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

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).

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α-1,6-Mannosylation of N-Linked Oligosaccharide Present on Cell Wall Proteins Is Required for Their Incorporation into the Cell Wall in the Filamentous Fungus Neurospora crassa

Eukaryotic Cell ◽

10.1128/ec.00134-10 ◽

2010 ◽

Vol 9 (11) ◽

pp. 1766-1775 ◽

Cited By ~ 39

Author(s):

Abhiram Maddi ◽

Stephen J. Free

Keyword(s):

Cell Wall ◽

Neurospora Crassa ◽

Mutant Cell ◽

Cell Wall Protein ◽

Cell Wall Proteins ◽

Wild Type ◽

Content Type ◽

Fold Reduction ◽

Total Lack ◽

Mutant Cells

ABSTRACT The enzyme α-1,6-mannosyltransferase (OCH-1) is required for the synthesis of galactomannans attached to the N-linked oligosaccharides of Neurospora crassa cell wall proteins. The Neurospora crassa och-1 mutant has a tight colonial phenotype and a defective cell wall. A carbohydrate analysis of the och-1 mutant cell wall revealed a 10-fold reduction in the levels of mannose and galactose and a total lack of 1,6-linked mannose residues. Analysis of the integral cell wall protein from wild-type and och-1 mutant cells showed that the mutant cell wall had reduced protein content. The och-1 mutant was found to secrete 18-fold more protein than wild-type cells. Proteomic analysis of the proteins released by the mutant into the growth medium identified seven of the major cell wall proteins. Western blot analysis of ACW-1 and GEL-1 (two glycosylphosphatidylinositol [GPI]-anchored proteins that are covalently integrated into the wild-type cell wall) showed that high levels of these proteins were being released into the medium by the och-1 mutant. High levels of ACW-1 and GEL-1 were also released from the och-1 mutant cell wall by subjecting the wall to boiling in a 1% SDS solution, indicating that these proteins are not being covalently integrated into the mutant cell wall. From these results, we conclude that N-linked mannosylation of cell wall proteins by OCH-1 is required for their efficient covalent incorporation into the cell wall.

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Coordination Between Fission Yeast Glucan Formation and Growth Requires a Sphingolipase Activity

Genetics ◽

10.1093/genetics/158.4.1397 ◽

2001 ◽

Vol 158 (4) ◽

pp. 1397-1411 ◽

Cited By ~ 2

Author(s):

Anna Feoktistova ◽

Paula Magnelli ◽

Claudia Abeijon ◽

Pilar Perez ◽

Robert L Lester ◽

...

Keyword(s):

Cell Wall ◽

Secretory Pathway ◽

Temperature Sensitive ◽

Cell Wall Formation ◽

Wild Type ◽

Wall Formation ◽

Biochemical Analyses ◽

Membrane Spanning ◽

Mutant Cells ◽

Large Deposits

Abstractcss1 mutants display a novel defect in Schizosaccharomyces pombe cell wall formation. The mutant cells are temperature-sensitive and accumulate large deposits of material that stain with calcofluor and aniline blue in their periplasmic space. Biochemical analyses of this material indicate that it consists of α- and β-glucans in the same ratio as found in cell walls of wild-type S. pombe. Strikingly, the glucan deposits in css1 mutant cells do not affect their overall morphology. The cells remain rod shaped, and the thickness of their walls is unaltered. Css1p is an essential protein related to mammalian neutral sphingomyelinase and is responsible for the inositolphosphosphingolipid-phospholipase C activity observed in S. pombe membranes. Furthermore, expression of css1+ can compensate for loss of ISC1, the enzyme responsible for this activity in Saccharomyces cerevisiae membranes. Css1p localizes to the entire plasma membrane and secretory pathway; a C-terminal fragment of Css1p, predicted to encode a single membrane-spanning segment, is sufficient to direct membrane localization of the heterologous protein, GFP. Our results predict the existence of an enzyme(s) or process(es) essential for the coordination of S. pombe cell wall formation and division that is, in turn, regulated by a sphingolipid metabolite.

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Differential Response of Two Tomato Genotypes, Wild Type cv. Ailsa Craig and Its ABA-Deficient Mutant flacca to Short-Termed Drought Cycles

Plants ◽

10.3390/plants10112308 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2308

Author(s):

Bojana Živanović ◽

Sonja Milić Komić ◽

Nenad Nikolić ◽

Dragosav Mutavdžić ◽

Tatjana Srećković ◽

...

Keyword(s):

Cell Wall ◽

Growth Regulation ◽

Stomatal Closure ◽

Dry Weight ◽

Wall Material ◽

Wild Type ◽

Spectra Analysis ◽

Isolated Cell ◽

Tomato Genotypes

Two tomato genotypes with constitutively different ABA level, flacca mutant and wild type of Ailsa Craig cv. (WT), were subjected to three repeated drought cycles, with the aim to reveal the role of the abscisic acid (ABA) threshold in developing drought tolerance. Differential responses to drought of two genotypes were obtained: more pronounced stomatal closure, ABA biosynthesis and proline accumulation in WT compared to the mutant were compensated by dry weight accumulation accompanied by transient redox disbalance in flacca. Fourier-transform infrared (FTIR) spectra analysis of isolated cell wall material and morphological parameter measurements on tomato leaves indicated changes in dry weight accumulation and carbon re-allocation to cell wall constituents in flacca, but not in WT. A higher proportion of cellulose, pectin and lignin in isolated cell walls from flacca leaves further increased with repeated drought cycles. Different ABA-dependent stomatal closure between drought cycles implies that acquisition of stomatal sensitivity may be a part of stress memory mechanism developed under given conditions. The regulatory role of ABA in the cell wall restructuring and growth regulation under low leaf potential was discussed with emphasis on the beneficial effects of drought priming in developing differential defense strategies against drought.

