Hormone-induced differentiation of antheridial branches in Achlya ambisexualis: dependence on ribonucleic acid synthesis

1974 ◽  
Vol 20 (7) ◽  
pp. 977-980 ◽  
Author(s):  
David K. Horowitz ◽  
Peter J. Russell
Keyword(s):  
Sexual Differentiation ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Steroid Hormone ◽  
Acid Synthesis ◽  
Aquatic Fungus ◽  
Induced Differentiation ◽  
Sexual Steroid ◽  
Achlya Ambisexualis

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.

scholarly journals Decreased ribonucleic acid synthesis in isolated rat liver nuclei during starvation

1970 ◽  
Vol 120 (2) ◽  
pp. 381-384 ◽  
Author(s):  
D. Rickwood ◽  
H. G. Klemperer
Keyword(s):  
Rna Polymerase ◽  
Ammonium Sulphate ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Isolated Nuclei ◽  
Isolated Rat Liver ◽  
Liver Nuclei ◽  
Isolated Rat

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.

GIBBERELLIN, AS A REGULATOR OF PROTEIN AND RIBONUCLEIC ACID SYNTHESIS DURING SENESCENCE IN LEAF CELLS OF TARAXACUM OFFICINALE

1966 ◽  
Vol 44 (6) ◽  
pp. 739-745 ◽  
Author(s):  
R. A. Fletcher ◽  
Daphne J. Osborne
Keyword(s):  
Leaf Senescence ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Taraxacum Officinale ◽  
Leaf Discs ◽  
Protein And Rna Synthesis ◽  
Chlorophyll Protein ◽  
Gibberellin Treatment

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.

scholarly journals Ribonucleic acid synthesis in porphyric rat liver induced by 3,5-dicarbethoxy-1,4-dihydrocollidine

1973 ◽  
Vol 136 (1) ◽  
pp. 209-215 ◽  
Author(s):  
Hajime Nawata ◽  
Kenichi Kato
Keyword(s):  
Rat Liver ◽  
Liver Cell ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Rapid Decrease ◽  
Aminolaevulinic Acid ◽  
Induction Mechanism

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.

ULTRASTRUCTURAL EVIDENCE FOR THE STIMULATION OF NUCLEAR RIBONUCLEIC ACID SYNTHESIS BY OESTRADIOL-17β IN THE VAGINAL EPITHELIUM OF THE OVARIECTOMIZED MOUSE

1970 ◽  
Vol 47 (2) ◽  
pp. 143-NP ◽  
Author(s):  
IRINA POLLARD
Keyword(s):  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Control Level ◽  
Staining Technique ◽  
Acid Synthesis ◽  
Vaginal Epithelium ◽  
Ovariectomized Mouse ◽  
Ultrastructural Evidence ◽  
Stimulation Of

SUMMARY The cytochemical nature of the ultrastructural nucleolar transformation previously observed in the vaginal epithelium of the ovariectomized mouse after local application of oestradiol-17β was investigated using a recently developed ultrastructural staining technique. Oestradiol treatment induced ribonucleic acid (RNA) synthesis, especially in the nucleolus but also in the nuclear chromatic region and ribosomes. Actinomycin D administered simultaneously with oestradiol reduced the oestrogen-induced nucleolar response to the control level. These findings are discussed with special reference to the mode of action of oestrogens.

Activité génétique au cours de l'embryogenèse de l'Oligochète Eisenia fœtida (autoradiographie à l'uracile-3H et traitement à l'actinomycine D)

Development ◽  
1976 ◽  
Vol 35 (2) ◽  
pp. 403-424
Author(s):  
Par J. Devriès
Keyword(s):  
Ribonucleic Acid ◽  
Actinomycin D ◽  
Acid Synthesis ◽  
Eisenia Foetida ◽  
Messenger Rnas ◽  
Blastula Stage ◽  
Stages Of Development ◽  
Interphase Nuclei ◽  
Nuclear Membranes

Embryos of Eisenia fœtida (Spiralia) have been cultivated with [3H]uracil precursor of RNA at different stages of development from egg to gastrula. The results show that ribonucleic acid synthesis detected by autoradiography begins precociously. During segmentation messenger RNAs are produced by interphase nuclei and liberated in cytoplasm cyclically at mitosis. After the blastula stage rRNAs (nucleoli), which can migrate through the nuclear membranes, predominate. The blastomeres, which contain polar plasm and also mesoderm, already known for its controlling part in embryogenesis after gastrulation, are the seats of the increasingly important ribonucleic acid synthesis. These genetic transcriptions, which are inhibited by actinomycin D, are implicated in the determination of the blastomeres and postblastular differentiation. Only the messages required for the segmentation divisions pre-exist in the undivided egg.

scholarly journals Anabolism versus catabolism of [5-3H]uridine and its relationship to ribonucleic acid labelling in mouse liver after partial hepatectomy

1979 ◽  
Vol 178 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Torsten Yngner ◽  
Claes Engelbrecht ◽  
Lillemor Lewan ◽  
Jan-Erik Annerfeldt
Keyword(s):  
Nucleic Acid ◽  
Partial Hepatectomy ◽  
Ribonucleic Acid ◽  
Mouse Liver ◽  
Rna Synthesis ◽  
Specific Radioactivity ◽  
Acid Synthesis ◽  
Liver Cells ◽  
Control Value

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.

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