Relationship between nucleoside triphosphate pools and DNA replication in the cell cycle of Escherichia coli

1974 ◽  
Vol 20 (5) ◽  
pp. 747-750 ◽  
Author(s):  
George G. Khachatourians ◽  
Lydia Huzyk
Keyword(s):  
Escherichia Coli ◽  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Specific Inhibitor ◽  
Replication Cycle ◽  
Nucleoside Triphosphate ◽  
E Coli ◽  
Synchronous Cultures ◽  
Inhibition Of Dna Synthesis

The correlation between DNA replication and the nucleoside triphosphate pool fluctuation in the cell cycle of Escherichia coli B/r was examined. 32P-labelled endogenous nucleoside triphosphates in normal synchronous cultures of E. coli B/r and those in which the chromosome replication cycle was inhibited by nalidixic acid, a specific inhibitor of DNA synthesis, were compared. No marked accumulation or depletion of nucleoside triphosphate pools was observed during the inhibition of DNA synthesis in the cell cycle. We suggest that changes in the pool levels during the cell cycle of E. coli occur independently of the DNA replication cycle.

scholarly journals Effect of inhibition of DNA synthesis on u.v. sensitive Bs strains ofEscherichia coli

1969 ◽  
Vol 14 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Michael H. L. Green ◽  
John Donch ◽  
Young S. Chung ◽  
Joseph Greenberg
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Dna Synthesis ◽  
Nalidixic Acid ◽  
Specific Inhibitor ◽  
Ofescherichia Coli ◽  
Inhibition Of Dna Synthesis ◽  
Division Mechanism

The effect of nalidixic acid, a specific inhibitor of DNA synthesis, onEscherichia colistrain B (lon) and its u.v.-sensitive derivatives is examined. Strain B itself is sensitive to nalidixic acid, whereas its u.v.-resistant derivative B/r is resistant.It is shown that in allexr Astrains, in which u.v.-induced filamentation is suppressed, resistance to nalidixic acid is increased. Amongexr Astrains, Bs4 is exceptionally resistant to nalidixic acid. This is because nalidixic acid kills only growing cells and strain Bs4, atryauxotroph, may grow poorly under the conditions used to test nalidixic acid.Theuvrgenes of the HCR strains Bs1, Bs8 and Bs12 do not suppress u.v.-induced filamentation nor do they affect the response to nalidixic acid. Theuvrgene of strain Bs3 is unusual in increasing the tendency to filament and also sensitivity to nalidixic acid.Strains Bs1, Bs3 and Bs8 are all doubly mutated from strain B, the second mutation (notuvr) being responsible for their increased resistance to nalidixic acid as well as partially or completely suppressing filamentation.It is concluded that the cell division mechanism of (lon) strain B is sensitive to inhibition of DNA synthesis. Mutations which suppress the tendency of strain B to filament reduce its sensitivity to inhibition of DNA synthesis.

Effect of inhibitors of DNA replication on early zebrafish embryos: evidence for coordinate activation of multiple intrinsic cell-cycle checkpoints at the mid-blastula transition

Zygote ◽  
1997 ◽  
Vol 5 (2) ◽  
pp. 153-175 ◽  
Author(s):  
Richard Ikegami ◽  
Alma K. Rivera-Bennetts ◽  
Deborah L. Brooker ◽  
Thomas D. Yager
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Adaptive Response ◽  
Topoisomerase I ◽  
Topoisomerase Ii ◽  
Cell Cycle Checkpoints ◽  
Zebrafish Embryos ◽  
Replication Process ◽  
Inhibition Of Dna Synthesis

SummaryWe address the developmental activation, in the zebrafish embryo, of intrinsic cell-cycle checkpoints which monitor the DNA replication process and progression through the cell cycle. Eukaryotic DNA replication is probably carried out by a multiprotein complex containing numerous enzymes and accessory factors that act in concert to effect processive DNA synthesis (Applegren, N. et al. (1995) J. Cell. Biochem. 59, 91–107). We have exposed early zebrafish embryos to three chemical agents which are predicted to specifically inhibit the DNA polymerase α, topoisomerase I and topoisomerase II components of the DNA replication complex. We present four findings: (1) Before mid-blastula transition (MBT) an inhibition of DNA synthesis does not block cells from attempting to proceed through mitosis, implying the lack of functional checkpoints. (2) After MBT, the embryo displays two distinct modes of intrinsic checkpoint operation. One mode is a rapid and complete stop of cell division, and the other is an ‘adaptive’ response in which the cell cycle continues to operate, perhaps in a ‘repair’ mode, to generate daughter nuclei with few visible defects. (3) The embryo does not display a maximal capability for the ‘adaptive’ response until several hours after MBT, which is consistent with a slow rranscriptional control mechanism for checkpoint activation. (4) The slow activation of checkpoints at MBT provides a window of time during which inhibitors of DNA synthesis will induce cytogenetic lesions without killing the embryo. This could be useful in the design of a deletion-mutagenesis strategy.

