Nucleolar RNA synthesis of meiotic prophase spermatocytes in the human testis

Chromosoma ◽  
1975 ◽  
Vol 53 (2) ◽  
pp. 141-151 ◽  
Author(s):  
Laura L. Tres
Keyword(s):  
Meiotic Prophase ◽  
Rna Synthesis ◽  
Human Testis ◽  
Nucleolar Rna

scholarly journals NUCLEOLAR AND PERICHROMOSOMAL RNA SYNTHESIS DURING MEIOTIC PROPHASE IN THE MOUSE TESTIS

1974 ◽  
Vol 60 (1) ◽  
pp. 39-53 ◽  
Author(s):  
A. L. Kierszenbaum ◽  
Laura L. Tres
Keyword(s):  
Sex Chromosomes ◽  
Meiotic Prophase ◽  
Rna Synthesis ◽  
Transcriptional Activity ◽  
Mouse Testis ◽  
Synthetic Activity ◽  
Synthetic Cell ◽  
Nucleolar Organizers ◽  
Nucleolar Rna ◽  
Silver Grains

The transcriptional activity during meiotic prophase in the mouse testis is studied with light microscopy and high-resolution autoradiographic techniques using [3H]uridine as a labeled precursor. In the present study, two types of RNA synthesis are detected during meiotic prophase: an extranucleolar RNA synthesis of perichromosomal localization and a nucleolar RNA synthetic activity. In some of the autosomes and close to the basal knobs, the activity of the nucleolar organizers is evidenced by the incorporation of [3H]uridine into nucleolar masses from zygotene on and at earlier labeling times. The evolution of nucleoli and the formation of a nucleolus attached to the sex pair are described during the different meiotic stages. Perichromosomal labeling, from leptotene on, reaches a maximum during middle pachytene and falls progressively to a low level at longer incorporation times. Sertoli's cell, the most active RNA synthetic cell in the seminiferous epithelium, rises to a maximum of labeling and drops at earlier times compared with the meiotic prophase cells. The condensed sex chromosomes show some scattered silver grains especially at middle pachytene. The axial chromosome cores and synaptonemal complexes are devoid of silver grains during the meiotic prophase. The observations suggest that a control mechanism operates during meiotic prophase to regulate transcriptional activity in the sex chromosomes and to provide differential RNA synthesis in autosomal bivalents at various stages of prophase and within certain segments of the chromosomes.

scholarly journals INHIBITING EFFECT OF THE NEW CYTOTOXIC ANTIBIOTIC DAUNOMYCIN ON NUCLEIC ACIDS AND MITOTIC ACTIVITY OF HELA CELLS

1965 ◽  
Vol 27 (3) ◽  
pp. 545-550 ◽  
Author(s):  
A. Di Marco ◽  
R. Silvestrini ◽  
S. Di Marco ◽  
T. Dasdia
Keyword(s):  
Mitotic Activity ◽  
Rna Synthesis ◽  
Thymidine Incorporation ◽  
Acid Synthesis ◽  
Acetyl Derivative ◽  
Total Inhibition ◽  
Nuclear Rna ◽  
Nucleolar Rna ◽  
Higher Doses

The effect has been studied of Actinomycin D, Daunomycin (Da.), and Da. N acetyl derivative on mitotic activity and on the nucleic acid synthesis of in vitro HeLa cell cultures. The experiments were carried out by means of the radioautographic technique using stripping films. The relative uptake of thymidine-H3 and uridine-H3 was determined by means of the reduced silver grain count present in the nuclei of controls and treated cells. The mitotic activity and thymidine incorporation were noticeably reduced by Daunomycin and Actinomycin, whereas both processes appeared less affected by Da. N acetyl derivative. As regards nuclear RNA synthesis, all three antibiotics at low doses chiefly inhibit nucleolar RNA synthesis. On the other hand, whilst Actinomycin at higher doses causes an almost total inhibition of the synthesis of the whole nuclear RNA, in Daunomycin- and Da. N acetyl derivative-treated cells extranucleolar RNA synthesis is less susceptible to inhibition.

scholarly journals Deoxyribonucleic acid-dependent ribonucleic acid polymerases from murine spleen cells. Increased amounts of the nucleolar species in leukaemic tissue

1973 ◽  
Vol 133 (4) ◽  
pp. 797-804 ◽  
Author(s):  
Donner F. Babcock ◽  
Marvin A. Rich
Keyword(s):  
Rna Synthesis ◽  
Rna Polymerases ◽  
Infected Tissue ◽  
Leukaemia Virus ◽  
Bivalent Cations ◽  
Murine Spleen ◽  
Insoluble Product ◽  
Polymerase I ◽  
Dna Template ◽  
Nucleolar Rna

