OBSERVATIONS ON VEGETATIVE NUCLEAR DIVISION IN SACCHAROMYCES CEREVISIAE

1962 ◽  
Vol 8 (5) ◽  
pp. 603-608 ◽  
Author(s):  
C. Ramirez ◽  
J. J. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Division ◽  
Nuclear Material ◽  
Parent Cell ◽  
Normal Division

In Giemsa-stained preparations of actively growing yeast, nuclear division normally occurred in the isthmus of each bud, but occasionally the nucleus divided in the parent cell and one of the products of division entered the bud, or else division occurred in the bud, following which one of the two nuclei migrated back into the parent cell. The frequency of intrabud divisions was increased by thymine, dihydrothymine, and thymidine. During normal division, the nuclear material entering the bud tended to be organized into two parallel rows, each comprising three densely staining bodies, and the latter were grouped into apparently homologous pairs.

THE METABOLISM OF YEAST SPORULATION: IV. CYTOLOGICAL AND PHYSIOLOGICAL CHANGES IN SPORULATING CELLS

1962 ◽  
Vol 8 (4) ◽  
pp. 573-584 ◽  
Author(s):  
R. D. Pontefract ◽  
J. J. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Nuclear Division ◽  
Respiratory Activity ◽  
Nuclear Material ◽  
Sporulation Medium ◽  
Physiological Changes ◽  
Early Stages ◽  
Sequence Of Events ◽  
Spore Walls

Parallel observations were made of respiratory activity, content of glycogen and fat, and appearance of the nucleus, during transition of cells of Saccharomyces cerevisiae from the vegetative to the sporulated state. With acetate as the carbon source in sporulation medium, the endogenous respiratory ability of the cells first increased (after about 10 hours) and finally declined. Ability to respire glucose remained high during sporogenesis but diminished somewhat by 42–43 hours, at which time most of the cells contained spores. Glycogen and fat increased in amount during the early stages of sporogenesis but appeared to diminish during formation of spore walls. In vegetative and reductional nuclear division the nuclear material appeared organized into rod-like structures, some regions of which stained more densely. Classical cytological configurations were not observed. With dihydroxyacetone as the carbon source in sporulation medium the sequence of events was similar, but required about twice as much time, possibly owing to the slower respiration of this substance.

scholarly journals The Highly Conserved tRNAHis Guanylyltransferase Thg1p Interacts with the Origin Recognition Complex and Is Required for the G2/M Phase Transition in the Yeast Saccharomyces cerevisiae

2005 ◽  
Vol 4 (4) ◽  
pp. 832-835 ◽  
Author(s):  
Terri S. Rice ◽  
Min Ding ◽  
David S. Pederson ◽  
Nicholas H. Heintz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Origin Recognition Complex ◽  
Nuclear Division ◽  
Permissive Temperature ◽  
Yeast Saccharomyces Cerevisiae ◽  
M Phase ◽  
And Migration ◽  
Origin Recognition

ABSTRACT Here we show that the Saccharomyces cerevisiae tRNAHis guanylyltransferase Thg1p interacts with the origin recognition complex in vivo and in vitro and that overexpression of hemagglutinin-Thg1p selectively impedes growth of orc2-1(Ts) cells at the permissive temperature. Studies with conditional mutants indicate that Thg1p couples nuclear division and migration to cell budding and cytokinesis in yeast.

scholarly journals Requirement for ESP1 in the nuclear division of Saccharomyces cerevisiae.