scholarly journals Effect of inhibition of DNA synthesis on mating inEscherichia coliK12

1965 ◽  
Vol 6 (3) ◽  
pp. 479-483 ◽  
Author(s):  
Susan Hollom ◽  
R. H. Pritchard
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Amino Acid Starvation ◽  
The Other ◽  
Thymine Starvation ◽  
Other Hand ◽  
Inhibition Of Dna Synthesis ◽  
Polynucleotide Chain

From studies involving inhibition of DNA synthesis in Hfr strains ofEscherichia coliK12, either by thymine starvation (Pritchard, 1963) or amino-acid starvation (Suit, Matney, Doudney & Billen, 1964), during mating withF−strains, it has been concluded that transfer of DNA from males to females can occur in the absence of DNA synthesis. This conclusion is at variance with the hypothesis (Jacob, Brenner & Cuzin, 1963) that the energy required for transfer is derived from the process of DNA replication. On the other hand, a second prediction from this hypothesis, that one polynucleotide chain of the DNA transferred during mating will have been synthesized during transfer, is strongly supported by recent experiments (Ptashne, 1965; Blinkova, Bresler & Lanzov, 1965; Gross & Caro, 1965).

scholarly journals Differential Effects of Myeloperoxidase-Derived Oxidants on Escherichia coli DNA Replication

1998 ◽  
Vol 66 (6) ◽  
pp. 2655-2659 ◽  
Author(s):  
Henry Rosen ◽  
Bryce R. Michel ◽  
Donald R. vanDevanter ◽  
James P. Hughes
Keyword(s):  
Escherichia Coli ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Dna Sequences ◽  
Regression Line ◽  
Chromosomal Dna ◽  
Chloride System ◽  
E Coli ◽  
Total Dna ◽  
Cell Envelopes

ABSTRACT The microbicidal myeloperoxidase (MPO)-H2O2-chloride system strongly inhibitsEscherichia coli DNA synthesis. Also, cell envelopes from MPO-treated E. coli cells lose their ability to interact with hemimethylated DNA sequences of oriC, the chromosomal origin of replication, raising the prospect that suppression of DNA synthesis involves impairment of oriC-related functions (H. Rosen, et al. Proc. Natl. Acad. Sci. USA, 87:10048–10052, 1990). To evaluate whether origin-specific DNA sequences play a role in the MPO effect on E. coli DNA synthesis, plasmid DNA replication was compared to total (chromosomal) DNA replication for six plasmids with three distinct origins of replication. Plasmid pCM700 replication, replicating from oriC, was as sensitive to MPO-mediated inhibition as was total (chromosomal) DNA replication. A regression line describing this relationship had a slope of 0.90, and ther 2 was 0.89. In contrast, the replication activities of three of four non-oriC plasmids, pUC19, pACYC184, and pSC101, demonstrated significant early resistance to inhibition by MPO-derived oxidants. The exception to this resistance pattern was plasmid pSP102, which has an origin derived from P1 phage. pSP102 replication declined similarly to that of total DNA synthesis. The regression line for pSP102 replication versus total DNA synthesis had a slope of 0.95, and the r 2 was 0.92. The biochemical requirements for P1-mediated replication are strikingly similar to those for oriC-mediated replication. It is proposed that one of these requirements, common to oriC and the P1 origin but not critical to the replication of the other non-oriC plasmids, is an important target for MPO-mediated oxidations that mediate the initial decline in E. colichromosomal DNA synthesis.

THE CHARACTERISTICS AND GENETIC MAP LOCATION OF A TEMPERATURE SENSITIVE DNA MUTANT OF E. COLI K12

Genetics ◽  
1972 ◽  
Vol 72 (4) ◽  
pp. 569-593
Author(s):  
Beverly Wolf
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Chain Elongation ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Bacterial Dna ◽  
E Coli ◽  
Dna Chain ◽  
Inhibition Of Dna Synthesis ◽  
Dna Mutant

