scholarly journals STUDIES ON FINE STRUCTURE AND CYTOCHEMICAL PROPERTIES OF ERYTHROPHORES IN SWORDTAIL, XIPHOPHORUS HELLERI, WITH SPECIAL REFERENCE TO THEIR PIGMENT GRANULES (PTERINOSOMES)

1965 ◽  
Vol 27 (3) ◽  
pp. 493-504 ◽  
Author(s):  
Jiro Matsumoto
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Special Reference ◽  
Water Soluble ◽  
Xiphophorus Helleri ◽  
Swordtail Fish ◽  
Pigment Granules ◽  
Pteridine Derivatives ◽  
Tubular Endoplasmic Reticulum

The fine structure and the composition of pteridine pigments of erythrophores in adults of the swordtail fish, Xiphophorus helleri, were studied by means of cytochemistry, paper chromatography, ionophoresis, centrifugal fractionation, and electron microscopy. It was found that water-soluble pigments of erythrophores consisted exclusively of pteridine derivatives including large amounts of drosopterin, isodrosopterin, neodrosopterin, and moderate amounts of sepiapterin. While these substances were responsible for red pigmentation, moderate quantities of colorless pteridines, biopterin, Rana-chrome 3, xanthopterin, isoxanthopterin, and others, were also detectable. The ultrastructure of the erythrophore is characterized by numerous pigment granules and a well developed tubular endoplasmic reticulum. The former consist of a three-layered limiting membrane and inner lamellae which appear to be whorl-like due to a concentric arrangement of parallel membranes. All of the mentioned pteridines are primarily contained in this organelle which is designated, accordingly, "pterinosome." The possible functions of erythrophores and pterinosomes are discussed in the light of their structure and pigmentary constitution.

scholarly journals Crystals of Protein Nature in the Cytoplasm of Lymphatic Cells in a Case of Lymphoreticular Malignancy

Blood ◽  
1962 ◽  
Vol 20 (4) ◽  
pp. 492-500 ◽  
Author(s):  
J. C. H. DE MAN ◽  
W. B. H. MEINERS ◽  
W. Beens
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Lymphocytic Leukemia ◽  
Water Soluble ◽  
Protein Nature

Abstract The occurrence of crystals in the cytoplasm of lymphatic cells in a case of lymphoreticular malignancy—probably lymphocytic leukemia—is reported. Histochemistry revealed the protein nature of these crystals. It appeared that the protein was water-soluble, with no admixture of polysaccharides. Electron microscopy of the crystals showed a fine structure of regularly arranged thin lines with a spacing of 100 Å. The crystals were surrounded by membranes of the endoplasmic reticulum.

Temperature Effects on Formation and Fine Structure of Brassica napus Leaf Waxes

1976 ◽  
Vol 24 (3) ◽  
pp. 309 ◽  
Author(s):  
DJ Armstrong ◽  
MI Whitecross
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Brassica Napus ◽  
Growth Temperature ◽  
Temperature Effects ◽  
Structural Changes ◽  
Leaf Waxes ◽  
Surface Waxes ◽  
Biochemical Level

Incorporation of 1-14C-palmitic acid, a precursor of leaf waxes, into leaf strips of Brassica napus was examined by thin section autoradiography and electron microscopy. Label was found to be associated with mitochrondria, Golgi vesicles and endoplasmic reticulum of epidermal cells, and also with the outer epidermal wall across which cuticular lipids are expected to migrate. Variations in growth temperatures produced structural changes in surface waxes as previously reported but no specific correlation could be found between changes in surface fine structure and variations in subcellular morphology. It is concluded that variations in wax fine structure, as influenced by growth temperature, resulted from effects at the biochemical level.

scholarly journals THE FINE STRUCTURE OF DIFFERENTIATING SIEVE TUBE ELEMENTS

1965 ◽  
Vol 25 (1) ◽  
pp. 79-95 ◽  
Author(s):  
G. Benjamin Bouck ◽  
James Cronshaw
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Fibrous Material ◽  
Sieve Tube ◽  
Longitudinal Direction ◽  
Sieve Plate ◽  
Wall Surface ◽  
Developmental Sequences ◽  
Tubular Form

