scholarly journals INDUCTION OF NUCLEAR ENVELOPES AROUND METAPHASE CHROMOSOMES AFTER FUSION WITH INTERPHASE CELLS

1971 ◽  
Vol 51 (1) ◽  
pp. 104-115 ◽  
Author(s):  
Tatsuro Ikeuchi ◽  
Mitsuyoshi Sanbe ◽  
Herbert Weinfeld ◽  
Avery A. Sandberg
Keyword(s):  
Nuclear Envelope ◽  
Sendai Virus ◽  
Chinese Hamster ◽  
Formation Factor ◽  
Electron Microscopic ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Multinucleate Cells ◽  
Interphase Cells ◽  
Nuclear Envelope Formation

The process of cellular fusion induced by Sendai virus in Chinese hamster cells (Don line) afforded us the opportunity to study nuclear envelope formation around metaphase sets in the presence of interphase nuclei, when chromosome pulverization failed to occur in such multinucleate cells. Morphologically, the enveloped metaphase chromosomes resembled a normal telophase nucleus, though minor differences prompted us to call it telophase-like. Electron microscopic observations demonstrated that the membranes enveloping the chromosomes appeared to be identical with a normal nuclear envelope. The longer the cells were incubated with Colcemid before fusion, the higher was the number of cells with telophase-like nuclei and the lower the percentage of cells with pulverizations. Furthermore, the number of pulverizations bore a somewhat direct relationship to the ratio of metaphase to interphase nuclei in multinucleate cells, and the number of telophase-like nuclei was inversely proportional to this ratio. A hypothesis is advanced in which a balance between the activities of a chromosome pulverization factor and a nuclear envelope formation factor, the former in metaphase cells and the latter in interphase cells, is decisive as to the nature of morphologic events observed in virus-induced fused cells.

scholarly journals PROPHASING OF INTERPHASE NUCLEI AND INDUCTION OF NUCLEAR ENVELOPES AROUND METAPHASE CHROMOSOMES IN HELA AND CHINESE HAMSTER HOMO- AND HETEROKARYONS

1974 ◽  
Vol 62 (1) ◽  
pp. 104-113 ◽  
Author(s):  
Yoshitaka Obara ◽  
Lee S. Chai ◽  
Herbert Weinfeld ◽  
Avery A. Sandberg
Keyword(s):  
Nuclear Envelope ◽  
Hela Cells ◽  
Interphase Nucleus ◽  
Chinese Hamster ◽  
Binucleate Cell ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Multinucleate Cells ◽  
Interphase Cells ◽  
Nuclear Envelope Formation

Fusing human HeLa metaphase cells with HeLa interphase cells resulted within 30 min in either of two phenomena in the resultant binucleate cell: either prophasing of the interphase nucleus or formation of a normal-appearing nuclear envelope around the metaphase chromosomes. The frequency of either occurrence was strongly dependent on environmental pH. At pH's of 6.6–8.0, prophasing predominated; at pH 8.5 nuclear envelope formation predominated. Additionally, the frequencies of the two events in multinucleate cells depended on the metaphase/interphase ratio. When the ratio was 0.33 nuclear envelope formation predominated; when it was 2.0 prophasing predominated. In their general features, the results with fused HeLa cells resembled those reported earlier with fused Chinese hamster Don cells. However, the results provided an indication that between pH 6.6 and 8.0 the HeLa metaphase cells possessed a much greater capacity than the Don metaphase cells to induce prophasing. Fusion of Don metaphase cells with HeLa interphase cells or of Don interphase cells with HeLa metaphase cells at pH 8.0 resulted in nuclear envelope formation or prophasing in each kind of heterokaryon. As in the homokaryons, the frequencies of the two events in the heterokaryons depended on the metaphase/interphase ratio. The statistics of prophasing and nuclear envelope formation in the homo- and heterokaryon populations were consistent with the notion that disruption or formation of the nuclear envelope depends on the balance attained between disruptive and formative processes.

scholarly journals INDUCTION OF PROPHASE IN INTERPHASE NUCLEI BY FUSION WITH METAPHASE CELLS

1972 ◽  
Vol 54 (1) ◽  
pp. 120-132 ◽  
Author(s):  
Sei-Ichi Matsui ◽  
Hiroshi Yoshida ◽  
Herbert Weinfeld ◽  
Avery A. Sandberg
Keyword(s):  
Cell Fusion ◽  
Sendai Virus ◽  
Morphological Changes ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Interphase Cell ◽  
Binucleate Cells ◽  
Sequence Of Events ◽  
Interphase Cells ◽  
Nuclear Stage

Fusion of an interphase cell with a metaphase cell results in profound changes in the interphase chromatin that have been called "chromosome pulverization" or "premature chromosome condensation" In addition to the usual light microscopy, the nature of the changes has been investigated in the present study with electron microscopy and biochemical techniques Metaphase and interphase cells were mixed and fused at 37°C by means of ultraviolet-inactivated Sendai virus. After cell fusion, morphological changes in interphase nuclei occurred only in binucleate cells which contained one intact set of metaphase chromosomes Irrespective of the nuclear stage at the time of cell fusion, the morphologic changes that occurred 5–20 min later simulated very closely a sequence of events that characterizes the normal G2-prophase transition. Radioautography revealed that, late in the process, substantial amounts of RNA and probably protein were transferred from the interphase nucleus into the cytoplasm of fused cells. Thus, the findings indicate the existence in metaphase cells of factor(s) which are capable of initiating biochemical and morphological events in interphase nuclei intrinsic to the normal mitotic process.

