Three-dimensional distribution of vasoactive intestinal polypeptide-containing structures in the rat stomach and their origins using whole mount tissue

1984 ◽  
Vol 59 (3) ◽  
pp. 195-205 ◽  
Author(s):  
H. Inoue ◽  
S. Shiosaka ◽  
Y. Sasaki ◽  
N. Hayashi ◽  
N. Satoh ◽  
...  
1984 ◽  
Vol 86 (1) ◽  
pp. 51-59 ◽  
Author(s):  
Hideo Minagawa ◽  
Sadao Shiosaka ◽  
Hiroyoshi Inoue ◽  
Norio Hayashi ◽  
Akinori Kasahara ◽  
...  

1998 ◽  
Vol 141 (2) ◽  
pp. 469-481 ◽  
Author(s):  
Peter Buchenau ◽  
Jacob Hodgson ◽  
Helen Strutt ◽  
Donna J. Arndt-Jovin

The subcellular three-dimensional distribution of three polycomb-group (PcG) proteins—polycomb, polyhomeotic and posterior sex combs—in fixed whole-mount Drosophila embryos was analyzed by multicolor confocal fluorescence microscopy. All three proteins are localized in complex patterns of 100 or more loci throughout most of the interphase nuclear volume. The rather narrow distribution of the protein intensities in the vast majority of loci argues against a PcG-mediated sequestration of repressed target genes by aggregation into subnuclear domains. In contrast to the case for PEV repression (Csink, A.K., and S. Henikoff. 1996. Nature. 381:529–531), there is a lack of correlation between the occurrence of PcG proteins and high concentrations of DNA, demonstrating that the silenced genes are not targeted to heterochromatic regions within the nucleus. There is a clear distinction between sites of transcription in the nucleus and sites of PcG binding, supporting the assumption that most PcG binding loci are sites of repressive complexes. Although the PcG proteins maintain tissue-specific repression for up to 14 cell generations, the proteins studied here visibly dissociate from the chromatin during mitosis, and disperse into the cytoplasm in a differential manner. Quantitation of the fluorescence intensities in the whole mount embryos demonstrate that the dissociated proteins are present in the cytoplasm. We determined that <2% of PH remains attached to late metaphase and anaphase chromosomes. Each of the three proteins that were studied has a different rate and extent of dissociation at prophase and reassociation at telophase. These observations have important implications for models of the mechanism and maintenance of PcG- mediated gene repression.


1980 ◽  
Vol 79 (1) ◽  
pp. 67-71 ◽  
Author(s):  
Tsutomu Chiba ◽  
Tomohiko Taminato ◽  
Seizo Kadowaki ◽  
Hiromi Abe ◽  
Kazuo Chihara ◽  
...  

1996 ◽  
Vol 315 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Stefan Willis ◽  
Hans-Dieter Allescher ◽  
Norbert Weigert ◽  
Volker Schusdziarra ◽  
Volker Schumpelick

Author(s):  
T. L. Hayes

Biomedical applications of the scanning electron microscope (SEM) have increased in number quite rapidly over the last several years. Studies have been made of cells, whole mount tissue, sectioned tissue, particles, human chromosomes, microorganisms, dental enamel and skeletal material. Many of the advantages of using this instrument for such investigations come from its ability to produce images that are high in information content. Information about the chemical make-up of the specimen, its electrical properties and its three dimensional architecture all may be represented in such images. Since the biological system is distinctive in its chemistry and often spatially scaled to the resolving power of the SEM, these images are particularly useful in biomedical research.In any form of microscopy there are two parameters that together determine the usefulness of the image. One parameter is the size of the volume being studied or resolving power of the instrument and the other is the amount of information about this volume that is displayed in the image. Both parameters are important in describing the performance of a microscope. The light microscope image, for example, is rich in information content (chemical, spatial, living specimen, etc.) but is very limited in resolving power.


Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.


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