Regular Papers / Articles OrdinairesIntine wall modifications during germination of Zygophyllum fabago (Zygophyllaceae) pollen grains

2003 ◽  
Vol 81 (12) ◽  
pp. 1267-1277 ◽  
Author(s):  
Teresa Castells ◽  
Juan A Seoane-Camba ◽  
María Suárez-Cervera
Keyword(s):  
Plasma Membrane ◽  
Pollen Grains ◽  
High Density ◽  
Hydration Process ◽  
Immunocytochemical Localization ◽  
Germination Process ◽  
Acidic Polysaccharides ◽  
Allergenic Proteins ◽  
Germinated Pollen

The composition of the inner layer (intine) of mature, activated, and germinated Zygophyllum fabago L. (Zygophyllaceae) pollen grains was studied. Cytochemical techniques showed neutral and acidic polysaccharides to be the major component of the thin and unlayered intine. The intine lacks lipids, with only scattered lipid globules being observed near the plasma membrane. Immunocytochemical localization of esterified and unesterified pectins in the intine was performed to determine the behaviour (permeability and elasticity) of germinal apertures. The high density of unesterified pectins in the intine of Z. fabago may be related to harmomegathic changes, which increase the elasticity of the intine during hydration and germination processes. A new layer was deposited in germinated pollen grains, recognized by 1,3-β-glucan (callose) antibodies; this layer plays a role in keeping the grains swollen during the germination process and probably forms a selective barrier to control the movement of substances through the pollen walls. Indeed, the composition of the Z. fabago intine was related to both the hydration process preceding germination and the passage of allergenic proteins through it.Key words: callose, germination, intine, pectins, pollen grains, Zygophyllum fabago.

Immunocytochemical localization of allergenic proteins from mature to activated Zygophyllum fabago L. (Zygophyllaceae) pollen grains

2002 ◽  
Vol 81 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Teresa Castells ◽  
Elsa Arcalís ◽  
Stella Moreno-Grau ◽  
Javier Bayo ◽  
Belen Elvira-Rendueles ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Immunocytochemical Localization ◽  
Allergenic Proteins

Freeze-substitution of rye grass and ragweed pollen grains

1990 ◽  
Vol 48 (3) ◽  
pp. 686-687
Author(s):  
Liza B. Martinez ◽  
Susan M. Wick
Keyword(s):  
Cell Function ◽  
Pollen Grains ◽  
Freeze Substitution ◽  
Cell Types ◽  
Rapid Freezing ◽  
Rye Grass ◽  
Acrylic Resins ◽  
Allergenic Proteins ◽  
Cold Embedding ◽  
Structural Preservation

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.

Immunocytochemical localization of p65 with one-nanometer gold particles following silver development

1989 ◽  
Vol 47 ◽  
pp. 1042-1043
Author(s):  
Richard W. Burry ◽  
Diane M. Hayes
Keyword(s):  
Plasma Membrane ◽  
Bovine Serum Albumin ◽  
Calf Serum ◽  
Specific Protein ◽  
Immunocytochemical Localization ◽  
Electron Microscopic ◽  
Gold Particles ◽  
Pass Through ◽  
Label Distribution ◽  
Phosphate Buffered Saline

Electron microscopic (EM) immunocytochemistry localization of the neuron specific protein p65 could show which organelles contain this antigen. Antibodies (Ab) labeled with horseradish peroxidase (HRP) followed by chromogen development show a broad diffuse label distribution within cells and restricting identification of organelles. Particulate label (e.g. 10 nm colloidal gold) is highly desirable but not practical because penetration into cells requires destroying the plasma membrane. We report pre-embedding immunocytochemistry with a particulate marker, 1 nm gold, that will pass through membranes treated with saponin, a mild detergent.Cell cultures of the rat cerebellum were fixed in buffered 4% paraformaldehyde and 0.1% glutaraldehyde (Glut.). The buffer for all incubations and rinses was phosphate buffered saline with: 1% calf serum, 0.2% saponin, 0.1% gelatin, 50 mM glycine 1 mg/ml bovine serum albumin, and (not in the HRP labeled cultures) 0.02% sodium azide. The monoclonal #48 to p65 was used with three label systems: HRP, 1 nm avidin gold with IntenSE M development, and 1 nm avidin gold with Danscher development.

