1 arrested H(2)O(2)-induced apoptosis in human fibroblasts and HeLa cells. Higher concentrations of SkQ are required to block necrosis initiated by reactive oxygen species (ROS). In the fungus Podospora anserina, the crustacean Ceriodaphnia affinis, Drosophila, and mice, SkQ1 prolonged lifespan, being especially effective at early and middle stages of aging. In mammals, the effect of SkQs on aging was accompanied by inhibition of development of such age-related diseases and traits as cataract, retinopathy, glaucoma, balding, canities, osteoporosis, involution of the thymus, hypothermia, torpor, peroxidation of lipids and proteins, etc. SkQ1 manifested a strong therapeutic action on some already pronounced retinopathies, in particular, congenital retinal dysplasia. With drops containing 250 nM SkQ1, vision was restored to 67 of 89 animals (dogs, cats, and horses) that became blind because of a retinopathy. Instillation of SkQ1-containing drops prevented the loss of sight in rabbits with experimental uveitis and restored vision to animals that had already become blind. A favorable effect of the same drops was also achieved in experimental glaucoma in rabbits. Moreover, the SkQ1 pretreatment of rats significantly decreased the H(2)O(2) or ischemia-induced arrhythmia of the isolated heart. SkQs strongly reduced the damaged area in myocardial infarction or stroke and prevented the death of animals from kidney ischemia. In p53(-/-) mice, 5 nmol/kgxday SkQ1 decreased the ROS level in the spleen and inhibited appearance of lymphomas to the same degree as million-fold higher concentration of conventional antioxidant NAC. Thus, SkQs look promising as potential tools for treatment of senescence and age-related diseases. PMID:19159610

Skulachev, Vladimir P; Anisimov, Vladimir N; Antonenko, Yuri N; Bakeeva, Lora E; Chernyak, Boris V; Erichev, Valery P; Filenko, Oleg F; Kalinina, Natalya I; Kapelko, Valery I; Kolosova, Natalya G; Kopnin, Boris P; Korshunova, Galina A; Lichinitser, Mikhail R; Obukhova, Lidia A; Pasyukova, Elena G; Pisarenko, Oleg I; Roginsky, Vitaly A; Ruuge, Enno K; Senin, Ivan I; Severina, Inna I; Skulachev, Maxim V; Spivak, Irina M; Tashlitsky, Vadim N; Tkachuk, Vsevolod A; Vyssokikh, Mikhail Yu; Yaguzhinsky, Lev S; Zorov, Dmitry B

2008-12-29

359

Stochastic population dynamics of clonal plants: Numerical experiments with ramet and genet models  

Microsoft Academic Search

Dynamics of ramer and genet populations were analyzed by use of stochastic matrix models. Based on field data, population\\u000a development and extinction rates during 50 simulated years were estimated for ramet populations of three speciesPotentilla anserina, Rubus saxatilis andLinnaea borealis. Only small initial populations (below 125–250 ramets), experienced a detectable risk of extinction within this time interval.\\u000a ForP. anserina andR.

Ove Eriksson

1994-01-01

360

Transcription of sterol Delta(5,6)-desaturase and sterol 14alpha-demethylase is induced in the plant pathogenic ascomycete, Leptosphaeria maculans, during treatment with a triazole fungicide.  

PubMed

Two genes whose derived amino acid sequences closely resemble the ergosterol biosynthetic enzymes, sterol Delta(5,6)-desaturase (erg3) and sterol 14alpha-demethylase (erg11), were cloned from the plant pathogenic fungus Leptosphaeria maculans. Transcript levels of both these genes increased following exposure of L. maculans to the triazole fungicide, flutriafol, which specifically inhibits the ergosterol biosynthetic pathway. This induction may be due to a decrease in ergosterol content or to abnormal levels of the ergosterol precursor, 24-methylene dihydrolanosterol. PMID:12445649

Griffiths, Katherine M; Howlett, Barbara J

2002-11-19

361

Optimization of solid state culture conditions for the production of adenosine, cordycepin, and D-mannitol in fruiting bodies of medicinal caterpillar fungus Cordyceps militaris (L.:Fr.) Link (Ascomycetes).  

PubMed

In general, Cordyceps sinensis is much more popular than C. militaris, though both species contain quite similar bioactive ingredients and exhibit medicinal activities. Many bioactive ingredients have been isolated from C. militaris, such as adenosine, cordycepin, D-mannitol, and exopolysaccharides. C. militaris is claimed to have extensive pharmacological properties, such as: anti-inflammatory; anti-fatigue; anti-bacterial; anti-diabetic; improve lung, liver, and kidney functions; to be beneficial for treating cancer as well as male and female sexual dysfunctions. C. militaris is fast gaining momentum for its so-called health benefits, and it is often used as a substitute for C. sinensis. In view of the growing popularity of C. militaris, nowadays C. militaris cultivation for stroma is also done. There is a great diversity of compounds from different strains of Cordyceps and different artificially cultivated products. This study is to determine the optimum culture parameters integrated with substrate of choice to bring the indoor-cultivated C. militaris to a higher and more consistent level of quality. To achieve the above objective, the resultant products after growth were analyzed for adenosine, cordycepin, and D-mannitol using the high-performance liquid chromatography method. The optimum culture condition to produce a high level of adenosine is by using millet as solid substrate. It must be cultivated in the dark for the first 7 days and harvested on day 40. The optimum culture condition to produce a high level of cordycepin is by using soybean as solid substrate. It must be cultivated in the dark for the first 14 days and harvested on day 50. While a high level of D-mannitol is achieved with millet as the solid substrate. It must be kept in the dark for the first 7 days and harvested on day 50. The adenosine level decreased and cordycepin increased from day 40 of culture to day 50 generally. PMID:22506578

Lim, LekTeng; Lee, ChiaYen; Chang, EngThuan

2012-01-01

362

78 FR 25623 - Importation of Fresh Beans, Shelled or in Pods, From Jordan Into the Continental United States  

Federal Register 2010, 2011, 2012, 2013

...Lepidoptera: Lycaenidae........ Medium Fungus...diversispora Ascomycete: Mitosporic fungi... Medium (Bub[aacute]k) Boerema...during packing. The remaining pest, the fungus Phoma exigua var. diversispora,...

2013-05-02

363

A new species of Jahnulales from Las Ilusiones Lagoon, Tabasco, Mexico  

Technology Transfer Automated Retrieval System (TEKTRAN)

During a study on biodiversity of freshwater ascomycetes from an urban tropical lagoon, an ascomycete with similar morphology to species of Jahnulales was obtained. Smooth surface test blocks of Pinus sp., Bucida sp., Cedrela sp. and Tabebuia sp. were submerged in pairs close to a private house whar...

