Ascospore development in the fission yeasts Schizosaccharomyces pombe and S. japonicus

1982 ◽  
Vol 56 (1) ◽  
pp. 263-279 ◽  
Author(s):  
K. Tanaka ◽  
A. Hirata
Keyword(s):  
Plasma Membrane ◽  
Schizosaccharomyces Pombe ◽  
Periodic Acid ◽  
Staining Technique ◽  
Membrane System ◽  
Spore Wall ◽  
Wall Material ◽  
Dense Granules ◽  
Thin Sectioning ◽  
Ascospore Development

The fine structure of ascospore formation in the fission yeasts Schizosaccharomyces pombe and Schizosaccharomyces japonicus var. japonicus was studied by serial thin-sectioning and electron microscopy. The morphogenetic events were almost the same in both species. Ascospore development was initiated by the formation of the forespore membrane on the cytoplasmic side of the differentiated nucleus-associated organelle (NAO) in the interval between meiosis I and II in S. pombe, or during the post-meiotic nuclear division in S. japonicus, and the process proceeded almost synchronously through the two or four nuclei in the ascus. The forespore membrane developed by fusion of the cytoplasmic vesicles and this was clearly demonstrated in S. japonicus where the behaviour of vesicles involved in the forespore membrane development could be traced as they were marked by the presence of electron-dense granules. The staining technique, by phosphotungustic acid—chromic acid (PTA-CA) after treatment with periodic acid, was used to attempt to elucidate the origin and the nature of the forespore membrane. The method specific to plasmalemma-type membranes stained both ascus and ascospore plasmalemmas; the forespore membrane was not stained at first but developed the same affinity for stain as the plasma membrane in the course of ascospore development. The results suggest that the forespore membrane did not come directly from the ascus plasma membrane, but from another membrane system such as the endoplasmic reticulum. Spore wall material was deposited in the space between the inner and outer leaflets of the forespore membrane.

Ultrastructure and development of urediospore ornamentation in Melampsora lini

1971 ◽  
Vol 49 (12) ◽  
pp. 2067-2073 ◽  
Author(s):  
L. J. Littlefield ◽  
C. E. Bracker
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Outer Surface ◽  
Spore Wall ◽  
Wall Material ◽  
Wild Type ◽  
Melampsora Lini ◽  
Inner Surface ◽  
External Position ◽  
Basal Portion

The urediospores of Melampsora lini (Ehrenb.) Lev. are echinulate, with spines ca. 1 μ long over their surface. The spines are electron-transparent, conical projections, with their basal portion embedded in the electron-dense spore wall. The entire spore, including the spines, is covered by a wrinkled pellicle ca. 150–200 Å thick. The spore wall consists of three recognizable layers in addition to the pellicle. Spines form initially as small deposits at the inner surface of the spore wall adjacent to the plasma membrane. Endoplasmic reticulum occurs close to the plasma membrane in localized areas near the base of spines. During development, the spore wall thickens, and the spines increase in size. Centripetal growth of the wall encases the spines in the wall material. The spines progressively assume a more external position in the spore wall and finally reside at the outer surface of the wall. A mutant strain with finely verrucose spores was compared to the wild type. The warts on the surface of the mutant spores are rounded, electron-dense structures ca. 0.2–0.4 μ high, in contrast to spines of the wild type. Their initiation near the inner surface of the spore wall and their eventual placement on the outer surface of the spore are similar to that of spines. The wall is thinner in mutant spores than in wild-type spores.

scholarly journals Alpha-granule pool of glycoprotein IIb-IIIa in normal and pathologic platelets and megakaryocytes

Blood ◽  
1990 ◽  
Vol 75 (6) ◽  
pp. 1220-1227 ◽  
Author(s):  
EM Cramer ◽  
GF Savidge ◽  
W Vainchenker ◽  
MC Berndt ◽  
D Pidard ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Polyclonal Antibodies ◽  
Staining Technique ◽  
Membrane System ◽  
Type I ◽  
Immunogold Staining ◽  
The Third ◽  
Granule Membrane ◽  
Gray Platelet Syndrome

Abstract Using an immunogold staining technique and electron microscopy, we investigated the localization of the alpha-granule pool of glycoprotein (GP) IIb-IIIa in normal platelets and maturing megakaryocytes (MK), in pathologic platelets from a patient with type I Glanzmann's thrombasthenia (GT), and from three patients with the gray platelet syndrome (GPS). In normal resting platelets, GPIIb-IIIa was observed on the plasmatic side of the plasma membrane, the open canicular system (OCS) membranes, and along the internal face of the alpha-granule membrane. This location was found with three monospecific polyclonal antibodies: one anti-GPIIb-IIIa antibody, the second specific for GPIIb, and the third specific for GPIIIa. After thrombin stimulation, the alpha-granule labeling disappeared whereas membrane labeling increased. Platelets from GT did not display labeling on plasma membranes, OCS membranes, or alpha-granule membranes. Platelets from the three patients with GPS displayed intense labeling of the plasma membrane and the OCS membrane, as well as the abnormal small alpha- granules and along the inside of large vacuoles (which contain the granule membrane protein [GMP]-140). In cultured immature MK from normal progenitors, both peptide components of GPIIb-IIIa appeared in the Golgi saccules and vesicles, and in the small precursors of alpha- granules, labeling both their membranes and their matrix. It was then observed only on the membrane of the mature MK alpha-granules, although labeling was less consistent than on the platelet granules. The MK plasma membrane and demarcation membrane system also displayed GPIIb- IIIa labeling. In conclusion, this study demonstrates that GPIIb-IIIa is present on the internal face of the alpha-granule membranes of platelets (where it appears early during MK maturation) as well as in the abnormal alpha-granules of gray platelets; it is absent from GT type I platelets.

