scholarly journals Two Distinct Distributions of F-actin are Present in the Hyphal Apex of the Oomycete Achlya bisexualis

2004 ◽  
Vol 45 (3) ◽  
pp. 275-280 ◽  
Author(s):  
Yu Ping Yu ◽  
Sandra L. Jackson ◽  
Ashley Garrill
Keyword(s):  
Achlya Bisexualis ◽  
Hyphal Apex

Movement of nutrients in fungi. I. The Mycelium

1968 ◽  
Vol 16 (1) ◽  
pp. 71 ◽  
Author(s):  
LB Thrower ◽  
SL Thrower
Keyword(s):  
Nutrient Medium ◽  
Natural Habitat ◽  
Taxonomic Position ◽  
Deficient Medium ◽  
The Difference ◽  
Hyphal Apex

Thirty-one species of fungi (representing 13 orders) were examined for their ability to grow from a nutrient medium onto a non-nutrient medium; 17 were capable of colonizing the deficient medium, 10 were not, and 4 were indeterminate. The ability to grow onto deficient medium appeared to be related to the natural habitat of the fungus rather than to taxonomic position. Experiments with isotopically labelled nutrients showed that both colonizing fungi and non-colonizing fungi were capable of some transport of nutrients, the difference between the two groups being one of degree. In transporting fungi, labelled nutrients were moved more rapidly when the fungus colonized a deficient medium than when it colonized a nutrient medium; this suggested that movement of nutrients is adaptive to some extent. The importance of the growing hyphal apex as a sink for nutrients was demonstrated.

The role of the cytoskeleton in the movement and positioning of nuclei in Coprinus cinereus

1995 ◽  
Vol 73 (S1) ◽  
pp. 364-368 ◽  
Author(s):  
Takashi Kamada ◽  
Shigeru Tanabe
Keyword(s):  
Life Cycle ◽  
Immunofluorescence Microscopy ◽  
Coprinus Cinereus ◽  
Nuclear Movement ◽  
Nuclear Positioning ◽  
Mitotic Apparatus ◽  
Tubulin Mutations ◽  
Early Phases ◽  
Hyphal Apex

Coprinus cinereus exhibits conspicuous nuclear movement and precise nuclear positioning during its life cycle. Examples include transhyphal migration of nuclei in compatible mating giving rise to a dikaryon, nuclear positioning relative to the hyphal apex in the dikaryon, the close spacing in interphase and conjugate division of the two nuclei in the dikaryon, and the migration of nuclei from the basidium into developing spores. We have investigated the roles of the cytoskeleton in these processes using cytoskeleton mutants as well as fluorescence microscopy. Some of the α1- and β1-tubulin mutations examined blocked nuclear migration in dikaryosis and disturbed nuclear pairing in the dikaryon, demonstrating that microtubules are involved in these processes. The same mutations, however, did not affect the positioning of nuclei in interphase nor in conjugate division in the dikaryon, nor the migration of nuclei into the developing spores. Immunofluorescence microscopy revealed that these mutations inhibit the formation of asters of the mitotic apparatus in conjugate division, providing evidence against direct involvement of astral microtubules in nuclear movement during conjugate division. Actin was concentrated in hyphal regions where the nuclei sit in early phases of conjugate division, suggesting the involvement of actin in conjugate division. Key words: Coprinus cinereus, dikaryon, nuclear movement, microtubules, aster, actin.

Actin has multiple roles in the formation and architecture of zoospores of the oomycetes, Saprolegnia ferax and Achlya bisexualis

1992 ◽  
Vol 102 (3) ◽  
pp. 611-627 ◽  
Author(s):  
I. BRENT HEATH ◽  
RUTH L. HAROLD
Keyword(s):  
Cell Wall ◽  
Germ Tube ◽  
Multiple Roles ◽  
Rhodamine Phalloidin ◽  
Saprolegnia Ferax ◽  
Functional Changes ◽  
Specific Effects ◽  
Changing Patterns ◽  
Microtubular Root ◽  
Achlya Bisexualis

Very similar changing patterns of actin are described with rhodamine-phalloidin labelling during the zoosporic life cycle of the oomycetes, Saprolegnia ferax and Achlya bisexualis. By comparing the changes with previously described ultrastructural and functional changes, we show that actin functions in numerous previously unrecognized processes. Most spectacularly, the directed vesicle expansions of the cytokinetic system involve newly formed actin which outlines the developing zoospores. Disruption of this actin with cytochalasins leads to abnormal cleavage as witnessed by the formation of enlarged and irregular cysts. Prior to cytokinesis, two new types of organelle are synthesized and one, known as K bodies, clusters around the nuclei. These organdies are actin-rich during development and clustering, consistent with actin functioning in their positioning. In the zoospores, actin is concentrated around the water expulsion vacuoles, indicating that they are contractile, and permeates the cytoplasm, probably with a skeletal role. This concept is supported by the first demonstration of actin specifically associated with a microtubular root in the secondary zoospore. Upon encystment there is a dramatic increase in stained actin in the form of peripheral plaques associated with the newly synthesized cell wall. When the cysts germinate, a fibrillar actin cap, comparable to that previously described in hyphal tips, forms in the germ tube apex, but only after cell wall softening to permit germ tube protrusion. This sequence is consistent with the actin cap modulating turgor-driven expansion of the tip as previously discussed for hyphae. In addition to disrupting cleavage-associated actin, cytochalasins show developmental stage, dose and drug (CE≥CD≥CB) specific effects on zoosporulation-related actin, which indicates that, contrary to previous suggestions, rhodamine-phalloidin staining is a useful indicator of actin behaviour in response to cytochalasins. These responses include differential effects on adjoining actin arrays, some of which are transient in the continued presence of the drugs, indicating a mechanism of drug adaptation.

