scholarly journals DNA and heterochromatin cycles in male gamete development of Oedogonium

2014 ◽  
Vol 50 (1-2) ◽  
pp. 349-352
Author(s):  
S. P. Shpilevaya
Keyword(s):  
Optical Density ◽  
Cell Nucleus ◽  
Mother Cell ◽  
Chromatin Condensation ◽  
Male Gamete ◽  
Cell Nuclei ◽  
Optimal Density ◽  
Gamete Formation ◽  
Two Peaks ◽  
Oedogonium Cardiacum

In antheridial nuclei of <em>Oedogonium cardiacum</em> (Hass.) Wittr. during male gamete formation, the DNA presynthetic period is shortened, the synthetic and postsynthetic periods are lengthened (G<sub>1</sub> - 15%, S - 58%, G<sub>2</sub> - 29%) as compared with those in vegetative cells (G<sub>1</sub> - 31%, S - 44%, G<sub>2</sub> - 25%). Differences in the ratio of the relative amounts of eu- and heterochromatin in the antheridial mother cell (AMC) nucleus and antheridial cell nucleus were determined. Hydrolysis curves revealed two peaks of higher optical density (3.5 and 8.5 h hydrolysis with 5N HCl at 23°C), corresponding to eu- and heterochromatin. Heterochromatin in antheridial cell nuclei was characterized by a greater optical density than that of heterochromatin in AMC nuclei. The presence of two local optimal density maxima is considered as facultative and constitutive increasing of chromatin condensation in the process of male cell development.

scholarly journals Cell nucleus and membrane recovery after exposure to microwaves

2011 ◽  
Vol 65 (1-2) ◽  
pp. 13-20 ◽  
Author(s):  
Yuriy Shckorbatov ◽  
Vladimir Pasiuga ◽  
Nicolay Kolchigin ◽  
Valentin Grabina ◽  
Dmitry Ivanchenko ◽  
...  
Keyword(s):  
Membrane Permeability ◽  
Cell Nucleus ◽  
Trypan Blue ◽  
Initial Level ◽  
Chromatin Condensation ◽  
Buccal Cells ◽  
Cell Plasma Membrane ◽  
Plasma Membrane Permeability ◽  
Microwave Exposure ◽  
Cell Plasma

Cell nucleus and membrane recovery after exposure to microwaves Cells of human buccal epithelium of six male donors were exposed to microwave radiation (frequency f = 36.64 GHz, power density W = 0.1, 1 and 4 W/m2). Exposure time was 10 seconds. The state of chromatin in cell nucleus was estimated by a number of heterochromatin granules after staining with 2% orcein in 45% acetic acid. Permeability of cell membranes was estimated by percentage of unstained cells after 5 min of staining the cells with vital dyes trypan blue (0.5%) and indigocarmine (5 mM). Cell exposure to microwaves induced chromatin condensation (increase of the number of heterochromatin granules) and increase of membrane permeability to trypan blue and indigocarmine. Isolated human buccal cells demonstrated the ability to recover after microwave exposure. The number of heterochromatin granules decreased to its initial level after 0.5 hour (W = 0.1 W/m2) and 2 hours (W = 1 and 4 W/m2) after cell exposure. Cell plasma membrane permeability recovered later — after 1 hour and 3 hours post exposure, respectively.

Nuclear envelope removal/maintenance determines the structural and functional remodelling of embryonic red blood cell nuclei in activated mouse oocytes

Zygote ◽  
1998 ◽  
Vol 6 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Daniel Szöllösi ◽  
Renata Czołowska ◽  
Ewa Borsuk ◽  
Maria S. Szöllösi ◽  
Pascale Debey
Keyword(s):  
Nuclear Envelope ◽  
Transcriptional Activity ◽  
Chromatin Condensation ◽  
Oocyte Activation ◽  
Cell Nuclei ◽  
Nuclear Envelope Breakdown ◽  
Mouse Oocytes ◽  
Female Pronucleus ◽  
Mouse Fetuses

