Structural relations between nucleus and cytoplasm during mitosis in Nicotiana tabacum mesophyll

1969 ◽  
Vol 47 (4) ◽  
pp. 581-591 ◽  
Author(s):  
Katherine Esau ◽  
Robert H. Gill
Keyword(s):  
Endoplasmic Reticulum ◽  
Nicotiana Tabacum ◽  
Nuclear Envelope ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Early Prophase ◽  
Nuclear Region ◽  
Spindle Poles ◽  
Nicotiana Tabacum L ◽  
Cytoplasmic Ribosomes

The changes in relation between the nucleus and the cytoplasm associated with mitosis were explored at the ultrastructural level in the mesophyll of Nicotiana tabacum L. The material was fixed in glutaraldehyde – formaldehyde – osmium tetroxide. During interphase and early prophase the nucleoplasm can be distinguished from the cytoplasm by its lack of granules comparable to those interpreted as ribosomes in the cytoplasm. After the nuclear envelope is disrupted the nuclear region shows a population of ribosomes identical with that in the cytoplasm, that is, the nucleoplasm and the cytoplasm become indistinguishable. The nuclear envelope differs from the endoplasmic reticulum located in the cytoplasm by the presence of pores. Pieces of the disrupted nuclear envelope assume the same appearance as the endoplasmic reticulum although they remain localized around the nuclear region until metaphase. Eventually the remnants of the envelope are carried to the spindle poles and serve as a source of envelopes for the daughter nuclei. The larger organelles are excluded from the nuclei during development of their envelopes but units of endoplasmic reticulum and apparently some cytoplasmic ribosomes become trapped among the chromosomes. Later, the extranuclear components disappear, probably by being disassembled.

FINE STRUCTURE IN DETACHED, SENESCING WHEAT LEAVES

1965 ◽  
Vol 43 (6) ◽  
pp. 747-755 ◽  
Author(s):  
Michael Shaw ◽  
M. S. Manocha
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Fine Structure ◽  
Osmium Tetroxide ◽  
Mesophyll Cells ◽  
Laboratory Bench ◽  
Detached Leaves ◽  
Petri Dishes ◽  
Wheat Leaves ◽  
Cytoplasmic Ribosomes

Detached leaves of Little Club wheat were allowed to senesce on water or on kinetin (10 mg/l.) in petri dishes on the laboratory bench. Samples taken at intervals of 24 to 48 hours for 8 to 10 days were fixed in permanganate or osmium tetroxide, embedded, usually in araldite or epon, and examined by electron microscopy. Abnormalities were noted in the endoplasmic reticulum (ER) of the mesophyll cells 2 days after the leaves were detached; ER and cytoplasmic ribosomes were not present after 4 or 5 days. Swelling of the mitochondria and degeneration of the cristae, collapse of the chloroplast grana, and abnormalities in nuclear structure were noted after 3 days. Vacuolar contraction occurred in some cells after 4 days but the plasma membrane usually remained unbroken until the seventh or eighth day, by which time the mitochondria were no longer recognizable and most of the chloroplasts and nuclei had also disintegrated.Kinetin induced an increase in the amount of ER and ribosomes and markedly delayed the degeneration of cellular fine structure.

scholarly journals Ca2+-sequestering smooth endoplasmic reticulum in an invertebrate photoreceptor. I. Intracellular topography as revealed by OsFeCN staining and in situ Ca accumulation.

