scholarly journals STABILITIES OF NUCLEAR AND MESSENGER RNA MOLECULES IN SEA URCHIN EMBRYOS

1972 ◽  
Vol 53 (2) ◽  
pp. 474-482 ◽  
Author(s):  
Bruce P. Brandhorst ◽  
Tom Humphreys
Keyword(s):  
Steady State ◽  
Sea Urchin ◽  
Half Life ◽  
Messenger Rna ◽  
Cell Fractionation ◽  
Rna Molecules ◽  
Sea Urchin Embryos ◽  
Cytoplasmic Rna ◽  
Nuclear Rna ◽  
Kinetics Of

The kinetics of accumulation of radioactive adenosine in adenosine triphosphate and in RNA of nuclear, cytoplasmic, and polysomal fractions of sea urchin embryos have been analyzed. 85% of the RNA synthesized decays in the nucleus with an apparently uniform half-life of about 7 min. The remaining 15% goes to the cytoplasm, mostly entering polysomes, and decays with a quite uniform half-life of about 75 min. The nuclear RNA accounts for one-third and the cytoplasmic RNA accounts for two-thirds of the total unstable RNA which accumulates at steady state in the embryo. The size distribution of short-labeled nuclear RNA is very similar to that of long-labeled messenger RNA, when both are extracted directly from the cells without a previous cell fractionation.

scholarly journals Kinetics of Labeling of the «Cap» of the Nuclear and Cytoplasmic RNA in Sea-urchin Embryos

1978 ◽  
Vol 45 (4) ◽  
pp. 423-425
Author(s):  
Gabriella Sconzo ◽  
Maria Grazia di Bernardo ◽  
Marta di Carlo ◽  
Maurizio di Liberto ◽  
Maria Teresa Faraci ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Sea Urchin Embryos ◽  
Cytoplasmic Rna ◽  
Kinetics Of

scholarly journals SYNTHESIS AND STORAGE OF MICROTUBULE PROTEINS BY SEA URCHIN EMBRYOS

1971 ◽  
Vol 50 (2) ◽  
pp. 516-528 ◽  
Author(s):  
Rudolf A. Raff ◽  
Gerald Greenhouse ◽  
Kenneth W. Gross ◽  
Paul R. Gross
Keyword(s):  
Amino Acids ◽  
Sea Urchin ◽  
Messenger Rna ◽  
Binding Activity ◽  
Total Soluble Protein ◽  
Cell Stage ◽  
Lytechinus Pictus ◽  
Sea Urchin Embryos ◽  
Tritiated Amino Acids ◽  
Vinblastine Sulfate

Studies employing colchicine binding, precipitation with vinblastine sulfate, and acrylamide gel electrophoresis confirm earlier proposals that Arbacia punctulata and Lytechinus pictus eggs and embryos contain a store of microtubule proteins. Treatment of 150,000 g supernatants from sea urchin homogenates with vinblastine sulfate precipitates about 5% of the total soluble protein, and 75% of the colchicine-binding activity. Electrophoretic examination of the precipitate reveals two very prominent bands. These have migration rates identical to those of the A and B microtubule proteins of cilia. These proteins can be made radioactive at the 16 cell stage and at hatching by pulse labeling with tritiated amino acids. By labeling for 1 hr with leucine-3H in early cleavage, then culturing embryos in the presence of unlabeled leucine, removal of newly synthesized microtubule proteins from the soluble pool can be demonstrated. Incorporation of labeled amino acids into microtubule proteins is not affected by culturing embryos continuously in 20 µg/ml of actinomycin D. Microtubule proteins appear, therefore, to be synthesized on "maternal" messenger RNA. This provides the first protein encoded by stored or "masked" mRNA in sea urchin embryos to be identified.

scholarly journals Studying RNA–DNA interactome by Red-C identifies noncoding RNAs associated with various chromatin types and reveals transcription dynamics

2020 ◽  
Vol 48 (12) ◽  
pp. 6699-6714 ◽  
Author(s):  
Alexey A Gavrilov ◽  
Anastasiya A Zharikova ◽  
Aleksandra A Galitsyna ◽  
Artem V Luzhin ◽  
Natalia M Rubanova ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Noncoding Rnas ◽  
K562 Cells ◽  
Biological Processes ◽  
Intron Splicing ◽  
Rna Molecules ◽  
Proximity Ligation ◽  
Data Support ◽  
Non Coding Rnas ◽  
Kinetics Of

Abstract Non-coding RNAs (ncRNAs) participate in various biological processes, including regulating transcription and sustaining genome 3D organization. Here, we present a method termed Red-C that exploits proximity ligation to identify contacts with the genome for all RNA molecules present in the nucleus. Using Red-C, we uncovered the RNA–DNA interactome of human K562 cells and identified hundreds of ncRNAs enriched in active or repressed chromatin, including previously undescribed RNAs. Analysis of the RNA–DNA interactome also allowed us to trace the kinetics of messenger RNA production. Our data support the model of co-transcriptional intron splicing, but not the hypothesis of the circularization of actively transcribed genes.

scholarly journals Large heterogeneous nuclear ribonucleic acid has three times as many 5' caps as polyadenylic acid segments, and most caps do not enter polyribosomes.