1992 ◽  
Vol 3 (12) ◽  
pp. 1443-1454 ◽  
Author(s):  
J T McGrew ◽  
L Goetsch ◽  
B Byers ◽  
P Baum
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Normal Cell ◽  
Cell Cycle Progression ◽  
Nuclear Division ◽  
Flow Cytometric Analysis ◽  
Spindle Pole ◽  
Spindle Pole Bodies ◽  
Mutant Cells ◽  
Normal Cell Cycle

Mutations in the ESP1 gene of Saccharomyces cerevisiae disrupt normal cell-cycle control and cause many cells in a mutant population to accumulate extra spindle pole bodies. To determine the stage at which the esp1 gene product becomes essential for normal cell-cycle progression, synchronous cultures of ESP1 mutant cells were exposed to the nonpermissive temperature for various periods of time. The mutant cells retained viability until the onset of mitosis, when their viability dropped markedly. Examination of these cells by fluorescence and electron microscopy showed the first detectable defect to be a structural failure in the spindle. Additionally, flow cytometric analysis of DNA content demonstrated that massive chromosome missegregation accompanied this failure of spindle function. Cytokinesis occurred despite the aberrant nuclear division, which often resulted in segregation of both spindle poles to the same cell. At later times, the missegregated spindle pole bodies entered a new cycle of duplication, thereby leading to the accumulation of extra spindle pole bodies within a single nucleus. The DNA sequence predicts a protein product similar to those of two other genes that are also required for nuclear division: the cut1 gene of Schizosaccharomyces pombe and the bimB gene of Aspergillus nidulans.

Temperature regulation of nuclear division in apomictic yeast

1984 ◽  
Vol 30 (6) ◽  
pp. 793-797 ◽  
Author(s):  
Carl A. Bilinski ◽  
John J. Miller
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Temperature Regulation ◽  
Nuclear Division ◽  
Spore Formation ◽  
Effect Of Temperature ◽  
Sporulation Medium ◽  
Temperature Shock ◽  
Mild Temperature

The effect of temperature on nuclear division and spore formation in an apomictic, two-spored strain of Saccharomyces cerevisiae (19e1) was investigated. Presporulation culture at 36 °C increased markedly the frequency of asci containing three or four spores that developed in sporulation medium, indicating a morphogenic role for temperature in control of meiosis in apomictic yeast. Mild temperature shock treatments administered to cells shortly after transfer from presporulation to sporulation medium also promoted nuclear division and three classes of asci developed: binucleate, trinucleate, and tetranucleate. Nuclear divisions were not always completed before the onset of spore formation in trinucleate asci.

scholarly journals AN ENDOMITOTIC EFFECT OF A CELL CYCLE MUTATION OF SACCHAROMYCES CEREVISIAE

Genetics ◽  
1981 ◽  
Vol 97 (3-4) ◽  
pp. 551-562 ◽  
Author(s):  
David Schild ◽  
Honnavara N Ananthaswamy ◽  
Robert K Mortimer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Analysis ◽  
Nuclear Division ◽  
Pedigree Analysis ◽  
Visual Observation ◽  
Temperature Sensitive ◽  
Cell Stage ◽  
Haploid Strain ◽  
A Cell ◽  
Dna Measurements

ABSTRACT A recessive temperature-sensitive mutation of Saccharomyces cerevisiae has been isolated and shown to cause an increase in ploidy in both haploids and diploids. Genetic analysis revealed that the strain carrying the mutation was an aa diploid, although MNNG mutagenesis had been done on an a haploid strain. When the mutant strain was crossed with an aa diploid and the resultant tetraploid sporulated, some of the meiotic progeny of this tetraploid were themselves tetraploid, as shown by both genetic analysis and DNA measurements, instead of diploid as expected of tetraploid meiosis. The ability of these tetraploids to continue to produce tetraploid meiotic progeny was followed for four generations. Homothallism was excluded as a cause of the increase in ploidy; visual pedigree analysis of spore clones to about the 32-cell stage failed to reveal any zygotes, and haploids that diploidized retained their mating type. An extra round of meiotic DNA synthesis was also considered and excluded. It was found that tetraploidization was independent of sporulation temperature, but was dependent on the temperature of germination and the growth of the spores. Increase in ploidy occurred when the spores were germinated and grown at 30°, but did not occur at 23°. Two cycles of sporulation and growth at 23° resulted in haploids, which were shown to diploidize within 24 hr when grown at 30°. Visual observation of the haploid cells incubated at 36° revealed a celldivisioncycle phenotype characteristic of mutations that affect nuclear division; complementation analysis demonstrated that the mutation, cdc31-2, is allelic to cdc31-1, a mutation isolated by HARTWEeLL et al.(1973) and characterized as causing a temperature-sensitive arrest during late nuclear division. The segregation of cdc31-2 in heterozygous diploids was 2:2 and characteristic of a noncentromere-linked gene.

