Structural Organization of Detergent-Extracted Cells

Author(s):  
Manfred Schliwa

Adequate visualization of the three-dimensional organization has always been a major problem in studies of cell architecture. Efforts of numerous investigators weredevoted to the question of how best information can be collected from specimens prepared with different procedures. In recent years, the potential of high voltage electron microscopy has been combined with a technique for sample preparation that circumvents embedding, namely critical point-drying from CO2, to study the three-dimensional fine structure of cells in culture. This approach has revealed new insights into the structural organization of the cytoplasm (1-4). A system of slender strands or microtrabeculae has been described to form an elaborate three-dimensional lattice in which other organelles are embedded. This system has been shown in some cells to undergo rapid conformational changes (3,5) and in general is believed to be an important component of the cytoskeleton, being responsible for the gelatious properties of the cytoplasm.

Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.


Author(s):  
G. E. Tyson ◽  
M. J. Song

Natural populations of the brine shrimp, Artemia, may possess spirochete- infected animals in low numbers. The ultrastructure of Artemia's spirochete has been described by conventional transmission electron microscopy. In infected shrimp, spirochetal cells were abundant in the blood and also occurred intra- and extracellularly in the three organs examined, i.e. the maxillary gland (segmental excretory organ), the integument, and certain muscles The efferent-tubule region of the maxillary gland possessed a distinctive lesion comprised of a group of spirochetes, together with numerous small vesicles, situated in a cave-like indentation of the base of the tubule epithelium. in some instances the basal lamina at a lesion site was clearly discontinuous. High-voltage electron microscopy has now been used to study lesions of the efferent tubule, with the aim of understanding better their three-dimensional structure.Tissue from one maxillary gland of an infected, adult, female brine shrimp was used for HVEM study.


2016 ◽  
Vol 57 (6) ◽  
pp. 918-921 ◽  
Author(s):  
Kazuhisa Sato ◽  
Shunya Tashiro ◽  
Yohei Yamaguchi ◽  
Takanori Kiguchi ◽  
Toyohiko J. Konno ◽  
...  

1975 ◽  
Vol 66 (2) ◽  
pp. 404-413 ◽  
Author(s):  
J J Paulin

The unitary nature of the chondriome of two species of trypanosomatids, Blastocrithidia culicis and Trypanosoma cruzi, has been demonstrated by utilizing serial thick-sectioning techniques combined with high voltage electron microscopy. Profiles of mitochondrial elements seen in thin sections and suspected to be parts of a continuum were confirmed by serial thick sectioning (0.25-0.50 mum thick) and stereopair analysis to be parts of the same mitochondrion. Three-dimensional models obtained from tracings of mitochondrial profiles on cellulose acetate reveal the mitochondrion of B. culicis to consist of a posterior mass with six tubular extensions extending upward and terminating in the anterior apex. The kinetoplast was found suspended between two of the tubular extensions, or less frequently, protuding as a nodule from one of the extensions. A bifurcation of one of the extensions was found in some specimens. The mitochondrion of T. cruzi consists of a triangular-shaped convoluted tubule, the base being the kinetoplast portion while the apex is directed posteriorly. The mitochondrion bifurcates behind the flagellar pocket, lateral to the kinetoplast, sending two entwined extensions into the tenuous anterior apex. Whether the mitochondrion of T. cruzi is unitary in the trypomastigote form was not determined in this study, since only epimastigote forms were used.


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