Growth-correlated distribution of two types of plasma membrane particles of Schizosaccharomyces pombe

1987 ◽  
Vol 33 (6) ◽  
pp. 528-533 ◽  
Author(s):  
Kanji Takeo
Keyword(s):  
Plasma Membrane ◽  
Schizosaccharomyces Pombe ◽  
Freeze Fracture ◽  
Exponential Phase ◽  
First Report ◽  
Membrane Particles ◽  
Yeast Plasma Membrane

The particle ultrastructure at or near the growing pole and in lateral regions of the plasma membrane of exponential phase Schizosaccharomyces pombe was examined by means of the freeze-fracture technique. The uninvaginated growing pole was predominantly embedded with small globular particles of 4–8 nm in diameter with no depressions. In contrast, densely invaginated lateral regions, where no growth occurs, were rich in large cratered particles of 10–15 nm in diameter with central depressions. On cytokinesis, the middle of the cell near the division furrow became uninvaginated and was predominantly embedded with small globular particles. This is the first report directly concerning the growth-correlated distribution of yeast plasma membrane particles.

Topographical stability of lateral regions of the Schizosaccharomyces pombe plasma membrane as revealed by invagination characteristics

1988 ◽  
Vol 34 (9) ◽  
pp. 1063-1068 ◽  
Author(s):  
Kanji Takeo ◽  
Kazuko Nishimura ◽  
Makoto Miyaji
Keyword(s):  
Plasma Membrane ◽  
Stationary Phase ◽  
Schizosaccharomyces Pombe ◽  
Freeze Fracture ◽  
Exponential Phase ◽  
High Density ◽  
The Stability

The characteristics, especially the stability, of plasma-membrane invaginations in Schizosaccharomyces pombe were studied using freeze-fracture techniques. The plasma membrane of exponential-phase S. pombe was characterized by the uninvaginated growing pole(s) and by the existence of particularly long invaginations, reaching up to 5 μm, in the nongrowing lateral regions. The stationary-phase plasma membrane was characterized by densely invaginated cell poles and by the high density of invaginations. After reinoculation of stationary-phase cells in fresh media, preexisting invaginations in the cell poles disappeared when the latter became the growing pole. In lateral regions of the plasma membrane, however, deep invaginations, characteristic of the stationary phase, were well conserved. The results obtained suggest the topographical stability of nongrowing lateral regions of the S. pombe plasma membrane.

Isolation of the Crystalline Arrays from the Yeast Plasma Membrane

1982 ◽  
Vol 40 ◽  
pp. 100-101
Author(s):  
Gina Sosinsky ◽  
Robert M. Glaeser
Keyword(s):  
Plasma Membrane ◽  
Test Specimen ◽  
Current Model ◽  
Hexagonal Lattice ◽  
Freeze Fracture ◽  
Structural Studies ◽  
Electron Microscopic ◽  
Threefold Axis ◽  
Yeast Plasma Membrane ◽  
Microscopic Techniques

Crystalline arrays of particles found in freeze-fracture replicas of the yeast plasma membrane have been used extensively as a test specimen for investigating artifacts that can occur during the freeze fracture process. No information has yet been obtained about the particles themselves from electron microscopic techniques other than freeze fracture. The current model of the paracrystals consists of three intramembranous particles arranged in a hexagonal lattice: 1) a large 100 K particle on the PF, which has a “volcano” appearance in replicas that are uncontaminated by water vapor, 2) a smaller EF particle at the threefold axis of the hexagonal lattice, and 3) an even smaller EF particle which fits into the crater of the PF volcano particle. We have now isolated the crystalline arrays of the yeast plasma membrane for further structural studies by freeze fracture, surface replication, and negative staining, in order to test this current model.

The effects of applied electric fields on Micrasterias. II. The distributions of cytoplasmic and plasma membrane components

1980 ◽  
Vol 42 (1) ◽  
pp. 279-290
Author(s):  
D.L. Brower ◽  
T.H. Giddings
Keyword(s):  
Plasma Membrane ◽  
Electric Fields ◽  
Freeze Fracture ◽  
Specific Effect ◽  
Wall Material ◽  
Membrane Particles ◽  
Large Asymmetry ◽  
Micrasterias Denticulata ◽  
Membrane Components ◽  
Applied Fields

The accompanying paper describes the effects of applied electric fields on the morphogenesis and patterns of wall deposition of growing cells of Micrasterias denticulata. This paper details the effects of electric fields (approximately 14 V cm-1) on the subcellular components of Micrasterias, including a description of the plasma membrane of growing semi-cells as visualized by freeze-fracturing. There are no gross cytoplasmic abnormalities or asymmetrics in the distributions of cytoplasmic organelles caused by the fields. In particular, neither the Large Vesicles nor Dark Vesicles are concentrated in the cathode-facing (CF) halves of lobes oriented perpendicular to the fields, where extra deposition of wall material has been shown to occur. In freeze-fracture replicas, there are about twice as many plasma membrane particles near the tips of growing lobes as there are in proximal regions of the lobes. Additionally, rosettes, consisting of 6 membrane particles, are seen predominantly in the distal parts of the lobes, and these rosettes are believed to be important in the synthesis of cell wall microfibrils. The applied fields cause a large asymmetry in the distributions of membrane particles, with larger numbers being found on the CF sides of lobes oriented perpendicular to the fields. We were not able to detect a specific effect on any class of particles. Taken all together, the data support the hypothesis that some of the factors responsible for growth localization in Micrasterias reside in the plasma membrane.

scholarly journals Freeze-fracture observations of the lactating rat mammary gland. Membrane events during milk fat secretion.