Cellulase activity during the growth of Achlya bisexualis on glucose, cellulose, and selected polysaccharides

1978 ◽  
Vol 56 (16) ◽  
pp. 1974-1981 ◽  
Author(s):  
W. H. Miele ◽  
A. E. Linkins
Keyword(s):  
Carbon Sources ◽  
Cellulase Activity ◽  
Extracellular Enzyme ◽  
Dry Weight ◽  
Soluble Form ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Transmission Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Achlya Bisexualis

The antheridial strain of the dioecious water mold Achlya bisexualis was grown in chemically defined media using glucose, cellobiose, and selected polysaccharides as carbon sources. Growth and cellulase levels were measured with media containing glucose, cellobiose, and cellulose. Evaluation of cellulase activity in the medium by viscometric and reducing sugar generation assays suggests that cellulase plays a significant role in degrading cellulose for uptake and catabolism by A. bisexualis. Cellulase in glucose-grown cultures exists as a soluble extracellular enzyme complex, while in cellulose-grown cultures much of the enzyme is absorbed to the cellulose. Elution of the cellulose substrate after 96 h growth with NaCl-fortified buffer releases absorbed cellulase in a soluble form. The absorption of cellulase to the substrate and possibly the cell walls of A. bisexualis could account for the rapid loss in dry weight of A. bisexualis during culture on cellulose in a closed system. Scanning electron microscopic (SEM) examination of the walls of A. bisexualis shows disruption in cellulose cultures, which is not evident for glucose-or cellobiose-grown hyphae. Transmission electron microscopic (TEM) photomicrographs show a significant reduction in the wall thickness of cellulose-grown hyphae as compared with glucose-grown samples. This evidence suggests that the enzyme(s) produced during growth on cellulose is (are) capable of binding as an active hydrolase to walls of A. bisexualis or to the cellulosic substrate.

INHERITANCE OF SEX IN ACHLYA BISEXUALIS

1975 ◽  
Vol 62 (3) ◽  
pp. 216-220 ◽  
Author(s):  
Linda L. Lasure ◽  
David H. Griffin
Keyword(s):  
Achlya Bisexualis

scholarly journals Growing Hyphae of Achlya bisexualis Generate a Longtitudinal pH Gradient in the Surrounding Medium

Microbiology ◽  
1984 ◽  
Vol 130 (11) ◽  
pp. 2967-2974 ◽  
Author(s):  
N. A. R. Gow ◽  
D. L. Kropf ◽  
F. M. Harold
Keyword(s):  
Surrounding Medium ◽  
Ph Gradient ◽  
Achlya Bisexualis

Influence de la monensine sur la composition des parois de quelques champignons filamenteux

1992 ◽  
Vol 38 (4) ◽  
pp. 277-283 ◽  
Author(s):  
Yahya Koulali ◽  
Jean-Louis Fonvieille ◽  
Jane-Marie Touze-Soulet ◽  
Émile Benizri ◽  
Robert Dargent
Keyword(s):  
Chemical Composition ◽  
Key Words ◽  
Botrytis Cinerea ◽  
Uronic Acid ◽  
Sclerotium Rolfsii ◽  
Total Lipids ◽  
Chemical Content ◽  
Neutral Sugars ◽  
Achlya Bisexualis

Walls of young hyphae of Achlya bisexualis, Botrytis cinerea, and Sclerotium rolfsii growing in the presence or the absence of monensin were isolated and their chemical content was determined. Monensin induced modified proportions of various monomers resulting in a reduction of the (neutral sugars + uronic acid)/amine sugar ratio of B. cinerea and S. rolfsii (species of group chitin–glucans), and of cellulose in A. bisexualis (species of group cellulose-glucans).The walls of hyphae grown in presence of monensin also contained less total lipids and proteins. These modificationsin chemical composition are related to changes in cytological structure. Key words: fungi, monensin, wall.

Isolation of a Sex Hormone from the Water Mould Achlya bisexualis

Nature ◽  
1967 ◽  
Vol 215 (5098) ◽  
pp. 320-321 ◽  
Author(s):  
T. C. MCMORRIS ◽  
ALMA W. BARKSDALE
Keyword(s):  
Sex Hormone ◽  
Achlya Bisexualis ◽  
Water Mould

scholarly journals Heavy metals have different effects on mycelial morphology of Achlya bisexualis as determined by fractal geometry

2001 ◽  
Vol 201 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Sarah D. Lundy ◽  
Richard J. Payne ◽  
Kristian R. Giles ◽  
Ashley Garrill
Keyword(s):  
Heavy Metals ◽  
Fractal Geometry ◽  
Mycelial Morphology ◽  
Achlya Bisexualis
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