GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Newark :John Wiley & Sons, Incorporated,
    Keywords: Protista. ; Electronic books.
    Type of Medium: Online Resource
    Pages: 1 online resource (624 pages)
    Edition: 1st ed.
    ISBN: 9781118308141
    DDC: 579
    Language: English
    Note: Intro -- EVOLUTION OF VIRULENCE IN EUKARYOTIC MICROBES -- CONTENTS -- PREFACE -- ACKNOWLEDGMENTS -- CONTRIBUTORS -- PART I: GENERAL OVERVIEWS -- CHAPTER 1: POPULATION GENETICS AND PARASITE DIVERSITY -- CHAPTER 2: EVOLUTION OF MEIOSIS, RECOMBINATION, AND SEXUAL REPRODUCTION INEUKARYOTIC MICROBES -- CHAPTER 3: PHYLOGENOMIC ANALYSIS -- CHAPTER 4: PHYLOGENETICS AND EVOLUTION OF VIRULENCE IN THE KINGDOM FUNGI -- PART II: POPULATION GENETICS AND EVOLUTIONARY APPROACHES -- CHAPTER 5: MALARIA: HOST RANGE, DIVERSITY, AND SPECIATION -- CHAPTER 6: FROM POPULATION GENOMICS TO ELUCIDATED TRAITS IN PLASMODIUM FALCIPARUM -- CHAPTER 7: SELECTIVE SWEEPS IN HUMAN MALARIA PARASITES -- CHAPTER 8: EVOLUTION OF DRUG RESISTANCE IN FUNGI -- CHAPTER 9: DISCOVERY OF EXTANT SEXUAL CYCLES IN HUMAN PATHOGENIC FUNGI AND THEIR ROLES IN THE GENERATION OF DIVERSITY AND VIRULENCE -- CHAPTER 10: WORLDWIDE MIGRATIONS, HOST SHIFTS, AND REEMERGENCE OF PHYTOPHTHORA INFESTANS, THE PLANT DESTROYER -- CHAPTER 11: EXPERIMENTAL AND NATURAL EVOLUTION OF THE CRYPTOCOCCUS NEOFORMANS AND CRYPTOCOCCUS GATTII SPECIES COMPLEX -- CHAPTER 12: POPULATION GENETICS, DIVERSITY, AND SPREAD OF VIRULENCE IN TOXOPLASMA GONDII -- PART III: FORWARD AND REVERSE GENETIC SYSTEMS FOR DEFINING VIRULENCE -- CHAPTER 13: GENETIC CROSSES IN PLASMODIUM FALCIPARUM: ANALYSIS OF DRUG RESISTANCE -- CHAPTER 14: GENETIC MAPPING OF VIRULENCE IN RODENT MALARIAS -- CHAPTER 15: GENETIC MAPPING OF ACUTE VIRULENCE IN TOXOPLASMA GONDII -- CHAPTER 16: VIRULENCE IN AFRICAN TRYPANOSOMES: GENETIC AND MOLECULAR APPROACHES -- CHAPTER 17: THE EVOLUTION OF ANTIGENIC VARIATION IN AFRICAN TRYPANOSOMES -- CHAPTER 18: ANTIGENIC VARIATION, ADHERENCE, AND VIRULENCE IN MALARIA -- CHAPTER 19: INVASION LIGAND DIVERSITY AND PATHOGENESIS IN BLOOD-STAGE MALARIA -- PART IV: COMPARATIVE "OMICS" APPROACHES TO DEFINING VIRULENCE. , CHAPTER 20: EVOLUTION OF VIRULENCE IN OOMYCETE PLANT PATHOGENS -- CHAPTER 21: EVOLUTION AND GENOMICS OF THE PATHOGENIC CANDIDA SPECIES COMPLEX -- CHAPTER 22: EVOLUTION OF ENTAMOEBA HISTOLYTICA VIRULENCE -- CHAPTER 23: SEX AND VIRULENCE IN BASIDIOMYCETE PATHOGENS -- CHAPTER 24: EMERGENCE OF THE CHYTRID FUNGUS BATRACHOCHYTRIUM DENDROBATIDIS AND GLOBAL AMPHIBIAN DECLINES -- CHAPTER 25: IMPACT OF HORIZONTAL GENE TRANSFER ON VIRULENCE OF FUNGAL PATHOGENS OF PLANTS -- CHAPTER 26: EVOLUTION OF PLANT PATHOGENICITY IN FUSARIUM SPECIES -- CHAPTER 27: GENETIC, GENOMIC, AND MOLECULAR APPROACHES TO DEFINE VIRULENCE OF ASPERGILLUS FUMIGATUS -- CHAPTER 28: CRYPTOSPORIDIUM: COMPARATIVE GENOMICS AND PATHOGENESIS -- INDEX.
