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.

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.

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.

scholarly journals The effect of CO2 on the timing of cell cycle events in fission yeast Schizosaccharomyces pombe

1988 ◽  
Vol 89 (3) ◽  
pp. 433-439
Author(s):  
B. NOVÁK ◽  
J. HALBAUER ◽  
E. LÁSZLÓ
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Co2 Production ◽  
Complete Medium ◽  
Co2 Removal ◽  
Wild Type ◽  
In The Wild ◽  
G2 Phase

The effect of CO2 removal on the cell cycle phases of Schizosaccharomyces pombe has been examinedin minimal, aspartate-containing and complete medium. The removal of CO2 shortened the G2 phase of the cell cycle and arrested the cells in G1 phase in minimal medium. The G1 block caused by CO2 deprivation was demonstrated by transition-point and flow-cytometry analyses. The slow-down of anapleurotic CO2 fixation might be responsible for this effect, as aspartic acid could abolish the G1 block. The shortening of G2 phase in the wild-type cells was observed in every medium irrespective of whether the growth rate was changed or not. The experiments in which growth rate was not changed by CO2 shift-down suggest that this CO2 effect can be independent from its action on CO2-fixing steps in metabolism. Therefore we propose that CO2 inhibits mitosis infission yeast and we explain the proportionality between growth rate and cell size at mitosis found by Fantes & Nurse by this CO2 inhibition. The larger CO2 production in fast-growing cells leads to a higher CO2 concentration, which could exerta stronger inhibition of mitosis. A wee mutant, which has lost its mitotic size control, also shows the G1 block after CO2 deprivation, but its mitosis is insensitive to CO2. Comparing the respiration of wee and wild-type cells we conclude that CO2 inhibits the citric acid cycle in the wild type. The consequence of these results in the regulation of fission yeast cell cycle is discussed.

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.

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.

Changes in the Activity of Alcohol Dehydrogenase During the Cell Cycle of the Fission Yeast Schizosaccharomyces Pombe

1991 ◽  
Vol 99 (1) ◽  
pp. 193-199
Author(s):  
J. VICENTE-SOLER ◽  
J. CREANOR ◽  
Y. BISSET ◽  
J. M. MITCHISON
Keyword(s):  
Cell Cycle ◽  
Alcohol Dehydrogenase ◽  
Schizosaccharomyces Pombe ◽  
Rate Change ◽  
Co2 Production ◽  
Activity Increase ◽  
Normal Cycle ◽  
Linear Pattern ◽  
Synchronous Cultures ◽  
Coordinate Control

The activity of alcohol dehydrogenase (ADHase) was followed in synchronous cultures of Schizosaccharomyces pombe. In selection synchronised cultures of wild-type cells, it followed a linear pattern in which there was a constant rate of increase of activity followed by a doubling of this rate at the end of the cycle. The same pattern was also found in selection synchronised cells of wee mutants except that the point of rate change was shifted to 0.27 of the cycle. A similar linear pattern was also found in the shortened cell cycles produced by induction synchrony (block and release of the mutant cdc2.33) but the rate change point was at about 0.75 of the cycle. In the mutant cdcl3.117, there was a marked fall in the rate of activity increase at 35°C but not at 37°C. In all these situations, the ADHase activity closely paralleled in pattern and in timing the rate of production of CO2 established in earlier papers. This suggests a coordinate control of the flux through glycolysis and the activity of the last enzyme in the glycolytic pathway in yeast. However, an interesting difference indicating a loss of the coordinate control occurred in ‘synchronous’ cultures of cdc2.33 in which small cells had been selected but in which the DNAdivision cycle had been blocked by a shift-up to the restrictive temperature. Rate changes both in CO2 production and in ADHase activity continued in these blocked synchronous cultures but the timing was different. With ADHase activity the timing was 15% greater than that in a normal cell cycle whereas with CO2 production it was 15% less. We suggest that these and other periodic events are subject to independent oscillatory controls in these blocked cultures with timings that differ from each other and from the normal cycle but in the normal cycle the oscillators are all entrained by one or more events of the DNA-division 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 cell cycle genes cdc22 + and suc22 + of the fission yeast Schizosaccharomyces pombe encode the large and small subunits of ribonucleotide reductase

1993 ◽  
Vol 238-238 (1-2) ◽  
pp. 241-251 ◽  
Author(s):  
Maria-Jose Fernandez Sarabia ◽  
Christopher McInerny ◽  
Pamela Harris ◽  
Colin Gordon ◽  
Peter Fantes
Keyword(s):  
Cell Cycle ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Ribonucleotide Reductase ◽  
Cell Cycle Genes
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