scholarly journals Regulation of tropomyosin gene expression during myogenesis.

1981 ◽  
Vol 1 (3) ◽  
pp. 289-301 ◽  
Author(s):  
M Moss ◽  
R Schwartz
Keyword(s):  
Gene Expression ◽  
Nucleic Acid ◽  
Messenger Rna ◽  
Deoxyribonucleic Acid ◽  
Critical Role ◽  
Fold Increase ◽  
Nucleic Acid Content ◽  
Total Nucleic Acid ◽  
Synthetic Capacity ◽  
Rna Levels

In skeletal muscle, tropomyosin has a critical role in transduction of calcium-induced contraction. Presently, little is known about the regulation of tropomyosin gene expression during myogenesis. In the present study, qualitative and quantitative changes in the nucleic acid populations of differentiating chicken embryo muscle cells in culture have been examined. Total nucleic acid content per nucleus increased about fivefold in fully developed myotubes as compared to mononucleated myoblasts. The contribution of deoxyribonucleic acid to the total nucleic acid population decreased from 24% in myoblasts to 5% of total nucleic acid in myotubes. Concomitant with the decrement in deoxyribonucleic acid contribution to total nucleic acid was an increase in polyadenylated ribonucleic acid (RNA) content per cell which reached levels in myotubes that were 17-fold higher than those of myoblasts. Specific changes in the RNA population during myogenesis were further investigated by quantitation of the synthetic capacity (messenger RNA levels) per cell for alpha- and beta-tropomyosin. Cell-free translation and immunoprecipitation demonstrated an approximately 40-fold increase in messenger RNA levels per nucleus for alpha- and beta-tropomyosin after fusion in the terminally differentiated myotubes. Indirect immunofluorescence with affinity-purified tropomyosin antibodies demonstrated the presence of tropomyosin-containing filaments in cells throughout myogenesis. Thus, the tropomyosin genes are constitutively expressed during muscle differentiation through the production of tropomyosin messenger RNA and translation into tropomyosin protein.

Regulation of tropomyosin gene expression during myogenesis

1981 ◽  
Vol 1 (3) ◽  
pp. 289-301
Author(s):  
M Moss ◽  
R Schwartz
Keyword(s):  
Gene Expression ◽  
Nucleic Acid ◽  
Messenger Rna ◽  
Deoxyribonucleic Acid ◽  
Critical Role ◽  
Fold Increase ◽  
Nucleic Acid Content ◽  
Total Nucleic Acid ◽  
Synthetic Capacity ◽  
Rna Levels

In skeletal muscle, tropomyosin has a critical role in transduction of calcium-induced contraction. Presently, little is known about the regulation of tropomyosin gene expression during myogenesis. In the present study, qualitative and quantitative changes in the nucleic acid populations of differentiating chicken embryo muscle cells in culture have been examined. Total nucleic acid content per nucleus increased about fivefold in fully developed myotubes as compared to mononucleated myoblasts. The contribution of deoxyribonucleic acid to the total nucleic acid population decreased from 24% in myoblasts to 5% of total nucleic acid in myotubes. Concomitant with the decrement in deoxyribonucleic acid contribution to total nucleic acid was an increase in polyadenylated ribonucleic acid (RNA) content per cell which reached levels in myotubes that were 17-fold higher than those of myoblasts. Specific changes in the RNA population during myogenesis were further investigated by quantitation of the synthetic capacity (messenger RNA levels) per cell for alpha- and beta-tropomyosin. Cell-free translation and immunoprecipitation demonstrated an approximately 40-fold increase in messenger RNA levels per nucleus for alpha- and beta-tropomyosin after fusion in the terminally differentiated myotubes. Indirect immunofluorescence with affinity-purified tropomyosin antibodies demonstrated the presence of tropomyosin-containing filaments in cells throughout myogenesis. Thus, the tropomyosin genes are constitutively expressed during muscle differentiation through the production of tropomyosin messenger RNA and translation into tropomyosin protein.

scholarly journals THE RIBONUCLEIC ACID AND DEOXYRIBONUCLEIC ACID CONTENT OF MONONUCLEAR LEUKOCYTES OF DIFFERENT SIZES STUDIED BY ULTRAVIOLET CYTOPHOTOMETRY