1981 ◽  
Vol 1 (2) ◽  
pp. 179-187 ◽  
Author(s):  
M Salditt-Georgieff ◽  
M M Harpold ◽  
M C Wilson ◽  
J E Darnell
Keyword(s):  
Ribonucleic Acid ◽  
Messenger Rna ◽  
Turnover Rate ◽  
Chinese Hamster ◽  
Chinese Hamster Cells ◽  
Rna Molecules ◽  
Rapid Turnover ◽  
Polyadenylic Acid ◽  
Nuclear Rna ◽  
Unstable Molecules

The rate of synthesis in Chinese hamster cells of 5' cap structures, m7 GpppNmp, in large (greater than 700 bases) heterogeneous nuclear ribonucleic acid (RNA) molecules is two to three times faster than the synthesis of 3'-terminal polyadenylic acid segments. As judged by presence of caps, newly synthesized polysomal messenger RNA, exclusive of messenger RNA the size of histone messenger RNA, is more than 90% in the polyadenylated category. It appears, therefore, that between half and two-thirds of the long capped heterogeneous nuclear RNA molecules do not contribute a capped polysomal derivative to the cytoplasm. There are capped, nonpolysomal, non-polyadenylated molecules with a rapid turnover rate that fractionate with the cytoplasm. These metabolically unstable molecules either could represent leakage into the cytoplasm during fractionation or could truly spend a brief time in the cytoplasm before decay.

A measurement of the sequence complexity of polysomal messenger RNA in sea urchin embryos

Cell ◽  
1974 ◽  
Vol 2 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Glenn A. Galau ◽  
Roy J. Britten ◽  
Eric H. Davidson
Keyword(s):  
Sea Urchin ◽  
Messenger Rna ◽  
Sea Urchin Embryos ◽  
Sequence Complexity

II. Distribution of DNA base sequences - Introductory remarks: DNA and genes

1978 ◽  
Vol 283 (997) ◽  
pp. 305-307
Keyword(s):  
Genetic Code ◽  
Messenger Rna ◽  
Transfer Rnas ◽  
Rna Molecules ◽  
Dna Base ◽  
Base Sequences ◽  
Nuclear Rna

After the genetic code was discovered in the early 1960s, it was generally accepted that nearly all DNA in higher organisms was used to specify messenger RNA molecules at some time during their development. A small fraction could be set aside for the ribosomal and transfer RNAs and there was a problem about the rapidly turning over nuclear RNA which did not appear in the cytoplasm as message. By and large we considered that most DNA was potentially coding and the lone voices who talked of other kinds of DNA on the basis of somewhat flimsy evidence were largely ignored.

scholarly journals Disposition kinetics of ceftriaxone and determination of its therapeutic dose in dogs

2020 ◽  
Vol 19 (8) ◽  
pp. 1735-1758
Author(s):  
Ifeanyi G. Eke ◽  
Ukamaka U. Eze ◽  
Aruh O. Anaga ◽  
Kennedy F. Chah ◽  
Boniface M. Anene ◽  
...  
Keyword(s):  
Steady State ◽  
Serum Concentration ◽  
Half Life ◽  
Therapeutic Dose ◽  
Maximum Serum ◽  
Elimination Half Life ◽  
Disposition Kinetics ◽  
Elimination Half ◽  
Significant Difference ◽  
Kinetics Of

Purpose: To evaluate the disposition kinetics of ceftriaxone (CFZ) in dogs with a view to determining its therapeutic dose and dosing frequency.Methods: Twelve (12) Basenji dogs (n = 4), divided into 3 groups (A, B and C), were used for the study. Ceftriaxone was administered intramuscularly at doses of 12.5, 25, and 50 mg/kg once to groups A, B and C respectively. Plasma CFZ concentration was determined by agar well diffusion assay at 0.25, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 24 h post-treatment, and the pharmacokinetic parameters were determined.Results: Intramuscular injection of CFZ to dogs resulted in rapid absorption, distribution and elimination (p < 0.05). The elimination half-life was short and did not change significantly with increase in dose. Serum concentration of CFZ changed significantly (p < 0.05) with increase in dose of CFZ. The maximum serum concentration (Cmax, 15.00 ± 1.18, 141.37 ± 15.87 and 259 ± 5.21 μg/mL) for groups A, B and C respectively were significantly (p < 0.05) different. The steady state CFZ concentrations; 0.94, 8.81 and 16.19 μg/mL for groups A, B and C, respectively, were significantly (p < 0.05) different. However, there was no significant difference in the time to reach steady state concentrations (Tmax, 00±0.021, 4.00±0.10 and 4.30±0.12 for groups A, B and C respectively). The therapeutic dose of CFZ was therefore determined to be 25 – 50 mg/kg every 4 h.Conclusion: Ceftriaxone undergoes rapid elimination in dogs with a short elimination half-life, thus making it an inconvenient prescription for out-patients in veterinary clinics. Keywords: Ceftriaxone, Pharmacokinetic profile, Dogs, Therapeutic dose, Veterinary clinic

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