1. In the spleens of infected mice, the Friend leukaemia virus induces a sharp increase in the ability of subsequently isolated nuclei to incorporate exogenous UTP into an acid-insoluble product. Inhibitor studies indicate that the incremental RNA synthesis proceeds from a DNA template and that both nucleolar and nucleoplasmic activities are involved. 2. The partially purified DNA-dependent RNA polymerases from control and virus-infected tissue are indistinguishable with respect to chromatographic mobility, dependence on bivalent cations, ionic strength, pH and their susceptibility to α-amanitin. The RNA polymerases of the murine spleen resemble the enzymes of other mammalian tissue in these properties. 3. A comparison of the amount of polymerase solubilized from normal and infected tissue correlates with the activity observed in assays of the respective nuclei. These experiments indicated that the increase in nucleolar RNA synthesis after infection is mediated by increased extractable polymerase I activity whereas the change in nucleoplasmic RNA synthesis results from an alteration of chromatin or a chromatin-associated factor.

Studies on Nucleolar RNA Synthesis in Drosophila Melanogaster

1972 ◽  
Vol 11 (3) ◽  
pp. 689-697
Author(s):  
H. M. KRIDER ◽  
W. PLAUT
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Glands ◽  
Rna Synthesis ◽  
First Generation ◽  
Nucleolus Organizer ◽  
Fifth Generation ◽  
Autoradiographic Analysis ◽  
Temporally Correlated ◽  
Nucleolar Rna ◽  
Nucleolus Organizers

The influence of conditions resulting in bobbed phenotypes on nucleolar RNA synthesis and the formation of constrictions at nucleolus organizers was examined in larval tissues of Drosophila melanogaster. By means of [3H]uridine incorporation and autoradiographic analysis, a mutation at the bobbed locus was shown to limit the rate of nucleolar RNA synthesis in salivary glands of XO larvae. The formation of constrictions at the organizer sites of a 4-nucleolus-organizer stock was monitored in dividing neuroblast cells stained with acridine orange. Loss of the ribosomal cistrons had been reported by other workers when such stocks were maintained for several generations. In the first generation in our work, constrictions were visible at only 2 of the 4 nucleolus organizers. This situation persisted until the fifth generation, when constrictions appeared at all 4 of the organizer sites. An increase in the rate of nucleolar RNA synthesis in the salivary glands was temporally correlated with the appearance of the extra constrictions. We interpret these observations to mean that 2 of the organizers of the 4-nucleolus-organizer stock were caused to function through the loss of ribosomal RNA cistrons; thus the functional status of an organizer would appear to be subject to control.

Effect of Cycloheximide on the Nucleolar RNA Synthesis in Rat Liver

1977 ◽  
Vol 82 (4) ◽  
pp. 1109-1119 ◽  
Author(s):  
Toshio ONISHI ◽  
Takashi MATSUI ◽  
Masami MURAMATSU
Keyword(s):  
Rat Liver ◽  
Rna Synthesis ◽  
Nucleolar Rna

scholarly journals NUCLEOLAR AND NUCLEAR RNA SYNTHESIS DURING THE CELL LIFE CYCLE IN MONKEY AND PIG KIDNEY CELLS IN VITRO

1967 ◽  
Vol 33 (2) ◽  
pp. 273-279 ◽  
Author(s):  
Jane L. Showacre ◽  
W. G. Cooper ◽  
D. M. Prescott
Keyword(s):  
Life Cycle ◽  
Rna Synthesis ◽  
Kidney Cells ◽  
Pig Kidney ◽  
Rna Labeling ◽  
Cell Life ◽  
Nuclear Rna ◽  
Nucleolar Rna ◽  
Pig Kidney Cells

The incorporation of 5-3H-uridine and 5-3H-cytidine into nucleolar and nonnucleolar RNA in the nucleus of monkey and pig kidney cells was measured in vitro during the cell life cycle. Time-lapse cinematographic records were made of cells during asynchronous exponential proliferation, in order to identify the temporal position of individual cells in relation to the preceding mitosis. Immediately following cinematography, cells were labeled with uridine-3H and cytidine-3H for a short period, fixed, and analyzed by radioautography. Since the data permit correlation of the rate of RNA labeling with the position of a cell within the cycle, curves could be constructed describing the rate of RNA synthesis over the average cell cycle. RNA synthesis was absent in early telophase, and rose very abruptly in rate in late telophase and in very early G1 in both the nucleus and the reconstituting nucleolus. Thereafter, through the G1 and S periods the rate of nuclear RNA synthesis rose gradually. When we used a 10-min pulse, there was no detectable change in the rate for nucleolar RNA labeling in monkey kidney cells during G1 or S. When we used a 30-min labeling time, the rate of nucleolar RNA labeling rose gradually in pig kidney cells. With increasing time after mitosis, the data became more variable, which may, in part, be related to the variation in generation times for individual cells.

