Germ-Tube Formation is Independent of DNA Synthesis during Spore Germination in the Fission Yeast, Schizosaccharomyces pombe

1982 ◽  
Keyword(s):  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Spore Germination ◽  
Germ Tube ◽  
Tube Formation

Differential effect of glucose and fructose on spore germination in the fission yeast, Schizosaccharomyces pombe

1980 ◽  
Vol 26 (7) ◽  
pp. 741-745 ◽  
Author(s):  
Chikashi Shimoda
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Spore Germination ◽  
Vegetative Growth ◽  
Nutrient Medium ◽  
Germ Tube ◽  
Glucose Solution ◽  
Tube Formation ◽  
Exogenous Glucose ◽  
Almost All ◽  
Effect Of Glucose

Germination of isolated spores of Schizosaccharomyces pombe, measured by loss of refractility and of resistance to ethanol, was induced in a simple solution of glucose. The subsequent outgrowth steps (swelling and germ-tube formation), however, did not occur in the glucose solution. Normal outgrowth required almost all nutrients essential to vegetative growth. Germination was also induced by sucrose and mannose but only weakly by fructose. Glucose-germinated spores normally outgrew in the fructose-containing nutrient medium. Generation of CO2 from exogenous fructose by ungerminated spores was only 10% of that from exogenous glucose. These facts suggested that ungerminated spores were defective in the ability to utilize fructose and that germinated spores acquired this ability.

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.

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.

The POL1 and POL3 DNA Synthesis Genes in Fission Yeast Schizosaccharomyces pombe

1992 ◽  
pp. 261-271 ◽  
Author(s):  
G. Baldacci ◽  
D. Bouvier ◽  
V. Damagnez ◽  
G. Pignède ◽  
A-M. de Recondo
Keyword(s):  
Dna Synthesis ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast

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.

scholarly journals Spore Germination Requires Ferrichrome Biosynthesis and the Siderophore Transporter Str1 in Schizosaccharomyces pombe

Genetics ◽  
2019 ◽  
Vol 211 (3) ◽  
pp. 893-911 ◽  
Author(s):  
Samuel Plante ◽  
Simon Labbé
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Spore Germination ◽  
Germ Tube ◽  
Expression Profiles ◽  
Mitotic Cell ◽  
External Source ◽  
Spore Wall ◽  
Amino Acid Residues ◽  
Loop Region ◽  
Timely Completion

Spore germination is a process whereby spores exit dormancy to become competent for mitotic cell division. In Schizosaccharomyces pombe, one critical step of germination is the formation of a germ tube that hatches out the spore wall in a stage called outgrowth. Here, we show that iron deficiency blocks the outgrowth of germinating spores. The siderophore synthetase Sib1 and the ornithine N5-oxygenase Sib2 participate in ferrichrome biosynthesis, whereas Str1 functions as a ferrichrome transporter. Expression profiles of sib1+, sib2+, and str1+ transcripts reveal that they are induced shortly after induction of germination and their expression remains upregulated throughout the germination program under low-iron conditions. sib1Δ sib2Δ mutant spores are unable to form a germ tube under iron-poor conditions. Supplementation with exogenous ferrichrome suppresses this phenotype when str1+ is present. Str1 localizes at the contour of swollen spores 4 hr after induction of germination. At the onset of outgrowth, localization of Str1 changes and it moves away from the mother spore to primarily localize at the periphery of the new daughter cell. Two conserved Tyr residues (Tyr553 and Tyr567) are predicted to be located in the last extracellular loop region of Str1. Results show that these amino acid residues are critical to ensure timely completion of the outgrowth phase of spores in response to exogenous ferrichrome. Taken together, the results reveal the essential requirement of ferrichrome biosynthesis to promote outgrowth, as well as the necessity to take up ferrichrome from an external source via Str1 when ferrichrome biosynthesis is blocked.

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