SummaryNuclei of embryonic red blood cells (e-RBC) from 12-day mouse fetuses are arrested in Go phase of the cell cycle and have low transcriptional activity. These nuclei were transferred with help of polyethylene glycol (PEG)-mediated fusion to parthenogenetically activated mouse oocytes and heterokaryons were analysed for nuclear structure and transcriptional activity. If fusion proceeded 25–45 min after oocyte activation, e-RBC nuclei were induced to nuclear envelope breakdown and partial chromatin condensation, followed by formation of nuclei structurally identical with pronuclei. These ‘pronuclei’, similar to egg (female) pronuclei, remained transcriptionally silent over several hours of in vitro culture. If fusion was performed 1 h or later (up to 7 h) after activation, the nuclear envelope of e-RBC nuclei remained intact and nuclear remodelling was less spectacular (slight chromatin decondensation, formation of nucleolus precursor bodies). These nuclei, however, reinforced polymerase-II-dependent transcription within a few hours of in vitro culture. Our present experiments, together with our previous work, demonstrate that nuclear envelope breakdown/maintenance are critical events for nuclear remodelling in activated mouse oocytes and that somatic dormant nuclei can be stimulated to renew transcription at a time when the female pronucleus remains transcriptionally silent.

scholarly journals Influence of extract from shoots of Taxus baccata var. elegantissima on ultrastructure and tubulin cytoskeleton of meristematic cells of Allium cepa L. roots

2014 ◽  
Vol 71 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Agnieszka Majewska ◽  
Mirosława Furmanowa ◽  
Kazimierz Głowniak ◽  
Joanna Guzewska ◽  
Alicja Zobel ◽  
...  
Keyword(s):  
Allium Cepa ◽  
Chromatin Condensation ◽  
Preprophase Band ◽  
Taxus Baccata ◽  
Cell Nuclei ◽  
Root Tips ◽  
Meristematic Cells ◽  
Allium Cepa L ◽  
Interphase Cells ◽  
Average Size

We investigated the influence of extract from <em>Taxus baccata</em> var. Elegantissima (TbE) shoots in 1:8 dilution, containing paclitaxel in concentration of 81,6 µg/g fresh mass on ultrastructure and tubulin cytoskeleton of meristematic cells of <em>Allium cepa</em> L. root tips. Incubation time 3, 6, 12 and 24 h was followed with postincubation in water for 12 and 24 h. During shorter incubation (till 12 h) the surface of the cell nuclei decreased and chromatin became condensed (in comparison to control) but after 24 h the average surface increased and chromatin condensation decreased. In the course of incubation the average size of plastids and vacuoles increased. Moreover, after treatment mitochondria and plastids showed degradation of ultrastructure, which was reversed after 12 h of postincubation. Immunocytochemical assays demonstrated that in the course of incubation in the ThE extract, the tubulin cytoskeleton became partially disorganised. In most interphase cells, cortical microtubules (MTs) lost their oval transverse orientation. The preprophase band (PPB) position in the cell was often asymmetrical. The MTs array of the karyokinetic spindle and phragmoplast was also disturbed. These alterations were completely reversed during postincubation.

scholarly journals THE PROPERTIES AND THE ENZYMATIC DEGRADATION OF DESOXYRIBONUCLEOPROTEIN FROM LIVER CELL NUCLEI

1958 ◽  
Vol 41 (3) ◽  
pp. 595-608 ◽  
Author(s):  
Kenneth J. Monty ◽  
Alexander L. Dounce
Keyword(s):  
Amino Acids ◽  
Cell Nucleus ◽  
Liver Cell ◽  
Enzymatic Degradation ◽  
Short Peptides ◽  
Chromosomal Protein ◽  
X Rays ◽  
Cell Nuclei ◽  
Desoxyribonucleic Acid ◽  
Mode Of Attachment

The isolation and properties of a desoxyribonucleoprotein of the rat liver cell nucleus are described. This material consists of DNA (desoxyribonucleic acid) bound to the residual chromosomal protein by what appear to be covalent linkages. Lipide is present, but can be removed by extraction in lipide solvents prior to isolation of the nucleoprotein, without much change in the physical properties of the latter. The nucleoprotein in question forms elastic, recoilable gels in molar saline at pH 7.0 or in water at pH 8.0 to 10.0 or even higher, which are similar to those that can be obtained from whole nuclei. The effects of x-rays, heat, and enzymes on the nucleoprotein are discussed, and the composition of the protein component is investigated. The latter contains an "occult" protein that can be liberated by heating in 0.1 N HCl. A study of the enzymatic degradation of the desoxyribonucleoprotein has been made, with the aim of attempting the isolation of small polynucleotide fragments attached to amino acids or short peptides that might be useful in characterizing the mode of attachment of the desoxyribonucleic acid to the protein in the desoxyribonucleoprotein. Evidence is presented indicating that such products can be isolated through the use of electrophoresis on paper.

