Über die Beziehungen der RNS- und Proteinsynthese zum Zellkern in Siebzellen von Vicia faba

1964 ◽  
Vol 19 (11) ◽  
pp. 1066-1071 ◽  
Author(s):  
Stefanie Neumann ◽  
Reinhold Wollgiehn
Keyword(s):  
Vicia Faba ◽  
Rna Synthesis ◽  
The Other ◽  
Other Hand ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Sieve Tubes

Autoradiographic investigations on the dependency of the RNA and protein syntheses on the nucleus have been carried out in sieve tubes of Vicia faba.In young nucleated sieve tubes 3H-uridine is incorporated primarily into the nuclear RNA and later into the cytoplasmic RNA. In sieve tubes with degenerated nuclei no incorporation of uridine in RNA takes place. On the other hand, 3H-phenylalanine is incorporated also into the proteins of old sieve tubes without RNA synthesis.

Uptake of [3H]Uridine into Precursor Pools and RNA in Osteogenic Cells

1967 ◽  
Vol 2 (1) ◽  
pp. 39-56
Author(s):  
MAUREEN OWEN
Keyword(s):  
Protein Synthesis ◽  
Mammalian Cells ◽  
Rna Synthesis ◽  
Degradation Products ◽  
Cell Types ◽  
Water Soluble ◽  
Radioactive Label ◽  
Cytoplasmic Rna ◽  
Nuclear Rna

Young rabbits were given a single intraperitoneal injection of [3H]uridine. Using the technique of water-soluble autoradiography a study was made of the uptake of the radioactive label into soluble precursors and RNA in cells on an actively growing bone surface. Labelling of the soluble intracellular pools was immediate, but incorporation of label from these pools into RNA was not completed until 24 h after injection. At this time all the label in the sections was in RNA but this represented only 30% of the total label initially in the soluble pools. This means that 70% of the label is lost from the cell in the first 24 h either as degradation products of RNA synthesis or by other as yet unknown mechanisms. The pattern of labelling of the RNA was similar to that previously found for other mammalian cells in vivo or in vitro. There was a rapid uptake of label into nuclear RNA which reached a maximum by 2 h after injection and a slower uptake into cytoplasmic RNA which reached a maximum by 24 h after injection. There was a slow loss of label from the cells after 24 h indicating a half-life of about 8 days for this relatively stable RNA. A comparison was made of RNA synthesis in the proliferating preosteoblasts and the highly differentiated non-dividing osteoblasts. Labelling of the nuclear RNA for the two cell types was identical. The rate of labelling of the cytoplasmic RNA was similar for the two cell types but the maximum level of labelling in the cytoplasm of the osteoblasts was 2 to 3 times that in the preosteoblasts. This could be correlated with the more active protein synthesis by the osteoblasts. There was a slow loss of labelled RNA by the osteoblasts and preosteoblasts and a rapid loss by the osteocytes after the cells had been incorporated within the bone. It was suggested that this loss paralleled the decline in the rate of protein synthesis by the cells as their environment changed.

scholarly journals Evidence for Two Metabolically Distinct Types of Ribonucleic Acid in Chromatin and Nucleoli

1958 ◽  
Vol 4 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Rachel McMaster-Kaye ◽  
J. Herbert Taylor
Keyword(s):  
Maximum Activity ◽  
The Other ◽  
Precise Localization ◽  
Isolated Nuclei ◽  
Metabolic Characteristics ◽  
Nucleolar Activity ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Time Courses ◽  
Nucleolar Rna

Patterns of radioisotope incorporation are useful characteristics in describing cellular RNA fractions, and have indicated a distinctive "nuclear" RNA. In order to characterize the RNA fractions of the two nuclear components, nucleoli and chromatin, and to determine thereby the precise localization of the RNA typical of isolated nuclei, time-courses of P32 incorporation into nucleolar, chromosomal, and cytoplasmic RNA of Drosophila salivary glands have been determined from autoradiograms. Two experiments are reported which cover 12 and 18 hour periods, including an initial 2 hour feeding on P32. Concentrations of RNA-P32 (identified by ribonuclease digestion) were determined by grain counts. After 1 hour only the nucleolar RNA is labelled. Activity is detectible in chromosomal and cytoplasmic RNA after the 2nd hour. The nucleolar fraction reaches its maximum activity shortly after transfer of the larvae to non-radioactive food, the other fractions several hours later. Maximum activities persist in the chromosomal and cytoplasmic fractions; nucleolar activity decreases after the 9th hour. The observed differences in times at which incorporation begins and maximum activities are reached, and in maintenance of maximum activities indicate that chromosomal and nucleolar RNA are distinct fractions. The metabolic characteristics which have been ascribed to "nuclear" RNA apply only to the nucleolar fraction.

