scholarly journals CHANGES IN THE BASE COMPOSITION OF NUCLEAR RIBONUCLEIC ACID OF NEURONS DURING A SHORT PERIOD OF ENHANCED PROTEIN PRODUCTION

1962 ◽  
Vol 15 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Holger Hydén ◽  
Endre Egyházi

Nuclei from isolated nerve cells were sampled by microdissection. The content and composition of the nuclear RNA was studied and compared with that of the cytoplasmic RNA of Deiters' nerve cells of rabbits. Analyses were made of control nerve cells and of cells in which an enhanced RNA and protein production had been induced by chemical means, tricyano-amino-propene, for 60 minutes. The nuclear RNA content of the control nerve cells was 56 µµg, i.e. 3 per cent of the total RNA content of the nerve cell. The base ratios were: adenine 21.3, guanine 26.6, cytosine 30.8, uracil 21.3. Purine-pyrimidine analyses showed that the nuclear RNA differed significantly from the cytoplasmic RNA in having higher adenine and uracil values. The guanine and cytosine values were high, however, and the ratio G/C was 0.86 as compared with 1.16 for the cytoplasmic RNA. The composition of the nuclear RNA was interpreted as reflecting the extraordinarily strong development of the nucleolus in these neurons. During the 60 minutes of enhanced neuronal RNA production (+25 per cent) the guanine value increased and the uracil value decreased significantly in the nuclear RNA. In the cytoplasmic RNA the guanine value also increased although not so much as the nuclear guanine. The cytoplasmic cytosine value decreased. The result indicated that the production of the characteristic cytoplasmic RNA had been influenced by the change in the nuclear RNA

1965 ◽  
Vol 27 (1) ◽  
pp. 47-52 ◽  
Author(s):  
R. Wiesner ◽  
G. Acs ◽  
E. Reich ◽  
A. Shafiq

The cellular RNA content of mouse fibroblasts incubated with actinomycin decreases at a rate of about 1 to 1.5 per cent per hour, while DNA and protein content remain unchanged. This degradation affects nuclear and cytoplasmic RNA, ribosomal and soluble RNA. The breakdown products appear quantitatively in the acid-soluble fraction of the cells and the medium. Polynucleotides synthesized a short period (120 minutes) prior to exposure to actinomycin are degraded before those synthesized 8 to 12 hours previously.


1961 ◽  
Vol 10 (3) ◽  
pp. 403-410 ◽  
Author(s):  
Endre Egyházi ◽  
Holger Hydén

The effect of tricyano-amino-propene, a dimer of malononitrile, on the base composition of the RNA in isolated Deiters' nerve cells and their oligodendroglial cells has been studied using a microelectrophoretic method. Tri-a-p in a dose of 20 mg/kg has the effect of increasing the RNA and protein content per nerve cell by 25 per cent and decreasing the glia RNA by 45 per cent. The RNA base composition of the nerve cells from the control animals differs from that of their glial cells. The guanine of the nerve cell is significantly higher than that of the glia, but the content of cytosine is higher in the glia than in the RNA of nerve cell. The cytosine of nerve cells decreased significantly after tri-a-p administration. In the glial cells the cytosine showed a 20 per cent increase, and the guanine a 25 per cent decrease. Tri-a-p sharpened the difference in RNA composition already existing between the control nerve cells and their glial cells by almost 300 per cent for the guanine and by 400 per cent for the cytosine. The chemical and functional relationship between the nerve cell and its oligodendroglial cells is discussed.


1960 ◽  
Vol 8 (1) ◽  
pp. 47-51 ◽  
Author(s):  
Jan-Erik Edström

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.


1901 ◽  
Vol IX (1) ◽  
pp. 208-209
Author(s):  
B. Vorotynsky

The work was carried out in the laboratory of the pathological anatomical institute of the University of St. Vladimira. First, the author describes the structure of the nerve cell, which is detected by staining by the Nissl method, and he separately stops at describing the structure of the processes, nucleus and nucleolus.