scholarly journals Modeling Apoptotic Chromatin Condensation in Normal Cell Nuclei

2002 ◽  
Vol 277 (24) ◽  
pp. 21683-21690 ◽  
Author(s):  
Piotr Widlak ◽  
Olena Palyvoda ◽  
Slawomir Kumala ◽  
William T. Garrard
Keyword(s):  
Normal Cell ◽  
Chromatin Condensation ◽  
Cell Nuclei

scholarly journals OPTICAL DENSITY OF YELLOW PRINTS AT COATED AND UNCOATED PAPER

2020 ◽  
Vol 7 (2) ◽  
pp. 9-13
Author(s):  
Gema Sukmawati Suryadi ◽  
Susiani Susiani ◽  
Mawan Nugraha ◽  
Balqis Azhar Ulfah Alifah ◽  
Meuthia Suryani
Keyword(s):  
Layer Thickness ◽  
Optical Density ◽  
Print Quality ◽  
Coated Paper ◽  
Optimal Density ◽  
Density Values ◽  
Print Materials ◽  
Uncoated Paper ◽  
Thickness Variations ◽  
Printing Ink

Optical Density is one of the important parameters used to control print quality. Optical density in print materials is form of interaction of ink with paper. This research is oriented to the investigation of optical density value of Yellow printing ink on coated and uncoated paper. The main purpose of this study is to analyze the effect of printing ink thickness on optimal density value. The optical density value of yellow prints obtained using densitometer measurement, printed using IGT method on coated and uncoated paper. Ink thickness variations are applied (0.8 - 9.6 μm). Density values was found to increase as the ink layer thickness increased to a certain point called the optimal density (2.4 μm ink thickness on coated paper and 4.5 μm on uncoated paper). Optical density of yellow printing ink on coated paper is higher uncoated paper, which relates to porosity on paper

scholarly journals Localization and Functional Roles of Components of the Translation Apparatus in the Eukaryotic Cell Nucleus

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3239
Author(s):  
Zaur M. Kachaev ◽  
Sergey D. Ivashchenko ◽  
Eugene N. Kozlov ◽  
Lyubov A. Lebedeva ◽  
Yulii V. Shidlovskii
Keyword(s):  
Gene Expression ◽  
Cell Nucleus ◽  
Ribosomal Proteins ◽  
Nuclear Translocation ◽  
Eukaryotic Cell ◽  
Current Data ◽  
Cell Nuclei ◽  
Functional Roles ◽  
Translation Apparatus ◽  
Cell Stress Response

Components of the translation apparatus, including ribosomal proteins, have been found in cell nuclei in various organisms. Components of the translation apparatus are involved in various nuclear processes, particularly those associated with genome integrity control and the nuclear stages of gene expression, such as transcription, mRNA processing, and mRNA export. Components of the translation apparatus control intranuclear trafficking; the nuclear import and export of RNA and proteins; and regulate the activity, stability, and functional recruitment of nuclear proteins. The nuclear translocation of these components is often involved in the cell response to stimulation and stress, in addition to playing critical roles in oncogenesis and viral infection. Many components of the translation apparatus are moonlighting proteins, involved in integral cell stress response and coupling of gene expression subprocesses. Thus, this phenomenon represents a significant interest for both basic and applied molecular biology. Here, we provide an overview of the current data regarding the molecular functions of translation factors and ribosomal proteins in the cell nucleus.

CATALASE LEVELS AND RADIOSENSITIVITY OF LIVER CELLS

1960 ◽  
Vol 38 (12) ◽  
pp. 1489-1498 ◽  
Author(s):  
D. K. Myers
Keyword(s):  
Liver Regeneration ◽  
Cell Nucleus ◽  
Liver Cells ◽  
The Other ◽  
Cell Nuclei ◽  
Average Amount ◽  
Normal Value ◽  
Long Period ◽  
Stage Of Development ◽  
High Doses

Following exposure of regenerating liver to 580 r X radiation at a time when the average amount of DNA per cell nucleus has reached 1.6 times the normal value, the usual increase in number of cell nuclei was retarded while the average amount of DNA per cell nucleus continued to rise until it approached twice the normal value. Cell division was delayed for an unusually long period following irradiation at this stage of development. On the other hand, there was no corresponding increase during liver regeneration in the effects of high doses of X radiation on diphosphopyridine nucleotide concentrations in the liver. Although the liver catalase concentration decreased during liver regeneration, inhibition of catalase activity failed to increase the radiosensitivity of liver cells.

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