scholarly journals PHASE-SPECIFIC GENES FOR MACROCONIDIATION IN NEUROSPORA CRASSA

Genetics ◽  
1974 ◽  
Vol 78 (2) ◽  
pp. 679-690 ◽  
Author(s):  
Claude P Selitrennikoff ◽  
Robert E Nelson ◽  
Richard W Siegel
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Neurospora Crassa ◽  
Sexual Life ◽  
Wild Type ◽  
A Cell ◽  
Autolytic Activity ◽  
Sexual Life Cycle ◽  
Mutant Genes ◽  
Active Formation

ABSTRACT Two new mutant genes in Neurospora crassa prevent the formation of free macroconidia from proconidial chains. These genes, called conidial separation-1 and conidial separation-2, are phase-specific, playing no role in either the sexual life cycle or other aspects of the asexual life cycle. A cell-wall-associated autolytic activity was found to increase in wild-type cultures at the time of active formation of free conidia from proconidial chains; no such increase was detected in mutant cultures. It appears that the products of these genes are both essential for and unique to macroconidiation.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

scholarly journals Affinity, life cycle, and intracellular complexity of organic-walled microfossils from the Mesoproterozoic of Shanxi, China

2015 ◽  
Vol 89 (1) ◽  
pp. 28-50 ◽  
Author(s):  
Heda Agić ◽  
Małgorzata Moczydłowska ◽  
Lei-Ming Yin
Keyword(s):  
Cell Wall ◽  
Life Cycle ◽  
Structural Complexity ◽  
Protective Role ◽  
Life Cycles ◽  
Wall Structure ◽  
Phenotypic Characters ◽  
Biological Affinity ◽  
New Material ◽  
A Cell

AbstractLight microscope and scanning electron microscope observations on new material of unicellular microfossilsDictyosphaera macroreticulataandShuiyousphaeridium macroreticulatum,from the Mesoproterozoic Ruyang Group in China, provide insights into the microorganisms’ biological affinity, life cycle and cellular complexity.Gigantosphaeridium fibratumn. gen. et sp., is described and is one of the largest Mesoproterozoic microfossils recorded. Phenotypic characters of vesicle ornamentation and excystment structures, properties of resistance and cell wall structure inDictyosphaeraandShuiyousphaeridiumare all diagnostic of microalgal cysts. The wide size ranges of the various morphotypes indicate growth phases compatible with the development of reproductive cysts. Conspecific biologically, each morphotype represents an asexual (resting cyst) or sexual (zygotic cyst) stage in the life cycle, respectively. We reconstruct this hypothetical life cycle and infer that the organism demonstrates a reproductive strategy of alternation of heteromorphic generations. Similarly inGigantosphaeridium,a metabolically expensive vesicle with processes suggests its protective role as a zygotic cyst. In combination with all these characters and from the resemblance to extant green algae, we propose the placement of these ancient microorganisms in the stem group of Chloroplastida (Viridiplantae). A cell wall composed of primary and secondary layers inDictyosphaeraandShuiyouisphaeridiumrequired a high cellular complexity for their synthesis and the presence of an endomembrane system and the Golgi apparatus. The plastid was also present, accepting the organism was photosynthetic. The biota reveals a high degree of morphological and cell structural complexity, and provides an insight into ongoing eukaryotic evolution and the development of complex life cycles with sexual reproduction by 1200 Ma.

Distribution of concanavalin a binding carbohydrates during mating in Chlamydomonas

1984 ◽  
Vol 66 (1) ◽  
pp. 223-239
Author(s):  
B.E. Millikin ◽  
R.L. Weiss
Keyword(s):  
Cell Wall ◽  
Cell Fusion ◽  
Concanavalin A ◽  
Sodium Dodecyl ◽  
Fluorescein Isothiocyanate ◽  
Affinity Column ◽  
Wild Type ◽  
Mating Structure ◽  
Autolytic Activity ◽  
Surface Carbohydrates