364

Phylogenetic Characterization and In Situ Detection of a Cytophaga-Flexibacter-Bacteroides Phylogroup Bacterium in Tuber borchii Vittad. Ectomycorrhizal Mycelium  

Microsoft Academic Search

Mycorrhizal ascomycetous fungi are obligate ectosymbionts that colonize the roots of gymnosperms and angiosperms. In this paper we describe a straightforward approach in which a combination of morphological and molecular methods was used to survey the presence of potentially endo- and epiphytic bacteria associated with the ascomycetous ectomycorrhizal fungus Tuber borchii Vittad. Universal eubacterial primers specific for the 5* and

ELENA BARBIERI; LUCIA POTENZA; ISMAELA ROSSI; DAVIDE SISTI; GIOVANNA GIOMARO; SIMONA ROSSETTI; CLAUDIA BEIMFOHR; VILBERTO STOCCHI

2000-01-01

365

Purification and characterization of mycoferritin from Aspergillus parasiticus (255)  

Microsoft Academic Search

As intracellular iron storage molecules, only hydroxymate type siderophores have been reported in ascomycetes and basidiomycetes. This is the first report documenting the presence of mycoferritin in ascomycetes. The fungus, Aspergillus parasiticus (255), is capable of producing mycoferritin only upon induction with iron in yeast extract sucrose (YES) medium. The same has been purified from Aspergillus sps by application of

J. Shashidhar; R. B. Sashidhar; Vijay Deshpande

2005-01-01

366

Observations on chytridiaceous parasites of Phanerogams  

Microsoft Academic Search

1.A Physoderma on Agropyron repens, common quack grass, infects in the laboratory all other congeneric hosts used.2.Within the Tribe Hordeae, to which Agropyron belongs, representatives of nine genera support growth of some phase of the fungus. The roseaceous host Potentilla anserina is also infected. Other plants associated in the field with infected Agropyron and known to harbor Physoderma are not

F. K. Sparrow; Joyce E. Griffin

1964-01-01

367

GENETIC DIVERSITY OF HUMAN PATHOGENIC MEMBERS OF THE FUSARIUM OXYSPORUM COMPLEX INFERRED FROM GENE GENALOGIES & AFLP ANALYSES: EVIDENCE FOR THE RECENT DISPERSION OF A GEOGRAPHICALLY WIDESPREAD CLONAL LINEAGE & NOSOCOMIAL ORIG  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fusarium oxysporum is a phylogenetically diverse monophyletic complex of filamentous ascomycetous fungi responsible for localized and systemic life-threatening opportunistic infections, respectively, in immunocompetent and severely neutropenic patients. Although members of this complex were isolate...

368

Didymella rabiei primary inoculum release from chickpea debris in relation to weather variables in the Pacific Northwest of the United States.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Didymella rabiei (anamorph: Ascochyta rabiei), the ascomycete fungus that causes Ascochyta blight of chickpea, produces pseudothecia on overwintered chickpea debris. Ascospores released from pseudothecia are thought to constitute an important primary inoculum source for Ascochyta blight epidemics i...

369

N-acetonylbenzamides and their use as fungicides  

US Patent & Trademark Office Database

Certain N-acetonylbenzamides exhibit low phytotoxicity and are useful for control of a wide range of fungi, including phytopathogenic fungi of the classes Oomycetes, Ascomycetes, Deuteromycetes and Basidiomycetes.

Michelotti; Enrique L. (Fort Washington, PA); Raney; Robert R. (Newtown Square, PA); Young; David H. (Ambler, PA)

1993-10-19

370

Genetic structure of the fungal grapevine pathogen Eutypa lata from four continents  

Technology Transfer Automated Retrieval System (TEKTRAN)

Deciphering the geographic origins of pathogens and elucidating the population biology of these microscopic organisms are necessary steps to establish effective disease-control strategies. The generalist ascomycete fungus Eutypa lata causes Eutypa dieback of grapevine (Vitis vinifera) worldwide. To ...

371

Peritonitis Due to Blastobotrys proliferans in a Patient Undergoing Continuous Ambulatory Peritoneal Dialysis?  

PubMed Central

Blastobotrys proliferans is an ascomycetous yeast never previously reported as a human pathogen. Here we report a case of peritonitis due to Blastobotrys proliferans in a 46-year-old man undergoing peritoneal dialysis.

Quirin, N.; Desnos-Ollivier, M.; Cantin, J. F.; Valery, J. C.; Doussy, Y.; Goursaud, R.; Dromer, F.; Tivollier, J. M.

2007-01-01

372

Role of Marine Fungi in the Biochemistry of the Oceans. V. Patterns of Constitutive Nutritional Growth Responses.  

National Technical Information Service (NTIS)

The observations reported extend to efforts to obtain a complete picture of physiological activity by testing the ability of representative marine Ascomycetes and Deuteromycetes to utilize an adequate array of high purity compounds as carbon or nitrogen s...

P. L. Sguros J. Rodrigues J. Simms

1972-01-01

373

Hyperproducing Cellulase Microorganism.  

National Technical Information Service (NTIS)

A process and a microorganism for synthesizing cellulase enzymes and soluble proteins are described. The microorganism is a mutant strain of an Ascomycete fungus capable of the synthesizing cellulases and soluble proteins in the presence of a growth mediu...

B. J. Gallo

1983-01-01

374

Analysis of Internal Transcribed Spacer (ITS) Regions of rRNA Genes in Fungal Communities in a Southeastern U.S. Salt Marsh  

Microsoft Academic Search

The ascomycete community colonizing decaying Spartina alterniflora blades in a southeastern U.S. salt marsh was characterized by analysis of internal transcribed spacer (ITS) regions of fungal rRNA genes. ITS sequences were amplified with ascomycete-specific primers from DNA extracted from S. alterniflora blades at two stages of decay (early and late) and were identified based on sequence analysis of a companion

A. Buchan; S. Y. Newell; J. I. L. Moreta; M. A. Moran

2002-01-01

375

A phylogenomic approach to reconstructing the diversification of serine proteases in fungi.  

PubMed

Using a phylogenomic approach with 10 fungi of very different virulence and habitat, we determined that there was substantial diversification of subtilase-type proteases early in ascomycete history (with subsequent loss in many lineages) but with no comparable diversification of trypsins. Patterns of intron loss and the degree of divergence between paralogues demonstrated that the proliferation of proteinase K subtilases and subtilisin type subtilases seen in pathogenic ascomycetes (Metarhizium anisopliae, Magnaporthe grisea, Fusarium graminearum) occurred after the basidiomycete/ascomycete split but predated radiation of ascomycete lineages. This suggests that the early ascomycetes had a lifestyle that selected for multiple proteases, whereas the current disparity in gene numbers between ascomycete lineages results from retention of genes in at least some pathogens that have been lost in other lineages (yeasts, Aspergillus nidulans, Neurospora crassa). A similar prevailing trend towards lineage specific gene loss of trypsins in saprophytes and some pathogens suggests that their phylogenetic breadth will have been much wider in early fungi than currently. PMID:15525405

Hu, G; Leger, R J St

2004-11-01

376

Meiotic drive in fungi: Chromosomal elements that cause fratricide and distort genetic ratios  

Microsoft Academic Search

Fungal Spore killers (Sk), studied most extensively inNeurospora and to a lesser extent inPodospora, Gibberella andCochliobolus, cause the death of ascospores (= meiospores) that do not contain the killer (Skk) element. When a Spore killer is heterozygous (SkK× Sks) inNeurospora, every ascus (= meiocyte) contains four normal-sized, black, viable ascospores (SkK), and four ascospores that are tiny, unpigmented and unviable

Namboori B. Raju

1996-01-01

377

Alien vs. native plants in a Patagonian wetland: elemental ratios and ecosystem stoichiometric impacts  

Microsoft Academic Search

Wetlands are subject to invasion by exotic plant species, especially during the dry season when they resemble terrestrial\\u000a systems; therefore, terrestrial plants could exploit this situation to colonize this environment. We analyzed P. anserina invading Patagonian wetlands in terms of elemental ratios that would modify wetland stoichiometry due to organic matter inputs.\\u000a We studied the elemental relationship (carbon\\/nitrogen\\/phosphorus) of P.