1978 ◽  
Vol 76 (3) ◽  
pp. 767-778 ◽  
Author(s):  
A Peixoto de Menezes ◽  
P Pinto da Silva
Keyword(s):  
Plasma Membrane ◽  
Mammary Gland ◽  
Milk Fat ◽  
Freeze Fracture ◽  
Apical Plasma Membrane ◽  
Milk Fat Globule Membrane ◽  
Membrane Particles ◽  
Milk Fat Globule ◽  
Rat Mammary Gland ◽  
Fat Globule

Membrane events during milk fat secretion were analyzed by freeze-fracture of the rat mammary gland. Two modes of milk fat secretion were observed: extrusion of fat droplets surrounded by a portion of the apical plasma membrane of the alveolar epithelial cells and, less frequently, release into the alveolar lumen of fat droplets contained in intracytoplasmic vacuoles. The extrusion process consists of two asynchronous events: clearing of membrane particles (probably including integral membrane proteins) and bulging of the apical plasma membrane. Most fat droplets are extruded with a bilayer membrane envelope (milk fat globule membrane) partially devoid of particles. The segregation of membrane particles may represent the onset of a process of structural degradation of the milk fat globule membrane.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

Deformation of Yeast Plasma Membrane by Ethidium Bromide

1988 ◽  
Vol 46 ◽  
pp. 254-255
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Thin Section ◽  
Ethidium Bromide ◽  
Freeze Fracture ◽  
Mutagenic Effect ◽  
Yeast Cells ◽  
Hydrophobic Region ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Deep Pits

The mutagenic effect of ethidium bromide on the mitochondrial DNA is well established. Using thin section electron microscopy, it was shown that when yeast cells were grown in the presence of ethidium bromide, besides alterations in the mitochondria, the plasma membrane also showed alterations consisting of 75 to 110 nm-deep pits. Furthermore, ethidium bromide induced an increase in the length and number of endoplasmic reticulum and in the number of intracytoplasmic vesicles.Freeze-fracture, by splitting the hydrophobic region of the membrane, allows the visualization of the surface view of the membrane, and consequently, any alteration induced by ethidium bromide on the membrane can be better examined by this method than by the thin section method.Yeast cells, Candida utilis. were grown in the presence of 35 μM ethidium bromide. Cells were harvested and freeze-fractured according to the procedure previously described.

Freeze-fracture observations on changes in the distribution of Filipin-sterol complexes during epididymal maturation and capacitation of boar spermatozoa

1990 ◽  
Vol 48 (3) ◽  
pp. 90-91
Author(s):  
N. Seki ◽  
Y. Toyama ◽  
T. Nagano
Keyword(s):  
Plasma Membrane ◽  
Essential Role ◽  
Freeze Fracture ◽  
Final Concentration ◽  
Freeze Fracturing ◽  
Physiological Conditions ◽  
Epididymal Maturation ◽  
Cacodylate Buffer ◽  
Sperm Membrane ◽  
Boar Spermatozoa

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.

A freeze-fracture-etched study of the physarum polycephalum plasma membrane during early formation of the macroplasmodial stage

1993 ◽  
Vol 51 ◽  
pp. 346-347
Author(s):  
Randolph W. Taylor ◽  
Henrie Treadwell
Keyword(s):  
Plasma Membrane ◽  
Life Cycle ◽  
Growth Phase ◽  
Filter Paper ◽  
Physarum Polycephalum ◽  
Freeze Fracture ◽  
Petri Dish ◽  
Wire Screen ◽  
Wide Mouth ◽  
Sterile Filter

The plasma membrane of the Slime Mold, Physarum polycephalum, process unique morphological distinctions at different stages of the life cycle. Investigations of the plasma membrane of P. polycephalum, particularly, the arrangements of the intramembranous particles has provided useful information concerning possible changes occurring in higher organisms. In this report Freeze-fracture-etched techniques were used to investigate 3 hours post-fusion of the macroplasmodia stage of the P. polycephalum plasma membrane.Microplasmodia of Physarum polycephalum (M3C), axenically maintained, were collected in mid-expotential growth phase by centrifugation. Aliquots of microplasmodia were spread in 3 cm circles with a wide mouth pipette onto sterile filter paper which was supported on a wire screen contained in a petri dish. The cells were starved for 2 hrs at 24°C. After starvation, the cells were feed semidefined medium supplemented with hemin and incubated at 24°C. Three hours after incubation, samples were collected randomly from the petri plates, placed in plancettes and frozen with a propane-nitrogen jet freezer.

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