Ultrastructure of teliospore formation in the rust fungus Puccinia podophylli

1979 ◽  
Vol 57 (22) ◽  
pp. 2533-2538 ◽  
Author(s):  
Charles W. Mims ◽  
E. Laurence Thurston
Keyword(s):  
Rust Fungus ◽  
Ultrastructural Level ◽  
Spore Wall ◽  
Dense Layer ◽  
Spore Surface ◽  
Outer Electron ◽  
Cytoplasmic Material

Teliospore initials of Puccinia podophylli develop from binucleate sporogenous cells lining the base of the telium. The teliospores are formed in basically the same fashion as those of other rusts that have been examined at the ultrastructural level. The long, straight or slightly curved spines present on mature teliospores initially develop as slight bulges or protrusions on the spore surface. The spore wall in such a region then evaginates to form a slender spine that is initially filled with cytoplasm. The cytoplasmic material is then progressively excluded from the tip of the spine as a result of the thickening of the spine wall. Mature teliospores of P. podophylli possess a wall consisting of a thick, outer, electron-dense layer in which stratification is only rarely visible and an inner thinner, less electron-dense layer.

scholarly journals The fission yeast spore is coated by a proteinaceous surface layer comprising mainly Isp3

2014 ◽  
Vol 25 (10) ◽  
pp. 1549-1559 ◽  
Author(s):  
Kana Fukunishi ◽  
Kana Miyakubi ◽  
Mitsuko Hatanaka ◽  
Natsumi Otsuru ◽  
Aiko Hirata ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Digestive Enzymes ◽  
Spore Wall ◽  
Environmental Stresses ◽  
Dense Layer ◽  
Spore Coat ◽  
Spore Surface ◽  
Wild Type ◽  
Dormant Cell ◽  
Spore Coat Protein

The spore is a dormant cell that is resistant to various environmental stresses. As compared with the vegetative cell wall, the spore wall has a more extensive structure that confers resistance on spores. In the fission yeast Schizosaccharomyces pombe, the polysaccharides glucan and chitosan are major components of the spore wall; however, the structure of the spore surface remains unknown. We identify the spore coat protein Isp3/Meu4. The isp3 disruptant is viable and executes meiotic nuclear divisions as efficiently as the wild type, but isp3∆ spores show decreased tolerance to heat, digestive enzymes, and ethanol. Electron microscopy shows that an electron-dense layer is formed at the outermost region of the wild-type spore wall. This layer is not observed in isp3∆ spores. Furthermore, Isp3 is abundantly detected in this layer by immunoelectron microscopy. Thus Isp3 constitutes the spore coat, thereby conferring resistance to various environmental stresses.

Spore wall development in Sphagnum lescurii

1982 ◽  
Vol 60 (11) ◽  
pp. 2394-2409 ◽  
Author(s):  
Roy Curtiss Brown ◽  
Betty E. Lemmon ◽  
Zane B. Carothers
Keyword(s):  
Plasma Membrane ◽  
Outer Layer ◽  
Mature Spore ◽  
Outer Wall ◽  
Spore Wall ◽  
Spore Surface ◽  
Proximal Surface ◽  
Complex Development ◽  
Surface Ornamentation ◽  
Cortical System

The spore wall of Sphagnum is unique in the Bryophyta. The Sphagnum spore exine consists of two layers: an inner, lamellate layer (A layer) and a thick, homogenous, outer layer (B layer). The exine of other mosses consists of only the outermost homogenous layer and, at most, a thin ill-defined opaque layer. During development of the A-layer exine and the intine, a cortical system of evenly spaced microtubules underlies the plasma membrane. The ontogeny of the wall layers is not strictly centripetal. The A-layer exine develops evenly around the young spore immediately after cytokinesis. As the intine is deposited centripetally inside it, the homogenous B-layer exine is deposited outside the first-formed A layer. The B layer is responsible for the primary sculpturing of the spore surface. The mature spore is covered by an outermost perine, which is responsible for secondary surface ornamentation. A trilaesurate aperture develops on the proximal surface of each spore after deposition of the A layer. Ridges of the laesurae develop as a result of deposition of thick areas of intine. The ridges are eventually covered by the outer wall layers, whereas the fissure is covered only by the A layer and a very thin B-layer exine. The complex development of the trilaesurate aperture is evidence that the structure is not merely a mechanically induced "trilete mark" or "scar" resulting from compression of tetrahedrally arranged spores within a sporocyte wall.

