scholarly journals Meiotic cohesins modulate chromosome compaction during meiotic prophase in fission yeast

2006 ◽  
Vol 174 (4) ◽  
pp. 499-508 ◽  
Author(s):  
Da-Qiao Ding ◽  
Nobuko Sakurai ◽  
Yuki Katou ◽  
Takehiko Itoh ◽  
Katsuhiko Shirahige ◽  
...  
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Meiotic Division ◽  
Meiotic Prophase ◽  
Living Cells ◽  
Chromosome Association ◽  
Wild Type ◽  
Chromatin Loops ◽  
Additional Role ◽  
Segregation Of Chromosomes

The meiotic cohesin Rec8 is required for the stepwise segregation of chromosomes during the two rounds of meiotic division. By directly measuring chromosome compaction in living cells of the fission yeast Schizosaccharomyces pombe, we found an additional role for the meiotic cohesin in the compaction of chromosomes during meiotic prophase. In the absence of Rec8, chromosomes were decompacted relative to those of wild-type cells. Conversely, loss of the cohesin-associated protein Pds5 resulted in hypercompaction. Although this hypercompaction requires Rec8, binding of Rec8 to chromatin was reduced in the absence of Pds5, indicating that Pds5 promotes chromosome association of Rec8. To explain these observations, we propose that meiotic prophase chromosomes are organized as chromatin loops emanating from a Rec8-containing axis: the absence of Rec8 disrupts the axis, resulting in disorganized chromosomes, whereas reduced Rec8 loading results in a longitudinally compacted axis with fewer attachment points and longer chromatin loops.

scholarly journals Nup132 modulates meiotic spindle attachment in fission yeast by regulating kinetochore assembly

2015 ◽  
Vol 211 (2) ◽  
pp. 295-308 ◽  
Author(s):  
Hui-Ju Yang ◽  
Haruhiko Asakawa ◽  
Tokuko Haraguchi ◽  
Yasushi Hiraoka
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Meiotic Prophase ◽  
Spindle Assembly Checkpoint ◽  
Meiotic Spindle ◽  
Spindle Attachment ◽  
Kinetochore Assembly ◽  
Sister Chromatids ◽  
Monopolar Spindle ◽  
Meiosis I

During meiosis, the kinetochore undergoes substantial reorganization to establish monopolar spindle attachment. In the fission yeast Schizosaccharomyces pombe, the KNL1–Spc7-Mis12-Nuf2 (KMN) complex, which constitutes the outer kinetochore, is disassembled during meiotic prophase and is reassembled before meiosis I. Here, we show that the nucleoporin Nup132 is required for timely assembly of the KMN proteins: In the absence of Nup132, Mis12 and Spc7 are precociously assembled at the centromeres during meiotic prophase. In contrast, Nuf2 shows timely dissociation and reappearance at the meiotic centromeres. We further demonstrate that depletion of Nup132 activates the spindle assembly checkpoint in meiosis I, possibly because of the increased incidence of erroneous spindle attachment at sister chromatids. These results suggest that precocious assembly of the kinetochores leads to the meiosis I defects observed in the nup132-disrupted mutant. Thus, we propose that Nup132 plays an important role in establishing monopolar spindle attachment at meiosis I through outer kinetochore reorganization at meiotic prophase.

scholarly journals Cell Surface Galactosylation Is Essential for Nonsexual Flocculation in Schizosaccharomyces pombe

1999 ◽  
Vol 181 (4) ◽  
pp. 1356-1359 ◽  
Author(s):  
Naotaka Tanaka ◽  
Atsuro Awai ◽  
M. Shah Alam Bhuiyan ◽  
Kiyotaka Fujita ◽  
Hiroshi Fukui ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Cell Surface ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Wild Type ◽  
Liquid Media ◽  
Calcium Dependent ◽  
Yeast Mutants

ABSTRACT We have isolated fission yeast mutants that constitutively flocculate upon growth in liquid media. One of these mutants, thegsf1 mutant, was found to cause dominant, nonsexual, and calcium-dependent aggregation of cells into flocs. Its flocculation was inhibited by the addition of galactose but was not affected by the addition of mannose or glucose, unlike Saccharomyces cerevisiae FLO mutants. The gsf1 mutant coflocculated withSchizosaccharomyces pombe wild-type cells, while no coflocculation was found with galactose-deficient (gms1Δ) cells. Moreover, flocculation of the gsf1 mutant was also inhibited by addition of cell wall galactomannan from wild-type cells but not from gms1Δ cells. These results suggested that galactose residues in the cell wall glycoproteins may be receptors ofgsf1-mediated flocculation, and therefore cell surface galactosylation is required for nonsexual flocculation in S. pombe.

