scholarly journals Changes in the Endoplasmic Reticulum of Beetroot Slices During Aging

1967 ◽  
Vol 20 (6) ◽  
pp. 1063 ◽  
Author(s):  
Margaret E Jackman ◽  
RFM Van Steveninck

Ultrastructural changes occurring in beetroot parenchyma were studied from the time of cutting into disks and throughout the following 192 hr of aerated washing. The most marked change was the reduction of the endoplasmic reticulum to small cytoplasmic vesicles immediately after cutting (when leakage of ions is greatest), followed by a reorganization into lamellae (coinciding with the onset of net ion accumulation) and subsequent extension of the lamellar system. The possible relationships between these observations and others on plant cells are discussed.

Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo ◽  
Fawzia Batti

To learn more of the nature and origin of alcoholic hyalin (AH), 15 liver biopsy specimens from patients with alcoholic hepatitis were studied in detail.AH was found not only in hepatocytes but also in ductular cells (Figs. 1 and 2), although in the latter location only rarely. The bulk of AH consisted of a randomly oriented network of closely packed filaments measuring about 150 Å in width. Bundles of filaments smaller in diameter (40-90 Å) were observed along the periphery of the main mass (Fig. 1), often surrounding it in a rim-like fashion. Fine filaments were also found close to the nucleus in both hepatocytes and biliary epithelial cells, the latter even though characteristic AH was not present (Figs. 3 and 4). Dispersed among the larger filaments were glycogen, RNA particles and profiles of endoplasmic reticulum. Dilated cisternae of endoplasmic reticulum were often conspicuous around the periphery of the AH mass. A limiting membrane was not observed.


Author(s):  
Kazushige Hirosawa ◽  
Eichi Yamada

The pigment epithelium is located between the choriocapillary and the visual cells. The pigment epithelial cell is characterized by a large amount of the smooth endoplasmic reticulum (SER) in its cytoplasm. In addition, the pigment epithelial cell of some lower vertebrate has myeloid body as a specialized form of the SER. Generally, SER is supposed to work in the lipid metabolism. However, the functions of abundant SER and myeloid body in the pigment epithelial cell are still in question. This paper reports an attempt, to depict the functions of these organelles in the frog retina by administering one of phospholipid precursors.


2010 ◽  
Vol 107 (15) ◽  
pp. 6894-6899 ◽  
Author(s):  
H. Ueda ◽  
E. Yokota ◽  
N. Kutsuna ◽  
T. Shimada ◽  
K. Tamura ◽  
...  

1983 ◽  
Vol 61 (4) ◽  
pp. 1025-1039 ◽  
Author(s):  
C. M. Gazeau

Wheat seedlings were treated at different temperatures and for various periods of time with a cold-protective substance, composed of a mixture of glycerol, dimethylsulfoxide, and saccharose. When the treatment was done at 20 °C, slight ultrastructural changes appeared in leaf primordia as soon as day 1. Thus numbers of lipid globules increased significantly. When the treatment period was increased to 4 days, numbers of starch grains increased, and there was a marked enlargement of mitochondria and plasts. When the treatment was done at 2 °C, cytoplasmic alterations occurred later than at 20 °C. After a 4-day treatment, they were similar to changes induced at 20 °C. When the treatment period was increased to 12 days, dictyosomes were markedly altered. They clustered close to the nucleus in two or three groups and gave rise to numerous pale vesicles with various shapes and sizes. Around each cluster of such vesicles, there gathered many endoplasmic reticulum vesicles and other organelles (mitochondria, plasts, microbodies, vacuoles). A further cooling of 1 °C/min, down to −15 or −30 °C, enhanced these phenomena. After the seedlings were warmed up to 20 °C in distilled water, the changes induced by the frost-protective treatment and then by freezing were shown to be reversible. [Journal translation]


1980 ◽  
Vol 28 (8) ◽  
pp. 818-823 ◽  
Author(s):  
M C Willingham ◽  
F R Maxfield ◽  
I Pastan

Alpha 2-macroglobulin is internalized into cultured fibroblasts by receptor-mediated endocytosis. This ligand binds initially to diffusely distributed receptors on the cell surface which cluster rapidly into bristle-coated pits. Within a few minutes at 37 degrees C, these complexes are internalized into uncoated cytoplasmic vesicles, called receptosomes, which move about in the cell by saltatory motion. These vesicles interact with the Golgi-endoplasmic reticulum-lysosome system in the cell to deliver the ligand to newly formed lysosomes within 30--60 min.