Fine structure of basidiospores of the cedar-apple rust fungus Gymnosporangium juniperi-virginianae

1977 ◽  
Vol 55 (9) ◽  
pp. 1057-1063 ◽  
Author(s):  
Charles W. Mims
Keyword(s):  
Fine Structure ◽  
Thin Layer ◽  
Lipid Droplets ◽  
Germ Tube ◽  
Rust Fungus ◽  
Spore Wall ◽  
Lipid Bodies ◽  
Pore Region ◽  
Hilar Region ◽  
Endoplasmic Reticula

Each basidiospore of Gymnosporangium juniperi-virginianae contains many ribosomes as well as lipid droplets, mitochondria, small vesicles, endoplasmic reticula, and structures thought to be microbodies. Mature spores are either uninucleate or binucleate although larger, tetranucleate spores were occasionally observed. The spore wall appears as a thin layer except around the hilar region where two layers are evident. Germination is almost always lateral although no germ pore region was noted in the wall. Vacuolation takes place during germination and lipid bodies disappear. The wall of the germ tube arising from the spore is continuous with that of the spore. A large number of vesicles is present in the germ tube. Basidiospores may also germinate by repetition.

A systematic evaluation of basidiospore symmetry and tegumentation in hypogeous and gasteroid Russulales

1988 ◽  
Vol 66 (12) ◽  
pp. 2561-2573 ◽  
Author(s):  
Steven L. Miller
Keyword(s):  
Light Microscope ◽  
Spore Wall ◽  
Systematic Evaluation ◽  
Spore Morphology ◽  
Spore Surface ◽  
Layer 2 ◽  
Spore Walls ◽  
Poorly Differentiated ◽  
Surface Ornamentation ◽  
Dark Blue

Spore wall architecture and ontogeny of ornamentation in several genera and species of hypogeous and gasteroid Russulales are similar to those described previously for agaricoid Lactarius lignyotellus. Spore walls are composed of four layers, each differing in thickness and electron density. Layer 2 is electron transparent and corresponds to a dark blue, amyloid layer when mounted in Melzer's iodine reagent and viewed with the light microscope. Establishment of spore symmetry may be regulated by the hilar appendix body, which is a poorly differentiated cytoplasmic region in the hilar appendix of asymmetric spores of Macowanites luteolus, Elasmomyces russuloides, and Zelleromyces versicaulus but which is absent in symmetric spores of Z. sculptisporus, Martellia subochracea, and Gymnomyces yubaensis. A continuum in spore morphology from truly symmetric to asymmetric is evident in spores from individual sporocarps of many species of the Russulales. The variation in spore symmetry and spore surface ornamentation has clouded taxonomic concepts in the Russulales. Systematically, development of orthotropic and heterotropic spores has been regarded as two distinct end points of evolution, when they are likely terms describing degrees of the same phenomenon. The current circumscription of families and genera in the Russulales based on spore symmetry, therefore, appears to be artificial.

Ultrastructure of conidiogenesis and appendage ontogeny in the coelomycete Bartalinia robillardoides

2003 ◽  
Vol 81 (11) ◽  
pp. 1083-1090 ◽  
Author(s):  
M KM Wong ◽  
E BG Jones ◽  
M A Abdel-Wahab ◽  
D WT Au ◽  
L LP Vrijmoed
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Cell Walls ◽  
Apical Cell ◽  
Conidiogenous Cell ◽  
Dense Layer ◽  
Basal Cells ◽  
Outer Electron ◽  
Transmission Electron ◽  
Scanning Electron

Conidiogenesis and conidial appendage ontogeny of the coelomycete Bartalinia robillardoides Tassi was studied at the light microscope, scanning electron microscope, and transmission electron microscope levels. Conidiogenesis in B. robillardoides is holoblastic. Appendage ontogeny begins as a cellular outgrowth of the apical and the basal cells of the young conidium, the former developing prior to the basal appendage. Conidia detach from the conidiogenous cells schizolytically. Mature conidial cell walls comprise two layers: an outer electron-dense layer, 30–38 nm, and an inner less electron-dense layer, 100–125 nm. The apical appendages arise from an outgrowth of the apical cell, which then branches to form the appendages. The single basal appendage arises from the junction between the basal cell of the conidium and the conidiogenous cell prior to conidial detachment from the conidiogenous cell, as an outgrowth of the conidial cell wall. Conidial appendage ontogeny is compared with those of other coelomycetes.Key words: Annellidic, appendage ontogeny, coelomycetes, holoblastic.