1973 ◽  
Vol 21 (7) ◽  
pp. 628-633 ◽  
Author(s):  
ALFREDO MARIANO GARCIA ◽  
PATRICIA A. N. SULLIVAN
Keyword(s):  
Nucleic Acid ◽  
Cell Size ◽  
Dna Content ◽  
Random Error ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Nucleic Acid Content ◽  
Mononuclear Leukocytes ◽  
Total Nucleic Acid ◽  
Dna And Rna

Rat mononuclears (lymphocytes and monocytes) were studied for total nucleic acid content by means of ultraviolet cytophotometry. Another set was treated with ribonuclease, and deoxyribonucleic acid (DNA) was measured using the same technique. It was found that total nucleic acid content (DNA and RNA) increases linearly with cell size from about 20 units in lymphocytes having 5 µ in diameter up to around 30 units in cells having 12-14 µ in diameter; this is to say, an almost 50% increase for a 6-7-fold enlargement. After ribonuclease treatment, however, the value of the integrated extinction (DNA) tends to remain constant for different cell sizes. A 650% variation in area is accompanied by a DNA change of less than 6%. The differences between treated and nontreated cells are nonsignificant for populations having up to 7.0-7.5 µ in diameter, which implies that small lymphocytes either have a negligible amount of RNA or that the instrument is not sensitive enough to detect it (less than 7% of the DNA content, this figure being the random error of our technique). These differences become highly significant for mononuclears having 8 µ or more in diameter. Therefore, while DNA tends to be constant and independent from cell size, RNA content tends to be harmoniously inconstant, since it is correlated with cell (and nuclear) size and degree of chromatin diffusion.

The nucleic acid content of peripheral nerve in degeneration and activity

1956 ◽  
Vol 144 (917) ◽  
pp. 520-527 ◽  
Keyword(s):  
Nucleic Acid ◽  
Sciatic Nerve ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Contralateral Side ◽  
Small Extent ◽  
Nucleic Acid Content ◽  
Total Nucleic Acid ◽  
Sciatic Nerves ◽  
Stimulation Of

Total nucleic acid (TNA) and deoxyribonucleic acid (DNA) of degenerating and stimulated sciatic nerves of rabbits have been determined. The ratio DNA/TNA in normal nerves was 0·59. In degenerating nerve the total nucleic acid content increased during the first 96 h, though there was little increase in DNA, the increase being presumably mainly in the fraction containing ribonucleic acid (RNA). On the contralateral side the TNA content remained unchanged, but the DNA/TNA ratio decreased to a small extent. After stimulation of the sciatic nerve for 4 h TNA remained unchanged but DNA decreased markedly.

scholarly journals Cytological and Biochemical Studies of Anucleolate Xenopus Larvae

1962 ◽  
Vol s3-103 (61) ◽  
pp. 25-35
Author(s):  
H. WALLACE
Keyword(s):  
Alkaline Phosphatase ◽  
Nucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Nucleic Acid Content ◽  
Tail Bud ◽  
Lethal Mutant ◽  
Cytoplasmic Rna ◽  
Biochemical Studies ◽  
And Function

A larval lethal mutant of Xenopus laevis lacks true nucleoli but possesses analogous intranuclear organelles, here termed blobs, which are smaller and more numerous than nucleoli. Cytochemical tests reveal that blobs (like nucleoli) contain ribonucleic acid (RNA), arginine, and alkaline phosphatase, but probably no Feulgen-positive material. Anucleolate larvae are deficient in cytoplasmic RNA. By biochemical methods the nucleic acid content of anucleolate embryos is found to be normal at the tail-bud stage, but does not increase after this. By the time they hatch, anucleolate larvae are deficient in both RNA and deoxyribonucleic acid (DNA). The implications of this and related mutations on the formation and function of the nucleolus are considered. The term ‘blob’ is justified in that it would be misleading to regard such organelles as nucleoli produced by normally latent organizers.

scholarly journals Chronic Exposure to High Glucose Concentrations Increases Proglucagon Messenger Ribonucleic Acid Levels and Glucagon Release from InR1G9 Cells1

Endocrinology ◽  
1999 ◽  
Vol 140 (10) ◽  
pp. 4644-4650 ◽  
Author(s):  
Eric Dumonteil ◽  
Beate Ritz-Laser ◽  
Chistophe Magnan ◽  
Iléana Grigorescu ◽  
Alain Ktorza ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Glucose ◽  
Messenger Rna ◽  
Cell Function ◽  
High Plasma ◽  
Glucagon Release ◽  
Cell Content ◽  
Messenger Ribonucleic Acid ◽  
Elevated Glucose ◽  
Rna Levels