1989 ◽  
Vol 9 (5) ◽  
pp. 1978-1986
Author(s):  
N J Karin ◽  
Z Kaprielian ◽  
D M Fambrough

cDNA encoding Ca2+-ATPase was cloned from a chicken skeletal muscle library. The cDNA (termed FCa) comprised 3,239 base pairs, including an open reading frame encoding 994 amino acids which showed the highest degree of homology with the adult rabbit fast-twitch Ca2+-ATPase isoform (C. J. Brandl, S. de Leon, D. R. Martin, and D. H. MacLennan, J. Biol. Chem. 262:3768-3774, 1987). Radiolabeled FCa hybridized to a 3.2-kilobase transcript in chicken skeletal muscle RNA but not to cardiac muscle RNA, which confirmed its identity as encoding the fast Ca2+-ATPase isoenzyme. FCa was transfected into the mouse myogenic line C2C12, from which a protein of 100 kilodaltons was immunopurified by using a monoclonal antibody specific for the avian fast Ca2+-ATPase. Immunofluorescence microscopy of a line (designated C2FCa2) stably expressing the avian Ca2+-ATPase localized the protein to the nuclear envelope and a population of cytoplasmic vesicles. A similar pattern was observed when C2FCa2 cells were stained with DiOC6(3), a cyanine dye that labels endoplasmic reticulum and mitochondria (M. Terasaki, J. Song, J. R. Wong, M. J. Weiss, and L. B. Chen, Cell 38:101-108, 1984). We conclude that the avian Ca2+-ATPase fast isoform is expressed and correctly targeted to the endoplasmic reticulum in mouse C2C12 cells.


1977 ◽  
Vol 14 (6) ◽  
pp. 629-642 ◽  
Author(s):  
A. H. Rebar ◽  
J. F. Van Vleet

Three hundred and seventy 1-day-old male, white Leghorn chicks were divided into seven groups and fed a series of semipurified torula yeast diets either deficient in or supplemented with selenium and vitamin E. Chicks in each group were necropsied sequentially and the pancreata examined by light microscopy. Selected pancreata of selenium deficient chicks in various stages of the deficiency disease were examined by electron microscopy. Supplements of either selenium (0.2 mg/kg) or vitamin E (100 IU/kg diet) resulted in protection against pancreatic lesions. Changes in pancreata of selenium deficient chicks progressed from cytoplasmic vacuolation of acinar cell cytoplasm to focal disseminated acinar necrosis. There was ductular proliferation and interstitial fibrosis in advanced lesions. Acini around islets were less frequently affected than acini further away. Ultrastructurally, the mildest lesions were focal dilation of the endoplasmic reticulum and autophagic vacuoles in acinar cell cytoplasm. Necrotic areas contained both membranous and granular debris and fragments of intact endoplasmic reticulum. In fibrotic pancreata the main acinar cell changes were uniform dilation of endoplasmic reticulum and reduction in number of zymogen granules.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
M. Gotelli ◽  
B. Galati ◽  
D. Medan

Tapetum, orbicule, and pollen grain ontogeny inColletia paradoxaandDiscaria americanawere studied with transmission electron microscopy (TEM). The ultrastructural changes observed during the different stages of development in the tapetal cells and related to orbicule and pollen grain formation are described. The proorbicules have the appearance of lipid globule, and their formation is related to the endoplasmic reticulum of rough type (ERr). This is the first report on the presence of orbicules in the family Rhamnaceae. Pollen grains are shed at the bicellular stage.


2007 ◽  
Vol 143 (4) ◽  
pp. 1601-1614 ◽  
Author(s):  
Myung Ki Min ◽  
Soo Jin Kim ◽  
Yansong Miao ◽  
Juyoun Shin ◽  
Liwen Jiang ◽  
...  

2000 ◽  
Vol 11 (4) ◽  
pp. 1329-1343 ◽  
Author(s):  
Robert P. Brendza ◽  
Kathy B. Sheehan ◽  
F.R. Turner ◽  
William M. Saxton

Null mutations in the Drosophila Kinesin heavy chain gene (Khc), which are lethal during the second larval instar, have shown that conventional kinesin is critical for fast axonal transport in neurons, but its functions elsewhere are uncertain. To test other tissues, single imaginal cells in young larvae were rendered null for Khc by mitotic recombination. Surprisingly, the null cells produced large clones of adult tissue. The rates of cell proliferation were not reduced, indicating that conventional kinesin is not essential for cell growth or division. This suggests that in undifferentiated cells vesicle transport from the Golgi to either the endoplasmic reticulum or the plasma membrane can proceed at normal rates without conventional kinesin. In adult eye clones produced by null founder cells, there were some defects in differentiation that caused mild ultrastructural changes, but they were not consistent with serious problems in the positioning or transport of endoplasmic reticulum, mitochondria, or vesicles. In contrast, defective cuticle deposition by highly elongated Khc null bristle shafts suggests that conventional kinesin is critical for proper secretory vesicle transport in some cell types, particularly ones that must build and maintain long cytoplasmic extensions. The ubiquity and evolutionary conservation of kinesin heavy chain argue for functions in all cells. We suggest interphase organelle movements away from the cell center are driven by multilayered transport mechanisms; that is, individual organelles can use kinesin-related proteins and myosins, as well as conventional kinesin, to move toward the cell periphery. In this case, other motors can compensate for the loss of conventional kinesin except in cells that have extremely long transport tracks.


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