Human p53 inhibits growth in Schizosaccharomyces pombe

1992 ◽  
Vol 12 (4) ◽  
pp. 1405-1411
Author(s):  
J R Bischoff ◽  
D Casso ◽  
D Beach
Keyword(s):  
Amino Acid ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Amino Acid Residue ◽  
Mechanism Of Action ◽  
Mammalian Cells ◽  
Simple System ◽  
Wild Type ◽  
Dominant Mutation ◽  
Mutant Forms

Overexpression of wild-type p53 in mammalian cells blocks growth. We show here that the overexpression of wild-type human p53 in the fission yeast Schizosaccharomyces pombe also blocks growth, whereas the overexpression of mutant forms of p53 does not. The p53 polypeptide is located in the nucleus and is phosphorylated at both the cdc2 site and the casein kinase II site in S. pombe. A new dominant mutation of p53, resulting in the change of a cysteine to an arginine at amino acid residue 141, was identified. The results presented here demonstrate that S. pombe could provide a simple system for studying the mechanism of action of human p53.

scholarly journals Intramitotic controls in the fission yeast Schizosaccharomyces pombe: the effect of cell size on spindle length and the timing of mitotic events.

1990 ◽  
Vol 110 (5) ◽  
pp. 1617-1621 ◽  
Author(s):  
I M Hagan ◽  
P N Riddle ◽  
J S Hyams
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Average Length ◽  
Nuclear Migration ◽  
Yeast Cells ◽  
Reverse Direction ◽  
Wild Type ◽  
Spindle Elongation ◽  
Anaphase B ◽  
In Cells

We have used a new cinemicroscopy technique in combination with antitubulin immunofluorescence microscopy to investigate the timing of mitotic events in cells of the fission yeast Schizosaccharomyces pombe having lengths at division between 7 and 60 microns. Wild-type fission yeast cells divide at a length of 14 microns. Separation of daughter nuclei (anaphase B) proceeds at a rate of 1.6 +/- 0.2 microns min-1, until the spindle extends the length of the cell. Coincident with spindle depolymerization, the nuclei reverse direction and take up positions that will become the center of the two daughter cells. This post-mitotic nuclear migration occurs at a rate of 1.4 +/- 0.5 microns-1. In cells in which the weel+ gene is overexpressed fivefold and that have an average length at mitosis of 28 microns, the rate of nuclear separation was only slightly reduced but, as spindles in these cells measure 20-22 microns, the duration of anaphase B was extended by approximately 40%. By contrast, in the mutant weel.50, which divides at 7 microns, both the rate and duration of anaphase B were indistinguishable from wild type. Nuclei reach the ends of these cells earlier but remain there until a point corresponding to the time of postmitotic nuclear migration in wild type. Thus, the events of mitosis can be extended but not abbreviated. These results are discussed in terms of a mitotic termination control that monitors many different events, one of which is spindle elongation.

scholarly journals Meiotic S-Phase Damage Activates Recombination without Checkpoint Arrest

2005 ◽  
Vol 16 (4) ◽  
pp. 1651-1660 ◽  
Author(s):  
Daniel G. Pankratz ◽  
Susan L. Forsburg
Keyword(s):  
Dna Damage ◽  
Fission Yeast ◽  
Meiotic Division ◽  
S Phase ◽  
Wild Type ◽  
Dna Breaks ◽  
Replication Checkpoint ◽  
Checkpoint Response ◽  
Homologous Chromosomes ◽  
Yeast Meiosis

Checkpoints operate during meiosis to ensure the completion of DNA synthesis and programmed recombination before the initiation of meiotic divisions. Studies in the fission yeast Schizosaccharomyces pombe suggest that the meiotic response to DNA damage due to a failed replication checkpoint response differs substantially from the vegetative response, and may be influenced by the presence of homologous chromosomes. The checkpoint responses to DNA damage during fission yeast meiosis are not well characterized. Here we report that DNA damage induced during meiotic S-phase does not activate checkpoint arrest. We also find that in wild-type cells, markers for DNA breaks can persist at least to the first meiotic division. We also observe increased spontaneous S-phase damage in checkpoint mutants, which is repaired by recombination without activating checkpoint arrest. Our results suggest that fission yeast meiosis is exceptionally tolerant of DNA damage, and that some forms of spontaneous S-phase damage can be repaired by recombination without activating checkpoint arrest.

scholarly journals Phosphatidylethanolamine Is Required for Normal Cell Morphology and Cytokinesis in the Fission Yeast Schizosaccharomyces pombe

2009 ◽  
Vol 8 (5) ◽  
pp. 790-799 ◽  
Author(s):  
Jun Luo ◽  
Yasuhiro Matsuo ◽  
Galina Gulis ◽  
Haylee Hinz ◽  
Jana Patton-Vogt ◽  
...  
Keyword(s):  
Cell Growth ◽  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Minimal Medium ◽  
Growth Media ◽  
Decarboxylase Activity ◽  
Rich Medium ◽  
Wild Type ◽  
Cellular Functions ◽  
Kennedy Pathway

