scholarly journals CYTOPLASMIC DNA SYNTHESIS IN AMOEBA PROTEUS

1962 ◽  
Vol 15 (3) ◽  
pp. 535-540 ◽  
Author(s):  
M. Rabinovitch ◽  
W. Plaut
Keyword(s):  
Nucleic Acid ◽  
Dna Synthesis ◽  
Acridine Orange ◽  
Particle Number ◽  
Amoeba Proteus ◽  
Acridine Orange Staining ◽  
Particle Population ◽  
Cell Age ◽  
Cytoplasmic Dna ◽  
Number Of Particles

Nucleic acid-containing particles in the cytoplasm of Amoeba proteus (cf. reference 1) were counted after acridine orange staining. The number of particles per ameba was found to be correlated with cell age and size. Fresh daughters had a mean particle number of 5400, whereas predivision amebae contained around 11,000 particles. Amebae from two other strains contained similar particles. The particles were found to be clustered in fasted cells and redispersed after feeding. A marked increase in the particle population was noted in anucleate fragments. These results, together with those previously presented, suggest that the particles multiply intracellularly. Their nature and their relationship to previous work on nucleic acid labeling in Amoeba are discussed.

scholarly journals CYTOPLASMIC DNA SYNTHESIS IN AMOEBA PROTEUS

1962 ◽  
Vol 15 (3) ◽  
pp. 525-534 ◽  
Author(s):  
M. Rabinovitch ◽  
W. Plaut
Keyword(s):  
Dna Synthesis ◽  
Tritiated Thymidine ◽  
Amoeba Proteus ◽  
Living Cells ◽  
Large Numbers ◽  
Cytoplasmic Dna ◽  
Basic Dyes ◽  
Nuclease Digestion ◽  
High Degree ◽  
Very High

The incorporation of tritiated thymidine in Amoeba proteus was reinvestigated in order to see if it could be associated with microscopically detectable structures. Staining experiments with basic dyes, including the fluorochrome acridine orange, revealed the presence of large numbers of 0.3 to 0.5 µ particles in the cytoplasm of all cells studied. The effect of nuclease digestion on the dye affinity of the particles suggests that they contain DNA as well as RNA. Centrifugation of living cells at 10,000 g leads to the sedimentation of the particles in the centrifugal third of the ameba near the nucleus. Analysis of centrifuged cells which had been incubated with H3-thymidine showed a very high degree of correlation between the location of the nucleic acid-containing granules and that of acid-insoluble, deoxyribonuclease-sensitive labeled molecules and leads to the conclusion that cytoplasmic DNA synthesis in Amoeba proteus occurs in association with these particles.

The fluorescent staining of a mycobacteriophage (C2) nucleic acid

1971 ◽  
Vol 17 (2) ◽  
pp. 171-174 ◽  
Author(s):  
Jose Menezes
Keyword(s):  
Nucleic Acid ◽  
Acridine Orange ◽  
Staining Technique ◽  
Fluorescent Staining ◽  
Green Fluorescence ◽  
Acridine Orange Staining ◽  
Fluorescence Characteristic ◽  
Phage Dna ◽  
Acid Dnase

By using the acridine orange staining technique a green fluorescence, characteristic of double-stranded nucleic acid, can be observed with purified preparations of mycobacteriophage C2 and its extracted nucleic acid. DNAse-treated samples do not show this fluorescence, which leads to the conclusion that this fluorescence is associated with phage DNA. Examination of preparations of phage grown in the presence of acridine orange supported these results.

Cytoplasmic DNA-Containing Bodies and the Response of Amoebae to Dimidium Bromide

1969 ◽  
Vol 5 (1) ◽  
pp. 57-63
Author(s):  
SHIRLEY E. HAWKINS ◽  
LESLEY R.WILLIS
Keyword(s):  
Acridine Orange ◽  
Quantitative Difference ◽  
Amoeba Proteus ◽  
Fluorescence Microscope ◽  
Dna And Rna ◽  
Cytoplasmic Bodies ◽  
Cytoplasmic Dna ◽  
The Difference

The growth of Amoeba proteus (T1P) and Amoeba discoides (T1) in the trypanocidal phenanthridlnium, dimidium bromide was examined. At concentrations of drug between 2 and 4 µg/ml, A. proteus divided twice before inhibition and death. A. discoides was able to undergo an additional cycle of division before death. At other concentrations there were no differences in their response. Heterotransfers between these strains resembled A. discoides, both dividing three times before death. Examination of clones derived from the micro-injection of small quantities of A. discoides cytoplasm into A. proteus showed that the ability to divide additionally in dimidium bromide could be transferred. Some other strains of A. proteus (DP, T4P) also resembled A. discoides in their response. Cells of all the strains used were treated with acridine orange and observed under the fluorescence microscope for the presence of DNA- and RNA-containing cytoplasmic ‘bodies’. All strains able to undergo an additional division cycle also possessed cytoplasmic DNAcontaining bodies. The converse was not 100%, but this may be due to a quantitative difference in the number of DNA-containing bodies in the cytoplasm. It is proposed that the difference in response to dimidium bromide observed in A. proteus and A. discoides may be associated with the presence of DNA- and RNA-containing bodies in the cytoplasm of A. discoides.

scholarly journals CYTOPLASMIC DNA SYNTHESIS IN AMOEBA PROTEUS

1964 ◽  
Vol 22 (3) ◽  
pp. 505-513 ◽  
Author(s):  
D. R. Wolstenholme ◽  
W. Plaut
Keyword(s):  
Electron Microscope ◽  
Dna Synthesis ◽  
Light Microscope ◽  
Tritiated Thymidine ◽  
Amoeba Proteus ◽  
Electron Microscope Autoradiography ◽  
Cytoplasmic Dna ◽  
Microscope Autoradiography ◽  
Normal Particle ◽  
Labeling Pattern

