A comparative light and electron microscopic study of microspore and tapetal development in male fertile and cytoplasmic male sterile oilseed rape (Brassica napus)

1986 ◽  
Vol 64 (5) ◽  
pp. 1055-1068 ◽  
Author(s):  
I. Grant ◽  
W. D. Beversdorf ◽  
R. L. Peterson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Brassica Napus ◽  
Microspore Development ◽  
Male Sterile ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Mother Cells ◽  
Scanning Electron

The cytological development of male cells and the tapetum of male fertile and combined cytoplasmic triazine-resistant cyto-plasmic-genetic male sterile (ctr) lines of B. napus L. was studied using light, scanning electron, and transmission electron microscopy. Development of the cytoplasmic-genetic male sterile anther was similar to the normal anther up to and including meiotic prophase I. After this stage, degeneration of the microspore mother cells occurs within the callose walls, and tetrads of microspores are not formed. These degenerating microspore mother cells appear to develop numerous endoplasmic reticulum derived vesiculated structures, which may be involved in lysis of organelles. Degeneration occurs simultaneously with a proliferation of the tapetum, which eventually fills the anther locule. It is not clear whether the abortion of the microspore mother cells during meiosis stimulates proliferation of the tapetum or whether the proliferating tapetum actually interferes with microspore development thereby causing degeneration. Dilated endoplasmic reticulum cisternae containing crystalline-like deposits, and plastids with osmiophilic bodies, are frequent in cells of the proliferated tapetum of cytoplasmic-genetic male sterile anthers.

A Scanning Electron Microscopic Study of the Nephrotic Kidney

1974 ◽  
Vol 32 ◽  
pp. 10-11
Author(s):  
Peter M. Andrews
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscopic ◽  
Vascular Perfusion ◽  
Transmission Electron ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Aminonucleoside Nephrosis ◽  
Scanning Electron

Scanning electron microscopy, supplemented with light microscopy and transmission electron microscopy, was used to study aminonucleoside nephrosis in rats. Aminonucleoside nephrosis was induced by daily injections of puromycin aminonucIeoside (1.5 mg/10 gm). When the rats exhibited considerable proteinuria (10 mg/ml after 14 days of injections), their kidneys were fixed by vascular perfusion, sectioned and critical point dried.

Electron Microscopic Study of the Polymyxin Treated Goat Erythrocytes

1984 ◽  
Vol 39 (7-8) ◽  
pp. 776-780
Author(s):  
T. K. Mandal ◽  
S. N. Chatterjee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Spherical Shape ◽  
Polymyxin B ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Treatment Changes ◽  
Dose Dependent ◽  
Scanning Electron

Abstract Polymyxin B produced dose dependent changes in the surface topography of the goat erythrocyte cells. Transformation from the normal biconcave discs through crenated structures to the final rounded or spherical shape was recorded by scanning electron microscopy. A maxim um of three to four crenations per cell was recorded corresponding to a polymyxin dose of 15.62 ng/ml. Transmission electron microscopy of the ultrathin sections of treated or untreated erythrocytes indicated that the crenations were formed by protrusions of the plasma membrane, occurring presumably because of the local increase of membrane fluidity after polymyxin treatment. Changes in the shape of the erythrocytes to the ultimate rounded forms were also indicated by the transmission electron microscopy.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

A Comparative Study of Fractographic Replicas

1974 ◽  
Vol 32 ◽  
pp. 566-567
Author(s):  
Loren Anderson ◽  
Pat Pizzo ◽  
Glen Haydon
Keyword(s):  
Electron Microscopy ◽  
Electron Microscopic Examination ◽  
Direct Examination ◽  
Electron Microscopic ◽  
Reliable Technique ◽  
Service Failures ◽  
Transmission Electron ◽  
Mode Of Failure ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Transmission electron microscopy of replicas has long been used to study the fracture surfaces of components which fail in service. Recently, the scanning electron microscope (SEM) has gained popularity because it allows direct examination of the fracture surface. However, the somewhat lower resolution of the SEM coupled with a restriction on the sample size has served to limit the use of this instrument in investigating in-service failures. It is the intent of this paper to show that scanning electron microscopic examination of conventional negative replicas can be a convenient and reliable technique for determining mode of failure.

