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.

Carbon dioxide evolution during the cell cycle of the fission yeast Schizosaccharomyces pombe

1978 ◽  
Vol 33 (1) ◽  
pp. 385-397
Author(s):  
J. Creanor
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Nuclear Division ◽  
Complete Medium ◽  
Co2 Evolution ◽  
Carbon Dioxide Evolution ◽  
Synchronous Cultures ◽  
Constant Addition

The rate of CO2 evolution was measured in synchronous cultures of the fission yeast Schizosaccharomyces pombe growing in a minimal medium. The rate of CO2 evolution was found to double sharply at about the time of nuclear division (0.75 of the way through the cell cycle). For the remainder of the cell cycle the rate remained constant. Addition of inhibitors of DNA synthesis or nuclear division did not affect the pattern of CO2 evolution in synchronous cultures. Similarly, in an induced synchronous culture, in which DNA synthesis, nuclear division and cell division—but not growth, were synchronized, CO2 evolution showed a continuous pattern and not the step-wise increase associated with the normal synchronous cultures. When S. pombe was grown in a complete medium, the evolution of CO2 in a synchronous cultures was shown to increase in a continuous manner but at a rate faster than the growth of the culture.

Rates of synthesis of polyadenylated messenger RNA and ribosomal RNA during the cell cycle of Schizosaccharomyces pombe. With an appendix: calculation of the pattern of protein accumulation from observed changes in the rate of messenger RNA synthesis

1976 ◽  
Vol 21 (3) ◽  
pp. 497-521
Author(s):  
R.S. Fraser ◽  
F. Moreno
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Ribosomal Rna ◽  
Messenger Rna ◽  
Rna Synthesis ◽  
Protein Accumulation ◽  
Synchronous Culture ◽  
Synchronous Cultures ◽  
Gene Copies

The rates of polyadenylated messenger RNA and ribosomal RNA synthesis were measured in synchronously dividing cultures of fission yeast (Schizosaccharomyces pombe). Control asynchronous cultures, which had been exposed to the conditions used for preparing synchronous cultures, were investigated to check for effects of the synchronization procedure itself on RNA synthesis. After each period of DNA synthesis in synchronous culture, the rates of messenger and ribosomal RNA synthesis doubled, suggesting that gene number controls the rate of messenger and ribosomal RNA synthesis. This was confirmed by experiments with asynchronous, exponential-phase cultures in which DNA synthesis was inhibited by hydroxyurea. Both synchronous culture and hydroxyurea experiments suggested that there is a delay of 15 min (0-1 of the cell generation time) between replication of the DNA and transcription of both gene copies. A pattern of protein accumulation was calculated from changes in the rate of polyadenylated messenger RNA synthesis during synchronous culture. The simulated pattern indicates that protein is accumulated linearly, with a doubling in the rate of accumulation once per cell cycle. The simulated pattern of protein accumulation is very similar to measurements previously reported by other workers of changes in activities of 3 enzymes in synchronous cultures. It is suggested that the doubling of the rate of messenger RNA synthesis, as a consequence of the replication of the DNA once per cycle, provides the basis of a mechanism for control of the doubling of other cellular constituents during the cell cycle.

Protein synthesis and its relation to the DNA-division cycle in the fission yeast Schizosaccharomyces pombe

1984 ◽  
Vol 69 (1) ◽  
pp. 199-210
Author(s):  
J. Creanor ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Protein Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Protein Content ◽  
Fission Yeast ◽  
Nuclear Division ◽  
Restrictive Temperature ◽  
Tentative Conclusion ◽  
Synchronous Cultures

The rate of protein synthesis has been measured with pulse labels of [3H]tryptophan in synchronous and asynchronous cultures of cdc mutants of Schizosaccharomyces pombe shifted up to the restrictive temperature. The cell cycle related fluctuations in rate that occur in normal synchronous cultures vanish when nuclear division is blocked in synchronous cultures of cdc2 and cdc10. But they persist in cdc11 where nuclear division continues and cleavage is stopped. We conclude that nuclear division affects the rate of synthesis and that this effect is inhibitory and probably persists for the last 40% of the cycle. When nuclear division has been blocked, the rate of synthesis continues to increase until a plateau is reached where the rate remains constant. Three size mutants of cdc2 reach the plateau at the same average protein content per cell although their initial protein contents vary over a threefold range. Comparison of these results with those from cdc10 leads to the tentative conclusion that the plateau starts when the cells reach a critical protein/DNA ratio.