The analysis of 40 kDa nuclear protein, p40, in interphase cells and mitotic cells

1993 ◽  
Vol 106 (3) ◽  
pp. 741-748 ◽  
Author(s):  
Y. Kaneda ◽  
K. Kinoshita ◽  
M. Sato ◽  
K. Tanaka ◽  
Y. Kaneda
Keyword(s):  
Monoclonal Antibody ◽  
Nuclear Envelope ◽  
Nuclear Protein ◽  
Dnase I ◽  
High Salt ◽  
The Other ◽  
Interphase Nuclei ◽  
Interphase Cells ◽  
Detergent Treatment ◽  
Sequential Treatments

We previously reported that the monoclonal antibody M108 recognized a 40 kDa protein both in the nucleus and the cytoplasm. This nuclear 40 kDa antigen was located in the nuclear envelope in interphase cells and in the perichromosomal region during mitosis. Now, we have analyzed this nuclear 40 kDa protein (p40) further, through morphological and biochemical approaches. At the beginning of mitosis, the perinuclear p40 detached from the nuclear envelope and moved to surround the condensing chromatin, while in the late stage of mitosis, the perichromosomal p40 moved back to the reassembled nuclear envelope. Most of the perichromosomal p40 on the metaphase chromosome was solubilized only by DNase I treatment, not by either high salt or detergent treatment. On the other hand, the perinuclear p40 was not solubilized by DNase1 alone, or high salt detergent alone. Sequential treatments with DNase I and high salt detergent were required to extract p40 in interphase nuclei. These results suggest that p40 was associated both with the nuclear envelope and chromatin DNA in interphase nuclei, while it bound only to chromatin DNA in mitosis.

scholarly journals A trypsin-sensitive receptor on membrane vesicles is required for nuclear envelope formation in vitro.

1988 ◽  
Vol 107 (1) ◽  
pp. 57-68 ◽  
Author(s):  
K L Wilson ◽  
J Newport
Keyword(s):  
Nuclear Envelope ◽  
Protein Interactions ◽  
Membrane Vesicles ◽  
Integral Membrane Protein ◽  
Electron Microscopic ◽  
Vitro Assay ◽  
Nuclear Envelope Assembly ◽  
Microscopic Studies ◽  
Nuclear Envelope Formation

The reformation of functioning organelles at the end of mitosis presents a problem in vesicle targeting. Using extracts made from Xenopus laevis frog eggs, we have studied in vitro the vesicles that reform the nuclear envelope. In the in vitro assay, nuclear envelope growth is linear with time. Furthermore, the final surface area of the nuclear envelopes formed is directly dependent upon the amount of membrane vesicles added to the assay. Egg membrane vesicles could be fractionated into two populations, only one of which was competent for nuclear envelope assembly. We found that vesicles active in nuclear envelope assembly contained markers (BiP and alpha-glucosidase II) characteristic of the endoplasmic reticulum (ER), but that the majority of ER-derived vesicles do not contribute to nuclear envelope size. This functional distinction between nuclear vesicles and ER-derived vesicles implies that nuclear vesicles are unique and possess at least one factor required for envelope assembly that is lacking in other vesicles. Consistent with this, treatment of vesicles with trypsin destroyed their ability to form a nuclear envelope; electron microscopic studies indicate that the trypsin-sensitive proteins is required for vesicles to bind to chromatin. However, the protease-sensitive component(s) is resistant to treatments that disrupt protein-protein interactions, such as high salt, EDTA, or low ionic strength solutions. We propose that an integral membrane protein, or protein tightly associated with the membrane, is critical for nuclear vesicle targeting or function.

scholarly journals ELECTRON MICROSCOPIC STUDIES OF MITOSIS IN AMEBAE

1960 ◽  
Vol 8 (1) ◽  
pp. 207-220 ◽  
Author(s):  
L. E. Roth ◽  
S. W. Obetz ◽  
E. W. Daniels
Keyword(s):  
Electron Microscope ◽  
Nuclear Envelope ◽  
Osmium Tetroxide ◽  
Thin Sheet ◽  
Amoeba Proteus ◽  
Electron Microscopic ◽  
Interphase Nuclei ◽  
Nucleolar Material ◽  
Microscopic Studies ◽  
Early Reconstruction