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    Newark :ASM Press,
    Keywords: Fungi. ; Electronic books.
    Type of Medium: Online Resource
    Pages: 1 online resource (1161 pages)
    Edition: 1st ed.
    ISBN: 9781683673040
    Series Statement: ASM Bks. ; v.35
    DDC: 579.5
    Language: English
    Note: Cover -- Half-Title Page -- Title Page -- Copyright Page -- Contents -- Contributors -- Foreword -- Preface -- Editors -- I: Fungal Branches on the Eukaryotic Tree of Life -- 1. The Fungal Tree of Life: From Molecular Systematics to Genome-Scale Phylogenies -- INTRODUCTION -- ZOOSPORIC FUNGI (Fig. 2) -- Cryptomycota/Microsporidia -- Blastocladiomycota -- Chytridiomycota -- ZYGOMYCETE FUNGI ( Fig. 3) -- Zoopagomycota -- Mucoromycota -- DIKARYA -- Ascomycota (Fig. 4) -- Basidiomycota (Fig. 5) -- Agaricomycotina -- SUMMARY -- References -- 2. Six Key Traits of Fungi: Their Evolutionary Origins and Genetic Bases -- INTRODUCTION -- THE EVOLUTION AND DE-EVOLUTION OF MULTICELLULARITY -- Polarized Growth and the Underlying Cellular Components -- The De-Evolution of the Multicellular Life Stage -- FUNGAL DIMORPHISM -- Molecular Mechanisms of Switching Between Yeast and Hyphal Stages -- Dimorphism Is Widespread among Fungi -- Plant Pathogenic Dimorphic Fungi -- FRUITING BODIES -- Diversity and Evolution of Fruiting Body Types -- Development of Fungal Fruiting Bodies -- The Genetic Bases of Fruiting Body Development -- PLANT CELL WALL DECOMPOSITION BY FUNGI -- The Diversity of Wood-Decay Types -- The Evolution of Decay-Related Enzyme Families -- The Cellular and Genetic Bases of Wood Decay -- SECONDARY METABOLISM -- Major Types of Secondary Metabolites -- The Evolution of Secondary Metabolism in Fungi -- MYCORRHIZAE -- Diversity of Mycorrhizal Types -- Arbuscular Mycorrhiza (AM) -- Ectomycorrhiza (ECM) -- EVOLUTIONARY CONVERGENCE IN FUNGI -- References -- 3. What Defines the "Kingdom" Fungi? -- IN SEARCH OF A SYNAPOMORPHY FOR FUNGI -- NO SYNAPOMORPHY FOR THE FUNGI -- EVOLUTION AT THE DAWN OF FUNGI AND THE RISE OF FUNGAL PHENOTYPES -- OSMOTROPHY RESULTS IN PUBLIC GOODS INTERACTIONS AND SYMBIOTIC ASSOCIATIONS -- WHY ARE FUNGI ECOLOGICALLY SUCCESSFUL?. , Older than Their Competitors -- Economic Coupling of Growth and Feeding -- INCREASED SAMPLING FURTHER CHALLENGES OUR UNDERSTANDING OF THE TREE OF LIFE -- Protistan Relatives of Fungi -- New Branches Near the Origin of Fungi -- Aquatic Environmental Sequencing and the Expansion of the Chytrid Branches -- Possible Fungal/Chytrid-Like Group Known as Basal Clone Group 1 -- Microsporidia -- Cryptomycota-Rozellomycota-Rozellida Rozellosporidia -- Aphelids -- PSEUDOPODIA FORMATION ACROSS THE DEEP BRANCHES OF THE FUNGI FURTHER CONFUSES THE FUNGI-PROTIST DISTINCTION -- CONCLUSION -- References -- 4. Fungal Diversity Revisited: 2.2 to 3.8 Million Species -- BACKGROUND -- EVIDENCE FROM PUBLICATION RATES OF NEW TAXA -- Numbers of Described Species -- Patterns in Taxon Discovery -- EVIDENCE FROM SPECIES RECOGNITION STUDIES -- EVIDENCE FROM EXTRAPOLATIONS BASED ON PLANT:FUNGUS RATIOS -- EVIDENCE FROM ENVIRONMENTAL SEQUENCING TECHNIQUES -- WHERE ARE THE UNDESCRIBED FUNGI? -- Biodiversity Hot Spots -- Little-Explored Habitats -- Existing Reference Collections -- TOWARD A WORKING NUMBER OF GLOBAL FUNGAL SPECIES RICHNESS -- References -- 5. Microsporidia: Obligate Intracellular Pathogens Within the Fungal Kingdom -- INTRODUCTION -- MORPHOLOGY AND LIFE CYCLES -- PHYLOGENETIC ANALYSIS OF THE MICROSPORIDIA -- STRUCTURE AND COMPOSITON OF THE MICROSPORIDIAN SPORE -- STRUCTURE AND COMPOSITION OF THE POLAR TUBE -- SUMMARY -- References -- II: Life of Fungi -- 6. Fungal Sex: The Ascomycota -- PHYLOGENY OF THE ASCOMYCETES -- SEX IN THE MODEL YEASTS -- Regulation of Cell Type Identity -- Pheromone Signaling in S. cerevisiae -- Pheromone Signaling in S. pombe -- Meiosis in S. cerevisiae -- Meiosis in S. pombe -- Mating Type Switching in Yeasts -- Evolution of Mating-Type Switching -- SEXUAL REPRODUCTION IN CANDIDA SPECIES -- REWIRING CELL IDENTITY IN YEASTS. , PARASEXUAL REPRODUCTION IN CANDIDA -- HOMOTHALLIC MATING IN CANDIDA -- SEXUAL DEVELOPMENT IN FILAMENTOUS ASCOMYCETES -- Heterothallic Mating-Type Lociin Pezizomycotina -- Homothallic Mating in Pezizomycotina -- Heterologous Expression of MAT Genes -- The Search for Sex in "Asexual"Filamentous Ascomycetes -- MATING SIGNALING IN FILAMENTOUS ASCOMYCETES -- MAT Gene Functions -- Pheromones and Receptors -- Transcriptional Analysis of Mating -- ADDITIONAL ROLES FOR SEXUAL SIGNALING IN THE ASCOMYCETES -- CONCLUSIONS -- References -- 7. Fungal Sex: The Basidiomycota -- BREEDING SYSTEMS AND LIFESTYLES IN THE BASIDIOMYCOTA -- Diversity and Phylogenetic Relationships : Phylum Basidiomycota -- Sexual Development and Determination of Cell Type Identity -- MOLECULAR DETERMINANTS OF MATING TYPE -- The Pheromone/Receptor Sensing System -- Homeodomain Transcription Factors: The Second Compatibility Checkpoint -- BREEDING SYSTEMS IN THE BASIDIOMYCOTA -- Tetrapolar Systems: U. maydis and Other Smut Relatives -- Variation in Tetrapolar Systemsbeyond Ustilago/Sporisorium -- Tetrapolar Systems with Multiple Alleles in the Agaricomycetes -- Bipolar Breeding Systems: Genomic Changes and Evolutionary Considerations -- New Genome Sequencing Projects : What Can They Tell Us about MAT Gene Structure and Evolution? -- CONCLUSIONS -- GLOSSARY OF TERMS -- References -- 8. Fungal Sex: The Mucoromycota -- INTRODUCTION TO THE MUCOROMYCOTA -- STRUCTURE AND GENE CONTENT OF THE sex/MAT LOCUS -- ROLES OF THE SexM AND SexP HMG DOMAIN PROTEINS IN MATING -- THE EVOLUTION OF HOMOTHALLISM FROM HETEROTHALLIC ANCESTORS VIA REARRANGEMENTS OF THE sex LOCUS -- THE TRISPORIC ACID MATING PHEROMONES -- MENDELIAN AND CLASSICAL GENETICS -- POPULATION GENETICS -- SIMILARITIES AND DIFFERENCES BETWEEN THE MUCORALES AND OTHER BASAL FUNGI -- CONCLUSIONS AND AREAS FOR FUTURE RESEARCH -- GLOSSARY. , References -- 9. Sex and the Imperfect Fungi -- INTRODUCTION -- EVIDENCE FOR SEXUAL POTENTIAL -- Population Genetics -- Mating-Type Genes -- Genome Studies -- Functionality of Sex-Related Genes -- Formation of Sex-Related Structures and Lichen Species Pairs -- DISCOVERY OF MATING AND SEXUAL REPRODUCTION-AND IMPLICATIONS -- Mating in C. albicans -- Sex in Aspergillus Species -- Sex in Penicillium Species -- Sex in Trichoderma and Other Genera -- Implications of the Discovery of Fungal Sex -- POTENTIAL FOR SEX IN OTHER