The application of electron microscope autoradiography to Amoeba proteus cells labeled with tritiated thymidine has permitted the identification of morphologically distinct particles in the cytoplasm as the sites of incorporated DNA precursor. The particles correspond to those previously described from light microscope studies, with respect to both H3Tdr incorporation and distribution in centrifugally stratified amoebae. Ingested bacteria differ from the particles, in morphology as well as in the absence of associated label. Attempts to introduce a normal particle labeling pattern by incubating amoebae with labeled sediment derived from used amoeba medium failed. The resultant conclusion, that the particles are maintained in the amoeba by self-duplication, is supported by the presence of particles in configurations suggestive of division.

STUDIES ON THE BIOLOGICAL PROPERTIES AND CLASSIFICATION OF SV4 VIRUS

1965 ◽  
Vol 11 (2) ◽  
pp. 325-335 ◽  
Author(s):  
S. A. Sattar ◽  
K. R. Rozee
Keyword(s):  
Electron Microscope ◽  
Rhesus Monkey ◽  
Red Blood Cells ◽  
Acridine Orange ◽  
Blood Cells ◽  
Magnesium Chloride ◽  
Fluorescent Microscopy ◽  
Biological Properties ◽  
Acridine Orange Staining

Cytopathic changes in LLC-MK2 cells infected with SV4 virus, observed with the electron microscope and using acridine orange staining and fluorescent microscopy, have been shown to be similar to that caused by picornaviruses and members of the Columbia-SK virus group. The virus was found to be stabilized against heat in the presence of molar magnesium chloride, and to be stable at pH 3.5. The virus was non-pathogenic for suckling mice, failed to agglutinate sheep and human "O" red blood cells, but agglutinated rhesus monkey erythrocytes at 4 °C. On the basis of these properties and those already known, it was suggested that SV4 virus be placed in the group Enteroviruses of lower animals.

The influence of acridine dyes and caffeine on recovery from ultraviolet damage in Eudorina elegans

1975 ◽  
Vol 21 (11) ◽  
pp. 1849-1854 ◽  
Author(s):  
C. L. Kemp ◽  
K. M. Malloy
Keyword(s):  
Dna Synthesis ◽  
Acridine Orange ◽  
Ultraviolet Light ◽  
Ultraviolet Irradiation ◽  
Repair Process ◽  
Repair System ◽  
Acridine Dyes ◽  
Dark Survival ◽  
High Doses ◽  
Ultraviolet Damage

Caffeine and the acridine dyes, acridine orange and acriflavine, were used to examine the repair potential in Eudorina elegans following ultraviolet irradiation. Acridines blocked photoreactivation primarily as a result of absorption of photoreactivating wavelengths, but acridines did not influence dark survival. Therefore, an acridine-sensitive excision–resynthesis–repair process is absent in Eudorina.Caffeine decreased both dark and light survival, the latter only after relatively high doses of ultraviolet light were used for inactivation. The caffeine-sensitive repair process appears to function most actively when the organisms are engaged in DNA synthesis, indicating that a postreplication–repair system exists in Eudorina. However, the data suggest that a repair system not associated with the DNA synthetic phases may also exist.

Cytoplasmic DNA and basic protein synthesis in Megalobatrachus davidianus oocytes

Development ◽  
1971 ◽  
Vol 26 (2) ◽  
pp. 271-283
Author(s):  
Y. C. Kong ◽  
I. F. Lau ◽  
W. L. Lam ◽  
C. M. Choy
Keyword(s):  
Protein Synthesis ◽  
Dna Synthesis ◽  
Dose Response ◽  
Dna Content ◽  
Active Site ◽  
Basic Protein ◽  
Basic Proteins ◽  
Biochemical Event ◽  
Cytoplasmic Dna

Mature Megalobatrachus oocytes contain 43 µg DNA per oocyte, as compared with 250 pg DNA in a hepatocyte of the same animal. Megalobatrachus oocytes respond to CdR treatment by an increased incorporation of [3H]lysine into basic proteins associated with ooplasmic particles, with an optimal CdR concentration at 2 mM. The nucleolus is the most active site of [3H]lysine incorporation. It is suggested that CdR-stimulated basic protein synthesis is a common biochemical event during amphibian oogenesis. The dose response to CdR treatment may be a function of the c-DNA content or c-DNA synthesis potential in the ooplasm.

Timing of nucleolar DNA replication in Amoeba proteus

1976 ◽  
Vol 22 (3) ◽  
pp. 521-530
Author(s):  
I. Minassian ◽  
L.G. Bell
Keyword(s):  
Electron Microscope ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Central Region ◽  
Thymidine Incorporation ◽  
Tritiated Thymidine ◽  
Amoeba Proteus ◽  
Electron Microscope Autoradiography ◽  
Microscope Autoradiography ◽  
G2 Phase

Light- and electron-microscope autoradiography have been used to follow the incorporation of [3H]thymidine at different stages during the interphase of synchronously growing populations of Amoeba proteus. Two main patterns were found for tritiated thymidine incorporation, i.e. DNA synthesis. The major incorporation was in the central region of the nucleus, but a lesser degree of incorporation occurred in the nucleolar region. The bulk of this nucleolar DNA was found to be late replicating, i.e. it replicated during the G2 phase.

Sign in / Sign up

Export Citation Format

Share Document