Individual organisms of Amoeba proteus have been fixed in buffered osmium tetroxide in either 0.9 per cent NaCl or 0.01 per cent CaCl2, sectioned, and studied in the electron microscope in interphase and in several stages of mitosis. The helices typical of interphase nuclei do not coexist with condensed chromatin and thus either represent a DNA configuration unique to interphase or are not DNA at all. The membranes of the complex nuclear envelope are present in all stages observed but are discontinuous in metaphase. The inner, thick, honeycomb layer of the nuclear envelope disappears during prophase, reappearing after telophase when nuclear reconstruction is in progress. Nucleoli decrease in size and number during prophase and re-form during telophase in association with the chromatin network. In the early reconstruction nucleus, the nucleolar material forms into thin, sheet-like configurations which are closely associated with small amounts of chromatin and are closely applied to the inner, partially formed layer of the nuclear envelope. It is proposed that nucleolar material is implicated in the formation of the inner layer of the envelope and that there is a configuration of nucleolar material peculiar to this time. The plasmalemma is partially denuded of its fringe-like material during division.

scholarly journals Distribution of kinetochore (centromere) antigen in mammalian cell nuclei.

1981 ◽  
Vol 90 (1) ◽  
pp. 254-259 ◽  
Author(s):  
Y Moroi ◽  
A L Hartman ◽  
P K Nakane ◽  
E M Tan
Keyword(s):  
Nuclear Envelope ◽  
Mammalian Species ◽  
Cell Types ◽  
Ultrastructural Level ◽  
Cell Nuclei ◽  
Light Microscopic Level ◽  
Electron Microscopic ◽  
Interphase Nuclei ◽  
Naturally Occurring ◽  
Antibody Method

Antigens associated with mammalian centromeres were localized at the high and electron microscopic levels using the peroxidase-labeled antibody method. The antibody used was of a type naturally occurring in the sera of patients with scleroderma. At the light microscopic level, it reacts specifically with the centromere regions of chromosomes in a variety of mammalian species and strains in discrete foci in interphase nuclei. We find that the number of foci approximates the number of chromosomes present in the various cell types. At the ultrastructural level, the antigenic foci are confirmed to lie in the kinetochore regions of each chromosome. In interphase nuclei, the antigenic foci were usually associated either with the inner surfaces of the nuclear envelope or with the nucleoli. These observations indicate that the centromere regions of the chromosomes in interphase are not randomly distributed within the nucleus but are usually fixed either to the inner surface of the nuclear envelope or to nucleoli.

Telomere arrangement in differentiated interphase cells of Allium cepa: a function of chromosome arm lengths at anaphase–telophase

1983 ◽  
Vol 25 (5) ◽  
pp. 478-486 ◽  
Author(s):  
Catharine P. Fussell
Keyword(s):  
Nuclear Envelope ◽  
Allium Cepa ◽  
Interphase Nucleus ◽  
Interphase Nuclei ◽  
Meristematic Cells ◽  
Differentiated Cells ◽  
Allium Cepa L ◽  
Interphase Cells ◽  
Chromosome Arm ◽  
Latitudinal Band

The arrangement of telomeres in eight types of differentiated Allium cepa L. interphase cells was studied to find whether the distribution pattern varies with differentiation as centromere distribution appears to in differentiated cells of mice and Triturus vulgaris L. The results show that telomere positions and groupings in A. cepa are essentially the same in differentiated and meristematic interphase nuclei; telomeres, which are roughly paired, are arranged in a telophase configuration along one side of the nucleus. Thus telomeres appear to maintain the same basic arrangement in differentiated and in meristematic cells. Comparison of chromosome arm lengths and interphase telomere positions suggests that interphase telomere arrangements are a function of chromosome arm lengths at the time the nuclear envelope forms. Such an arrangement would place homologous telomeres in the same latitudinal band of the interphase nucleus.

Temporal and spatial interrelationships of confronting cisternae to nuclear envelope

1992 ◽  
Vol 50 (1) ◽  
pp. 930-931
Author(s):  
John R. Palisano
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Tumor Cells ◽  
Hela Cells ◽  
Microscopic Investigation ◽  
Electron Microscopic Investigation ◽  
Serial Sections ◽  
Electron Microscopic ◽  
Fetal Rat ◽  
Temporal And Spatial

Although confronting cistemae (CC) have been observed in a variety of tumor cells and normal fetal rat, mouse, and human epithelial tissues, little is known about their origin or role in mitotic cells. While several investigators have suggested that CC arise from nuclear envelope (NE) folding back on itself during prophase, others have suggested that CC arise when fragments of NE pair with endoplasmic reticulum. An electron microscopic investigation of 0.25 um thick serial sections was undertaken to examine the origin of CC in HeLa cells.

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