1982 ◽  
Vol 93 (3) ◽  
pp. 839-848 ◽  
Author(s):  
B Walz
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Osmium Tetroxide ◽  
Photoreceptor Cell ◽  
Smooth Endoplasmic Reticulum ◽  
Photoreceptor Cells ◽  
Submicrovillar Cisternae ◽  
Invertebrate Photoreceptor ◽  
Ca Oxalate

Two ultrastructural approaches were used in photoreceptor cells of the leech, Hirudo medicinalis, to (a) investigate the intracellular topography of the smooth endoplasmic reticulum (SER) and (b) identify among the various subregions of the SER those which might function as Ca-sequestering sites. When the cells are prefixed with CaCl2-containing glutaraldehyde and postfixed with osmium tetroxide-ferricyanide (OsFeCN), only a part of the total SER is specifically stained. The stained SER cisternae include the submicrovillar cisternae (SMC), subsurface cisternae (SSC), the nuclear envelope, Golgi-associated SER, paracrystalline SER, and SER associated with glycogen areas. An extensive tubular SER cisternal system always remains unstained. When the cells are permeabilized by saponin and subsequently incubated with Ca2+, MgATP, and oxalate, the SMC (Walz, 1979, Eur. J. Cell Biol. 20:83-91), the SSC and the nuclear envelope contain electron-opaque Ca-oxalate precipitates indicating their ability to function as an effective Ca2+ sink. The results show that the very elaborate SER in this photoreceptor cell includes many functionally heterogeneous subregions. Of special physiological significance are those components (SMC and SSC) which are effective in Ca2+-buffering in the immediate vicinity of the plasma membrane.

Identification of endoplasmic reticulum in the primitive eukaryote Giardia lamblia using cryoelectron microscopy and antibody to Bip

1996 ◽  
Vol 109 (7) ◽  
pp. 1909-1917 ◽  
Author(s):  
B.J. Soltys ◽  
M. Falah ◽  
R.S. Gupta
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Giardia Lamblia ◽  
Ultrastructural Level ◽  
Live Cells ◽  
Cryoelectron Microscopy ◽  
Endomembrane System ◽  
Western Blots ◽  
Eukaryotic Species ◽  
Adhesive Disk

Giardia lamblia trophozoites contain a complex endomembrane system as demonstrated by fluorescence and cryoelectron microscopy. The endomembrane system was weakly detected in live cells using the fluorescent membrane dye 3,3′-dihexyloxacarbocyanine iodide. The definitive identification of endoplasmic reticulum required the development of a molecular label. We expressed Giardial Bip in Escherichia coli and raised a polyclonal antibody to the purified protein. In western blots, the antibody was specific for Giardial Bip and did not react with human, monkey and rodent homologs. By immunofluorescence microscopy in methanol fixed cells the antibody visualized tubular structures and other subcellular components that required characterization by electron microscopy. Using cryotechniques we directly demonstrate the presence of a complex endomembrane system at the ultrastructural level. In conjunction with Bip immunogold labeling of cryosections we identify: (1) endoplasmic reticulum cisternae and tubules; (2) stacked perinuclear membranes; and (3) Bip presence in the nuclear envelope. Both the endoplasmic reticulum and nuclear envelope were found either with or without a cleft region suggesting each may contain common specialized sub-regions. In stacked perinuclear membranes, which may represent either multilamellar endoplasmic reticulum or a Golgi apparatus, Bip labeling was restricted to peripheral layers, also suggesting specialized sub-regions. Labeled endomembrane systems could be observed associated with microtubule structures, including axonemes and the adhesive disk. The presence of an extensive endomembrane system in Giardia lamblia, which represents one of the earliest diverging eukaryotic species, supports the view that both the nucleus and endomembrane system co-evolved in a common ancestor of eukaryotic cells.

Glycogen metabolism and the nuclear envelope-annulate lamella system in the early chick embryo

1985 ◽  
Vol 73 (1) ◽  
pp. 399-407
Author(s):  
H. Eyal-Giladi ◽  
N. Feinstein ◽  
M. Friedlander ◽  
D. Raveh
Keyword(s):  
Endoplasmic Reticulum ◽  
Enzyme Activity ◽  
Chick Embryo ◽  
Nuclear Envelope ◽  
Glycogen Metabolism ◽  
Ultrastructural Level ◽  
Annulate Lamellae ◽  
Cytochemical Localization ◽  
Early Chick Embryo

The intracellular sites of glycogen degradation in the mid to late uterine chick embryo were determined by cytochemical localization of glucose-6-phosphatase at the ultrastructural level. Enzyme activity was found between the two membranes of the nuclear envelope, in the annulate lamellae and in specialized glycogen-containing membrane scrolls. Annulate lamellae and glycogen scrolls were most frequent during the stages of intensive glycogen degradation. Annulate lamellae appear to be formed from the nuclear envelope. During the early post-laying stages annulate lamellae disappeared and were replaced by endoplasmic reticulum that appeared initially in scroll-like formations.