ASEXUAL SPECIES-CONSIDERATIONS -- CONCLUSIONS -- References -- 10. Molecular Mechanisms Regulating Cell Fusion and Heterokaryon Formation in Filamentous Fungi -- INTRODUCTION -- SOMATIC FUSION IN FILAMENTOUS FUNGI AND ITS CONSEQUENCES: BENEFITS AND DETRIMENTS -- RECOGNITION, CELL FUSION, AND COLONY ESTABLISHMENT -- NONSELF RECOGNITION EVENTS ACTING PREFUSION -- NONSELF RECOGNITION MECHANISMS ACTING POSTFUSION -- Genetic Control and Molecular Characterization of Heterokaryon Incompatibility -- HI Determinants: at the Molecular Crossroad of Allo- and Xenorecognition -- CONCLUSIONS AND FUTURE OUTLOOK -- References -- 11. Cell Biology of Hyphal Growth -- INTRODUCTION -- REGULATION OF HYPHAL MORPHOGENESIS -- Spatial Regulation of Hyphal Morphogenesis -- Temporal Regulation of Hyphal Morphogenesis -- FUNGAL EXOCYTOSIS -- The Golgi and Its Regulation -- The Master Regulators of the Golgi : RABs, Arf1, and Their Regulators -- The Fungal SPK and Delivery of Cell Wall-Building Enzymes -- Myosin-Chitin Synthases in Apical Exocytosis -- FUNGAL ENDOCYTOSIS AND EE MOTILITY -- Fungal Endocytosis -- The Molecular Machinery for EE Motility -- Multiple Functions for Fungal EEs -- SEPTATION IN FUNGAL HYPHAE -- Septum Formation -- Communication and Differentiation of Hyphal Compartments -- The Mechanism of Septal Pore Closure. , CONCLUDING REMARKS AND FUTURE DIRECTIONS -- References -- 12. The Fungal Cell Wall: Structure, Biosynthesis, and Function -- INTRODUCTION -- COMPOSITION AND STRUCTURE -- Structural Organization and Cell Wall Layers -- Biofilms -- GENETICS, ENZYMOLOGY, AND BIOSYNTHESIS -- Biosynthesis of the Polysaccharides -- Core Polysaccharides : Chitin and β-(1,3) Glucan -- Biosynthesis of Mannan and Other Decorating Polysaccharides -- Melanin -- Cell Wall Proteins -- GPI proteins -- REGULATION AND SIGNALING -- The Cell Wall Salvage Response -- Regulation of Septation -- Regulation of Polarized Growth -- CELL WALL AS A TARGET -- Antifungal Target -- Target for Mammalian Immune System -- Target for the Plant Immune System -- Diagnostics and Immunotherapeutic Targets -- Diagnostic Antigens -- CONCLUSIONS -- References -- 13. Fungal Ecology: Principles and Mechanisms of Colonization and Competition by Saprotrophic Fungi -- INTRODUCTION -- COLONIZATION -- Arrival -- Entry and Establishment -- Community Development -- COMPETITION -- Antagonism at a Distance -- Mycoparasitism -- Larger-Scale Mycelia Interactions : Antagonistic Mechanisms -- CONCLUSIONS -- References -- 14. Long-Distance Dispersal of Fungi -- INTRODUCTION -- DEFINING FUNGAL LDD -- MEASURING LDD -- DISPERSAL VECTORS -- Wind -- Plants -- Oceans, Rivers, and Lakes -- Animals -- Humans -- MORPHOLOGICAL, BIOPHYSICAL, AND PHYSIOLOGICAL PROPERTIES INFLUENCING LDD -- Spore Size and Shape -- A Spore's External Surface -- Do Spores "Clump?" -- The Physiological Hardiness of Spores -- Sporocarp Properties Influencing LDD -- UNKNOWN AND CONFOUNDING VARIABLES: FREQUENCY OF LDD, VICARIANCE, AND CHANGING PATTERNS OF HUMAN-MEDIATED DISPERSAL -- CONCLUSIONS: UNANSWERED QUESTIONS AND FUTURE DIRECTIONS -- References -- 15. The Mycelium as a Network -- INTRODUCTION -- THE BUILDING BLOCKS FOR NETWORK CONSTRUCTION. , Growth at the Hyphal Tip.