Changes in the rate of oxygen consumption in synchronous cultures of the fission yeast Schizosaccharomyces pombe

1990 ◽  
Vol 96 (3) ◽  
pp. 429-433
Author(s):  
B. Novak ◽  
J.M. Mitchison
Keyword(s):  
Cell Cycle ◽  
Oxygen Consumption ◽  
Oxygen Uptake ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Oxygen Electrode ◽  
Co2 Production ◽  
Synchronous Cultures ◽  
Rate Of Oxygen Consumption

Oxygen consumption was measured with an oxygen electrode in synchronous cultures of S. pombe. There were changes during the cell cycle in the rate of oxygen uptake, which are most clearly shown as oscillations in acceleration curves (rate of the rate of uptake). Under various conditions of selection and induction synchrony the acceleration curves are similar to those found earlier for CO2 production. As with CO2 production, the oscillations continued after a block to the DNA-division cycle. There were, however, two differences between oxygen uptake and CO2 production. The oxygen oscillations were more marked and also were out of phase by half a cycle. The respiratory coefficient therefore changes through the cycle.

Overexpression Phenotypes of Plk1 and Ndrg2 in Schizosaccharomyces Pombe: Fission Yeast System for Mammalian Gene Study

2005 ◽  
Vol 277-279 ◽  
pp. 1-6 ◽  
Author(s):  
Young Joo Jang ◽  
Young Sook Kil ◽  
Jee Hee Ahn ◽  
Jae Hoon Ji ◽  
Jong Seok Lim ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Rna Splicing ◽  
Mammalian Cells ◽  
Protein Modification ◽  
Genetic System ◽  
Functional Study ◽  
Mammalian Genes

The fission yeast, Schizosaccharomyces pombe is a single-celled free-living fungus that shares many features with cells of more complicated eukaryotes. Many of the genes required for the cell-cycle control, proteolysis, protein modification, and RNA splicing are highly conserved with those of higher eukaryotes. Moreover, fission yeast has the merit of genetics and its genetic system is already well characterized. As such, the current study evaluated the use of a fission yeast system as a tool for the functional study of mammalian genes and attempted to set up an assay system for novel genes. Since the phenotypes of a deletion mutant and the overexpression of a gene are generally analyzed for a functional study of specific genes in yeast, the present study used overexpression phenotypes to study the functions of mammalian genes. Therefore, based on using a thiamine-repressive promoter, two mammalian genes were expressed in fission yeast, and their overexpressed phenotypes compared with those in mammalian cells. The phenotypes resulting from overexpression were analyzed using a FACS, which analyzes the DNA contents, and a microscope. One of the selected genes was the mammalian Polo-like kinase 1 (Plk1), which is activated and plays a role in the mitotic phase of the cell division cycle. The overexpression of various constructs of Plk1 in the HeLa cells caused cell cycle defects, suggesting that the ectopic Plk1s blocked the endogenous Plk1 in the cells. As expected, when the constructs were overexpressed in the fission yeast system, the cells were arrested in mitosis and defected at the end of mitosis. As such, this data suggests that the Plk1-overexpressed phenotypes were similar in the mammalian cells and the fission yeast, thereby enabling the mammalian Plk1 functions to be approximated in the fission yeast. The other selected gene was the N-Myc downstream-regulated gene 2 (ndrg2), which is upregulated during cell differentiation, yet still not well characterized. When the ndrg2 gene was overexpressed in the fission yeast, the cells contained multi-septa. The septa were positioned well, yet their number increased per cell. Therefore, this gene was speculated to block cell division in the last stage of the cell cycle, making the phenotype potentially useful for explaining cell growth and differentiation in mammalian cells. Accordingly, fission yeast is demonstrated to be an appropriate species for the functional study of mammalian genes.

The Effect of 2-Phenyl Ethanol on the DNA Synthesis Cycle of Schizosaccharomyces Pombe

1970 ◽  
Vol 7 (2) ◽  
pp. 523-530
Author(s):  
C. J. BOSTOCK
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Normal Growth ◽  
S Phase ◽  
G1 Phase ◽  
Synchronous Cultures ◽  
Number Of Cells

The effect of different concentrations of 2-phenyl ethanol (PE) on growth and DNA synthesis of Schizosaccharomyces pombe is described. o.3% PE inhibits the entry of cells into S phase, but allows a doubling in the number of cells in the culture. The effect of o.2% PE on random and synchronous cultures of S. pombe shows that, in the continued presence of the inhibitor, the S phase is moved to a different point in the cell cycle. Cells continue to grow in the presence of o.2% PE with a G1 phase occupying a significant portion of the cell cycle. This differs from normal growth when the G1 phase is absent.

Arginase and sucrase potential in the fission yeast Schizosaccharomyces pombe

1980 ◽  
Vol 46 (1) ◽  
pp. 399-431
Author(s):  
T. Benitez ◽  
P. Nurse ◽  
J.M. Mitchison
Keyword(s):  
Dna Replication ◽  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Gene Dosage ◽  
Critical Ratio ◽  
Restrictive Temperature ◽  
Wild Type ◽  
Synchronous Cultures ◽  
Short Period