Florencia Cuassolo; Esteban Balseiro; Beatriz Modenutti

378

The Genome and Development-Dependent Transcriptomes of Pyronema confluens: A Window into Fungal Evolution  

PubMed Central

Fungi are a large group of eukaryotes found in nearly all ecosystems. More than 250 fungal genomes have already been sequenced, greatly improving our understanding of fungal evolution, physiology, and development. However, for the Pezizomycetes, an early-diverging lineage of filamentous ascomycetes, there is so far only one genome available, namely that of the black truffle, Tuber melanosporum, a mycorrhizal species with unusual subterranean fruiting bodies. To help close the sequence gap among basal filamentous ascomycetes, and to allow conclusions about the evolution of fungal development, we sequenced the genome and assayed transcriptomes during development of Pyronema confluens, a saprobic Pezizomycete with a typical apothecium as fruiting body. With a size of 50 Mb and ?13,400 protein-coding genes, the genome is more characteristic of higher filamentous ascomycetes than the large, repeat-rich truffle genome; however, some typical features are different in the P. confluens lineage, e.g. the genomic environment of the mating type genes that is conserved in higher filamentous ascomycetes, but only partly conserved in P. confluens. On the other hand, P. confluens has a full complement of fungal photoreceptors, and expression studies indicate that light perception might be similar to distantly related ascomycetes and, thus, represent a basic feature of filamentous ascomycetes. Analysis of spliced RNA-seq sequence reads allowed the detection of natural antisense transcripts for 281 genes. The P. confluens genome contains an unusually high number of predicted orphan genes, many of which are upregulated during sexual development, consistent with the idea of rapid evolution of sex-associated genes. Comparative transcriptomics identified the transcription factor gene pro44 that is upregulated during development in P. confluens and the Sordariomycete Sordaria macrospora. The P. confluens pro44 gene (PCON_06721) was used to complement the S. macrospora pro44 deletion mutant, showing functional conservation of this developmental regulator.

Traeger, Stefanie; Altegoer, Florian; Freitag, Michael; Gabaldon, Toni; Kempken, Frank; Kumar, Abhishek; Marcet-Houben, Marina; Poggeler, Stefanie; Stajich, Jason E.; Nowrousian, Minou

2013-01-01

379

The Genome and Development-Dependent Transcriptomes of Pyronema confluens: A Window into Fungal Evolution.  

PubMed

Fungi are a large group of eukaryotes found in nearly all ecosystems. More than 250 fungal genomes have already been sequenced, greatly improving our understanding of fungal evolution, physiology, and development. However, for the Pezizomycetes, an early-diverging lineage of filamentous ascomycetes, there is so far only one genome available, namely that of the black truffle, Tuber melanosporum, a mycorrhizal species with unusual subterranean fruiting bodies. To help close the sequence gap among basal filamentous ascomycetes, and to allow conclusions about the evolution of fungal development, we sequenced the genome and assayed transcriptomes during development of Pyronema confluens, a saprobic Pezizomycete with a typical apothecium as fruiting body. With a size of 50 Mb and ?13,400 protein-coding genes, the genome is more characteristic of higher filamentous ascomycetes than the large, repeat-rich truffle genome; however, some typical features are different in the P. confluens lineage, e.g. the genomic environment of the mating type genes that is conserved in higher filamentous ascomycetes, but only partly conserved in P. confluens. On the other hand, P. confluens has a full complement of fungal photoreceptors, and expression studies indicate that light perception might be similar to distantly related ascomycetes and, thus, represent a basic feature of filamentous ascomycetes. Analysis of spliced RNA-seq sequence reads allowed the detection of natural antisense transcripts for 281 genes. The P. confluens genome contains an unusually high number of predicted orphan genes, many of which are upregulated during sexual development, consistent with the idea of rapid evolution of sex-associated genes. Comparative transcriptomics identified the transcription factor gene pro44 that is upregulated during development in P. confluens and the Sordariomycete Sordaria macrospora. The P. confluens pro44 gene (PCON_06721) was used to complement the S. macrospora pro44 deletion mutant, showing functional conservation of this developmental regulator. PMID:24068976

Traeger, Stefanie; Altegoer, Florian; Freitag, Michael; Gabaldon, Toni; Kempken, Frank; Kumar, Abhishek; Marcet-Houben, Marina; Pöggeler, Stefanie; Stajich, Jason E; Nowrousian, Minou

2013-09-19

380

Relationships among genera of the Saccharomycotina (Ascomycota) from multigene phylogenetic analysis of type species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phylogenetic relatedness among ascomycetous yeast genera (subphylum Saccharomycotina, phylum Ascomycota) has been uncertain. In the present study, type species of 70 currently recognized genera are compared from divergence in the nearly entire nuclear gene sequences for large subunit rRNA, small sub...

381

Ein neuentdeckter Wirkstoff (Vitamin-T-Komplex)  

Microsoft Academic Search

Summary The recently discovered vitamin T complex can be extracted from different kinds of yeast and ascomycets, but also from insects that feed on such micro-organisms. In case of a sufficient amount of protein in the food, vitamin T causes an “acceleration of development”; thus it is possible that insects may attain new and varied proportions of their bodies, such

Wilhelm Goetsch

1947-01-01

382

Identification of potentially safe promising fungal cell factories for the production of polyketide natural food colorants using chemotaxonomic rationale  

Microsoft Academic Search

BACKGROUND: Colorants derived from natural sources look set to overtake synthetic colorants in market value as manufacturers continue to meet the rising demand for clean label ingredients – particularly in food applications. Many ascomycetous fungi naturally synthesize and secrete pigments and thus provide readily available additional and\\/or alternative sources of natural colorants that are independent of agro-climatic conditions. With an

Sameer AS Mapari; Anne S Meyer; Ulf Thrane; Jens C Frisvad

2009-01-01

383

FVABC1, A FUSARIUM VERTICILLIOIDES GENE ENCODING AN ATP-BINDING CASSETTE PROTEIN, MAY BE REQUIRED FOR TOLERANCE OF PHYTOANTICIPINS PRODUCED BY CORN (ZEA MAYS)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The ascomycete Fusarium verticillioides, a common pathogen of corn (Zea mays) throughout the world, often causes significant concern due to production of mycotoxins such as fumonisins. Corn produces the phytoanticipins 6-methoxy-2-benzoxazolinone (MBOA) and 2-benzoxazolinone (BOA) as a general chemi...

384

DISEASE CONTROL VIA UNDERSTANDING MOLECULAR DETERMINANTS OF SEXUAL REPRODUCTION  

Technology Transfer Automated Retrieval System (TEKTRAN)

Gibberella zeae (anamorph Fusarium graminearum), a self fertile (homothallic) ascomycete, causes wheat head blight and corn ear rot, destructive diseases that impose a serious economic toll on North American farmers. Damage includes both yield loss due to kernel rot and reduced quality resulting fr...

385

A glimpse of lignicolous marine fungi occurring in coastal water bodies of Tamil Nadu (India)  

Microsoft Academic Search

In the present investigation, a total of 51 marine fungi were obtained from wood samples collected from four locations of Tamil Nadu (Tuthukudi, Chennai, Kanyakumari and Pichavaram), India. Out of these 51, 28 were ascomycetes, one was basidiomycete and 22 were mitosporic fungi. Maximum fungal diversity was encountered from Tuthukudi, followed by Chennai, Kanyakumari, and the minimum from Pichavaram. Periconia

Gayatri R. Nambiar; Kalathil Raveendran; Zhao Changxing; Cheruth Abdul Jaleel

2008-01-01

386

Genetic Diversity of Polyketide Synthase/Nonribosomal Peptide Synthetase Genes in Isolates of the Barley Net Blotch Fungus Pyrenophora teres f. teres  

Technology Transfer Automated Retrieval System (TEKTRAN)

Polyketide synthases (PKSs) and nonribosomal peptide synthetases (NRPSs) are multifunctional enzymes responsible for biosynthesis of diverse small molecules (e.g., mycotoxins and phytotoxins) in filamentous ascomycetes. Both PKS and NRPS genes are present in fungal genomes as large gene families but...