Abstract α cell function is impaired in diabetes. In diabetics, plasma levels of glucagon are high despite persistently elevated glucose levels and may even rise paradoxically in response to a glucose load; high plasma glucagon levels are accompanied by increased proglucagon gene expression. We have investigated the effects of high glucose concentrations on InR1G9 cells, a glucagon-producing cell line. We show here that chronically elevated glucose concentrations increase glucagon release by 2.5- to 4-fold, glucagon cell content by 2.5- to 3-fold, and proglucagon messenger RNA levels by 4- to 8-fold, whereas changes for 24 h have no effect on proglucagon messenger RNA levels. Persistently elevated glucose affects proglucagon gene expression at the level of transcription and insulin is capable of preventing this effect. We conclude that chronically elevated glucose may be an important factor in the α cell dysfunction that occurs in diabetes and thus that glucose may not only affect the β cell but also the α cell.

Changes in the nucleic acid content of the uterus of sheep during involution following ovariectomy and following oestrogenic stimulation

1976 ◽  
Vol 27 (5) ◽  
pp. 669 ◽  
Author(s):  
DA Little ◽  
LJ Lambourne
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Total Content ◽  
Mean Value ◽  
Nucleic Acid Content ◽  
Uterine Tissue ◽  
Rna Concentration

The concentrations of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), in ovine uterine tissue were studied to determine whether the ratio RNA/DNA might be used in the bioassay of oestrogenic activity. As the uterus decreased in size with time after ovariectomy, the concentration of DNA increased markedly, but the total content of DNA in the uterus remained constant (mean value 342 ? 8 (SE) mg). The RNA concentration of the tissue decreased during involution, with the result that a highly significant reduction of 33% in the RNA/DNA ratio occurred within 2 weeks of ovariectomy. The ratio decreased further with time. Other ewes were treated for 3 days with diethylstilboestrol dipropionate (10 µg/day), commencing 2 weeks after ovariectomy; the stage of the oestrous cycle at which the ovaries were removed had no effect on the response to the oestrogen. Changes in the nucleic acid concentrations in the uteri of these ewes, and the results obtained during involution, indicate that the RNA/DNA ratio of uterine tissue in ovariectomized ewes has potential as a basis for the bioassay of materials of low oestrogenic potency.

Level of nutrition and visceral organ protein synthetic capacity and nucleic acid content in sheep2

1992 ◽  
Vol 70 (4) ◽  
pp. 1137-1145 ◽  
Author(s):  
D. G. Burrin ◽  
R. A. Britton ◽  
C. L. Ferrell ◽  
M. L. Bauer
Keyword(s):  
Nucleic Acid ◽  
Acid Content ◽  
Nucleic Acid Content ◽  
Visceral Organ ◽  
Synthetic Capacity

THE INFLUENCE OF GROWTH HORMONE ON THE NUCLEIC ACID CONTENT OF RAT LIVER AND MUSCLE

1956 ◽  
Vol 13 (4) ◽  
pp. 429-432 ◽  
Author(s):  
BARBARA J. GRAY
Keyword(s):  
Skeletal Muscle ◽  
Growth Hormone ◽  
Nucleic Acid ◽  
Rat Liver ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Female Rats ◽  
Nucleic Acid Content ◽  
Pituitary Growth Hormone

SUMMARY Adult female rats were treated with purified pituitary growth hormone for 9 days, and the nucleic acid content of the liver and skeletal muscle determined. An increase was observed in the concentration of muscle ribonucleic acid, expressed per gram of nitrogen, as a result of the treatment. There were no changes in the ribonucleic acid concentration of liver. No changes were observed in the concentration of deoxyribonucleic acid in muscle or liver.

Hydroxyindole-O-methyltransferase gene expression in the pineal gland of chicken embryo: development of messenger RNA levels and regulation by serum

1995 ◽  
Vol 88 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Aline Grechez-Cassiau ◽  
Pierre Grève ◽  
Jérôme Guerlotté ◽  
Jean-Pierre Collin ◽  
Pierre Voisin
Keyword(s):  
Gene Expression ◽  
Pineal Gland ◽  
Embryo Development ◽  
Chicken Embryo ◽  
Messenger Rna ◽  
Methyltransferase Gene ◽  
Rna Levels
Sign in / Sign up

Export Citation Format

Share Document