Blood ◽  
1985 ◽  
Vol 66 (1) ◽  
pp. 39-46
Author(s):  
HM Kantarjian ◽  
B Barlogie ◽  
M Pershouse ◽  
D Swartzendruber ◽  
MJ Keating ◽  
...  

In an effort to develop a new tumor marker suitable for flow cytometric analysis, we examined the value of double-stranded ribonucleic acid (ds- RNA) measurements using propidium iodide after DN'ase treatment. Cellular ds-RNA content was evaluated both in experimental cell lines and in clinical specimens. Higher levels of ds-RNA were present in tumor cells as compared with normal cells. In tumor cells, fluorescence was intensely localized in the nucleolus and was more diffuse in the cytoplasm. Change of less than 10% in the ds-RNA levels was observed in cell lines as a function of cytokinetic determinants such as cycle phase, culture age, and cycle traverse rate. Tumor differentiation by dimethylsulfoxide resulted in a significant decrease in cellular ds-RNA content. For quantitative comparison of clinical material, a ds-RNA excess was defined in relationship to normal peripheral blood lymphocytes. ds-RNA excess greater than 30% was observed in only one of 34 normal tissues (3%) as compared with 124 of 201 neoplastic tissue samples (62%). This incidence was higher in patients with acute leukemia (76%), high-grade and intermediate-grade lymphoma (75%), and high tumor stage myeloma (83%), as compared with chronic leukemia (20%), low-grade lymphoma (25%), and intermediate or low tumor mass myeloma (43%). Prognostically, a high pretreatment ds-RNA excess in myeloma was associated with a lower remission rate. The persistence of ds-RNA excess in the bone marrow of patients with acute myelogenous leukemia in remission predicted for a shorter remission duration (seven v 22 months; P = .05). We conclude that ds-RNA excess, as readily measured objectively and quantitatively by flow cytometry, may have important diagnostic and prognostic implications for the management of patients with malignant disease.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4286 ◽  
Author(s):  
Erik M. Quandt ◽  
Charles C. Traverse ◽  
Howard Ochman

The maintenance of a G + C content that is higher than the mutational input to a genome provides support for the view that selection serves to increase G + C contents in bacteria. Recent experimental evidence fromEscherichia colidemonstrated that selection for increasing G + C content operates at the level of translation, but the precise mechanism by which this occurs is unknown. To determine the substrate of selection, we asked whether selection on G + C content acts across all sites within a gene or is confined to particular genic regions or nucleotide positions. We systematically altered the G + C contents of the GFP gene and assayed its effects on the fitness of strains harboring each variant. Fitness differences were attributable to the base compositional variation in the terminal portion of the gene, suggesting a connection to the folding of a specific protein feature. Variants containing sequence features that are thought to result in rapid translation, such as low G + C content and high levels of codon adaptation, displayed highly reduced growth rates. Taken together, our results show that purifying selection acting against A and T mutations most likely results from their tendency to increase the rate of translation, which can perturb the dynamics of protein folding.


2021 ◽  
Vol 30 (1) ◽  
pp. 102-109
Author(s):  
Dhananjay Mishra ◽  
K.Venu Achari

We determined the kinetics of metamorphosis, apoptosis, and tail regression in Rana tigrina. Acid phosphatase activity (µMole Pi.hr-1.tail-1) in the growing and regressing tail attended six to thirty fold increase respectively. However total activity in the trunk was decreased through progressive growing stages of metamorphosis. Total protein content in the trunk of tadpoles at climax stage (XXI) was decrease (35%) from 2.6mg/ml to 1.7mg/ml. The tail of tadpole tissue has shown a two fold increase in total Ribonucleic Acid (RNA) content from stage III to stage XVIII. But there was again decrease in total RNA content at climax stage (stage XXI). This might be possible due to decreased protein synthetic status. When the experiment was performed in trunk homogenate the amount of total carbohydrate (mg/ml) was slightly increased from 37mg/ml to 38.6mg/ml. this might be due to increase in the activity of α-amylase enzymes in the viscera of developing tadpole when it reached the climax stage.


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