ABSTRACT A temperature sensitive strain of E. coli K12 has been isolated in which residual DNA synthesis occurs at the 40°C restrictive temperature; syntheses of RNA, protein and DNA precursors are not directly affected. The mutation has been designated dna-325 and is located at 89 min on the E. coli map in the same region where the dnaC locus is found. dnaC mutants are considered to be defective in DNA initiation. Some of the data are consistent with the view that the dna-325 mutation is temperature sensitive in the process of DNA initiation rather than DNA chain elongation: (1) more than two cell divisions occur after a shift to 40°C; (2) upon a shift down to 30°C, cell division occurs again only after the DNA content of the cells has doubled; (3) 80% more DNA is made at 30°C in the presence of chloramphenicol after prior inhibition of DNA synthesis at 40°C. These three observations indicate that rounds of DNA replication were completed at 40°C. Also (4) infective λ particles can be made at 40°C long after bacterial DNA replication has ceased. It appears however that some DNA initiation can occur at 40°C since (1) a limited amount of DNA synthesis does occur at 40°C after prior alignment of the chromosomes by amino acid starvation at 30°C, and (2) after incubation in bromouracil at the restrictive temperature, heavy DNA is found with both strands containing bromouracil.

scholarly journals Correlation between DNA synthesis in the second, third and fourth generations of spermatogonia and the occurrence of apoptosis in both spermatogonia and spermatocytes

Reproduction ◽  
2003 ◽  
pp. 661-668 ◽  
Author(s):  
J Blanco-Rodriguez ◽  
C Martinez-Garcia ◽  
A Porras
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Functional Significance ◽  
Tunel Assay ◽  
Seminiferous Epithelium ◽  
Cell Cycle Checkpoints ◽  
Clear Correlation ◽  
Cellular Events ◽  
Dna Strand

In the seminiferous epithelium, both DNA synthesis and apoptosis occur at equivalent stages in various species, with apoptosis taking place mainly at the same stages as DNA replication in the second, third and fourth spermatogonial generations. As preservation of the cellular associations found at these stages may have some functional significance, it is important to determine whether there is a correlation between these cellular events. In this study, pairs of immunoperoxidase-stained adjacent testis sections from rats, mice, rabbits and cats in which either bromodeoxyuridine incorporated into the newly synthesized DNA strand (BrdU labelling) or DNA 3' end labelling of the apoptotic DNA fragments (TUNEL assay) were detected were compared. In addition, both events were analysed in double-labelled sections. These two methods revealed a clear correlation between the occurrence of DNA replication in the second to fourth generations of spermatogonia and most physiological apoptosis taking place in both spermatogonia and spermatocytes in the three different mammalian orders (Rodentia, Lagomorpha and Carnivora). This correlation may result from the synchronization of mitotic spermatogonial and meiotic spermatocyte cell cycle checkpoints operating at these stages.

Oxygen uptake during the cell cycle of the fission yeast Schizosaccharomyces pombe

1978 ◽  
Vol 33 (1) ◽  
pp. 399-411
Author(s):  
J. Creanor
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Oxygen Uptake ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Nuclear Division ◽  
Synchronous Culture ◽  
Synchronous Cultures ◽  
The Many

Oxygen uptake was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe. The rate of oxygen uptake was found to increase in a step-wise manner at the beginning of the cycle and again in the middle of the cycle. The increases in rate were such that overall, oxygen uptake doubled in rate once per cell cycle. Addition of inhibitors of DNA synthesis or nuclear division to a synchronous culture did not affect the uptake of oxygen. In an induced synchronous culture, in which DNA synthesis, cell division, and nuclear division, but not ‘growth’ were synchronized, oxygen uptake increased continuously in rate and did not show the step-wise rises which were shown in the selection-synchronized culture. These results were compared with previous measurements of oxygen uptake in yeast and an explanation is suggested for the many different patterns which have been reported.

A Comparison of the Effects of Endotoxin Upon Fibroblast Proliferation and Macromolecular Syntheses

1979 ◽  
Vol 58 (6) ◽  
pp. 1634-1639 ◽  
Author(s):  
R.E. Singer ◽  
W.G. Dutton
Keyword(s):  
Escherichia Coli ◽  
Cell Proliferation ◽  
Protein Synthesis ◽  
Dna Synthesis ◽  
L929 Cell ◽  
Cell Protein ◽  
Fibroblast Proliferation ◽  
Proline Incorporation ◽  
Inhibition Of Dna Synthesis

The effects of Escherichia coli endotoxin upon mouse L929 cell proliferation, DNA synthesis, protein synthesis, and proline incorporation were determined. It was found that a level of endotoxin which inhibited cell proliferation prompted a similar inhibition of DNA synthesis and overall cell protein synthesis. In contrast, endotoxin was shown to inhibit incorporation of proline into cell protein to a significantly greater extent.

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