Scanning and Transmission Electron Microscopy of Human Red Blood Cells

1969 ◽  
Vol 27 ◽  
pp. 44-45
Author(s):  
A.J. Tousimis ◽  
T.R. Padden
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Blood Cells ◽  
Room Temperature ◽  
Type Specimen ◽  
New Combination ◽  
Human Red Blood Cells ◽  
Transmission Electron ◽  
Microscope Slides ◽  
Scanning Electron

The size, shape and surface morphology of human erythrocytes (RBC) were examined by scanning electron microscopy (SEM), of the fixed material directly and by transmission electron microscopy (TEM) of surface replicas to compare the relative merits of these two observational procedures for this type specimen.A sample of human blood was fixed in glutaraldehyde and washed in distilled water by centrifugation. The washed RBC's were spread on freshly cleaved mica and on aluminum coated microscope slides and then air dried at room temperature. The SEM specimens were rotary coated with 150Å of 60:40- gold:palladium alloy in a vacuum evaporator using a new combination spinning and tilting device. The TEM specimens were preshadowed with platinum and then rotary coated with carbon in the same device. After stripping the RBC-Pt-C composite film, the RBC's were dissolved in 2.5N HNO3 followed by 0.2N NaOH leaving the preshadowed surface replicas showing positive topography.

Copper Localization in Cirrhotic Rat Liver by Scanning Electron Microscopy

1969 ◽  
Vol 27 ◽  
pp. 38-39 ◽  
Author(s):  
J. C. Russ ◽  
E. McNatt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Copper Acetate ◽  
Lead Citrate ◽  
Dense Bodies ◽  
Transmission Electron ◽  
Electron Mode ◽  
Scanning Electron

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.

Comparative Study of the Fine Morphology of Sensory Receptors in Aspidogaster conchicola and Cotylaspis insignis

1972 ◽  
Vol 30 ◽  
pp. 150-151
Author(s):  
Venita F. Allison ◽  
J. E. Ubelaker ◽  
J. H. Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nervous System ◽  
Osmic Acid ◽  
Sensory Receptors ◽  
Transmission Electron ◽  
Sensory Structures ◽  
Fine Morphology ◽  
Scanning Electron

It has been suggested that parasitism results in a reduction of sensory structures which concomitantly reflects a reduction in the complexity of the nervous system. The present study tests this hypothesis by examining the fine morphology and the distribution of sensory receptors for two species of aspidogastrid trematodes by transmission and scanning electron microscopy. The species chosen are an ectoparasite, Cotylaspis insignis and an endoparasite, Aspidogaster conchicola.Aspidogaster conchicola and Cotylaspis insignis were obtained from natural infections of clams, Anodonta corpulenta and Proptera purpurata. The specimens were fixed for transmission electron microscopy in phosphate buffered paraformaldehyde followed by osmic acid in the same buffer, dehydrated in an ascending series of ethanol solutions and embedded in Epon 812.

Anisotropic Membranes as Substrates for Sem

1976 ◽  
Vol 34 ◽  
pp. 444-445
Author(s):  
Thomas P. Turnbull ◽  
W. F. Bowers
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Flow ◽  
Polymer Chemistry ◽  
Surface Porosity ◽  
Transmission Electron ◽  
Pore Texture ◽  
Spongy Layer ◽  
Scanning Electron

Until recently the prime purposes of filters have been to produce clear filtrates or to collect particles from solution and then remove the filter medium and examine the particles by transmission electron microscopy. These filters have not had the best characteristics for scanning electron microscopy due to the size of the pores or the surface topography. Advances in polymer chemistry and membrane technology resulted in membranes whose characteristics make them versatile substrates for many scanning electron microscope applications. These polysulphone type membranes are anisotropic, consisting of a very thin (0.1 to 1.5 μm) dense skin of extremely fine, controlled pore texture upon a much thicker (50 to 250μm), spongy layer of the same polymer. Apparent pore diameters can be controlled in the range of 10 to 40 A. The high flow ultrafilters which we are describing have a surface porosity in the range of 15 to 25 angstrom units (0.0015-0.0025μm).

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