Membranous alterations in the cytoplasm and nucleus in a primitive neuroectodermal tumor of the brain

1978 ◽  
Vol 36 (2) ◽  
pp. 628-629
Author(s):  
C. N. Sun ◽  
C. Araoz ◽  
H. J. White
Keyword(s):  
Nuclear Envelope ◽  
Tumor Cells ◽  
Osmium Tetroxide ◽  
Primitive Neuroectodermal Tumor ◽  
Uranyl Acetate ◽  
Neuroectodermal Tumor ◽  
Annulate Lamellae ◽  
Lead Citrate ◽  
Thin Sections ◽  
The Brain

The ultrastructure of a cerebral primitive neuroectodermal tumor has been reported previously. In the present case, we will present some unusual previously unreported membranous structures and alterations in the cytoplasm and nucleus of the tumor cells.Specimens were cut into small pieces about 1 mm3 and immediately fixed in 4% glutaraldehyde in phosphate buffer for two hours, then post-fixed in 1% buffered osmium tetroxide for one hour. After dehydration, tissues were embedded in Epon 812. Thin sections were stained with uranyl acetate and lead citrate.In the cytoplasm of the tumor cells, we found paired cisternae (Fig. 1) and annulate lamellae (Fig. 2) noting that the annulate lamellae were sometimes associated with the outer nuclear envelope (Fig. 3). These membranous structures have been reported in other tumor cells. In our case, mitochondrial to nuclear envelope fusions were often noted (Fig. 4). Although this phenomenon was reported in an oncocytoma, their frequency in the present study is quite striking.

Compound Symbiosis in Peridinium Balticum

1973 ◽  
Vol 31 ◽  
pp. 500-501
Author(s):  
R. N. Tomas
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
The Other ◽  
Exact Nature ◽  
Symbiotic Relationship

Peridinium balticum appears to be unusual among the dinoflagellates in that it possesses two DNA-containing structures as determined by histochemical techniques. Ultrastructurally, the two dissimilar nuclei are contained within different protoplasts; one of the nuclei is characteristically dinophycean in nature, while the other is characteristically eucaryotic. The chloroplasts observed within P. balticum are intrinsic to an eucaryotic photosynthetic endosymbiont and not to the dinoflagellate. These organelles are surrounded by outpocketings of endoplasmic reticulum which are continuous with the eucaryotic nuclear envelope and are characterized by thylakoids composed of three apposed lamellae. Girdle lamellae and membranebounded interlamellar pyrenoids are also present. Only the plasmalemma of the endosymbiont segregates its protoplast from that of the dinophycean cytoplasm. The exact nature of this symbiotic relationship is at present not known.

The Ultrastructure of Metastatic Human Mammary Carcinoma After Prolonged Estrogen Therapy

1967 ◽  
Vol 25 ◽  
pp. 180-181
Author(s):  
John H.L. Watson ◽  
John L. Swedo ◽  
R.W. Talley
Keyword(s):  
Mammary Carcinoma ◽  
Osmium Tetroxide ◽  
Estrogen Therapy ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Human Mammary Carcinoma ◽  
Surgical Biopsy ◽  
Lead Hydroxide ◽  
Preliminary Study ◽  
Hormonal Therapies

A preliminary study of human mammary carcinoma on the ultrastructural level is reported for a metastatic, subcutaneous nodule, obtained as a surgical biopsy. The patient's tumor had responded favorably to a series of hormonal therapies, including androgens, estrogens, progestins, and corticoids for recurring nodules over eight years. The pertinent nodule was removed from the region of the gluteal maximus, two weeks following stilbestrol therapy. It was about 1.5 cms in diameter, and was located within the dermis. Pieces from it were fixed immediately in cold fixatives: phosphate buffered osmium tetroxide, glutaraldehyde, and paraformaldehyde. Embedment in each case was in Vestopal W. Contrasting was done with combinations of uranyl acetate and lead hydroxide.