The developmental sequences leading to the formation of mature sieve tube elements were studied in pea plants by electron microscopy. From this study it has been found that the peripheral layer of cytoplasm in the mature element is composed of flattened cisternae which are apparently derived from a tubular form of endoplasmic reticulum (ER) and possibly the nuclear envelope. These flattened cisternae, designated in this report as sieve tube reticula, are attached perpendicularly to the wall surface and are oriented in a predominantly longitudinal direction. Cisternae of the sieve tube reticulum are frequently associated with the slime in mature elements, and tubular ER may be associated with slimelike material in the developing sieve tube element. During differentiation mitochondria become reduced in size and chloroplasts either fail to develop stroma and grana lamellae or lose them early in development. In agreement with other workers it is found that the sieve plate pores appear to be plugged with a finely fibrous material, presumably "slime." Nacreous wall formation is well established before reorganization of cytoplasmic components. Microtubules are prevalent during these early stages, but are lost as the element matures.

scholarly journals OBSERVATIONS ON THE FINE STRUCTURE OF LUTEIN CELLS

1962 ◽  
Vol 12 (1) ◽  
pp. 101-113 ◽  
Author(s):  
Allen C. Enders
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Steroid Hormones ◽  
Osmium Tetroxide ◽  
Secretory Activity ◽  
Corpora Lutea ◽  
Pericapillary Space ◽  
Lutein Cell

Corpora lutea from the period of delayed implantation and from early postimplantation stages of the armadillo, mink, and rat were fixed in buffered osmium tetroxide-sucrose or potassium permanganate. After rapid dehydration, the portions of the corpora lutea were embedded in either methacrylate or epoxy resin. Examination of the lutein cells by electron microscopy revealed the presence, in the better preserved material, of an extensive development of tubular agranular endoplasmic reticulum. Although the membranes of the endoplasmic reticulum are the most striking feature of the lutein cells of both stages of the three animals examined, very numerous large mitochondria with cristae that exhibit a variety of forms tending toward villiform, and protrusions and foldings of the lutein cell margins on the pericapillary space are also characteristic of these cells. Certain minor differences in the lutein cells of the species examined are also noted. No indications of conversion of mitochondria into lipid, of accumulation of lipid in the Golgi area, or of the protrusion of lutein cells into spaces between the endothelial cells, as suggested by other authors, were noted in these preparations. Some of the difficulties inherent in the visualization of the secretory activity of cells producing steroid hormones are briefly discussed.

scholarly journals FINE STRUCTURE AND ORGANELLE ASSOCIATIONS IN BROWN ALGAE

1965 ◽  
Vol 26 (2) ◽  
pp. 523-537 ◽  
Author(s):  
G. Benjamin Bouck
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Golgi Apparatus ◽  
Nuclear Envelope ◽  
Brown Algae ◽  
Algal Cell ◽  
Plant Cells ◽  
Membrane Systems ◽  
Two Envelopes

The structural interrelationships among several membrane systems in the cells of brown algae have been examined by electron microscopy. In the brown algae the chloroplasts are surrounded by two envelopes, the outer of which in some cases is continuous with the nuclear envelope. The pyrenoid, when present, protrudes from the chloroplast, is also surrounded by the two chloroplast envelopes, and, in addition, is capped by a third dilated envelope or "pyrenoid sac." The regular apposition of the membranes around the pyrenoid contrasts with their looser appearance over the remainder of the chloroplast. The Golgi apparatus is closely associated with the nuclear envelope in all brown algae examined, but in the Fucales this association may extend to portions of the cytoplasmic endoplasmic reticulum as well. Evidence is presented for the derivation of vesicles, characteristic of those found in the formative region of the Golgi apparatus, from portions of the underlying nuclear envelope. The possibility that a structural channeling system for carbohydrate reserves and secretory precursors may be present in brown algae is considered. Other features of the brown algal cell, such as crystal-containing bodies, the variety of darkly staining vacuoles, centrioles, and mitochondria, are examined briefly, and compared with similar structures in other plant cells.