387

Sex-linked phenotypic divergence in the hermaphrodite fungus Neurospora tetrasperma  

Technology Transfer Automated Retrieval System (TEKTRAN)

Here we present a study of the molecular phenotype linked to a large region of suppressed recombination (extending over ~ 7 Mbp and >1,500 genes) surrounding the mating-type (mat) locus of the filamentous ascomycete Neurospora tetrasperma. While the remainder of the genome is largely homoallelic, th...

388

Epidemiological Investigation of Vaginal Saccharomyces cerevisiae Isolates by a Genotypic Method  

Microsoft Academic Search

Saccharomyces cerevisiae is a ubiquitous, ascomycetous yeast, and vaginitis caused by this organism has been reported only very rarely. The aim of the present investigation was to assess the epidemiological relatedness of a group of vaginal and commercial S. cerevisiae isolates by a previously reported genetic typing method, which divided the isolates into two broad groups with numerous subtypes. Nineteen

MICHAEL J. MCCULLOUGH; KARL V. CLEMONS; CLAUDIO FARINA; JOHN H. MCCUSKER; DAVID A. STEVENS

1998-01-01

389

Asterotexis cucurbitacearum, a poorly known pathogen of Cucurbitaceae new to Costa Rica, Grenada and Panama  

Microsoft Academic Search

A pathogenic bitunicate ascomycetous fungus, identified as Asterotexis cucurbitacearum, was found repeatedly on living leaves of Cucurbita pepo (gourd) and Sechium edule (chayote) in Panama. A. cucurbitacearum represents a new report for Panama and S. edule is a new host plant for this fungus. Based on an examination of herbarium specimens, this species is also reported for the first time

Yuriza Guerrero; Tina Antje Hofmann; Carl Williams; Marco Thines; Meike Piepenbring

2011-01-01

390

Release of Dimethylsulfide from Dimethylsulfoniopropionate by Plant-Associated Salt Marsh Fungi  

Microsoft Academic Search

The range of types of microbes with dimethylsulfoniopropionate (DMSP) lyase capability (enzymatic release of dimethylsulfide (DMS) from DMSP) has recently been expanded from bacteria and eukaryotic algae to include fungi (a species of the genus Fusarium (M. K. Bacic and D. C. Yoch, Appl. Environ. Microbiol. 64:106-111, 1998)). Fungi (especially ascomycetes) are the predominant decomposers of shoots of smooth cordgrass,

M. K. BACIC; S. Y. NEWELL; D. C. YOCH

1998-01-01

391

Purification and characterization of laccase from Monocillium indicum Saxena  

Microsoft Academic Search

An ascomycete Monocillium indicum Saxena producing extracellular laccase was isolated. The culture filtrate on native polyacrylamide gel electrophoresis (PAGE) revealed four bands of activity, one of which was a major one. The major laccase band, a glycoprotein, was purified and characterized. Gel filtration chromatography showed that the relative molecular weight (Mr) of laccase was 100 000. On sodium dodecyl sulphate

Geeta D. Thakker; Christine S. Evans; K. Koteswara Rao

1992-01-01

392

A Morphological and Molecular Perspective of Trichoderma viride: Is It One or Two Species?  

Microsoft Academic Search

Trichoderma (Ascomycetes, Hypocreales) strains that have warted conidia are traditionally identified as T. viride, the type species of Trichoderma. However, two morphologically distinct types of conidial warts (I and II) have been found. Because each type corresponds to a unique mitochondrial DNA pattern, it has been questioned whether T. viride comprises more than one species. Combined molecular data (sequences of

ELKE LIECKFELDT; GARY J. SAMUELS; HELGARD I. NIRENBERG; ORLANDO PETRINI; Systematic Botany

1999-01-01

393

New Phomopsis species identified from wood cankers in eastern North American vineyards.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Phomopsis cane and leaf spot, caused by the Ascomycete fungus Phomopsis viticola, is a destructive fruit and foliar disease in eastern North American vineyards. The pathogen typically attacks green tissues, but can also cause wood cankers, presumably due to infection of pruning wounds, as is the cas...

394

The tomato powdery mildew fungus Oidium neolycopersici  

Microsoft Academic Search

SUMMARY Pathogen: Powdery mildew fungus; Ascomycete although sexual stage is yet to be found; an obligate biotroph. Identification: Superficial mycelium with hyaline hyphae; unbranched erect conidiophores; conidia, ellipsoid-ovoid or doliform, 22 - 46 ? 10 -20 ? m, lack fibrosin bodies; conidia formed singly, rarely in short chains of 2 - 6 conidia; appressoria lobed to multi- lobed, rarely nipple-shaped.

Hannah Jones; John M. Whipps; Sarah Jane Gurr

2001-01-01

395

DEVELOPMENT AND PROGNOSIS OF DECAY IN THE SAPWOOD OF LIVING TREES  

Microsoft Academic Search

Fungal growth within reaction zones of London plane (Platanus x hispanico Muenchh.), beech (Fagus sylvatica L.) and large-leaved lime (Tilia platyphyllos Scop.) infected with three basidiomycetes Inonotus hispidus (Bull.:Fr.) Karst., Ganoderma adspersum (Schulz.) Donk, Fomitopsis pinicola (Fr.) Karst, and one ascomycete Ustulina deusta (Fr.) Petrak, was studied in naturally colonised and artificially inoculated wood. With the exception of F. pinicola

F. W. M. R. Schwarze

2001-01-01

396

Cryptic speciation and recombination in the aflatoxin-producing fungus Aspergillus flavus  

Microsoft Academic Search

Aspergillus flavus, like approximately one- third of ascomycete fungi, is thought to be cosmopolitan and clonal because it has uniform asexual morphology. A. flavus produces af latoxin on nuts, grains, and cotton, and assump- tions about its life history are being used to develop strategies for its biological control. We tested the assumptions of clonality and conspecificity in a sample

DAVID M. GEISER; J OHN I. PITT; JOHN W. TAYLOR

1998-01-01

397

Yeasts associated with insects in agricultural areas of Perugia, Italy  

Microsoft Academic Search

The association of some yeast species with insects (Dermaptera, Rynchota, Diptera, Hymenoptera) collected around Perugia, Italy was investigated. Whole or specif- ic body contents (gut, hemolymph and fat body) of over 450 insects were studied. Isolates, identified by conventional and molecular analyses, were represented by both ascomycetous (64%) and basidiomycetous (36%) strains. While Pichia guilliermondii and Rhodotorula mucilaginosa were the

L. ZACCHI; A. VAUGHAN-MARTINI

398

Regulation of gene expression in industrial fungi: Trichoderma  

Microsoft Academic Search

The genus Trichoderma comprises a group of filamentous ascomycetes that are now widely used in industrial applications because of their ability to produce extracellular hydrolases in large amounts. In addition, strong inducible promoters together with high secretory capacity have made Trichoderma an attractive host for heterologous protein production. Several promoters of genes encoding hydrolytic enzymes have been investigated in detail

R. Mach; S. Zeilinger

2003-01-01

399

[Cordyceps sinensis, a fungi used in the Chinese traditional medicine].  

PubMed

Cordyceps sinensis (Berk.) Sacc. is an ascomycete fungus known in China since antiquity, which is still being used today. A summary, showing relevant papers about this fungus, regarding habitat, history, marketing, consumption, nomenclature, pharmacological composition, culture and medical use, is presented. PMID:18095756

Illana Esteban, Carlos

2007-12-31

400

In vivo stimulatory effect of Cordyceps sinensis mycelium and its fractions on reproductive functions in male mouse  

Microsoft Academic Search

Cordyceps sinensis (CS), an Ascomycetes fungus parasitic to Lepidoptera larvae, has been traditionally used as nutritious food for the enhancement on sexual performance and the restitution of impairment in sexual function in Chinese society. We have previously demonstrated the stimulatory effect of CS and its fractions on steroidogenesis both on primary mouse Leydig cells and MA-10 mouse Leydig tumor cells.

