Control of RNA synthesis. 3. Control of ribonucleic acid synthesis in eukaryotes. 3. The effect of cycloheximide and edeine on RNA synthesis in yeast

Biochemistry ◽  
1976 ◽  
Vol 15 (10) ◽  
pp. 2082-2086 ◽  
Author(s):  
Kurt J. Gross ◽  
A. Oscar Pogo
1974 ◽  
Vol 20 (7) ◽  
pp. 977-980 ◽  
Author(s):  
David K. Horowitz ◽  
Peter J. Russell

Sexual differentiation in male strains of the aquatic fungus Achlya ambisexualis Raper is induced by antheridiol, a sexual steroid hormone secreted by female strains. Antheridiol-induced initiation of the morphologically distinct antheridial branches in male Achlya is completely prevented when DNA-dependent RNA synthesis is inhibited by actinomycin D. In addition antheridial branch elongation is inhibited to a degree proportional to the concentration of actinomycin D added. Thus, evidence indicates that RNA synthesis is required for antheridiol-induced initiation of antheridial branching and that continued RNA synthesis is required for elongation of antheridial branches.


1970 ◽  
Vol 120 (2) ◽  
pp. 381-384 ◽  
Author(s):  
D. Rickwood ◽  
H. G. Klemperer

1. Isolated nuclei from starved rats showed a lowered incorporation of [14C]UMP into RNA. 2. The Mg2+-dependent incorporation was decreased by 30% after 1 day of starvation, but incorporation in the presence of Mn2+ and ammonium sulphate decreased only after longer periods of starvation. 3. RNA synthesis by nuclei in the presence of excess of added RNA polymerase was unchanged after 1 day of starvation and was inhibited by 20% after 4 days. 4. The capacity of nuclei to bind actinomycin D was unchanged after 1 day and was decreased by 20% after 4 days of starvation.


1979 ◽  
Vol 178 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Torsten Yngner ◽  
Claes Engelbrecht ◽  
Lillemor Lewan ◽  
Jan-Erik Annerfeldt

The balance between anabolism and catabolism of [5-3H]uridine was studied in the mouse after partial hepatectomy. Labelling of RNA and UDP-glucose was determined and evaluated in relation to changes in the specific radioactivity of UTP. The amounts of labelled catabolic products of uridine were increased several-fold in liver and blood after partial hepatectomy. The specific radioactivity of RNA decreased to about 60% of the control value at 6h and was in the same range as that of control liver at 24h after operation. Decreased labelling of RNA and UDP-glucose was attributable to decreased specific radioactivity of UTP. No changes in the size of the UTP pool or in the balance between uridine anabolism and catabolism were found that could explain the decreased specific radioactivity of UTP. Rather, the alterations in the labelling of this metabolite induced by the partial hepatectomy may be related to decreased phosphorylating capacity in the liver cells and/or dilution of the labelled precursor in an expanded uridine pool. The enhanced amounts of uridine catabolic products in liver and blood were probably a consequence of accumulation and altered incorporation of the metabolites from the blood into the liver cells. Despite the increased amounts of labelled catabolic products and the decreased labelling of RNA, the results reported here actually suggest decreased uridine catabolism and slightly increased RNA synthesis in mouse liver after partial hepatectomy. The results stress the importance of proper controls in determination of nucleic acid synthesis and in metabolic studies by use of labelled precursors.


1966 ◽  
Vol 44 (6) ◽  
pp. 739-745 ◽  
Author(s):  
R. A. Fletcher ◽  
Daphne J. Osborne

The addition of gibberellin A3 (GA) to leaf discs of Taraxacum officinale Weber retards their senescence and delays the decline in the levels of chlorophyll, protein, and RNA. Incorporation of 14C leucine and 14C adenine into protein and RNA respectively was increased by GA. This enhancement of protein and RNA synthesis did not occur if the discs were supplied with actinomycin D before treatment with gibberellin. If, however, actinomycin D was added after the gibberellin treatment then the stimulatory effect of the hormone was maintained. These results suggest that the retarding action of gibberellins on leaf senescence could be mediated through a regulation of RNA synthesis that is DNA dependent.