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: Fungi ; Fungi Genetics ; Medical mycology ; Fungi ; Medical mycology ; Pilze
    Type of Medium: Book
    Pages: xxiii, 1136 Seiten , Illustrationen , 29 cm
    ISBN: 9781555819576 , 1555819575
    DDC: 579.5
    RVK:
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2022-10-26
    Description: © The Authors, 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Amend, A., Burgaud, G., Cunliffe, M., Edgcomb, V. P., Ettinger, C. L., Gutiérrez, M. H., Heitman, J., Hom, E. F. Y., Ianiri, G., Jones, A. C., Kagami, M., Picard, K. T., Quandt, C. A., Raghukumar, S., Riquelme, M., Stajich, J., Vargas-Muñiz, J., Walker, A. K., Yarden, O., & Gladfelter, A. S. Fungi in the Marine Environment: Open Questions and Unsolved Problems. MBio, 10(2), (2019):e01189-18, doi:10.1128/mBio.01189-18.
    Description: Terrestrial fungi play critical roles in nutrient cycling and food webs and can shape macroorganism communities as parasites and mutualists. Although estimates for the number of fungal species on the planet range from 1.5 to over 5 million, likely fewer than 10% of fungi have been identified so far. To date, a relatively small percentage of described species are associated with marine environments, with ∼1,100 species retrieved exclusively from the marine environment. Nevertheless, fungi have been found in nearly every marine habitat explored, from the surface of the ocean to kilometers below ocean sediments. Fungi are hypothesized to contribute to phytoplankton population cycles and the biological carbon pump and are active in the chemistry of marine sediments. Many fungi have been identified as commensals or pathogens of marine animals (e.g., corals and sponges), plants, and algae. Despite their varied roles, remarkably little is known about the diversity of this major branch of eukaryotic life in marine ecosystems or their ecological functions. This perspective emerges from a Marine Fungi Workshop held in May 2018 at the Marine Biological Laboratory in Woods Hole, MA. We present the state of knowledge as well as the multitude of open questions regarding the diversity and function of fungi in the marine biosphere and geochemical cycles.
    Description: We thank the Gordon and Betty Moore Foundation and the Marine Biological Laboratory in Woods Hole, MA, for their generous support of the Marine Fungi Workshop that generated this perspective.
    Keywords: Mycology ; Chytrid ; Marine fungi ; Marine microbiology
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Genetics 36 (2002), S. 557-615 
    ISSN: 0066-4197
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology
    Notes: Abstract Cryptococcus neoformans is a pathogenic fungus that primarily afflicts immunocompromised patients, infecting the central nervous system to cause meningoencephalitis that is uniformly fatal if untreated. C. neoformans is a basidiomycetous fungus with a defined sexual cycle that has been linked to differentiation and virulence. Recent advances in classical and molecular genetic approaches have allowed molecular descriptions of the pathways that control cell type and virulence. An ongoing genome sequencing project promises to reveal much about the evolution of this human fungal pathogen into three distinct varieties or species. C. neoformans shares features with both model ascomycetous yeasts (Saccharomyces cerevisiae, Schizosaccharomyces pombe) and basidiomycetous pathogens and mushrooms (Ustilago maydis, Coprinus cinereus, Schizophyllum commune), yet ongoing studies reveal unique features associated with virulence and the arrangement of the mating type locus. These advances have catapulted C. neoformans to center stage as a model of both fungal pathogenesis and the interesting approaches to life that the kingdom of fungi has adopted.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Calcineurin is a Ca2+–calmodulin-regulated protein phosphatase that is the target of the immunosuppressive drugs cyclosporin A and FK506. Calcineurin is a heterodimer composed of a catalytic A and a regulatory B subunit. In previous studies, the calcineurin A homologue was identified and shown to be required for growth at 37°C and hence for virulence of the pathogenic fungus Cryptococcus neoformans. Here, we identify the gene encoding the calcineurin B regulatory subunit and demonstrate that calcineurin B is also required for growth at elevated temperature and virulence. We show that the FKR1-1 mutation, which confers dominant FK506 resistance, results from a 6 bp duplication generating a two-amino-acid insertion in the latch region of calcineurin B. This mutation was found to reduce FKBP12–FK506 binding to calcineurin both in vivo and in vitro. Molecular modelling based on the FKBP12–FK506–calcineurin crystal structure illustrates how this mutation perturbs drug interactions with the phosphatase target. In summary, our studies reveal a central role for calcineurin B in virulence and antifungal drug action in the human fungal pathogen C. neoformans.