Yuan-Li Huang; Sew-Fen Leu; Bi-Ching Liu; Chia-Chin Sheu; Bu-Miin Huang

2004-01-01

401

Millerozyma Kurtzman & M. Suzuki (2010)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycete yeast genus Millerozyma and is to be published in "The Yeasts, A Taxonomic Study, 5th edition." The genus Millerozyma has two described species that were earlier assigned to the genus Pichia, but gene sequence analysis showed that the species, now reclassified ...

402

Lipomyces Lodder & Kreger-van Rij (1952)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The chapter describes the ascomycete yeast genus Lipomyces and is to be published in “The Yeasts, A Taxonomic Study, 5th edition.” The genus Lipomyces has 16 known species, most of which are isolated exclusively from soil. Cultures of Lipomyces are generally slimy because of the copious production...

403

Starmera Y. Yamada, Higashi, Ando & Mikata (1997)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycete yeast genus Starmera and is to be published in "The Yeasts, A Taxonomic Study, 5th edition." The genus Starmera was described for three species initially assigned to the genus Pichia, but these species proved quite distant from the type species of Pichia when a...

404

A microbial population-species interface: nested cladistic and coalescent inference with multilocus data  

Microsoft Academic Search

Using sequence data from seven nuclear loci in 385 isolates of the haploid, plant parasitic, ascomycete fungus, Sclerotinia , divergence times of populations and of species were distin- guished. The evolutionary history of haplotypes on both population and species scales was reconstructed using a combination of parsimony, maximum likelihood and coalescent methods, implemented in a specific order. Analysis of site

I. Carbone; L. M. Kohn

2001-01-01

405

Aspects of sexual reproduction in Mycosphaerella species on wheat and barley : genetic studies on specificity, mapping, and fungicide resistance  

Microsoft Academic Search

Mycosphaerella species are haploid ascomycetes that cause major economic losses in crops that include cereals, citrus fruits, and bananas, among others. Two organisms in this genus are Mycosphaerella graminicola (Fuckel) .I. Schröt (anamorph Sepioria tritici) and Septoriapasserinii. M graminicola is the causal agent of septoria tritici blotch of both bread wheat and durum wheat species, and S. passerinii causes septoria

S. B. Ware

2006-01-01

406

Analyses of expressed sequence tags from the maize foliar pathogen Cercospora zeae-maydis identify novel genes expressed during vegetative, infectious, and reproductive growth  

Microsoft Academic Search

BACKGROUND: The ascomycete fungus Cercospora zeae-maydis is an aggressive foliar pathogen of maize that causes substantial losses annually throughout the Western Hemisphere. Despite its impact on maize production, little is known about the regulation of pathogenesis in C. zeae-maydis at the molecular level. The objectives of this study were to generate a collection of expressed sequence tags (ESTs) from C.

Burton H Bluhm; Braham Dhillon; Erika A Lindquist; Gert HJ Kema; Stephen B Goodwin; Larry D Dunkle

2008-01-01

407

Cryptic Sexuality in Aspergillus parasiticus and A. flavus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ascomycetous fungi of the genus Aspergillus comprise a wide variety of species of biotechnological importance (e.g. A. sojae, A. oryzae, A. niger) as well as pathogens and toxin producers (e.g. A. flavus, A. parasiticus, A. fumigatus, A. nidulans). With the exception of A. nidulans, which is a homot...

408

The WW Domain Protein PRO40 Is Required for Fungal Fertility and Associates with Woronin Bodies  

Microsoft Academic Search

Fruiting body formation in ascomycetes is a highly complex process that is under polygenic control and is a fundamental part of the fungal sexual life cycle. However, the molecular determinants regulating this cellular process are largely unknown. Here we show that the sterile pro40 mutant is defective in a 120-kDa WW domain protein that plays a pivotal role in fruiting

Ines Engh; Christian Wurtz; Konstanze Witzel-Schlomp; Hai Yu Zhang; Birgit Hoff; Minou Nowrousian; Hanspeter Rottensteiner; Ulrich Kuck

2007-01-01

409

Isocitrate Lyase Is Essential for Pathogenicity of the Fungus Leptosphaeria maculans to Canola (Brassica napus)  

Microsoft Academic Search

Received 17 June 2002\\/Accepted 29 July 2002 A pathogenicity gene has been identified in Leptosphaeria maculans, the ascomycetous fungus that causes blackleg disease of canola (Brassica napus). This gene encodes isocitrate lyase, a component of the glyoxylate cycle, and is essential for the successful colonization of B. napus. It was identified by a reverse genetics approach whereby a plasmid conferring

Alexander Idnurm; Barbara J. Howlett

2002-01-01

410

Miconazole: An effective antifungal agent for plant tissue culture  

Microsoft Academic Search

Miconazole at concentrations between 5 and 20 mgl-1 inhibited hyphal growth and sporulation in a wide range of fungi commonly associated with plants. These fungi included 4 Oomycetes, 11 Deuteromycetes, 4 Ascomycetes and 4 common airborne contaminants of plant tissue culture. The phytotoxicity of 20 mgl-1 miconazole was also tested against a wide range of in vitro plant cultures. Shoot

J. L. Tynan; A. J. Conner; R. C. Macknight; R. T. M. Poulter

1993-01-01

411

Trigonopsis Schachner emend. Kurtzman & Robnett (2007)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The chapter describes the asexual ascomycete yeast genus Trigonopsis and is to be published in “The Yeasts, A Taxonomic Study, 5th edition.” The genus Trigonopsis has four known species and T. variabilis is famous for producing triangular cells, whereas the other described species do not. Multigen...

412

Detection and identification of decay fungi in spruce wood by restriction fragment length polymorphism analysis of amplified genes encoding rRNA.  

PubMed

We have developed a DNA-based assay to reliably detect brown rot and white rot fungi in wood at different stages of decay. DNA, isolated by a series of CTAB (cetyltrimethylammonium bromide) and organic extractions, was amplified by the PCR using published universal primers and basidiomycete-specific primers derived from ribosomal DNA sequences. We surveyed 14 species of wood-decaying basidiomycetes (brown-rot and white-rot fungi), as well as 25 species of wood-inhabiting ascomycetes (pathogens, endophytes, and saprophytes). DNA was isolated from pure cultures of these fungi and also from spruce wood blocks colonized by individual isolates of wood decay basidiomycetes or wood-inhabiting ascomycetes. The primer pair ITS1-F (specific for higher fungi) and ITS4 (universal primer) amplified the internal transcribed spacer region from both ascomycetes and basidiomycetes from both pure culture and wood, as expected. The primer pair ITS1-F (specific for higher fungi) and ITS4-B (specific for basidiomycetes) was shown to reliably detect the presence of wood decay basidiomycetes in both pure culture and wood; ascomycetes were not detected by this primer pair. We detected the presence of decay fungi in wood by PCR before measurable weight loss had occurred to the wood. Basidiomycetes were identified to the species level by restriction fragment length polymorphisms of the internal transcribed spacer region. PMID:11055916

Jasalavich, C A; Ostrofsky, A; Jellison, J

2000-11-01

413

Endophytic hyphal compartmentalization is required for successful symbiotic Ascomycota association with root cells  