scholarly journals The effect of convulsions induced by flurothyl on ribonucleic acid synthesis in rat cerebral cortex during the recovery phase

1975 ◽  
Vol 152 (3) ◽  
pp. 449-467 ◽  
Author(s):  
C V Wynter ◽  
P Ioannou ◽  
A P Mathias
Keyword(s):  
Cerebral Cortex ◽  
Rna Synthesis ◽  
Sodium Dodecyl ◽  
Acid Synthesis ◽  
Recovery Phase ◽  
Major Effect ◽  
Rat Cerebral Cortex ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Double Label

The effect of convulsions, induced by flurothyl, on RNA synthesis in purified unfractionated nuclei and the cytoplasm of rat cerebral cortex was studied by using a double-label technique involving injection of [3H]- and [14C]-orotate intracisternally. 2. Intact RNA was extracted in 80% yield by an enzymic method by using a proteinase in the presence of sodium dodecyl sulphate followed by deoxyribonuclease. Electrophoresis on 1.5% polyacrylamide-0.5% agarose gels revealed the presence of giant nuclear RNA of size up to approx. 300 × 10(6) daltons and mRNA of maximal mol.wt. 9 × 10(6)-16 × 10(6). 3. Nuclear RNA synthesis was decreased to 27% in the first 15 min after convulsions but rapidly increased, so that at 1 1/2 h it was 124% of the control, and at 6 h 147%. 4. Labelling of cytoplasmic RNA was decreased to 15% at 15 min after convulsions but had not recovered to control values by 6 h. 5. Analysis of radioactive gel patterns and the 3H/14C ratio at six time-points (15 min-6h) showed that the major effect was inhibition of the processing of heterogeneous nuclear RNA resulting in a sharp decline in the export of newly synthesized RNA from the nucleus. 6. Cytoplasmic RNA patterns indicated that specific messengers were synthesized at different times during the recovery of the cell after convulsions.

THE PHOSPHORUS FRACTIONS OF BACILLUS CEREUS AND BACILLUS MEGATERIUM: II. A CORRELATION OF THE CHEMICAL WITH THE CYTOLOGICAL CHANGES OCCURRING DURING SPORE GERMINATION

1955 ◽  
Vol 1 (7) ◽  
pp. 525-548 ◽  
Author(s):  
P. C. Fitz-James
Keyword(s):  
Bacillus Cereus ◽  
Rna Synthesis ◽  
Dry Weight ◽  
Acid Synthesis ◽  
Nuclear Material ◽  
The Other ◽  
Other Hand ◽  
Soluble P ◽  
Labile P ◽  
Time Required

The oxygen uptake, the changes in the concentrations of the phosphorus (P) fractions, and the dry weights of Bacillus cereus and B. megaterium germinating in thick suspension were followed from the spore to the young vegetative cell. Parallel cytological studies were made using standard procedures of bacterial cytology. During the initial minutes of germination the dry weight of the spores fell, respiratory activity began, the concentration of cold trichloroacetic acid (TCA)-soluble P rose, and the concentration of a residual P fraction insoluble in hot TCA fell. In complete media, nucleic acid synthesis began soon after this initial activation and was accompanied by an uptake of P, a further rise in the acid-soluble P, and in the rate of respiration. The cells began to recover weight. Ribosenucleic acid (RNA) synthesis was detectable by about 10 min. after inoculation and desoxyribosenucleic acid (DNA) synthesis by 15–20 min. Following its initial rise, the rate of RNA synthesis declined and continued parallel to that of DNA for some 10 min. During this period, the uptake of P from the medium appeared to be depressed and the spores (B. cereus) changed in shape from ovoids to short rods. After this period, the RNA synthesis was steady throughout germination. The rise of DNA, on the other hand, was continuous and steady throughout, even in cultures where growth was synchronous. The nuclear material of germinating spores grew and separated in step with the continuous rise of DNA P and the increase in cell volume was of the same order as the increase in RNA P. Under crowded conditions, or in inadequate media, germinating spores and young vegetative cells of B. cereus showed a decreased RNA/DNA ratio and accumulations of labile P. Crowded cultures of B. megaterium, on the other hand, accumulated Sudan positive (fatty) granules, but no labile P. The time required for the germinating spore to duplicate its chromatin varied in different media and could, in some instances, be shortened by subculturing. Nevertheless, the product of this time of germination and the increase in RNA during the germination period approximated to a fixed value that was independent of medium, species, or cell concentration.