Ultrastructural comparison of prolactin adenomas of pituitary in men and women

1988 ◽  
Vol 46 ◽  
pp. 346-347
Author(s):  
R.C. Caughey ◽  
U.P. Kalyan-Raman
Keyword(s):  
Endoplasmic Reticulum ◽  
Electron Microscope ◽  
Phosphate Buffer ◽  
Pituitary Adenomas ◽  
Osmium Tetroxide ◽  
Secretory Granules ◽  
Uranyl Acetate ◽  
En Bloc ◽  
Men And Women ◽  
Transmission Electron

Prolactin producing pituitary adenomas are ultrastructurally characterized by secretory granules varying in size (150-300nm), abundance of endoplasmic reticulum, and misplaced exocytosis. They are also subclassified as sparsely or densely granulated according to the amount of granules present. The hormone levels in men and women vary, being higher in men; so also the symptoms vary between both sexes. In order to understand this variation, we studied 21 prolactin producing pituitary adenomas by transmission electron microscope. This was out of a total of 80 pituitary adenomas. There were 6 men and 15 women in this group of 21 prolactinomas.All of the pituitary adenomas were fixed in 2.5% glutaraldehyde, rinsed in Millonig's phosphate buffer, and post fixed with 1% osmium tetroxide. They were then en bloc stained with 0.5% uranyl acetate, rinsed with Walpole's non-phosphate buffer, dehydrated with graded series of ethanols and embedded with Epon 812 epoxy resin.

Fine Structure of Planarian Neuroglial Cell

1976 ◽  
Vol 34 ◽  
pp. 188-189 ◽  
Author(s):  
Michio Morita ◽  
Jay Boyd Best
Keyword(s):  
Endoplasmic Reticulum ◽  
Ventral Nerve Cord ◽  
Osmium Tetroxide ◽  
Golgi Body ◽  
Nerve Fibers ◽  
Neuroglial Cell ◽  
Glutaraldehyde Solution ◽  
Deep Indentation ◽  
Cytoplasmic Processes ◽  
Longitudinal Nerve

The species of the planarian Dugesia dorotocephala was used as the experimental animal to study a neuroglial cell in the ventral nerve cord. Animals were fixed with 3% buffered glutaraldehyde solution and postfixed with 1% buffered osmium tetroxide.The neuroglial cell is multipolar, expanding into three or four cytoplasmic processes with many daughter branches. Some neuroglial processes are found to extend perpendicular to the longitudinal nerve fibers, whereas others are seen to be parallel to them. The nucleus of the neuroglial cell is irregular in shape and frequently has a deep indentation. Convex portions of the nucleus seem to be related to the areas from which cytoplasmic processes are extended. Granular endoplasmic reticulum (Fig. 4), Golgi body (Fig. 2), mitochondria (Figs. 1 and 2), microtubules (Fig. 4), and many glycogen granules are observable in the electron dense neuroglial cytoplasm. Neuroglial cells are also observed to contain various sizes of phagosomes and lipids (Fig. 2).

X-Ray Microanalysis of Nickel and Cobalt Intensified Peroxidase- Antiperoxidase For Verification of Reaction Sites

1985 ◽  
Vol 43 ◽  
pp. 468-469
Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel
Keyword(s):  
Reaction Mechanisms ◽  
Visual Discrimination ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
X Ray ◽  
Insoluble Polymer ◽  
Cytochemical Reaction

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.

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