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The role of extracellular carbonic anhydrase for accumulation of inorganic carbon in the green alga Chlamydomonas reinhardtii. A comparison between wild-type and cell-wall-less mutant cells

Physiologia Plantarum ◽

10.1034/j.1399-3054.1990.800217.x ◽

1990 ◽

Vol 80 (2) ◽

pp. 267-276 ◽

Cited By ~ 2

Author(s):

Kristin Palmqvist ◽

Zakir Ramazanov ◽

Goran Samuelsson

Keyword(s):

Cell Wall ◽

Carbonic Anhydrase ◽

Chlamydomonas Reinhardtii ◽

Green Alga ◽

Inorganic Carbon ◽

Wild Type ◽

Mutant Cells

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O-Mannosylation in Candida albicans Enables Development of Interkingdom Biofilm Communities

mBio ◽

10.1128/mbio.00911-14 ◽

2014 ◽

Vol 5 (2) ◽

Cited By ~ 41

Author(s):

Lindsay C. Dutton ◽

Angela H. Nobbs ◽

Katy Jepson ◽

Mark A. Jepson ◽

M. Margaret Vickerman ◽

...

Keyword(s):

Cell Wall ◽

Candida Albicans ◽

Biofilm Formation ◽

Early Stage ◽

Growth Conditions ◽

Wild Type ◽

Content Type ◽

Subsequent Performance ◽

Biofilm Development ◽

Mutant Cells

ABSTRACTCandida albicansis a fungus that colonizes oral cavity surfaces, the gut, and the genital tract.Streptococcus gordoniiis a ubiquitous oral bacterium that has been shown to form biofilm communities withC. albicans. Formation of dual-speciesS. gordonii-C. albicansbiofilm communities involves interaction of theS. gordoniiSspB protein with the Als3 protein on the hyphal filament surface ofC. albicans. Mannoproteins comprise a major component of theC. albicanscell wall, and in this study we sought to determine if mannosylation in cell wall biogenesis ofC. albicanswas necessary for hyphal adhesin functions associated with interkingdom biofilm development. AC. albicans mnt1Δmnt2Δ mutant, with deleted α-1,2-mannosyltransferase genes and thus defective inO-mannosylation, was abrogated in biofilm formation under various growth conditions and produced hyphal filaments that were not recognized byS. gordonii. Cell wall proteomes of hypha-formingmnt1Δmnt2Δ mutant cells showed growth medium-dependent alterations, compared to findings for the wild type, in a range of protein components, including Als1, Als3, Rbt1, Scw1, and Sap9. Hyphal filaments formed bymnt1Δmnt2Δ mutant cells, unlike wild-type hyphae, did not interact withC. albicansAls3 or Hwp1 partner cell wall proteins or withS. gordoniiSspB partner adhesin, suggesting defective functionality of adhesins on themnt1Δmnt2Δ mutant. These observations imply that early stageO-mannosylation is critical for activation of hyphal adhesin functions required for biofilm formation, recognition by bacteria such asS. gordonii, and microbial community development.IMPORTANCEIn the human mouth, microorganisms form communities known as biofilms that adhere to the surfaces present.Candida albicansis a fungus that is often found within these biofilms. We have focused on the mechanisms by whichC. albicansbecomes incorporated into communities containing bacteria, such asStreptococcus. We find that impairment of early stage addition of mannose sugars toC. albicanshyphal filament proteins deleteriously affects their subsequent performance in mediating formation of polymicrobial biofilms. Our analyses provide new understanding of the way that microbial communities develop, and of potential means to controlC. albicansinfections.

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Carbon source dependent differences in the composition of the cell walls of the basidiomycete Picnoporus cinnabarinus

Canadian Journal of Microbiology ◽

10.1139/m77-199 ◽

1977 ◽

Vol 23 (9) ◽

pp. 1313-1317 ◽

Cited By ~ 1

Author(s):

J. A. Cury ◽

Déa Amaral

Keyword(s):

Cell Wall ◽

Carbon Source ◽

Cell Walls ◽

Amino Sugars ◽

Enzymatic Analysis ◽

Wild Type ◽

Monokaryotic Strain ◽

Morphological Differences ◽

Isolated Cell

A wild-type monokaryotic strain of Picnoporus cinnabarinus grown on glucose produced shorter and thicker hyphae than cultures grown on acetate. Colonies from glucose media were smaller and more compact than acetate-grown colonies. Chemical and enzymatic analysis of the isolated cell wall of both morphological types showed that the amount of amino sugars and the ratio glucosamine:galactosamine were higher in the acetate-grown cells. This may be the cause of morphological differences observed.

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The role of extracellular carbonic anhydrase for accumulation of inorganic carbon in the green alga Chlamydomonas reinhardtii. A comparison between wild-type and cell-wall-less mutant cells

Physiologia Plantarum ◽

10.1111/j.1399-3054.1990.tb04407.x ◽

1990 ◽

Vol 80 (2) ◽

pp. 267-276 ◽

Cited By ~ 25

Author(s):

Kristin Palmqvist ◽

Zakir Ramazanov ◽

Goran Samuelsson

Keyword(s):

Cell Wall ◽

Carbonic Anhydrase ◽

Chlamydomonas Reinhardtii ◽

Green Alga ◽

Inorganic Carbon ◽

Wild Type ◽

Mutant Cells

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PHASE-SPECIFIC GENES FOR MACROCONIDIATION IN NEUROSPORA CRASSA

Genetics ◽

10.1093/genetics/78.2.679 ◽

1974 ◽

Vol 78 (2) ◽

pp. 679-690 ◽

Cited By ~ 1

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.

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