Failure of poxvirus replication in the presence of an inhibitor of nucleolar RNA synthesis

1977 ◽  
Vol 53 (1-2) ◽  
pp. 163-166 ◽  
Author(s):  
H. Nishigori ◽  
C. Nishimura
Keyword(s):  
Rna Synthesis ◽  
Nucleolar Rna

scholarly journals INORGANIC CATIONS IN THE CELL NUCLEUS

1972 ◽  
Vol 53 (2) ◽  
pp. 483-493 ◽  
Author(s):  
Laura L. Tres ◽  
A. L. Kierszenbaum ◽  
C. J. Tandler
Keyword(s):  
Meiotic Prophase ◽  
Rna Synthesis ◽  
Adult Mouse ◽  
Divalent Cations ◽  
Synthetic Activity ◽  
Inorganic Cations ◽  
Transcription Process ◽  
Inorganic Cation ◽  
Interchromatin Granules ◽  
Potassium Pyroantimonate

Earlier reports indicated the presence of significant amounts of inorganic salts in the nucleus. In the present study the possibility that this might be related to the transcription process was tested on seminiferous epithelium of the adult mouse, using potassium pyroantimonate as a fixative. The results indicated that a correlation exists between the inorganic cations comprising the pyroantimonate-precipitable fraction and the RNA synthetic activity. During meiotic prophase an accumulation of cation-antimonate precipitates occurs dispersed through the middle pachytene nuclei, the stage in which RNA synthesis reaches a maximum. At other stages (zygotene to diplotene), where RNA synthesis falls to a low level, that pattern is not seen; cation-antimonate deposits are restricted to a few masses in areas apparently free of chromatin. The condensed sex chromosomes, the heterochromatin of the "basal knobs," the axial elements, and the synaptonemal complexes are devoid of antimonate deposits during the meiotic prophase. The Sertoli cells, active in RNA synthesis in both nucleoplasm and nucleolus, show cation-antimonate deposits at these sites. In the nucleoplasm some "patches" of precipitates appear coincident with clusters of interchromatin granules; in the nucleolus the inorganic cations are mainly located in the fibrillar and/or amorphous areas, whereas relatively few are shown by the granular component. The condensed chromatin bodies associated with the nucleolus were always free of antimonate precipitates. It is suggested that the observed sites of inorganic cation accumulation within the nucleus may at least partially indicate the presence of RNA polymerases, the activity of which is dependent on divalent cations.

scholarly journals REPOPULATION OF POSTMITOTIC NUCLEOLI BY PREFORMED RNA

1973 ◽  
Vol 58 (1) ◽  
pp. 54-63 ◽  
Author(s):  
David M. Phillips ◽  
Stephanie Gordon Phillips
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Normal Morphology ◽  
L929 Cells ◽  
Full Cell ◽  
Nucleolar Rna ◽  
Mitotic Cells

The reconstruction of the nucleolus after mitosis was analyzed by electron microscopy in cultured mammalian (L929) cells in which nucleolar RNA synthesis was inhibited for a 3 h period either after or before mitosis. When synchronized mitotic cells were plated into a concentration of actinomycin D sufficient to block nucleolar RNA synthesis preferentially, nucleoli were formed at telophase as usual. 3 h after mitosis, these nucleoli had fibrillar and particulate components and possessed the segregated appearance characteristic of nucleoli of actinomycin D-treated cells. Cells in which actinomycin D was present for the last 3 h preceding mitosis did not form nucleoli by 3 h after mitosis though small fibrillar prenucleolar bodies were detectable at this time. These bodies subsequently grew in size and eventually acquired a particulate component. It took about a full cell cycle before nucleoli of these cells were completely normal in appearance. Thus, nucleolar RNA synthesis after mitosis is not necessary for organization of nucleoli after mitosis. However, inhibition of nucleolar RNA synthesis before mitosis renders the cell incapable of forming nucleoli immediately after mitosis. If cells are permitted to resume RNA synthesis after mitosis, they eventually regain nucleoli of normal morphology.

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