Functional, Organizational, and Biochemical Analysis of Actin in Hyphal Tip Cells of Allomyces macrogynus

Mycologia ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 57 ◽  
Author(s):  
Srijayanthi Srinivasan ◽  
Maria M. Vargas ◽  
Robert W. Roberson
Keyword(s):  
Biochemical Analysis ◽  
Allomyces Macrogynus ◽  
Tip Cells ◽  
Hyphal Tip

Functional, organizational, and biochemical analysis of actin in hyphal tip cells ofAllomyces macrogynus

Mycologia ◽  
1996 ◽  
Vol 88 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Srijayanthi Srinivasan ◽  
Maria M. Vargas ◽  
Robert W. Roberson
Keyword(s):  
Biochemical Analysis ◽  
Tip Cells ◽  
Hyphal Tip

Spatial heterogeneity of glycogen and its metabolizing enzymes in Aspergillus nidulans hyphal tip cells

2018 ◽  
Vol 110 ◽  
pp. 48-55 ◽  
Author(s):  
Shunsuke Masuo ◽  
Airi Komatsuzaki ◽  
Norio Takeshita ◽  
Eriko Itoh ◽  
Okazoe Takaaki ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Aspergillus Nidulans ◽  
Metabolizing Enzymes ◽  
Tip Cells ◽  
Hyphal Tip

Ultrastructural analysis of hyphal tip cell growth in fungi: Spitzenkorper, cytoskeleton and endomembranes after freeze-substitution

1981 ◽  
Vol 48 (1) ◽  
pp. 89-103
Author(s):  
R.J. Howard
Keyword(s):  
Freeze Substitution ◽  
Hyphal Growth ◽  
Coated Vesicle ◽  
Fusarium Acuminatum ◽  
Tip Cell ◽  
Transmission Electron ◽  
Cytoplasmic Vesicles ◽  
Cytoskeletal Elements ◽  
Tip Cells ◽  
Hyphal Tip

The ultrastructure of freeze-substituted tip cells of Fusarium acuminatum was analysed by conventional and high-voltage transmission electron microscopy (HVEM). At least 2 morphologically distinct types of Golgi-like endomembrane cisternae were observed, each existing as single, fenestrated sheets and tubular elements that were often very closely associated with mitochondria. From HVEM observations of thick (0.25 and 0.5 micron) sections, the Spitzenkorper appeared to correspond to an apical mass of vesicles. A network of microfilaments was identified among component vesicles of the Spitzenkorper and adjacent to developing septa. Microtubules were oriented primarily parallel to the direction of hyphal growth and were located in all areas of the cytoplasm, including the tip cell apex. Cytoplasmic vesicles were closely associated with these microtubules. From these observations it is suggested that cytoskeletal elements play important roles in localized cell wall formation. The filasome, a previously unreported type of coated vesicle in fungi, might also be involved in wall synthesis.

scholarly journals DNA Synthesis in Relation to Hyphal Branching and Wall Composition in Allomyces macrogynus

1985 ◽  
Vol 38 (1) ◽  
pp. 67 ◽  
Author(s):  
Jean Youatt
Keyword(s):  
Dna Synthesis ◽  
Sodium Sulfide ◽  
Methionine Sulfoxide ◽  
Cylindrical Shape ◽  
Sulfur Amino Acids ◽  
Hyphal Branching ◽  
The Third ◽  
Methionine Sulfone ◽  
Allomyces Macrogynus ◽  
Hyphal Tip

In A. macrogynus the first replication of DNA occurred after germination, at the time of the first branching of rhizoids. Before the second replication galactan in the wall exceeded the glucan content and was not firmly attached. After the second DNA replication hyphallengthening commenced with an increase in the content of glucan but the walls lacked rigidity. At the time of the third replication walls underwent a change which commenced at the hyphal tip and worked back to the rhizoids, converting the hyphae to a rigid, cylindrical shape. Branching commenced after the fourth replication of DNA. Multiple branching occurred when mature plants were transferred to glucose-histidine-methionine solution without further DNA synthesis. Hyphal branching was used to show that A. macrogynus was able to use methionine, methionine sulfoxide, methionine sulfone, sodium sulfide, cysteine, cystathionine and homocysteine but not cystine. Thioacetamide supported growth through many subcultures showing that A. macrogynus can synthesize its sulfur amino acids.

scholarly journals CHARACTERIZATION OF THE HETEROKARYOTIC AND VEGETATIVE DIPLOID PHASES OF MAGNAPORTHE GRISEA

Genetics ◽  
1986 ◽  
Vol 114 (4) ◽  
pp. 1111-1129
Author(s):  
Mark S Crawford ◽  
Forrest G Chumley ◽  
Carolyn G Weaver ◽  
Barbara Valent
Keyword(s):  
Minimal Medium ◽  
Magnaporthe Grisea ◽  
Fast Growing ◽  
Dominance Testing ◽  
Wide Range ◽  
Nutritional Characteristics ◽  
Single Nucleus ◽  
Tip Cells ◽  
Hyphal Tip