Immunolocalization of H+-ATPases in the plasma membrane of pollen grains and pollen tubes ofLilium longiflorum

PROTOPLASMA ◽  
1992 ◽  
Vol 171 (1-2) ◽  
pp. 55-63 ◽  
Author(s):  
G. Obermeyer ◽  
M. L�tzelschwab ◽  
H. -G. Heumann ◽  
M. H. Weisenseel
Keyword(s):  
Plasma Membrane ◽  
Pollen Grains ◽  
Pollen Tubes

scholarly journals Biosynthesis of the insulin receptor in rat adipose cells. Intracellular processing of the Mr-190 000 pro-receptor

1985 ◽  
Vol 232 (1) ◽  
pp. 71-78 ◽  
Author(s):  
J A Hedo ◽  
I A Simpson
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Insulin Receptor ◽  
Golgi Complex ◽  
Microsomal Fraction ◽  
Primary Cultures ◽  
Sodium Dodecyl ◽  
High Density ◽  
Low Density ◽  
Adipose Cells

We investigated the biosynthesis of the insulin receptor in primary cultures of isolated rat adipose cells. Cells were pulse-chase-labelled with [3H]mannose, and at intervals samples were homogenized. Three subcellular membrane fractions were prepared by differential centrifugation: high-density microsomal (endoplasmic-reticulum-enriched), low-density microsomal (Golgi-enriched), and plasma membranes. After detergent solubilization, the insulin receptors were immunoprecipitated with anti-receptor antibodies and analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and autoradiography. After a 30 min pulse-label [3H]mannose first appeared in a band of Mr 190 000. More than 80% of the Mr-190 000 component was recovered in the microsomal fractions. Its intensity reached a maximum at 1 h in the high-density microsomal fraction and at 2 h in the low-density microsomal fraction, and thereafter declined rapidly (t 1/2 approx. 3 h) in both fractions. In the plasma-membrane fraction, the radioactivity in the major receptor subunits, of Mr 135 000 (alpha) and 95 000 (beta), rose steadily during the chase and reached a maximum at 6 h. The Mr-190 000 precursor could also be detected in the high-density microsomal fraction by affinity cross-linking to 125I-insulin. In the presence of monensin, a cationic ionophore that interferes with intracellular transport within the Golgi complex, the processing of the Mr-190 000 precursor into the alpha and beta subunits was completely inhibited. Our results suggest that the Mr-190 000 pro-receptor originates in the endoplasmic reticulum and is subsequently transferred to the Golgi complex. Maturation of the pro-receptor does not seem to be necessary for the expression of the insulin-binding site. Processing of the precursor into the mature receptor subunits appears to occur during the transfer of the pro-receptor from the Golgi complex to the plasma membrane.

scholarly journals High-density-lipoprotein subfraction 3 interaction with glycosylphosphatidylinositol-anchored proteins

1997 ◽  
Vol 328 (2) ◽  
pp. 415-423 ◽  
Author(s):  
Stéphane NION ◽  
Olivier BRIAND ◽  
Sophie LESTAVEL ◽  
Gérard TORPIER ◽  
Françoise NAZIH ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
High Density Lipoprotein ◽  
Cultured Cells ◽  
Density Lipoprotein ◽  
High Density ◽  
Soluble Form ◽  
Purification Method ◽  
Molecular Masses ◽  
Lipoprotein Subfraction ◽  
Gpi Proteins

To elucidate further the binding of high-density-lipoprotein subfraction 3 (HDL3) to cells, the involvement of glycosylphosphatidylinositol-anchored proteins (GPI-proteins) was studied. Treatment of cultured cells, such as fibroblasts or SK-MES-1 cells, with a phosphatidylinositol-specific phospholipase C (PI-PLC) significantly decreases specific HDL3 binding. Moreover, PI-PLC treatment of cultured cells or cellular plasma membrane fractions results in releasing proteins. These proteins have a soluble form and can also bind HDL3, as revealed by ligand blotting experiments with HDL3. In order to obtain enriched GPI-proteins, we used a detergent-free purification method to prepare a caveolar membrane fraction. In the caveolar fraction, we obtained, by ligand blotting experiments, the enrichment of two HDL3-binding proteins with molecular masses of 120 and 80 kDa. These proteins were also revealed in a plasma membrane preparation with two other proteins, with molecular masses of 150 and 104 kDa, and were sensitive to PI-PLC treatment. Electron microscopy also showed the binding of Au-labelled HDL3 inside the caveolar membrane invaginations. In SK-MES-1 cells, HDL3 are internalized into a particular structure, resulting in the accumulation and concentration of such specific membrane domains. To sum up, a demonstration has been made of the implication of GPI-proteins as well as caveolae in the binding of HDL3 to cells.