The measurement of the production of during erythroid differentiation of the Friend erythroleukemia cell

1987 ◽  
Vol 65 (3) ◽  
pp. 188-194 ◽  
Author(s):  
E. Schmedt ◽  
L. Kleiman
Keyword(s):  
Rna Synthesis ◽  
Rna Polymerase Iii ◽  
Erythroid Differentiation ◽  
Gene Probe ◽  
5S Rna ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Nuclear Synthesis

The production of [Formula: see text] during Friend cell erythroid differentiation has been studied. In vitro measurements of total nuclear RNA synthesis in nuclei isolated from Friend cells at different stages of differentiation show the total RNA synthesis increases 1.5-fold at day 1 of induction and then decreases through days 2 and 3 to approximately 75% of its rate of synthesis in the nuclei of uninduced cells. The synthesis of RNA polymerase III transcripts undergoes a similar fluctuation through day 2 of induction, but increases again at day 3. The specific synthesis of [Formula: see text] was measured by hybridization of labelled nuclear RNA to a [Formula: see text] gene probe. During erythroid differentiation the percentage of nuclear RNA represented by [Formula: see text] remains constant (0.065%), so that the absolute synthesis of [Formula: see text] fluctuates during differentiation, in parallel with the fluctuations in the synthesis of total nuclear RNA. The relative synthesis of [Formula: see text]in vivo was studied by labelling cells with 35Pi, isolating the resulting radioactive tRNA – 5S RNA population, and hybridizing this population to a [Formula: see text] gene probe. The ratio of [Formula: see text] in newly synthesized cytoplasmic RNA remains similar throughout differentiation (averaging 0.0171), implying that the fluctuations observed in the nuclear synthesis of [Formula: see text] during differentiation probably also occur for the nuclear synthesis of most tRNA and 5S RNA species. Attempts were made to measure the relative steady-state concentration of [Formula: see text] using both aminoacylation and in vitro end labelling of tRNA followed by hybridization to a [Formula: see text] gene probe. These two methods gave different results and we discuss the possible pitfalls of using enzymatic methods for quantitating tRNA concentrations in the cell.

Translational Control of Protein Synthesis in Eat Anterior Pituitary by N-2′-O-dibutyryl adenosine 3′,5′-monophosphate

1973 ◽  
Vol 51 (6) ◽  
pp. 913-919 ◽  
Author(s):  
Roger Boucher ◽  
Marie Gauthier ◽  
Paul Jolicoeur ◽  
Fernand Labrie
Keyword(s):  
Protein Synthesis ◽  
Translational Control ◽  
Rna Synthesis ◽  
Actinomycin D ◽  
Short Term ◽  
Nucleotide Pools ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Preferential Incorporation ◽  
Stimulation Of

Actinomycin D, at doses (25 and 50 μg/ml) that block RNA synthesis to less than 3% of the control rate, inhibits the incorporation of [3H]leucine into adenohypophyseal proteins and the release of newly synthesized proteins by 50 and 60%, respectively, of the control rates. Despite this lowering of basal levels of total protein synthesis and release in presence of the antibiotic, the percentage of stimulation of both protein synthesis and release by 5 mM N6-2′-O-dibutyryl adenosine 3′5′-monophosphate (dbcAMP) is not depressed by actinomycin D. When rat hemipituitaries are incubated with [3H]uridine, dbcAMP does not stimulate the labeling of total cytoplasmic RNA or the preferential labeling of any cytoplasmic RNA species resolved on sucrose gradient. There is no stimulatory effect of dbcAMP on total labeling or preferential incorporation into nuclear RNA species extracted at 24 °C or at 65 °C. Labeling of the nucleotide pools was unchanged up to 1 h of incubation but was increased (40–70%) during the last [Formula: see text] of incubation. These data suggest that the short-term stimulatory effects of dbcAMP on total adenohypophyseal protein synthesis and release are exerted at the transiational level.