Acaulospora papillosa, a new mycorrhizal fungus from NE Brazil, and Acaulospora rugosa from Norway

Phytotaxa ◽  
2016 ◽  
Vol 260 (1) ◽  
pp. 14 ◽  
Author(s):  
CAMILLA M.R. PEREIRA ◽  
LEONOR C. MAIA ◽  
IVÁN SÁNCHEZ-CASTRO ◽  
JAVIER PALENZUELA ◽  
DANIELLE K.A. SILVA ◽  
...  
Keyword(s):  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Single Species ◽  
Spore Wall ◽  
Wall Layer ◽  
Northeastern Brazil ◽  
Tropical Atlantic ◽  
Spore Surface ◽  
Phylogenetic Placement ◽  
Light Yellow

A new arbuscular mycorrhizal species, Acaulospora papillosa, was isolated from the biological reserve ‘Saltinho’ within a coastal tropical Atlantic forest of the ‘Mata Atlântica’ biome in Pernambuco State of Northeastern Brazil. It was trapped and propagated as single species cultures on Zea mays. The spores are yellow white to light yellow to creamy, globose to subglobose, 69–100(–110) × 65–93(–101) µm. The spore surface is roughened as crowded with fine papillae, which are formed on the outermost, evanescent to semi-persistent spore wall layer. These papillae may disintegrate or completely disappear as the spores age and the layer becomes completely evanescent. Phylogenetically, the fungus clusters together with several small-spored Acaulospora species having smooth spore surfaces, such as A. delicata, A. longula, A. morrowiae and A. mellea. In the Acaulospora clade, A. papillosa is the third taxon known to have a roughened spore surface, in addition to A. dilatata and A. rugosa. The phylogenetic placement of A. rugosa is provided, together with colored illustrations of the spore morphology. The isolation of A. papillosa from such protected nature reserves as ‘Saltinho’ further supports the need to protect these areas and determine the biodiversity of beneficial microorganisms.

Ultrastructural studies of primary spores of Conidiobolus, Erynia, and related Entomophthorales

1989 ◽  
Vol 67 (9) ◽  
pp. 2576-2589 ◽  
Author(s):  
J. P. Latgé ◽  
D. F. Perry ◽  
M. C. Prévost ◽  
R. A. Samson
Keyword(s):  
Outer Layer ◽  
Germ Tube ◽  
Spore Wall ◽  
Wall Layer ◽  
Spore Formation ◽  
Dense Layer ◽  
Nuclear Ultrastructure ◽  
Ultrastructural Studies ◽  
Thin Electron ◽  
Definition Of

Wall development during primary spore formation, discharge, and germination of Entomophthorales is emphasized in ultrastructural studies of Conidiobolus, Entomophaga, Neozygites, and Erynia. In the fungi examined, spore and sporophore walls consist of a thick, electron-translucent inner layer and a thin, electron-dense outer layer. During spore formation, cytoplasm of the supporting sporophore cell migrates into the spore initial. As the former cell empties, a septum develops. Discharge is caused by inversion of the papillum, which lacks the electron-dense layer. Only in Erynia did the two spore wall layers separate upon impact. Intracytoplasmic organization of the primary spore is typical of the Zygomycotina; the morphology of organelles was characteristic of species, whereas nuclear ultrastructure was consistent within genera. Conidiobolus nuclei have a prominent nucleolus that lacks heterochromatin, in contrast with the other genera where large patches of heterochromatin were observed. Upon germination, no rupture of the spore outer layer was observed other than at points of germ tube emergence. The germ tube wall was continuous with the inner spore wall layer. The results are discussed in reference to Entomophthorales taxonomy and definition of the terms conidium and monosporous sporangiolum.

scholarly journals Dtr1p, a Multidrug Resistance Transporter of the Major Facilitator Superfamily, Plays an Essential Role in Spore Wall Maturation in Saccharomyces cerevisiae

2002 ◽  
Vol 1 (5) ◽  
pp. 799-810 ◽  
Author(s):  
Thomas Felder ◽  
Edith Bogengruber ◽  
Sandra Tenreiro ◽  
Adi Ellinger ◽  
Isabel Sá-Correia ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Multidrug Resistance ◽  
De Novo ◽  
Physiological Role ◽  
Spore Wall ◽  
Major Facilitator Superfamily ◽  
Spore Surface ◽  
Prospore Membrane ◽  
A Genome ◽  
Major Facilitator

ABSTRACT The de novo formation of multilayered spore walls inside a diploid mother cell is a major landmark of sporulation in the yeast Saccharomyces cerevisiae. Synthesis of the dityrosine-rich outer spore wall takes place toward the end of this process. Bisformyl dityrosine, the major building block of the spore surface, is synthesized in a multistep process in the cytoplasm of the prospores, transported to the maturing wall, and polymerized into a highly cross-linked macromolecule on the spore surface. Here we present evidence that the sporulation-specific protein Dtr1p (encoded by YBR180w) plays an important role in spore wall synthesis by facilitating the translocation of bisformyl dityrosine through the prospore membrane. DTR1 was identified in a genome-wide screen for spore wall mutants. The null mutant accumulates unusually large amounts of bisformyl dityrosine in the cytoplasm and fails to efficiently incorporate this precursor into the spore surface. As a result, many mutant spores have aberrant surface structures. Dtr1p, a member of the poorly characterized DHA12 (drug:H+ antiporter with 12 predicted membrane spans) family, is localized in the prospore membrane throughout spore maturation. Transport by Dtr1p may not be restricted to its natural substrate, bisformyl dityrosine. When expressed in vegetative cells, Dtr1p renders these cells slightly more resistant against unrelated toxic compounds, such as antimalarial drugs and food-grade organic acid preservatives. Dtr1p is the first multidrug resistance protein of the major facilitator superfamily with an assigned physiological role in the yeast cell.