Microsoft Academic Search

Root endophytic fungi are seen as promising alternatives to replace chemical fertilizers and pesticides in sustainable and organic agriculture systems. Fungal endophytes structure formations play key roles in symbiotic intracellular association with plant-roots. To compare the morphologies of Ascomycete endophytic fungi in wheat, we analyzed growth morphologies during endophytic development of hyphae within the cortex of living vs. dead root

Lobna Abdellatif; Sadok Bouzid; Susan Kaminskyj; Vladimir Vujanovic

2009-01-01

414

The obligately lichenicolous genus Lichenoconium represents a novel lineage in the Dothideomycetes  

Microsoft Academic Search

Lichenicolous fungi are obligately lichen-associated organisms that have evolved many times throughout the Ascomycota and Basidiomycota. Approximately 20% of lichenicolous ascomycetes are recognized only from asexual (anamorphic) characteristics, so the phylogenetic position of many groups has never been resolved. Here we present the first molecular phylogeny of Lichenoconium, a genus of strictly asexual, obligately lichenicolous species with broad geographic distributions

James D. Lawrey; Paul Diederich; Matthew P. Nelsen; Masoumeh Sikaroodi; Patrick M. Gillevet; A. Maarten Brand; Pieter van den Boom

2011-01-01

415

A hypothesis for the initiation of genetic recombination in eukaryotes  

Microsoft Academic Search

Initiation of genetic recombination at meiosis in Ascomycete fungi is thought to occur from fixed sites, at least in the majority of events. The simplest way to initiate recombination from fixed sites would be if an endonuclease recognized them and cut one strand of the DNA duplex to allow formation of asymmetric hybrid DNA, as proposed in the Meselson-Radding model

Paul Markham; Harold L. K. Whitehouse

1982-01-01

416

RFLP Markers Show Genetic Recombination in Botryotinia fuckeliana (Botrytis cinerea) and Transposable Elements Reveal Two Sympatric Species  

Microsoft Academic Search

Molecular markers revealed that Botryotinia jiickeliana (the teleomorph of Botrytis cinerea), a haploid, filamentous, heterothallic ascomycete, contained a large amount of intrapopulation genetic variation. The markers were used to determine the mode of reproduction and the population structure of this fungus. We did not detect any differentiation between isolates from different organs, collection dates, varieties of grape, or locations in

Tatiana Giraud; Dominique Fortini; Caroline Levis; Pierre Leroux; Yves Brygoo

417

Immune Response of Mormon Crickets that Survived Infection by Beauveria Bassiana  

Technology Transfer Automated Retrieval System (TEKTRAN)

Beauveria bassiana is an entomopathogenic Ascomycete fungus that serves as a biological control agent of Mormon crickets (Anabrus simplex Haldeman) and other grasshopper pests. To measure the dose dependent response of Mormon crickets to fungal attack, we applied B. bassiana strain GHA topically to...

418

A Relationship between Carotenoid Accumulation and the Distribution of Species of the Fungus Neurospora in Spain  

Microsoft Academic Search

The ascomycete fungus Neurospora is present in many parts of the world, in particular in tropical and subtropical areas, where it is found growing on recently burned vegetation. We have sampled the Neurospora population across Spain. The sampling sites were located in the region of Galicia (northwestern corner of the Iberian peninsula), the province of Cáceres, the city of Seville,

Eva M. Luque; Gabriel Gutiérrez; Laura Navarro-Sampedro; María Olmedo; Julio Rodríguez-Romero; Carmen Ruger-Herreros; Víctor G. Tagua; Luis M. Corrochano

2012-01-01

419

Phylogenetic classification of peltigeralean fungi (Peltigerales, Ascomycota) based on ribosomal RNA small and large subunits  

Microsoft Academic Search

To provide a comprehensive molecular phylogeny for peltigeralean fungi and to establish a classification based on monophyly, phylogenetic analyses were carried out on sequences from the nuclear ribosomal large (LSU) and small (SSU) subunits obtained from 113 individuals that represent virtually all main lineages of ascomycetes. Analyses were also conducted on a subset of 77 individuals in which the ingroup

JOLANTA MIADLIKOWSKA; F. Lutzoni

2004-01-01

420

Zygotorulaspora Kurtzman (2003)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycete yeast genus Zygotorulaspora and is to be published in “The Yeasts, A Taxonomic Study, 5th edition.” The two species in this genus were at different times placed in the genera Torulaspora, Zygosaccharomyces and Saccharomyces. Multigene phylogenetic analysis sho...

421

Torulaspora Lindner (1904)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycete yeast genus Torulaspora and is to be published in "The Yeasts, A Taxonomic Study," 5th edition. The genus Torulaspora is closely related to Zygosaccharomyces and Zygotorulaspora and has six described species. Many of the species are worldwide in distribution. ...

422

Evolutionary History of Vegetative Reproduction in Porpidia s.l. (Lichen-Forming Ascomycota)  

Microsoft Academic Search

The evolutionary history of gains and losses of vegetative reproductive propagules (soredia) in Porpidia s.l., a group of lichen-forming ascomycetes, was clarified using Bayesian Markov chain Monte Carlo (MCMC) approaches to monophyly tests and a combined MCMC and maximum likelihood approach to ancestral character state reconstructions. The MCMC framework provided confidence estimates for the reconstructions of relationships and ancestral character

Jutta Buschbom; Daniel Barker

2006-01-01

423

Schwanniomyces Klocker emend. M. Suzuki & Kurtzman (2010)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycete yeast genus Schwanniomyces and is to be published in The Yeasts, A Taxonomic Study, 5th edn. The genus Schwanniomyces has seven assigned species, many worldwide in distribution. Schwanniomyces is one of the few yeast genera with species that seem to live in th...

424

Cephaloascus Hanawa (1920)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycete yeast genus Cephaloascus and is to be published in “The Yeasts, A Taxonomic Study, 5th edition.” The genus Cephaloascus has two species. One, C. albidus, has been isolated from spoiled cranberry pumace, and the second, C. fragrans, is predominantly isolated fr...

425

LACHANCEA MEYERSII SP. NOV., AN ASCOSPOROGENOUS YEAST FROM MANGROVE REGIONS IN THE BAHAMA ISLANDS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Lachancea meyersii sp. nov. (type strain NRRL Y-27269, CBS 8951, ML 3925) is described from mangrove habitats in the northern Bahamas Islands. This species is homothallic, forms spherical ascospores in asci that become deliquescent and is delineated from other ascomycetous yeasts by sequence analys...

426

Intertidal marine fungi from San Juan Island and comments on temperate water species  

Microsoft Academic Search

Temperate marine fungi are a distinct ecological group and differ from those found in tropical habitats, with the exception of a few cosmopolitan species. Sixty-two marine fungi were collected at San Juan Island, a temperate site, in 1994. The most frequently collected species were: Halosphaeria appendiculata, Monodictyspelagica, Halosarpheia trullifera, Ceriosporopsis halima and a new ascomycete. Eight records of Capronia ciliomaris

E. B. G. Jones; L. L. P. Vrijmoed; S. A. Alias

1998-01-01

427

First radiobiological results of LDEF-1 experiment A0015 with Arabidopsis seed embryos and Sordaria fungus spores  

Microsoft Academic Search

This article highlights the first results of investigations on the general vitality and damage endpoints caused by cosmic ionizing radiation in dry, dormant plant seeds of the crucifer plant Arabidopsis thaliana (L.) Hennh. and the ascomycete Sordaria fimicola after 69 month stay in space. Wild-type and mutant gene marker lines were included in Free Flyer Biostack containers and exposed on

M. W. Zimmermann; K. E. Gartenbach; A. R. Kranz

1994-01-01

428

Leucine biosynthesis and its regulation in the basidiomycete Rhodosporidium toruloides  