ABSTRACT To investigate the contributions of phosphatidylethanolamine to the growth and morphogenesis of the fission yeast Schizosaccharomyces pombe, we have characterized three predicted genes in this organism, designated psd1, psd2, and psd3, encoding phosphatidylserine decarboxylases, which catalyze the conversion of phosphatidylserine to phosphatidylethanolamine in both eukaryotic and prokaryotic organisms. S. pombe mutants carrying deletions in any one or two psd genes are viable in complex rich medium and synthetic defined minimal medium. However, mutants carrying deletions in all three psd genes (psd1-3Δ mutants) grow slowly in rich medium and are inviable in minimal medium, indicating that the psd1 to psd3 gene products share overlapping essential cellular functions. Supplementation of growth media with ethanolamine, which can be converted to phosphatidylethanolamine by the Kennedy pathway, restores growth to psd1-3Δ cells in minimal medium, indicating that phosphatidylethanolamine is essential for S. pombe cell growth. psd1-3Δ cells produce lower levels of phosphatidylethanolamine than wild-type cells, even in medium supplemented with ethanolamine, indicating that the Kennedy pathway can only partially compensate for the loss of phosphatidylserine decarboxylase activity in S. pombe. psd1-3Δ cells appear morphologically indistinguishable from wild-type S. pombe cells in medium supplemented with ethanolamine, but when cultured in nonsupplemented medium, they produce high frequencies of abnormally shaped cells as well as cells exhibiting severe septation defects, including multiple, mispositioned, deformed, and misoriented septa. Our results demonstrate that phosphatidylethanolamine is essential for cell growth and for normal cytokinesis and cellular morphogenesis in S. pombe, and they illustrate the usefulness of this model eukaryote for investigating potentially conserved biological and molecular functions of phosphatidylethanolamine.

Pseudo-exponential growth in length of the fission yeast, Schizosaccharomyces pombe

1988 ◽  
Vol 34 (12) ◽  
pp. 1338-1343 ◽  
Author(s):  
Hisao Miyata ◽  
Machiko Miyata ◽  
Byron F. Johnson
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Exponential Growth ◽  
Linear Growth ◽  
Normal Growth ◽  
Growth Patterns ◽  
Birth Length ◽  
Yeast Cells ◽  
Wild Type ◽  
Constant Length

The growth patterns of individual cells of the fission yeast (Schizosaccharomyces pombe wild-type cells, strain 972 h−; cells exposed to hydroxyurea; and cdc mutants, 11-123, 2-33) were investigated by time-lapse photomicrography. Wild-type cells showed one, two, or three linear-growth segments followed by a constant-length stage. Cells with two segments were most frequent. Hydroxyurea cells that divided as oversized cells (about three times the birth length) had three linear-growth segments in a cycle. Mutant cdc11-123 cells did not divide but had a constant-length stage separating the cycles; both the first and second cycles consisted of two linear-growth segments, and cells were oversized at the second constant-length stage (about 3.5 times the birth length). Elongating cdc2-33 cells that did not divide and were oversized (about five times the birth length) while under observation, showed four linear-growth segments. Cells of all strains showed 30 to 40% increase in growth rate at the rate-change point and maintained approximate exponential (pseudo-exponential) growth. We conclude that the normal growth pattern of individual fission-yeast cells is the pseudo-exponential pattern.

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 Profilin Binding to Poly-l-Proline and Actin Monomers along with Ability to Catalyze Actin Nucleotide Exchange Is Required for Viability of Fission Yeast

2001 ◽  
Vol 12 (4) ◽  
pp. 1161-1175 ◽  
Author(s):  
Jia Lu ◽  
Thomas D. Pollard
Keyword(s):  
Schizosaccharomyces Pombe ◽  
Fission Yeast ◽  
Point Mutations ◽  
Biochemical Properties ◽  
Actin Binding ◽  
Temperature Sensitive ◽  
Nucleotide Exchange ◽  
Wild Type ◽  
Lower Affinity ◽  
Essential Function

We tested the ability of 87 profilin point mutations to complement temperature-sensitive and null mutations of the single profilin gene of the fission yeast Schizosaccharomyces pombe. We compared the biochemical properties of 13 stable noncomplementing profilins with an equal number of complementing profilin mutants. A large quantitative database revealed the following: 1) in a profilin null background fission yeast grow normally with profilin mutations having >10% of wild-type affinity for actin or poly-l-proline, but lower affinity for either ligand is incompatible with life; 2) in thecdc3-124 profilin ts background, fission yeast function with profilin having only 2–5% wild-type affinity for actin or poly-l-proline; and 3) special mutations show that the ability of profilin to catalyze nucleotide exchange by actin is an essential function. Thus, poly-l-proline binding, actin binding, and actin nucleotide exchange are each independent requirements for profilin function in fission yeast.

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.

Sign in / Sign up

Export Citation Format

Share Document