Physiological Investigations on Restrictions to Transport of Sucrose in Ears of Wheat

1976 ◽  
Vol 3 (3) ◽  
pp. 337 ◽  
Author(s):  
CF Jenner
Keyword(s):  
Grain Growth ◽  
Water Transport ◽  
The Other ◽  
Metabolic Inhibitors ◽  
External Concentration ◽  
Transpiration Stream ◽  
Other Hand ◽  
Sieve Tubes

Accumulation of sucrose in glumes and pales of detached ears of wheat cultured on solutions of sucrose is directly dependent on external concentration; compared with the external level, sugar builds up to higher levels inside these organs, and the uptake of sugar is not reduced much by metabolic inhibitors. In contrast, influx of sucrose into the grains is saturated at relatively low (external) levels of sucrose; the concentration within the grains is lower than in the supplying solution, and movement into the grains is very sensitive to the action of metabolic inhibitors. Sucrose enters the cultured ear in the transpiration stream and its build-up in the structures enclosing the grain is due to the evaporation of water. Transport to the grain, on the other hand, is dependent upon translocation in the phloem. It is suggested that the passage of sucrose to the grain is restricted by processes involved in transfer from xylem to phloem, or by translocation within the sieve tubes, or both. It is postulated that similar limitations operate on the transport of sucrose derived from normal assimilation. The detached-ear technique may be of value as a method of estimating the scale of limitations to grain growth conferred by the supply of assimilates to the grain.

scholarly journals COMPOSITION OF RIBONUCLEIC ACID FROM VARIOUS PARTS OF SPIDER OOCYTES

1960 ◽  
Vol 8 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Jan-Erik Edström
Keyword(s):  
Ribonucleic Acid ◽  
The Other ◽  
Total Rna ◽  
Other Hand ◽  
Cytoplasmic Rna ◽  
The Difference ◽  
Nucleolar Rna ◽  
Purine Pyrimidine ◽  
Different Parts

Microphoretic purine-pyrimidine analyses of the ribonucleic acid (RNA) in nucleoli, nucleoplasm, cytoplasm, and yolk nuclei of spider oocytes have been carried out. The material necessary for the analyses was isolated by micromanipulation. Determinations of the amounts of RNA in the different parts of the cell were also performed. No differences between the composition of RNA in the nucleolus and the cytoplasm could be disclosed. Nucleoplasmic RNA was, on the other hand, distinctly different from that in the nucleolus and in the cytoplasm. The difference lies in the content of adenine, which is highest in nucleoplasmic RNA. The few analyses carried out on yolk nuclei showed their RNA to be variable in composition with a tendency to high purine values. The cytoplasm contains about 99 per cent of the total RNA in these cells, the nucleoplasm about 1 per cent, and the nucleolus not more than 0.3 per cent, although the highest concentrations are found in these latter structures. When considered in the light of other recent findings the results are compatible with the view that nucleolar RNA is the precursor of cytoplasmic RNA.

Effect of growth hormone and hydrocortisone on the synthesis of rapidly labeled, high molecular weight, nuclear RNA in rat liver

1969 ◽  
Vol 47 (2) ◽  
pp. 226-229 ◽  
Author(s):  
Maurice Brossard ◽  
Louis Nicole
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
High Molecular Weight ◽  
Rat Liver ◽  
Orotic Acid ◽  
The Other ◽  
Other Hand ◽  
Nuclear Rna ◽  
Nucleolar Rna

The effects of growth hormone and hydrocortisone on the synthesis of rat liver RNA have been studied. Administration of growth hormone stimulated the incorporation of 14C-orotic acid into 45 S preribosomal nucleolar RNA, and had no effect on the 6–50 S polydisperse nuclear RNA of extra-nucleolar origin. On the other hand, hydrocortisone stimulated the synthesis of all types of nuclear RNA, but mainly that of the 18 S class of 6–50 S polydisperse nuclear RNA.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

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