scholarly journals Alpha-granule pool of glycoprotein IIb-IIIa in normal and pathologic platelets and megakaryocytes

Blood ◽  
1990 ◽  
Vol 75 (6) ◽  
pp. 1220-1227 ◽  
Author(s):  
EM Cramer ◽  
GF Savidge ◽  
W Vainchenker ◽  
MC Berndt ◽  
D Pidard ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Plasma Membranes ◽  
Polyclonal Antibodies ◽  
Staining Technique ◽  
Membrane System ◽  
Type I ◽  
Immunogold Staining ◽  
The Third ◽  
Granule Membrane ◽  
Gray Platelet Syndrome

Using an immunogold staining technique and electron microscopy, we investigated the localization of the alpha-granule pool of glycoprotein (GP) IIb-IIIa in normal platelets and maturing megakaryocytes (MK), in pathologic platelets from a patient with type I Glanzmann's thrombasthenia (GT), and from three patients with the gray platelet syndrome (GPS). In normal resting platelets, GPIIb-IIIa was observed on the plasmatic side of the plasma membrane, the open canicular system (OCS) membranes, and along the internal face of the alpha-granule membrane. This location was found with three monospecific polyclonal antibodies: one anti-GPIIb-IIIa antibody, the second specific for GPIIb, and the third specific for GPIIIa. After thrombin stimulation, the alpha-granule labeling disappeared whereas membrane labeling increased. Platelets from GT did not display labeling on plasma membranes, OCS membranes, or alpha-granule membranes. Platelets from the three patients with GPS displayed intense labeling of the plasma membrane and the OCS membrane, as well as the abnormal small alpha- granules and along the inside of large vacuoles (which contain the granule membrane protein [GMP]-140). In cultured immature MK from normal progenitors, both peptide components of GPIIb-IIIa appeared in the Golgi saccules and vesicles, and in the small precursors of alpha- granules, labeling both their membranes and their matrix. It was then observed only on the membrane of the mature MK alpha-granules, although labeling was less consistent than on the platelet granules. The MK plasma membrane and demarcation membrane system also displayed GPIIb- IIIa labeling. In conclusion, this study demonstrates that GPIIb-IIIa is present on the internal face of the alpha-granule membranes of platelets (where it appears early during MK maturation) as well as in the abnormal alpha-granules of gray platelets; it is absent from GT type I platelets.

scholarly journals New methods for confocal imaging of infection threads in crop and model legumes

Plant Methods ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Angus E. Rae ◽  
Vivien Rolland ◽  
Rosemary G. White ◽  
Ulrike Mathesius
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Periodic Acid ◽  
Confocal Imaging ◽  
Wall Material ◽  
Future Research ◽  
Thin Sections ◽  
New Methods ◽  
Infection Threads ◽  
Imaging Of Infection

Abstract Background The formation of infection threads in the symbiotic infection of rhizobacteria in legumes is a unique, fascinating, and poorly understood process. Infection threads are tubes of cell wall material that transport rhizobacteria from root hair cells to developing nodules in host roots. They form in a type of reverse tip-growth from an inversion of the root hair cell wall, but the mechanism driving this growth is unknown, and the composition of the thread wall remains unclear. High resolution, 3-dimensional imaging of infection threads, and cell wall component specific labelling, would greatly aid in our understanding of the nature and development of these structures. To date, such imaging has not been done, with infection threads typically imaged by GFP-tagged rhizobia within them, or histochemically in thin sections. Results We have developed new methods of imaging infection threads using novel and traditional cell wall fluorescent labels, and laser confocal scanning microscopy. We applied a new Periodic Acid Schiff (PAS) stain using rhodamine-123 to the labelling of whole cleared infected roots of Medicago truncatula; which allowed for imaging of infection threads in greater 3D detail than had previously been achieved. By the combination of the above method and a calcofluor-white counter-stain, we also succeeded in labelling infection threads and plant cell walls separately, and have potentially discovered a way in which the infection thread matrix can be visualized. Conclusions Our methods have made the imaging and study of infection threads more effective and informative, and present exciting new opportunities for future research in the area.

scholarly journals Characterization of Glycoside Hydrolase Family 5 Proteins in Schizosaccharomyces pombe