Microsoft Academic Search

Complementation tests and enzyme analyses separated 29 leucine auxotrophs of the Basidiomycete Rhodosporidium toruloides into three groups, each deficient in one of the leucine biosynthetic enzymes. The following differences are suggested between the organization of the leucine pathway in R. toruloides and the Ascomycetes Saccharomyces cerevisiae and Neurospora crassa: (1) isopropylmalate, the product of the first enzymic reaction appears not

Michael Tully

1994-01-01

429

ent-Kaurene and squalene synthesis in Fusarium fujikuroi cell-free extracts  

Microsoft Academic Search

Sterols and gibberellins are the main terpenoids in the Ascomycete Fusarium fujikuroi. Their respective precursors squalene and ent-kaur-16-ene (henceforth called kaurene) were the main terpenoids synthesised from radioactive mevalonate by extracts of F. fujikuroi in vitro. Kaurene predominated when the extracts were obtained from mycelia engaged in gibberellin production. Squalene predominated in all other cases, and particularly when the extracts

Rafael Fernández-Mart??n; Carlos Domenech; Enrique Cerdá-Olmedo; Javier Avalos

2000-01-01

430

Preoperative administration of FTY720 prolonged renal allograft survival  

Microsoft Academic Search

BackgroundFTY729 is an immunomodulator obtained by chemical modification of Myriocin(ISI-1) which exists in the culture filtrate of an ascomycete, Isaria sinclairii. It has been reported that postoperative administration of FTY720 prolonged survival of various kinds of transplanted organs. In the present study, we evaluated the effect of 2-day preoperative administration of FTY 720 on graft survival.

Haruhiko Ueda; Shiro Takahara; Susumu Itoh; Hayahito Nomi; Nobuhisa Shibahara; Yoji Katsuoka

2005-01-01

431

Altering sexual reproductive mode by interspecific exchange of MAT loci  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sexual fungi can be self-sterile (heterothallic, requiring genetically distinct partners) or selffertile (homothallic, no partner required). In most ascomycetes, a single mating type locus (MAT) controls the ability to reproduce sexually. In the genus Cochliobolus, all heterothallic species have eit...

432

Yarrowia van der Walt & von Arx (1980)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This book chapter describes the ascomycete yeast genus Yarrowia and is to be published in The Yeasts, A Taxonomic Study, 5th edition. The genus has just one described species, Y. lipolytica, and is commonly known by its asexual name Candida lipolytica. The species is widely distributed in name and...

433

Ascosporas de Monosporascus cannonballus en Suelo  

Microsoft Academic Search

Analysis of different types of sugar in the extraction method of ascospores of Monosporascus cannonballus in soil The objective of this work was to test different kinds of sugar for the extraction of ascospores of M. cannonballus. The ascospores of this ascomycete involved in melon (Cucumis melo) collapse can be recovered from soil by a physical method using a gradient

Rui Sales Junior; Roberto Beltrán; Sami J. Michereff; Josep Armengol; José García-Jiménez; Érika Valente de Medeiros

434

Module evolution and substrate specificity of fungal nonribosomal peptide synthetases involved in siderophore biosynthesis  

Microsoft Academic Search

BACKGROUND: Most filamentous ascomycete fungi produce high affinity iron chelators called siderophores, biosynthesized nonribosomally by multimodular adenylating enzymes called nonribosomal peptide synthetases (NRPSs). While genes encoding the majority of NRPSs are intermittently distributed across the fungal kingdom, those encoding ferrichrome synthetase NRPSs, responsible for biosynthesis of ferrichrome siderophores, are conserved, which offers an opportunity to trace their evolution and the

Kathryn E Bushley; Daniel R Ripoll; B Gillian Turgeon

2008-01-01

435

Improved conditions for the aerobic reductive decolourisation of azo dyes by Candida zeylanoides  

Microsoft Academic Search

A number of anaerobic and aerobic bacterial species are known to decolourise azo dyes through the reduction of the azo bonds, forming the corresponding amines. In this work, we describe improved decolourisation conditions for model azo dyes by the ascomycete yeast Candida zeylanoides. The dyes were derived from the diazonium salts of metanilic and sulfanilic acids and N,N-dimethylaniline or 2-naphthol

Patricia A. Ramalho; H. Scholze; M. Helena Cardoso; M. Teresa Ramalho; A. M Oliveira-Campos

2002-01-01

436

Cloning, characterization and chromosomal location of three genes encoding host-cell-wall-degrading enzymes in Leptosphaeria maculans, a fungal pathogen of Brassica spp  

Microsoft Academic Search

The ascomycete, Leptosphaeria maculans, causes blackleg disease of oilseed Brassica spp. such as canola (Brassica napus). We have cloned a gene encoding endopolygalacturonase, pg1, and two genes encoding cellulases, cel1 and cel2, in L. maculans. These genes are not clustered in the genome, as they are located on different chromosomes. The deduced amino acid sequences of all three genes predict

Adrienne C. Sexton; Martina Paulsen; Johannes Woestemeyer; Barbara J. Howlett

2000-01-01

437

Protomyces Unger (1833)  

Technology Transfer Automated Retrieval System (TEKTRAN)

This chapter describes the ascomycetous fungal genus Protomyces and is to be published in "The Yeasts, A Taxonomic Study, 5th edition." Species of the genus Protomyces are plant pathogens that attack asters, wild celery, coriander and certain other plants. Symptoms include disruption of stems, lea...

438

Functional Genomic Analysis of the Rice Blast Fungus Magnaporthe grisea  

Microsoft Academic Search

Magnaporthe grisea, a filamentous, heterothallic ascomycete fungus, which infects a wide variety of grasses, has emerged as a model system to study genes involved in fungal pathogenesis. This is largely due to the successful application of numerous molecular genetic techniques for the manipulation of this fungus as well as the use of classical genetic techniques to examine all aspects of

Martin J. Gilbert; Darren M. Soanes; Nicholas J. Talbot

2004-01-01

439

Implications of cellobiohydrolase glycosylation for use in biomass conversion  

Microsoft Academic Search

The cellulase producing ascomycete, Trichoderma reesei (Hypocrea jecorina), is known to secrete a range of enzymes important for ethanol production from lignocellulosic biomass. It is also widely used for the commercial scale production of industrial enzymes because of its ability to produce high titers of heterologous proteins. During the secretion process, a number of post-translational events can occur, however, that

Tina Jeoh; William Michener; Michael E Himmel; Stephen R Decker; William S Adney

2008-01-01

440

A methodology for risk analysis of plurivorous fungi in biological weed control: Sclerotinia sclerotiorum as a model  

Microsoft Academic Search

In New Zealand, research is being performed on the use of the ubiquitous plurivorous ascomycete Sclerotinia sclerotiorum, as a biocontrol agent for Cirsium arvense in pasture. As a consequence of the wide host range of this fungus, the proposed biocontrol may pose a risk to non-target arable plants. Crop disease risk is primarily due to the formation of sclerotia. These

Meindert D. De Jong; Donald E. Aylor; Graeme W. Bourdôt

1999-01-01

441

Molecular Phylogeny of Truffles (Pezizales: Terfeziaceae, Tuberaceae) Derived from Nuclear rDNA Sequence Analysis  

Microsoft Academic Search

Extensive morphological convergence or divergence, a common occurrence in fungi, tends to obscure recognition of phylogenetic relationships among Pezizales, widespread filamentous Ascomycetes with either enclosed underground (hypogeous) or exposed (epigeous) fruit bodies, that often establish mutualistic interactions with arboreous plants. Focusing on hypogeous Pezizales commonly known as truffles, we sequenced the 18S rDNA from nine species belonging to three different

