NUCLEIC ACID METABOLISM IN INTESTINAL MUCOSA: V. HETEROGENEITY OF DEOXYRIBONUCLEIC ACID ISOLATED FROM THE INTESTINAL MUCOSA OF THE RAT

1967 ◽  
Vol 45 (3) ◽  
pp. 375-386
Author(s):  
C. Mezei ◽  
S. H. Zbarsky
Keyword(s):  
Intestinal Mucosa ◽  
Enzymatic Degradation ◽  
Thermal Denaturation ◽  
Deoxyribonucleic Acid ◽  
Acid Metabolism ◽  
Cesium Chloride ◽  
Nucleic Acid Metabolism ◽  
Dna Molecule ◽  
Physical Chemical ◽  
The Individual

Doubly labeled DNA was isolated from the intestinal mucosa of rats injected intravenously with 3H-thymidine and 24 hours later with 14C-thymidine. The DNA was chromatographed on columns of methylated albumin–kieselguhr. The 3H/14C ratios of the individual subfractions comprising the main DNA fraction eluted from the column increased from the earlier to the later sub-fractions in the DNA isolated from rats receiving the 14C-labeled thymidine 20 minutes before they were killed. This result indicated a slower incorporation of the 14C-labeled material into the DNA molecules represented by the later sub-fractions. In experiments in which the interval before the death of the animals was extended to 40 minutes, the 3H/14C ratios were constant throughout the main DNA fraction. Enzymatic degradation of the doubly labeled DNA indicated that incorporation of both types of precursors had occurred well within the DNA molecule. Physical chemical differences were also detected among the subfractions. There appeared to be two main types of DNA which could be grouped according to thermal denaturation temperatures (Tm), and ultracentrifugation in cesium chloride gave evidence of differences in buoyant densities between the leading and final subfractions.

scholarly journals KINETOPLAST DEOXYRIBONUCLEIC ACID OF THE HEMOFLAGELLATE TRYPANOSOMA LEWISI

1970 ◽  
Vol 47 (3) ◽  
pp. 689-702 ◽  
Author(s):  
Hartmut C. Renger ◽  
David R. Wolstenholme
Keyword(s):  
Electron Microscope ◽  
Ethidium Bromide ◽  
Thermal Denaturation ◽  
Deoxyribonucleic Acid ◽  
Cesium Chloride ◽  
Kinetoplast Dna ◽  
Microscope Examination ◽  
Main Band ◽  
Trypanosoma Lewisi ◽  
High Degree

Cesium chloride centrifugation of DNA extracted from cells of blood strain Trypanosoma lewisi revealed a main band, ρ = 1.707, a light satellite, ρ = 1.699, and a heavy satellite, ρ = 1.721. Culture strain T. lewisi DNA comprised only a main band, ρ = 1.711, and a light satellite, ρ = 1.699. DNA isolated from DNase-treated kinetoplast fractions of both the blood and culture strains consisted of only the light satellite DNA. Electron microscope examination of rotary shadowed preparations of lysates revealed that DNA from kinetoplast fractions was mainly in the form of single 0.4 µ circular molecules and large masses of 0.4 µ interlocked circles with which longer, often noncircular molecules were associated. The 0.4 µ circular molecules were mainly in the covalently closed form: they showed a high degree of resistance to thermal denaturation which was lost following sonication; and they banded at a greater density than linear DNA in cesium chloride-ethidium bromide gradients. Interpretation of the large masses of DNA as comprising interlocked covalently closed 0.4 µ circles was supported by the findings that they banded with single circular molecules in cesium chloride-ethidium bromide gradients, and following breakage of some circles by mild sonication, they disappeared and were replaced by molecules made up of low numbers of apparently interlocked 0.4 µ circles. When culture strain cells were grown in the presence of either ethidium bromide or acriflavin, there was a loss of stainable kinetoplast DNA in cytological preparations. There was a parallel loss of light satellite and of circular molecules from DNA extracted from these cells.

EFFECT OF OESTRADIOL-17β ON CLEAVAGE, NUCLEIC ACID METABOLISM AND PROTEIN SYNTHESIS IN SEA URCHIN, STRONGYLOCENTROTUS PURPURATUS, EMBRYOS

1962 ◽  
Vol 25 (2) ◽  
pp. 183-NP ◽  
Author(s):  
W. B. JOLLEY ◽  
W. E. MARTIN ◽  
J. W. BAMBERGER ◽  
L. W. STEARNS
Keyword(s):  
Protein Synthesis ◽  
Nucleic Acid ◽  
Sea Urchin ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Acid Metabolism ◽  
Strongylocentrotus Purpuratus ◽  
Nucleic Acid Metabolism ◽  
Dna And Rna ◽  
Moderate Effect

SUMMARY Oestradiol-17β at a concentration of 3 × 10−3 m inhibits cleavage in sea urchin (Strongylocentrotus purpuratus) embryos. This inhibition is accompanied by a reduction in deoxyribonucleic acid (DNA) synthesis and little change in ribonucleic acid (RNA). The effects of oestradiol-17β upon the incorporation of glycine-1-14C and glycine-2-14C into the purines of DNA and RNA and the incorporation of glycine-2-14C into serine were studied. The incorporation of glycine-1-14C and glycine-2-14C into RNA was reduced, but the incorporation of glycine-2-14C into DNA was increased considerably over that of the controls. The incorporation of glycine-2-14C into serine was also accelerated by oestradiol. A possible explanation of the action of oestradiol-17β is offered. The moderate effect upon RNA is not surprising because there is little or no synthesis of this compound from the time of fertilization to blastulation under normal conditions.

EFFECT OF L-CYSTEINE ON α-AMYLASE PRODUCTION AND NUCLEIC ACID METABOLISM IN BACILLUS SUBTILIS

1963 ◽  
Vol 9 (3) ◽  
pp. 337-341 ◽  
Author(s):  
MICHIO OISHI ◽  
SHIGERU KITAYAMA ◽  
HAJIME TAKAHASHI ◽  
BUNJI MARUO
Keyword(s):  
Bacillus Subtilis ◽  
Nucleic Acid ◽  
Acid Metabolism ◽  
Nucleic Acid Metabolism ◽  
Amylase Production

Chlorinated Organics in Nearshore Waters and Tributaries of the St. Clair River

1986 ◽  
Vol 21 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Barry G. Oliver ◽  
Klaus L.E. Kaiser
Keyword(s):  
United States ◽  
Suspended Sediment ◽  
Waste Disposal ◽  
Large Volume ◽  
Water Samples ◽  
Chemical Properties ◽  
Low Level ◽  
Chemical Company ◽  
Physical Chemical ◽  
The Individual

Abstract The concent rat ions of hexachloroethane (HCE), hexachlorobutadiene (HCBD), pentachlorobenzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in large volume water samples show that the major sources of these chemicals to the St. Clair River are Dow Chemical Company effluents and, to a lesser degree, Sarnia’s Township ditch which drains one of Dow’s waste disposal sites. Tributaries entering the river on both sides of the Canada/United States border contain measurable concentrations of these chemicals indicating low level contamination throughout the area. The degree of water/suspended sediment partitioning of the chemicals (Kp) was studied. Kp values for the individual chemicals changed in a manner consistent with changes in their physical-chemical properties.

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