Chromatin behaviour during the mitotic cell cycle of Saccharomyces cerevisiae

1977 ◽  
Vol 24 (1) ◽  
pp. 81-93
Author(s):  
C.N. Gordon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Division ◽  
Mitotic Cell ◽  
Spindle Pole ◽  
Chromosomal Distribution ◽  
Yeast Saccharomyces Cerevisiae ◽  
Thin Sections ◽  
Daughter Cells ◽  
Spindle Pole Bodies ◽  
Direct Attachment

Chromatin behaviour during the cell division cycle of the yeast Saccharomyces cerevisiae has been investigated in cells which have been depleted of 90% of their RNA by digestion with ribonuclease. Removal of large amounts of RNA from the yeast nucleus before treatment of the cells with heavy metal fixatives and stains permits chromatin to be visualized with extreme clarity in thin sections of cells processed for electron microscopy by conventional procedures. Spindle pole bodies were also visualized by this treatment, although the associated microtubules were not. Chromatin is dispersed during interphase and occupies the non-nucleolar region of the nucleus which is known to be Feulgen-positive from light microscopy. Because spindle microtubules are not visualized, direct attachment of microtubules to chromatin fibrils could not be verified. However, chromatin was not attached directly to the spindle pole bodies and kinetochore differentiations were not observed in the nucleoplasm. During nuclear division chromatin remains dispersed and does not condense into discrete chromatids. As the nucleus expands into the bud, chromosomal distribution to the daughter cells is thought to result from the separation of the poles of the spindle apparatus with attached chromatin fibrils. However, that such distribution is occurring as the nucleus elongates is not obvious until an advanced stage of nuclear division is reached and partition of the nucleus is nearly complete. Thus, no aggregation of chromatin into metaphase or anaphase plates occurs and the appearance of chromatin during mitosis is essentially the same as in interphase. These observations indicate that the marked changes in the topological structure of chromatin which characterize mitosis in the higher eukaryotes do not occur in S. cerevisiae.

The product of the Saccharomyces cerevisiae cell cycle gene DBF2 has homology with protein kinases and is periodically expressed in the cell cycle

1990 ◽  
Vol 10 (4) ◽  
pp. 1358-1366
Author(s):  
L H Johnston ◽  
S L Eberly ◽  
J W Chapman ◽  
H Araki ◽  
A Sugino
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Synthesis ◽  
Protein Kinases ◽  
Nuclear Division ◽  
Cell Cycle Gene ◽  
Restrictive Temperature ◽  
Histone H2a ◽  
Reading Frame ◽  
Polymerase I

Several Saccharomyces cerevisiae dbf mutants defective in DNA synthesis have been described previously. In this paper, one of them, dbf2, is characterized in detail. The DBF2 gene has been cloned and mapped, and its nucleotide sequence has been determined. This process has identified an open reading frame capable of encoding a protein of molecular weight 64,883 (561 amino acids). The deduced amino acid sequence contains all 11 conserved domains found in various protein kinases. DBF2 was periodically expressed in the cell cycle at a time that clearly differed from the time of expression of either the histone H2A or DNA polymerase I gene. Its first function was completed very near to initiation of DNA synthesis. However, DNA synthesis in the mutant was only delayed at 37 degrees C, and the cells blocked in nuclear division. Consistent with this finding, the execution point occurred about 1 h after DNA synthesis, and the nuclear morphology of the mutant at the restrictive temperature was that of cells blocked in late nuclear division. DBF2 is therefore likely to encode a protein kinase that may function in initiation of DNA synthesis and also in late nuclear division.

scholarly journals A dependent pathway of gene functions leading to chromosome segregation in Saccharomyces cerevisiae.

