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.

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 Differences in Viral RNA Synthesis but Not Budding or Entry Contribute to the In Vitro Attenuation of Reston Virus Compared to Ebola Virus

2020 ◽  
Vol 8 (8) ◽  
pp. 1215
Author(s):  
Bianca S. Bodmer ◽  
Josephin Greßler ◽  
Marie L. Schmidt ◽  
Julia Holzerland ◽  
Janine Brandt ◽  
...  
Keyword(s):  
Life Cycle ◽  
Rna Synthesis ◽  
Ebola Virus ◽  
Severe Disease ◽  
Case Fatality ◽  
Viral Rna ◽  
Pathogenic Potential ◽  
Rnp Complex ◽  
Reston Virus

Most filoviruses cause severe disease in humans. For example, Ebola virus (EBOV) is responsible for the two most extensive outbreaks of filovirus disease to date, with case fatality rates of 66% and 40%, respectively. In contrast, Reston virus (RESTV) is apparently apathogenic in humans, and while transmission of RESTV from domestic pigs to people results in seroconversion, no signs of disease have been reported in such cases. The determinants leading to these differences in pathogenicity are not well understood, but such information is needed in order to better evaluate the risks posed by the repeated spillover of RESTV into the human population and to perform risk assessments for newly emerging filoviruses with unknown pathogenic potential. Interestingly, RESTV and EBOV already show marked differences in their growth in vitro, with RESTV growing slower and reaching lower end titers. In order to understand the basis for this in vitro attenuation of RESTV, we used various life cycle modeling systems mimicking different aspects of the virus life cycle. Our results showed that viral RNA synthesis was markedly slower when using the ribonucleoprotein (RNP) components from RESTV, rather than those for EBOV. In contrast, the kinetics of budding and entry were indistinguishable between these two viruses. These data contribute to our understanding of the molecular basis for filovirus pathogenicity by showing that it is primarily differences in the robustness of RNA synthesis by the viral RNP complex that are responsible for the impaired growth of RESTV in tissue culture.

The Induction of Chromosomal Aberrations in Pig Kidney Cells by Far-Red Light

1971 ◽  
Vol 45 (2) ◽  
pp. 274 ◽  
Author(s):  
S. A. Gordon ◽  
A. N. Stroud ◽  
C. H. Chen
Keyword(s):  
Chromosomal Aberrations ◽  
Red Light ◽  
Kidney Cells ◽  
Pig Kidney ◽  
Pig Kidney Cells
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