The induction potentials of 2 enzymes, sucrase and arginase, have been measured in asynchronous and synchronous cultures of the fission yeast Schizosaccharomyces pombe. The effect on potential of inhibiting DNA synthesis is asynchronous cultures has been studied using 2 temperature-sensitive dcd mutants, one blocked in DNA replication and the other blocked in mitosis. The results show that despite inhibition of DNA synthesis, sucrase and arginase potential both continue to increase exponentially for at least a generation of growth after shifting the cdc mutants from the permissive to the restrictive temperature. A second method of inhibiting DNA synthesis, using deoxyadenosine, has also been tested. Cells treated with deoxyadenosine stop the increase in potential for a short period. However, experiments carried out using a cdc mutant together with deoxyadenosine show that the block to the increase in potential is due to a side effect of the inhibitor. It appears that increase in potential is not dependent upon continued DNA replication, and that gene dosage does not control potential in the normal cell cycle. This conclusion is supported by measurements on mutants of different cell sizes. potential is proportional to size (protein content per cell is asynchronous culture) and not to DNA content. Although potential is not gene limited in normal cells, it does appear to be so in the abnormally large cells produced by a cdc block. If cdc mutants of different sizes are grown asynchronously, and DNA synthesis is inhibited by a shift to the restrictive temperature, there is no increase in potential. This critical ratio is different for the 2 enzymes, but for each enzyme it is similar in all the mutants tested. When large cells (produced by a mutant block for 4.5 h) are shifted down in temperature, there are synchronous rounds of DNA synthesis and division and also step doublings in potential. In synchronous cultures of wild type cells, both enzymes show a stepwise doubling of potential at 0.2 of a cycle after DNA replication. In synchronous cultures of cdc mutants blocked either in replication or in mitosis, the potential steps continue with the normal timing observed in wild type cells. This shows that the steps are not dependent on the events of the DNA-division cycle but are controlled by another mechanism. Attainment of a critical size might be part of this mechanism, but tests with size mutants argue against this.

scholarly journals Mitochondrial adenosine triphosphatase of the fission yeast, Schizosaccharomyces pombe 972h−. Changes in activity and oligomycin-sensitivity during the cell cycle of catabolite-repressed and -de-repressed cells

1977 ◽  
Vol 162 (1) ◽  
pp. 39-46 ◽  
Author(s):  
S W Edwards ◽  
D Lloyd
Keyword(s):  
Cell Cycle ◽  
Atpase Activity ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Adenosine Triphosphatase ◽  
Total Activity ◽  
Stages Of Growth ◽  
Synchronous Cultures ◽  
A Cell ◽  
In Cells

1. Changes in activity of ATPase (adenosine triphosphatase) during the cell cycle of Schizosaccharomyces pombe were analysed in cell-free extracts of cells harvested from different stages of growth of synchronous cultures and also after cell-cycle fractionation. 2. Oligomycin-sensitive ATPase oscillates in both glucose-repressed synchronous cultures and shows four maxima of activity approximately equally spaced through the cell cycle. The amplitude of the oscillations accounts for between 13 and 80% of the total activity at different times in the cell cycle. 3. Oligomycin sensitivity varies over a fourfold range at different stages of the cell cycle. 4. The periodicity of maximum oligomycin sensitivity is one-quarter of a cell cycle. 5. These results were confirmed for the first three-quarters of the cell cycle by cell-cycle fractionation. 6. In cells growing synchronously with glycerol, ATPase activity increases in a stepwise pattern, with two steps per cell cycle; the first of these occurs at 0.54 of the cell cycle and the second at 0.95. 7. These results are discussed in relation to previously obtained data on the development of mitochondrial activities during the cell cycle.

scholarly journals The Schizosaccharomyces pombe cdc14 gene is required for septum formation and can also inhibit nuclear division.

1993 ◽  
Vol 4 (5) ◽  
pp. 531-539 ◽  
Author(s):  
C Fankhauser ◽  
V Simanis
Keyword(s):  
Cell Cycle ◽  
Amino Acids ◽  
Cell Division ◽  
Schizosaccharomyces Pombe ◽  
Cell Cycle Arrest ◽  
Null Allele ◽  
Nuclear Division ◽  
Septum Formation ◽  
Cycle Arrest ◽  
Mitotic Inhibitor

A conditional heat-sensitive mutation in the cdc14 gene of the fission yeast Schizosaccharomyces pombe results in failure to form a septum. Cells become highly elongated and multinucleate as growth and nuclear division continue in the absence of cell division. This article describes the cloning of the cdc14 gene and the identification of its product, a protein of 240 amino acids, p28cdc14. A null allele of the cdc14 gene shows that the gene is essential for septum formation and completion of the cell-division cycle. Overexpression of the gene product, p28cdc14, causes cell-cycle arrest in late G2 before mitosis. Cells leaking past the block activate p34cdc2 kinase and show condensed chromosomes, but the normal rearrangements of the microtubules and microfilaments that are associated with the transition from interphase to mitosis do not occur. Overexpression of p28cdc14 in mutants, in which the timing of mitosis is altered, suggests that these effects may be mediated upstream of the mitotic inhibitor wee1. These data are consistent with the idea that p28cdc14 may play a role in both the initiation of mitosis and septum formation and, by doing so, be part of the mechanism that coordinates these two cell-cycle events.

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