Cytochemistry of acid mucosubstance and acid phosphatase in Cryptococcus neoformans

1974 ◽  
Vol 20 (6) ◽  
pp. 833-838 ◽  
Author(s):  
Thomas A. Mahvi ◽  
Samuel S. Spicer ◽  
Nancy J. Wright
Keyword(s):  
Cell Wall ◽  
Acid Phosphatase ◽  
Cryptococcus Neoformans ◽  
Ultrastructural Level ◽  
Dense Layer ◽  
Strong Activity ◽  
Thin Sections ◽  
Cytoplasmic Bodies ◽  
Cryostat Sections ◽  
Substrate Medium

At the ultrastructural level, dialyzed iron stains only the mucoid capsule in Cryptococcus neoformans, converting it from the most lucent to an extremely dense layer and thus demonstrating its content of acid mucosubstance. After lead staining of thin sections of dialyzed iron treated specimens, the wall exhibits a dense inner and translucent outer layer. The inner layer and mucoid capsule appear thicker in the mother than the daughter cell of budding organisms. C. neoformans cells fixed in suspension and incubated in acid phosphatase substrate medium exhibit at the ultrastructural level activity confined to the mucoid capsule, cell wall, and internal extensions presumed to be plasmalemmasomes. Organisms in small blocks or cryostat sections of pellets fixed in clotted fibrin, when incubated for acid phosphatase, reveal moderate to no reactivity in cell wall and mucoid capsule but strong activity in surrounding fibrin aggregates. In the latter specimens, reaction product indicative of acid phosphatase also is evident in the nuclear envelope, in some of the profiles of presumed granular reticulum, in complex lamellar profiles presumed to be Golgi elements, and in small cytoplasmic bodies and large vacuoles. The morphological specimens disclose counterparts of acid phosphatase reactive structures and show lucent cytoplasm segregated by circular mitochondrial profiles and a difference between the thickness and density of the plasmalemma and other cell membranes.

Lectin binding to secretory structures, the cuticle and the surface coat ofToxocara canisinfective larvae

Parasitology ◽  
1992 ◽  
Vol 105 (2) ◽  
pp. 285-296 ◽  
Author(s):  
A. P. Page ◽  
W. Rudin ◽  
R. M. Maizels
Keyword(s):  
Lectin Binding ◽  
Helix Pomatia ◽  
Toxocara Canis ◽  
Surface Expression ◽  
Ultrastructural Level ◽  
Dense Layer ◽  
Surface Coat ◽  
Surface Binding ◽  
Dense Area ◽  
Secretory Structures

SUMMARYToxocara canisinfective larvae are known to produce abundant glycosylated molecules which may be found associated with the surface or secreted into their environment. Using a range of fluorescein-conjugated and gold-conjugated lectins, the localization of particular carbohydrates was defined on the surface of live parasites, and internally at the ultrastructural level. Surface exposure ofN-acetyl galactosamine andN-acetyl glucosamine was deduced by binding of FITC-conjugatedHelix pomatia(HPA) and wheat-germ agglutinins (WGA). These sugars appear to be associated with a densely staining surface coat as conventional immuno-electron microscopy procedures dissipate this coat and reveal no surface binding site for these lectins. However, by using cryo-immuno-electron microscopical (C-IEM) techniques, the surface coat is retained and can be shown to bind WGA. The fluorescent lectins also revealed strong WGA binding to the secretory and amphidial pores, while the buccal opening and the cuticular alae bound HPA. Corresponding results were obtained at the ultrastructural level. Thus, HPA bound to the electron-dense area of the cuticle, areas of local cuticular thickening such as the alae and buccal labia, as well as to the oesophageal lumen. WGA also bound to the thickened cuticle of the alae and the buccal opening, but showed no reaction to either the electron-dense layer of the cuticle or the oesophageal lumen. Unlike HPA, WGA did bind specifically to the secretory column contents and the electron-dense regions of the lips associated with the chemosensory amphids. The compartmentalization of the sugarsN-acetyl galactosamine andN-acetyl glucosamine, their sources and routes of surface expression and the possible association with the TES glycoprotein antigens are discussed.

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