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 38 (2000), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Cryptococcus neoformans is an important human pathogenic fungus with a defined sexual cycle and well-developed molecular and genetic approaches. C. neoformans is predominantly haploid and has two mating types, MATa and MATα. Mating is known to be regulated by nutritional limitation and thought also to be regulated by pheromones. Previously, a portion of the MATα locus was cloned, and a presumptive pheromone gene, MFα1, was identified by its ability to induce conjugation tube-like filaments when introduced by transformation into MATa cells. Here, the ability of the MFα1 gene to induce these morphological changes in MATa cells was used as a phenotypic assay to perform a structure–function analysis of the gene. We show that the MFα1 open reading frame is required for the morphological response of MATa cells. We also find that the cysteine residue of the C-terminal CAAX motif is required for activity of the MFα1 pheromone. In addition, we use a reporter system to measure the expression levels of the MFα1 pheromone gene and find that two signals, nutrient starvation and the presence of factors secreted by mating partner cells, impinge on this promoter and regulate MFα1 expression. We identify a second pheromone gene, MFα2, and show phenotypically that this gene is also expressed. Finally, we have synthesized the MFα1 pheromone and show that only the predicted mature modified form of the α-factor peptide triggers morphological responses in MATa cells.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Molecular microbiology 36 (2000), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Cryptococcus neoformans is a basidiomycete yeast and opportunistic human pathogen of increasing clinical importance due to the increasing population of immunocompromised patients. To further investigate signal transduction cascades regulating fungal pathogenesis, we have identified the gene encoding a RAS homologue in this organism. The RAS1 gene was disrupted by transformation and homologous recombination. The resulting ras1 mutant strain was viable, but failed to grow at 37°C, and exhibited significant defects in mating and agar adherence. The ras1 mutant strain was also avirulent in an animal model of cryptococcal meningitis. Reintroduction of the wild-type RAS1 gene complemented these ras1 mutant phenotypes and restored virulence in animals. A dominantly active RAS1 mutant allele, RAS1Q67L, induced a differentiation phenotype known as haploid fruiting, which involves filamentation, agar invasion and sporulation in response to nitrogen deprivation. The ras1 mutant mating defect was suppressed by overexpression of MAP kinase signalling elements and partially suppressed by exogenous cAMP. Additionally, cAMP also suppressed the agar adherence defect of the ras1 mutant. However, the ability of the ras1 mutant strain to grow at elevated temperature was not restored by cAMP or MAP kinase overexpression. Our findings support a model in which RAS1 signals in C. neoformans through cAMP-dependent, MAP kinase, and RAS-specific signalling cascades to regulate mating and filamentation, as well as growth at high temperature which is necessary for maintenance of infection.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Oxford BSL : Blackwell Science Ltd
    Molecular microbiology 33 (1999), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: Two mutants of the EcoRI endonuclease (R200K and E144C) predominantly nick only one strand of the DNA substrate. Temperature sensitivity of the mutant enzymes allowed us to study the consequences of inflicting DNA nicks at EcoRI sites in vivo. Expression of the EcoRI endonuclease mutants in the absence of the EcoRI methyltransferase induces the SOS DNA repair response and greatly reduces viability of recA56, recB21 and lexA3 mutant strains of Escherichia coli. In parallel studies, overexpression of the EcoRV endonuclease in cells also expressing the EcoRV methyltransferase was used to introduce nicks at non-cognate EcoRV sites in the bacterial genome. EcoRV overproduction was lethal in recA56 and recB21 mutant strains and moderately toxic in a lexA3 mutant strain. The toxic effect of EcoRV overproduction could be partially alleviated by introduction into the cells of multiple copies of the E. coli DNA ligase gene. These observations suggest that an increased number of DNA nicks can overwhelm the repair capacity of DNA ligase, resulting in the conversion of a proportion of DNA nicks into DNA lesions that require recombination for repair.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Molecular microbiology 8 (1993), S. 0 
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The transposon Tn5 expresses a gene, ble, whose product increases the viability of Escherichia coli and also confers resistance to the DNA-cleaving antibiotic bleomycin and the DNA-alkylating agent ethyl-methanesulphonate. We find that the Ble protein induces expression of an alkylation inducible gene, aidC, and that both the AidC gene product and DNA polymerase I are required for Ble to confer bleomycin resistance. These findings support models in which Ble enhances DNA repair and suggest that Tn5 confers a fitness advantage to the host bacterium by increasing the repair of spontaneous DNA lesions. Such co-operation between a transposon and its host suggests that Tn5 is a symbiotic rather than a selfish DNA element.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...