2010 ◽  
Vol 9 (11) ◽  
pp. 1650-1660 ◽  
Author(s):  
Encarnación Dueñas-Santero ◽  
Ana Belén Martín-Cuadrado ◽  
Thierry Fontaine ◽  
Jean-Paul Latgé ◽  
Francisco del Rey ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Protein Characterization ◽  
Wall Material ◽  
Glycoside Hydrolase Family ◽  
Content Type ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis ◽  
Hydrolase Family

ABSTRACT In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1 + (locus SPBC1105.05), exg2 + (SPAC12B10.11), and exg3 + (SPBC2D10.05). The three proteins have different localizations: Exg1 is secreted to the periplasmic space, Exg2 is a membrane protein, and Exg3 is a cytoplasmic protein. Characterization of the biochemical activity of the proteins indicated that Exg1 and Exg3 are active only against β(1,6)-glucans while no activity was detected for Exg2. Interestingly, Exg1 cleaves the glucans with an endohydrolytic mode of action. exg1 + showed periodic expression during the cell cycle, with a maximum coinciding with the septation process, and its expression was dependent on the transcription factor Sep1. The Exg1 protein localizes to the septum region in a pattern that was different from that of the endo-β(1,3)-glucanase Eng1. Overexpression of Exg2 resulted in an increase in cell wall material at the poles and in the septum, but the putative catalytic activity of the protein was not required for this effect.

Isolation of a pure suspension of rat proximal tubules

1981 ◽  
Vol 241 (4) ◽  
pp. F403-F411 ◽  
Author(s):  
P. Vinay ◽  
A. Gougoux ◽  
G. Lemieux
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Periodic Acid ◽  
Vital Staining ◽  
Staining Technique ◽  
Proximal Tubules ◽  
Periodic Acid Schiff ◽  
Homogeneous Population ◽  
Proximal Tubular ◽  
Percoll Density Gradient ◽  
Enzyme Location

A suspension of cortical tissue fragments prepared by collagenase digestion of renal cortex obtained from fed and chronically acidotic (NH4Cl) rats was separated into four bands on a Percoll density gradient. By microscopic examination, vital staining with trypan blue, and histologic staining technique (periodic acid-Schiff) the F4 band was shown to contain only (greater than 98%) proximal tubules, whereas the F1 band was significantly enriched (70%) with distal tubules contaminated by glomeruli and short segments of proximal tubules. Intra/extracellular ratios for PAH of 15 were measured in the F4 band and of 2 in F1 band. ATP was 1.4 and 2.8 mumol/g in the F4 and F1 bands, respectively, and was stable for at least 60 min. The proximal F4 band was shown to be gluconeogenic (L-glutamine or L-lactate 2.5 mM as substrate) and to adapt to metabolic acidosis. The distal F1 band was shown to be glycolytic (glucose 2.5 mM) with no changes with acid-base status. All fractions were shown to metabolize glutamine, but the metabolic fate of this amino acid was different in proximal and distal structures. A F4/F1 activity ratio for the proximal cytoplasmic phosphoenolpyruvate carboxykinase enzyme of 2.6 and 4.3 was observed in normal and acidotic rats, respectively. In contrast, a F4/F1 ratio of 0.13 and 0.22 was observed for the distal cytoplasmic hexokinase enzyme. This preparation, therefore, allows the metabolism of a homogeneous population of proximal tubular fragments to be studied and can be used to obtain information on enzyme location within the nephron.

scholarly journals Caveolin-3 Associates with Developing T-tubules during Muscle Differentiation

1997 ◽  
Vol 136 (1) ◽  
pp. 137-154 ◽  
Author(s):  
Robert G. Parton ◽  
Michael Way ◽  
Natasha Zorzi ◽  
Espen Stang
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Muscle Cells ◽  
Membrane System ◽  
C2c12 Cells ◽  
Double Labeling ◽  
Specific Antibodies ◽  
T Tubules ◽  
Α1 Subunit

Caveolae, flask-shaped invaginations of the plasma membrane, are particularly abundant in muscle cells. We have recently cloned a muscle-specific caveolin, termed caveolin-3, which is expressed in differentiated muscle cells. Specific antibodies to caveolin-3 were generated and used to characterize the distribution of caveolin-3 in adult and differentiating muscle. In fully differentiated skeletal muscle, caveolin-3 was shown to be associated exclusively with sarcolemmal caveolae. Localization of caveolin-3 during differentiation of primary cultured muscle cells and development of mouse skeletal muscle in vivo suggested that caveolin-3 is transiently associated with an internal membrane system. These elements were identified as developing transverse-(T)-tubules by double-labeling with antibodies to the α1 subunit of the dihydropyridine receptor in C2C12 cells. Ultrastructural analysis of the caveolin-3– labeled elements showed an association of caveolin-3 with elaborate networks of interconnected caveolae, which penetrated the depths of the muscle fibers. These elements, which formed regular reticular structures, were shown to be surface-connected by labeling with cholera toxin conjugates. The results suggest that caveolin-3 transiently associates with T-tubules during development and may be involved in the early development of the T-tubule system in muscle.

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