Intentional clay-mixing in the production of traditional and ancient ceramics and its identification in thin section

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

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Deformation of Yeast Plasma Membrane by Ethidium Bromide

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103334 ◽

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.

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The Mechanomorphology of Microtubule Sliding

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s143192760000266x ◽

1980 ◽

Vol 38 ◽

pp. 604-607

Author(s):

P. Satir ◽

J. Wais-Steder ◽

J. Avolio

Keyword(s):

Thin Section ◽

Dynein Arms

In 1977, Sale and Satir showed that active microtubule sliding in trypsin-treated Tetrahymena axonemes is always of a single polarity. If the doublet bearing active arms is labelled N, by convention, the doublet that is pushed by those arms is N+l. In active sliding in trypsin-treated axonemes doublet N+l is always displaced tipwards with respect to N. Several different configurations of the dynein arms have been described. These include: (1) an extended configuration, where the dynein arms are tilted about 40° towards the base of the axoneme and are long enough to span the space between doublets N and Ntl completely (2) a standard, unattached image, such as is usually seen in thin section. In this configuration, the arms do not span the interdoublet gap. (3) the rigor image, where the arms always bridge the gap. This differs from the extended configuration because tilt is often absent, so that the arms often lie normal to doublets N and N+l.

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