Cell surface carbohydrates, detected by fluorescein isothiocyanate/concanavalin A (FITC-ConA), were identified at four locations on gametes of Chlamydomonas reinhardtii. (1) The cell wall: uniform labelling with FITC-ConA was observed; a substantial number of sites were localized in the sodium dodecyl sulphate-insoluble inner wall, which contains the flagellar collars. (2) The periplasm: a crescent-shaped area was visualized with FITC-ConA and localized by ferritin-ConA. We were able to recover autolytic activity on a ConA affinity column from the mating medium of wild-type cells after the release of these periplasmic sites. The cell-wall-less mutant CW15 displays no periplasmic sites and demonstrates a corresponding inability to release autolytic activity after mating for 60 min. A model for wall lysis is presented, which considers the involvement of these sites in the lytic process. (3) The mating structure: during mating a small fluorescent plaque-like site was observed on cells at a location corresponding to the carbohydrate-like zone of the mating type minus mating structure and may indicate the involvement of ConA binding material in gametic cell fusion. (4) Secreted products: following cell fusion zygotes begin to secrete ConA positive material at about 1 1/2 h. After 24 h a ConA positive zygote wall and pellicle appear.

scholarly journals Preparation of a cell-free translation system from a wild-type strain of Neurospora crassa

1988 ◽  
Vol 13 (4) ◽  
pp. 323-326 ◽  
Author(s):  
M. Devchand ◽  
F. P. Buxton ◽  
D. I. Gwynne ◽  
R. W. Davies
Keyword(s):  
Neurospora Crassa ◽  
Type Strain ◽  
Wild Type Strain ◽  
Translation System ◽  
Wild Type ◽  
Free Translation ◽  
A Cell

Live Cell Imaging of the Schizosaccharomyces pombe Sexual Life Cycle

2017 ◽  
Vol 2017 (10) ◽  
pp. pdb.prot090225 ◽  
Author(s):  
Laura Merlini ◽  
Aleksandar Vjestica ◽  
Omaya Dudin ◽  
Felipe Bendezú ◽  
Sophie G. Martin
Keyword(s):  
Life Cycle ◽  
Schizosaccharomyces Pombe ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Sexual Life ◽  
Sexual Life Cycle

Structural investigation of a cell-wall galactomannan from Neurospora crassa and N. sitophila

1996 ◽  
Vol 283 ◽  
pp. 215-222 ◽  
Author(s):  
Juan Antonio Leal ◽  
Jesús Jiménez-Barbero ◽  
Begoña Gómez-Miranda ◽  
Alicia Prieto ◽  
Jezabel Domenech ◽  
...  
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Structural Investigation ◽  
A Cell

scholarly journals Sexual Life Cycle of Aspergillus fumigatus

2011 ◽  
Vol 16 (3) ◽  
pp. 81-85
Author(s):  
권경주 ◽  
J. A. Sugui
Keyword(s):  
Life Cycle ◽  
Aspergillus Fumigatus ◽  
Sexual Life ◽  
Sexual Life Cycle

scholarly journals Binding of Serum Mannan Binding Lectin to a Cell Integrity-Defective Cryptococcus neoformans ccr4Δ Mutant

2007 ◽  
Vol 75 (10) ◽  
pp. 4769-4779 ◽  
Author(s):  
John C. Panepinto ◽  
Kazimierz W. Komperda ◽  
Moshe Hacham ◽  
Soowan Shin ◽  
Xiaoguang Liu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cryptococcus Neoformans ◽  
Wall Stress ◽  
Cell Integrity ◽  
Wild Type ◽  
Immune Mediator ◽  
A Cell ◽  
Bacteria And Fungi ◽  
Mannan Binding Lectin ◽  
Binding Lectin

ABSTRACT Mannan binding lectin (MBL) is an innate immune mediator belonging to the collectin family known to bind to the surfaces of many viruses, bacteria, and fungi. However, pathogenic strains of the fungus Cryptococcus neoformans are resistant to MBL binding. To dissect the mechanism of cryptococcal resistance to MBL, we compared MBL binding to an encapsulated wild-type strain, an encapsulated ccr4Δ mutant defective in cell integrity, and an acapsular cap60Δ strain. No MBL binding was detected on wild-type C. neoformans. In contrast, the ccr4Δ mutant bound MBL to the cell wall, predominantly at the ends of enlarged buds, whereas the acapsular strain bound MBL only at the bud neck and bud scars. In addition, the ccr4Δ mutant was sensitive to the cell wall-active antifungal caspofungin and other cell wall stress inducers, and its virulence was reduced in a mouse model of cryptococcosis. Interestingly, treatment of wild-type cells with caspofungin also increased MBL binding to C. neoformans. These results suggest that both the presence of capsule and wild-type cell wall architecture preclude MBL binding to C. neoformans.

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