Evidence for Golgi Origin of Melanosomes

1968 ◽  
Vol 26 ◽  
pp. 148-149
Author(s):  
Gerd G. Maul
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Golgi Complex ◽  
Serial Sections ◽  
Human Malignant Melanoma ◽  
Close Proximity ◽  
Membrane Bound ◽  
Tubular Endoplasmic Reticulum ◽  
Internal Architecture

Electron microscopy has provided evidence that the melanosome evolves as a membrane bound structure with a highly complex internal architecture. The premelanosomes are found in close proximity to the golgi apparatus. Therefore, it was generally agreed that the melanosomes originate from the golgi apparatus.Vesicles have been described to pinch off the cysternae of the golgi apparatus. The vesicles would then grow and acquire a dense material. This material is aggregating to form the characteristic helical strands onto which melanin is deposited. Cloned human malignant melanoma lines were used to reinvestigate the problem of melanosome formation. The reconstruction of serial sections revealed the arrangement of premelanosomes and melanosomes in relation to the golgi complex. This study demonstrated that premelanosomes and melanosomes are continuous with the golgi complex by a smooth-surfaced tubular endoplasmic reticulum (SER) (Fig. la-d). The continuity of membranes of the SER and the premelanosome is depicted in Fig. 2. In this early premelanosome the protein strands have not yet coiled up into a helix. Rough-surfaced endoplasmic reticulum (RER) was also observed to be continuous with the golgi apparatus and melanosomes. After melanogenesis has started (Fig. 3) small vesicles appear inside the premelanosomes.

scholarly journals THE ACTION OF EXCESS OF VITAMIN A ALCOHOL ON THE FINE STRUCTURE OF RAT DERMAL FIBROBLASTS

1966 ◽  
Vol 30 (3) ◽  
pp. 465-475 ◽  
Author(s):  
Mary R. Daniel ◽  
J. T. Dingle ◽  
Audrey M. Glauert ◽  
J. A. Lucy
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Vitamin A ◽  
Respiratory Activity ◽  
Dermal Fibroblasts ◽  
Rapid Decline ◽  
Primary Action ◽  
Membranous Material

Rat dermal fibroblasts were grown as monolayers, and changes in the fine structure of the cells that occurred during 12 hr incubation in a medium containing protein and excess of retinol (vitamin A alcohol) were studied by electron microscopy. There is little change during the first 6 hr, although some of the nuclei have highly convoluted membranes. During the subsequent 3 hr, there is some disorganization of the mitochondrial cristae; the cisternae of the rough-surfaced endoplasmic reticulum diminish in number; and the amount of smooth membranous material and free ribosomes increases. There is a rapid decline in the respiratory activity of the cells after 6 hr exposure to the vitamin. It is concluded that the primary action of excess of retinol is to cause alterations in the membranes of the cells and that these alterations affect the functions of the mitochondria and endoplasmic reticulum.

scholarly journals Ultrastructure of rhesus monkey renomedullary interstitial cells

1979 ◽  
Vol 13 (2) ◽  
pp. 75-80 ◽  
Author(s):  
David J. Lewis ◽  
David E. Prentice
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Rhesus Monkey ◽  
Rough Endoplasmic Reticulum ◽  
Lipid Droplets ◽  
Stellate Cells ◽  
Interstitial Cells ◽  
Prominent Feature

Summary The fine structure of rhesus monkey renomedullary interstitial cells was studied by electron microscopy. These stellate cells contained variable numbers of lipid droplets, moderate numbers of mitochondria, moderate amounts of rough endoplasmic reticulum, and prominent Golgi zones. In rare instances, apparent release of lipid droplets into the interstitium was observed. The most prominent feature of the interstitial cells was large nuclear pseudoinclusions which were observed in a high proportion of the animals examined.

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