Localization of profilin- and actin-like immunoreactivity in in vitro-germinated tobacco pollen tubes by electron microscopy after special water-free fixation techniques

1995 ◽  
Vol 8 (3) ◽  
Author(s):  
Monika Grote ◽  
Ines Swoboda ◽  
RichardB. Meagher ◽  
Rudolf Valenta
Keyword(s):  
Electron Microscopy ◽  
Pollen Tubes ◽  
Tobacco Pollen ◽  
Fixation Techniques

Morphology of Cell Injury: An Approach to the EDIT Programme by the Use of Tobacco Pollen Tubes

2002 ◽  
Vol 30 (3) ◽  
pp. 323-329 ◽  
Author(s):  
Udo Kristen ◽  
Natalie Bischoff ◽  
Saskia Lisboa ◽  
Enno Schirmer ◽  
Sören Witt ◽  
...  
Keyword(s):  
Tip Growth ◽  
Cell Injury ◽  
Cytosolic Calcium ◽  
Pollen Tubes ◽  
In Vitro Cytotoxicity ◽  
Toxic Compounds ◽  
In Vitro System ◽  
Tobacco Pollen ◽  
Different Types

Tobacco pollen tubes were used as a standard in vitro system to investigate cell growth aberrations caused by some of the Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) programme chemicals and other toxic compounds. Changes in cytoskeletal pattern were observed in the tube cells by using tubu-lin immunofluorescence and rhodamin–phalloidin fluorescence for the localisation of microtubules and actin filaments, respectively. Four different types of cell malformation were found: screw-like growth, isodiametric tip swelling, hook formation, and pollen grain enlargement. We suggest that these malformations resulted from an interference by the chemicals with the cytosolic calcium gradient which controls tip growth and the orientation of the pollen tube. The results may contribute to a general understanding of toxicity-based cell malformations.

Toxicity of some herbicides to in vitro growing tobacco pollen tubes (the pollen test)

1991 ◽  
Vol 31 (2) ◽  
pp. 217-222 ◽  
Author(s):  
K. Strube ◽  
D. Janke ◽  
R. Kappler ◽  
U. Kristen
Keyword(s):  
Pollen Tubes ◽  
Tobacco Pollen

Cytosolic proteins from tobacco pollen tubes that crosslink microtubules and actin filaments in vitro are metabolic enzymes

Cytoskeleton ◽  
2010 ◽  
Vol 67 (12) ◽  
pp. 745-754 ◽  
Author(s):  
Silvia Romagnoli ◽  
Claudia Faleri ◽  
Luca Bini ◽  
Tobias I. Baskin ◽  
Mauro Cresti
Keyword(s):  
Actin Filaments ◽  
Metabolic Enzymes ◽  
Pollen Tubes ◽  
Cytosolic Proteins ◽  
Tobacco Pollen

Molecular control of the glucan synthase-like protein NaGSL1 and callose synthesis during growth of Nicotiana alata pollen tubes

2008 ◽  
Vol 414 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Lynette Brownfield ◽  
Sarah Wilson ◽  
Ed Newbigin ◽  
Antony Bacic ◽  
Steve Read
Keyword(s):  
Pollen Tube ◽  
Pollen Tube Growth ◽  
Pollen Tubes ◽  
Tube Growth ◽  
Nicotiana Alata ◽  
Molecular Control ◽  
Intracellular Location ◽  
Glucan Synthase ◽  
Tobacco Pollen

The protein NaGSL1 (Nicotiana alata glucan synthase-like 1) is implicated in the synthesis of callose, the 1,3-β-glucan that is the major polysaccharide in the walls of N. alata (flowering tobacco) pollen tubes. Here we examine the production, intracellular location and post-translational processing of NaGSL1, and relate each of these to the control of pollen-tube callose synthase (CalS). The 220 kDa NaGSL1 polypeptide is produced after pollen-tube germination and accumulates during pollen-tube growth, as does CalS. A combination of membrane fractionation and immunoelectron microscopy revealed that NaGSL1 was present predominantly in the endoplasmic reticulum and Golgi membranes in younger pollen tubes when CalS was mostly in an inactive (latent) form. In later stages of pollen-tube growth, when CalS was present in both latent and active forms, a greater proportion of NaGSL1 was in intracellular vesicles and the plasma membrane, the latter location being consistent with direct deposition of callose into the wall. N. alata CalS is activated in vitro by the proteolytic enzyme trypsin and the detergent CHAPS, but in neither case was activation associated with a detectable change in the molecular mass of the NaGSL1 polypeptide. NaGSL1 may thus either be activated by the removal of a few amino acids or by the removal of another protein that inhibits NaGSL1. These findings are discussed in relation to the control of callose biosynthesis during pollen germination and pollen-tube growth.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

Some Structural Features of Metaphase Chromosomes of Mice and Men

1967 ◽  
Vol 25 ◽  
pp. 190-191
Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Electron Micrographs ◽  
Structural Features ◽  
Metaphase Chromosomes ◽  
The Future ◽  
Of Mice And Men ◽  
Mouse Cells ◽  
Human And Mouse

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.

Electron Microscopy of Fibroblasts from Myotonic Muscular Dystrophy Patients

1981 ◽  
Vol 39 ◽  
pp. 498-499
Author(s):  
S. E. Miller ◽  
G. B. Hartwig ◽  
R. A. Nielsen ◽  
A. P. Frost ◽  
A. D. Roses
Keyword(s):  
Electron Microscopy ◽  
Muscular Dystrophy ◽  
Genetic Diseases ◽  
Skin Fibroblasts ◽  
Inborn Errors ◽  
Cytoplasmic Inclusions ◽  
Cultured Skin ◽  
Myotonic Muscular Dystrophy ◽  
Glycosaminoglycan Metabolism

Many genetic diseases can be demonstrated in skin cells cultured in vitro from patients with inborn errors of metabolism. Since myotonic muscular dystrophy (MMD) affects many organs other than muscle, it seems likely that this defect also might be expressed in fibroblasts. Detection of an alteration in cultured skin fibroblasts from patients would provide a valuable tool in the study of the disease as it would present a readily accessible and controllable system for examination. Furthermore, fibroblast expression would allow diagnosis of fetal and presumptomatic cases. An unusual staining pattern of MMD cultured skin fibroblasts as seen by light microscopy, namely, an increase in alcianophilia and metachromasia, has been reported; both these techniques suggest an altered glycosaminoglycan metabolism An altered growth pattern has also been described. One reference on cultured skin fibroblasts from a different dystrophy (Duchenne Muscular Dystrophy) reports increased cytoplasmic inclusions seen by electron microscopy. Also, ultrastructural alterations have been reported in muscle and thalamus biopsies from MMD patients, but no electron microscopical data is available on MMD cultured skin fibroblasts.

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