scholarly journals GRAMP 100: a membrane protein concentrated on secretory granule membranes and the apical cell surface in exocrine acinar cells.

1992 ◽  
Vol 40 (12) ◽  
pp. 1827-1835 ◽  
Author(s):  
S M Laurie ◽  
M B Mixon ◽  
J D Castle
Keyword(s):  
Plasma Membrane ◽  
Apical Cell ◽  
Reduced Form ◽  
Electron Microscopic Level ◽  
Apical Plasma Membrane ◽  
Cell Fractionation ◽  
Immunocytochemical Localization ◽  
Electron Microscopic ◽  
Common Component ◽  
Rat Parotid

Using a monoclonal antibody (SG10A6) raised against secretion granule membranes of the rat parotid gland, we have identified an antigen that is a common component of both exocrine pancreatic and parotid granule membranes. SG10A6 (an IgM) immunoprecipitates antigen that migrates as a single band (M(r) approximately 80 KD unreduced; M(r) approximately 100 KD reduced) and immunoblots at least two polypeptides that are similar to the reduced and nonreduced immunoprecipitated antigen. This granule-associated membrane polypeptide (GRAMP 100; named for the apparent M(r) in reduced form) is also a prominent component of plasma membrane fractions. Immunocytochemical localization at the electron microscopic level demonstrates the presence of GRAMP 100 on granule membranes, especially condensing vacuoles and exocytotic figures, and the apical plasma membrane. Lower levels of antigen are detected on basolateral plasma membrane and on peri-Golgi membranes that may be part of the endosomal system. Both the cell fractionation and immunocytochemical localization indicate that GRAMP 100 differs in distribution from GRAMP 92 and 30K SCAMPs, two other components of exocrine granule membranes identified with monoclonal antibodies. To date, no polypeptides have been identified with this approach that are exclusive components of exocrine granule membranes.

scholarly journals Biology of Flowering, Fruit and Viability of Pollen of Varieties and Forms of Quince Cultivated on the Territory of the Nakhchivan Autonomous Republic

2021 ◽  
Vol 7 (3) ◽  
pp. 64-69
Author(s):  
L. Bayramov
Keyword(s):  
Pollen Fertility ◽  
Pollen Germination ◽  
Glucose Solution ◽  
Pollen Viability ◽  
Pollen Grains ◽  
Weather Conditions ◽  
Distilled Water ◽  
Water Control ◽  
Germinated Pollen ◽  
Autonomous Republic

Abstract. The zones of distribution of varieties and forms of quince on the territory of the Nakhchivan Autonomous Republic have been established, phenological observations have been carried out, their flowering and fruiting have been studied. On the territory of the Autonomous Republic, flowering of varieties and forms of quince begins in the second decade of April, depending on the distribution zone, with an average daily temperature of 12–13 °C and lasts 12–13 days, depending on weather conditions. Each flower has 10–12 stamens arranged in one row. The article also studied the viability of pollen in a number of quince varieties. Pollen viability was studied in the varieties Sary, Tursh, Ordubad, Gara and wild forms. Pollen fertility was determined by staining with acetocarmine. Pollen germinates in 2–5–10–15 and 20% glucose solution. Counting of germinated pollen grains was carried out under a microscope. The study showed that of all the experimental varieties, the pollen fertility of the Sary quince and Tursh quince varieties is high (up to 96.6–97.1%). The best medium for the germination of quince pollen is a 10–15% glucose solution. Pollen germination in this solution reaches 47.4–88.0%. In distilled water (control), the germination of quince pollen reached from 9.7% to 35.6% for varieties. Quince pollen remains viable for 31–43 days.

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