1964 ◽  
Vol 22 (3) ◽  
pp. 521-532 ◽  
Author(s):  
Valerio Monesi

The pattern of ribonucleic acid synthesis during germ cell development, from the stem cell to the mature spermatid, was studied in the mouse testis, by using uridine-H3 or cytidine-H3 labeling and autoradiography. Incorporation of tritiated precursors into the RNA occurs in spermatogonia, resting primary spermatocytes (RPS), throughout the second half of pachytene stage up to early diplotene, and in the Sertoli cells. Cells in leptotene, zygotene, and in the first half of pachytene stage do not synthesize RNA. No RNA synthesis was detected in meiotic stages later than diplotene, with the exception of a very low rate of incorporation in a fraction of secondary spermatocytes and very early spermatids. At long intervals after administration of the tracer, as labeled cells develop to more mature stages, late stages of spermatogenesis also become labeled. The last structures to become labeled are the residual bodies of Regaud. Thus, the RNA synthesized during the active meiotic stages is partially retained within the cell during further development. The rate of RNA synthesis declines gradually with the maturation from type A to intermediate to type B spermatogonia and to resting primary spermatocytes. "Dormant" type A spermatogonia synthesize little or no RNA. The incorporation of RNA precursors occurs exclusively within the nucleus: at later postinjection intervals the cytoplasm also becomes labeled. In spermatogonia all mitotic stages, except metaphase and anaphase, were shown to incorporate uridine-H3. RNA synthesis is then a continuous process throughout the cell division cycle in spermatogonia (generation time about 30 hours), and stops only for a very short interval (1 hour) during metaphase and anaphase.


1975 ◽  
Vol 147 (1) ◽  
pp. 185-186 ◽  
Author(s):  
M K Sardana ◽  
M R Satyanarayana Rao ◽  
G Padmanaban

The porphyrogenic drug allylisopropylacetamide, a potent inducer of delta-aminolaevulinate synthetase, specifically increases nucleoplasmic RNA synthesis in rat liver. The drug-mediated increase in nucleoplasmic RNA synthesis is blocked by cycloheximide and haemin, which also inhibit the enzyme induction.


1959 ◽  
Vol 6 (2) ◽  
pp. 203-206 ◽  
Author(s):  
David M. Prescott

The enucleation technique has been applied to Amoeba proteus by several laboratories in attempts to determine whether the cytoplasm is capable of nucleus-independent ribonucleic acid synthesis. This cell is very convenient for micrurgy, but its use requires a thorough starvation period to eliminate the possibility of metabolic influence by food vacuoles and frequent washings and medium renewal to maintain asepsis. In the experiments described here, amoebae were starved for periods of 24 to 96 hours, cut into nucleated and enucleated halves, and exposed to either C-14 uracil, C-14 adenine, C-14 orotic acid, or a mixture of all three. When the starvation period was short (less than 72 hours), organisms (especially yeast cells) contained within amoeba food vacuoles frequently showed RNA synthesis in both nucleated and enucleated amoebae. When the preperiod of starvation was longer than 72 hours, food vacuole influence was apparently negligible, and a more meaningful comparison between enucleated and nucleated amoebae was possible. Nucleated cells incorporated all three precursors into RNA; enucleated cells were incapable of such incorporation. The experiments indicate a complete dependence on the nucleus for RNA synthesis. The conflict with the experimental results of others on this problem could possibly stem from differences in culture conditions, starvation treatment, or experimental conditions. For an unequivocal answer in experiments of this design, ideally the cells should be capable of growth on an entirely synthetic medium under aseptic conditions. The use of a synthetic medium (experiments with A. proteus are done under starvation conditions) would permit, moreover, a more realistic comparison of metabolic capacities of nucleated and enucleated cells.


1970 ◽  
Vol 12 (1) ◽  
pp. 44-51 ◽  
Author(s):  
K. Mann ◽  
B. B. Mukherjee

The patterns of ribonucleic acid synthesis by the two X chromosomes during mitotic interphase were studied at metaphase. Cultured cow leucocytes were pulsed with H3-uridine for 15 minutes, washed, resuspended in tracer-free medium and collected at different times after the end of the pulse. Autoradiography of the cells failed to show any significant differences in the number of grains located over the two X chromosomes. The incorporation of H3-uridine into RNA by both X chromosomes indicates that at least part of the 'inactive' X chromosome must be actively synthesizing some RNA.


1973 ◽  
Vol 136 (1) ◽  
pp. 209-215 ◽  
Author(s):  
Hajime Nawata ◽  
Kenichi Kato

1. Administration of 3,5-dicarbethoxy-1,4-dihydrocollidine to rats caused a marked increase in the activity of δ-aminolaevulinic acid synthetase as well as a slight net increase in RNA in the livers. 2. 3,5-Dicarbethoxy-1,4-dihydrocollidine primarily stimulated the synthesis of RNA in the nucleus of the liver cell. 3. The decrease in RNA synthesis after administration of this drug resulted in a rapid decrease in the activity of this induced enzyme. This was also confirmed by treatment with actinomycin D. 4. From kinetic experiments on synthesis of RNA and δ-aminolaevulinic acid synthetase in vivo the induction mechanism of this enzyme was discussed.


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