1982 ◽  
Vol 94 (3) ◽  
pp. 718-726 ◽  
Author(s):  
J S Wood ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Chromosome Segregation ◽  
Nuclear Division ◽  
Mitotic Cell ◽  
Mitotic Cell Cycle ◽  
Gene Products ◽  
Dependent Pathway

Methyl-benzimidazole-2-ylcarbamate (MBC) inhibits the mitotic cell cycle of Saccharomyces cerevisiae at a stage subsequent to DNA synthesis and before the completion of nuclear division (Quinlan, R. A., C. I. Pogson, and K, Gull, 1980, J Cell Sci., 46: 341-352). The step in the cell cycle that is sensitive to MBC inhibition was ordered to reciprocal shift experiments with respect to the step catalyzed by cdc gene products. Execution of the CDC7 step is required for the initiation of DNA synthesis and for completion of the MBC-sensitive step. Results obtained with mutants (cdc2, 6, 8, 9, and 21) defective in DNA replication and with an inhibitor of DNA replication (hydroxyurea) suggest that some DNA replication required for execution of the MBC-sensitive step but that the completion of replication is not. Of particular interest were mutants (cdc5, 13, 14, 15, 16, 17, and 23) that arrest cell division after DNA replication but before nuclear division since previous experiments had not been able to resolve the pathway of events in this part of the cell cycle. Execution of the CDC17 step was found to be a prerequisite for execution of the MBC-sensitive step; the CDC13, 16 and 23 steps are executed independently of the MBC-sensitive step; execution of the MBC-sensitive step is prerequisite for execution of the MBC-sensitive step; execution of the MBC-sensitive step is prerequisite for execution of the CDC14 and 23 steps. These results considerably extend the dependent pathway of events that constitute the cell cycle of S. cerevisiae.

scholarly journals mRNAs Encoding Polarity and Exocytosis Factors Are Cotransported with the Cortical Endoplasmic Reticulum to the Incipient Bud in Saccharomyces cerevisiae

2007 ◽  
Vol 27 (9) ◽  
pp. 3441-3455 ◽  
Author(s):  
Stella Aronov ◽  
Rita Gelin-Licht ◽  
Gadi Zipor ◽  
Liora Haim ◽  
Einat Safran ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Nuclear Division ◽  
Mrna Localization ◽  
Dependent Manner ◽  
Protein Enrichment ◽  
Bud Emergence ◽  
Bud Site ◽  
Cortical Endoplasmic Reticulum ◽  
Asymmetrically Distributed

ABSTRACT Polarized growth in the budding yeast Saccharomyces cerevisiae depends upon the asymmetric localization and enrichment of polarity and secretion factors at the membrane prior to budding. We examined how these factors (i.e., Cdc42, Sec4, and Sro7) reach the bud site and found that their respective mRNAs localize to the tip of the incipient bud prior to nuclear division. Asymmetric mRNA localization depends upon factors that facilitate ASH1 mRNA localization (e.g., the 3′ untranslated region, She proteins 1 to 5, Puf6, actin cytoskeleton, and a physical association with She2). mRNA placement precedes protein enrichment and subsequent bud emergence, implying that mRNA localization contributes to polarization. Correspondingly, mRNAs encoding proteins which are not asymmetrically distributed (i.e., Snc1, Mso1, Tub1, Pex3, and Oxa1) are not polarized. Finally, mutations which affect cortical endoplasmic reticulum (ER) entry and anchoring in the bud (myo4Δ, sec3Δ, and srp101) also affect asymmetric mRNA localization. Bud-localized mRNAs, including ASH1, were found to cofractionate with ER microsomes in a She2- and Sec3-dependent manner; thus, asymmetric mRNA transport and cortical ER inheritance are connected processes in yeast.

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