ABSTRACT The heterokaryotic and vegetative diploid phases of Magnaporthe grisea, a fungal pathogen of grasses, have been characterized. Prototrophic heterokaryons form when complementary auxotrophs are paired on minimal medium. Hyphal tip cells and conidia (vegetative spores) taken from these heterokaryons are auxotrophs with phenotypes identical to one or the other of the parents. M. grisea heterokaryons thus resemble those of other fungi that have completely septate hyphae with a single nucleus per cell. Heterokaryons have been utilized for complementation and dominance testing of mutations that affect nutritional characteristics of the fungus. Heterokaryons growing on minimal medium spontaneously give rise to fast-growing sectors that have the genetic properties expected of unstable heterozygous diploids. In fast-growing sectors, most hyphal tip cells are unstable prototrophs. The conidia collected from fast-growing sectors include stable and unstable prototrophs, as well as auxotrophs that exhibit a wide range of phenotypes, including many recombinant classes. Genetic linkage in meiosis has been detected between two auxotrophic mutations that recombine in vegetatively growing unstable diploids. The appearance of recombinants suggests that homologous recombination occurs during vegetative growth of M. grisea. No interstrain barriers to heterokaryosis and diploid formation have been detected. The mating type of the strains that are paired does not influence the formation of heterokaryons or diploids.

scholarly journals MesA, a Novel Fungal Protein Required for the Stabilization of Polarity Axes inAspergillus nidulans

2004 ◽  
Vol 15 (8) ◽  
pp. 3658-3672 ◽  
Author(s):  
Claire L. Pearson ◽  
Kaimei Xu ◽  
Kathryn E. Sharpless ◽  
Steven D. Harris
Keyword(s):  
Molecular Characterization ◽  
Regulatory Mechanisms ◽  
Membrane Domains ◽  
Wild Type ◽  
Actin Ring ◽  
Fungal Protein ◽  
Hyphal Morphogenesis ◽  
Actin Cables ◽  
Tip Cells ◽  
Hyphal Tip

The Aspergillus nidulans proteome possesses a single formin, SepA, which is required for actin ring formation at septation sites and also plays a role in polarized morphogenesis. Previous observations imply that complex regulatory mechanisms control the function of SepA and ensure its correct localization within hyphal tip cells. To characterize these mechanisms, we undertook a screen for mutations that enhance sepA defects. Of the mutants recovered, mesA1 causes the most dramatic defect in polarity establishment when SepA function is compromised. In a wild-type background, mesA1 mutants undergo aberrant hyphal morphogenesis, whereas septum formation remains unaffected. Molecular characterization revealed that MesA is a novel fungal protein that contains predicted transmembrane domains and localizes to hyphal tips. We show that MesA promotes the localized assembly of actin cables at polarization sites by facilitating the stable recruitment of SepA. We also provide evidence that MesA may regulate the formation or distribution of sterol-rich membrane domains. Our results suggest that these domains may be part of novel mechanism that directs SepA to hyphal tips.

Effects of the sterol demethylase inhibitor, cyproconazole, on hyphal tip cells of Sclerotium rolfsii

1990 ◽  
Vol 36 (2) ◽  
pp. 115-126 ◽  
Author(s):  
Melvin S. Fuller ◽  
Robert W. Roberson ◽  
Ulrich Gisi
Keyword(s):  
Sclerotium Rolfsii ◽  
Tip Cells ◽  
Hyphal Tip

scholarly journals Ash1 Protein, an Asymmetrically Localized Transcriptional Regulator, Controls Filamentous Growth and Virulence of Candida albicans

2002 ◽  
Vol 22 (24) ◽  
pp. 8669-8680 ◽  
Author(s):  
Diane O. Inglis ◽  
Alexander D. Johnson
Keyword(s):  
Candida Albicans ◽  
Mouse Model ◽  
Regulatory Protein ◽  
Cell Nuclei ◽  
Yeast Form ◽  
Disseminated Candidiasis ◽  
Transcriptional Regulatory ◽  
Tip Cells ◽  
Hyphal Tip

ABSTRACT In response to a number of distinct environmental conditions, the fungal pathogen Candida albicans undergoes a morphological transition from a round, yeast form to a series of elongated, filamentous forms. This transition is believed to be critical for virulence in a mouse model of disseminated candidiasis. Here we describe the characterization of C. albicans ASH1, a gene that encodes an asymmetrically localized transcriptional regulatory protein involved in this response. We show that C. albicans ash1 mutants are defective in responding to some filament-inducing conditions. We also show that Ash1p is preferentially localized to daughter cell nuclei in the budding-yeast form of C. albicans cell growth and to the hyphal tip cells in growing filaments. Thus, Ash1p “marks” newly formed cells and presumably directs a specialized transcriptional program in these cells. Finally, we show that ASH1 is required for full virulence of C. albicans in a mouse model of disseminated candidiasis.

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