Riccardo Percudani; Aurelio Trevisi; Alessandra Zambonelli; Simone Ottonello

1999-01-01

442

Maturation-associated alterations of the biochemical characteristics of the black truffle Tuber melanosporum Vitt  

Microsoft Academic Search

Tuber melanosporum is a mycorrhizal ascomycetous fungus with subterranean fruiting bodies. With the aim of characterizing its state of maturity, we have undertaken a comparative analysis of the biochemical composition of tree stages. The various components were determined by the usual chromatographic and spectrometric techniques. The results showed that the factors characterizing the mature truffle are a relatively high level

E. Harki; D. Bouya; R. Dargent

2006-01-01

443

Reevaluation of the Life Cycle of Tuber magnatum  

Microsoft Academic Search

Tuber spp. are Ascomycetes fungi that establish an ecto- mycorrhizal symbiosis with trees and shrubs. As a result of this mutualistic symbiosis, ascocarps known as truffles are pro- duced. Some Tuber spp. produce edible truffles that, given their distinctive taste and aroma, are highly valued by gourmets. Research on these fungi has focused on promoting the culti- vation of these

Francesco Paolocci; Andrea Rubini; Claudia Riccioni; Sergio Arcioni

2006-01-01

444

Chemotaxonomy of the genus Talaromyces  

Microsoft Academic Search

Species of the ascomycetous genus Talaromyces have been examined for profiles of secondary metabolites on TLC. The greatest number of specific metabolites were produced on oatmeal-, malt extract- and yeast-extract sucrose agars. Profiles of intracellular secondary metabolites produced on oatmeal agar were specific for each species and provided a means of simple differentiation of the taxa. Examination of the most

J. C. Frisvad; O. Filtenborg; R. A. Samson; A. C. Stolk

1990-01-01

445

A Review of the Phylogeny and Biology of the Diaporthales  

Technology Transfer Automated Retrieval System (TEKTRAN)

The ascomycete order Diaporthales is reviewed based on recent phylogenetic data that outline the families and integrate related asexual fungi. The order is now considered to consist of nine families one of which is newly recognized as the Schizoparmeaceae fam. nov. and two families are recircumscri...

446

The AMT1 Arginine Methyltransferase Gene Is Important for Plant Infection and Normal Hyphal Growth in Fusarium graminearum  

Microsoft Academic Search

Arginine methylation of non-histone proteins by protein arginine methyltransferase (PRMT) has been shown to be important for various biological processes from yeast to human. Although PRMT genes are well conserved in fungi, none of them have been functionally characterized in plant pathogenic ascomycetes. In this study, we identified and characterized all of the four predicted PRMT genes in Fusarium graminearum,

Guanghui Wang; Chenfang Wang; Rui Hou; Xiaoying Zhou; Guotian Li; Shijie Zhang; Jin-Rong Xu

2012-01-01

447

Multiple Origins of Lichen Symbioses in Fungi Suggested by SSU rDNA Phylogeny  

Microsoft Academic Search

Phylogenetic hypotheses provide a context for examining the evolution of heterotrophic lifestyles. The lichen lifestyle, which is the symbiotic association of fungi with algae, is found in various representatives of Dicaryomycotina, both Ascomycetes and Basidiomycetes. A highly resolved parsimony analysis of small subunit ribosomal DNA (SSU rDNA) sequences suggests at least five independent origins of the lichen habit in disparate

Andrea Gargas; Paula T. Depriest; Martin Grube; Anders Tehler

1995-01-01

448

Micromycetes from the Saline Arubotaim Cave: Mount Sedom, The Dead Sea Southwestern Shore, Israel  

Microsoft Academic Search

We examined the soil microfungal community of the saline Arubotaim Cave, Israel. A total of 68 species from 28 genera were isolated. The most prominent features of the cave mycobiota were: the prevailing number of melanin-containing micromycetes; the abundant presence of the Aspergillus species; a comparatively large share of sexual ascomycetes; and the spatial and temporal variation of the mycobiota

Isabella Grishkan; Eviatar Nevo; Solomon P Wasser

2004-01-01

449

What is Scirrhia?  

Microsoft Academic Search

The ascomycetous genus Scirrhia is presently treated as a member of Dothideomycetidae, though uncertainty remains as to which family it belongs in Capnodiales, Ascomycota. Recent collections on stems of a fern, Pteridium aquilinum {Dennstaedtiaceae) in Brazil, led to the discovery of a new species of Scirrhia, described here as S. brasiliensis. Based on DNA sequence data of the nuclear ribosomal

P. W. Crous; A. M. Minnis; O. L. Pereira; A. C. Alfenas; R. F. Alfenas; A. Y. Rossman; J. Z. Groenewald

2011-01-01

450

ATP citrate lyase is required for normal sexual and asexual development in Gibberella zeae  

Microsoft Academic Search

Adenosine triphosphate (ATP) citrate lyase (ACL) is a key enzyme in the production of cytosolic acetyl-CoA, which is crucial for de novo lipid synthesis and histone acetylation in mammalian cells. In this study, we characterized the mechanistic roles of ACL in the homothallic ascomycete fungus Gibberella zeae, which causes Fusarium head blight in major cereal crops. Deletion of ACL in

Hokyoung Son; Jungkwan Lee; Ae Ran Park; Yin-Won Lee

2011-01-01

451

Molecular data and ploidal levels indicate several putative allopolyploidization events in the genus Potentilla (Rosaceae)  

PubMed Central

Several naturally occurring hybrids in Potentilla (Rosaceae) have been reported, but no molecular evidence has so far been available to test these hypotheses of hybridization. We have compared a nuclear and a chloroplast gene tree to identify topological incongruences that may indicate hybridization events in the genus. Furthermore, the monophyly and phylogenetic position of the proposed segregated genera Argentina, Ivesia and Horkelia have been tested. The systematic signal from the two morphological characters, style- and anther shape, has also been investigated by ancestral state reconstruction, to elucidate how well these characters concur with the results of the molecular phylogenies. Six major clades, Anserina, Alba, Fragarioides, Reptans, ivesioid and Argentea, have been identified within genus Potentilla. Horkelia, Ivesia and Horkeliella (the ivesioid clade), form a monophyletic group nested within Potentilla. Furthermore, the origin of the proposed segregated genus Argentina (the Anserina clade) is uncertain but not in conflict with a new generic status of the group. We also found style morphology to be an informative character that reflects the phylogenetic relationships within Potentilla. Five well-supported incongruences were found between the nuclear and the chloroplast phylogenies, and three of these involved polyploid taxa. However, further investigations, using low copy molecular markers, are required to infer the phylogeny of these species and to test the hypothesis of hybrid origin.

Topel, Mats; Lundberg, Magnus; Eriksson, Torsten; Eriksen, Bente

2011-01-01

452

In vitro decomposition of Sphagnum by some microfungi resembles white rot of wood.  

PubMed

The abilities of some ascomycetes (Myxotrichaceae) from a Sphagnum bog in Alberta to degrade cellulose, phenolics, and Sphagnum tissue were compared with those of two basidiomycetes. Most Myxotrichaceae degraded cellulose and tannic acid, and removed cell-wall components simultaneously from Sphagnum tissues, whereas the basidiomycetes degraded cellulose and insoluble phenolics, and preferentially removed the polyphenolic matrix from Sphagnum cell walls. Mass losses from Sphagnum varied from up to 50% for some ascomycetes to a maximum of 35% for the basidiomycetes. The decomposition of Sphagnum by the Myxotrichaceae was analogous to the white rot of wood and indicates that these fungi have the potential to cause significant mineralization of carbon in bogs. PMID:16689870