scholarly journals GENETIC CONTROL OF THE CELL DIVISION CYCLE IN YEAST: V. GENETIC ANALYSIS OF cdc MUTANTS

Genetics ◽  
1973 ◽  
Vol 74 (2) ◽  
pp. 267-286
Author(s):  
Leland H Hartwell ◽  
Robert K Mortimer ◽  
Joseph Culotti ◽  
Marilyn Culotti
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Nuclear Gene ◽  
Temperature Shift ◽  
Time Lapse ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Diploid Cells

ABSTRACT One hundred and forty-eight temperature-sensitive cell division cycle (cdc) mutants of Saccharomyces cerevisiae have been isolated and characterized. Complementation studies ordered these recessive mutations into 32 groups and tetrad analysis revealed that each of these groups defines a single nuclear gene. Fourteen of these genes have been located on the yeast genetic map. Functionally related cistrons are not tightly clustered. Mutations in different cistrons frequently produce different cellular and nuclear morphologies in the mutant cells following incubation at the restrictive temperature, but all the mutations in the same cistron produce essentially the same morphology. The products of these genes appear, therefore, each to function individually in a discrete step of the cell cycle and they define collectively a large number of different steps. The mutants were examined by time-lapse photomicroscopy to determine the number of cell cycles completed at the restrictive temperature before arrest. For most mutants, cells early in the cell cycle at the time of the temperature shift (before the execution point) arrest in the first cell cycle while those later in the cycle (after the execution point) arrest in the second cell cycle. Execution points for allelic mutations that exhibit first or second cycle arrest are rather similar and appear to be cistron-specific. Other mutants traverse several cycles before arrest, and its suggested that the latter type of response may reveal gene products that are temperature-sensitive for synthesis, whereas the former may be temperature-sensitive for function. The gene products that are defined by the cdc cistrons are essential for the completion of the cell cycle in haploids of a and α mating type and in a/α diploid cells. The same genes, therefore, control the cell cycle in each of these stages of the life cycle.

DIPLOID SPORE FORMATION AND OTHER MEIOTIC EFFECTS OF TWO CELL-DIVISION-CYCLE MUTATIONS OF SACCHAROMYCES CEREVISIAE

Genetics ◽  
1980 ◽  
Vol 96 (4) ◽  
pp. 859-876 ◽  
Author(s):  
David Schild ◽  
Breck Byers
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Single Spore ◽  
Diploid Cells ◽  
Meiosis I

ABSTRACT The meiotic effects of two cell-division-cycle mutations of Saccharomyces cerevisiae (cdc5 and cdc14) have been examined. These mutations were isolated by L. H. Hartwell and his colleagues and characterized as defective in mitosis, causing a temperature-sensitive arrest in late nuclear division. When subjected to the restrictive temperature in meiosis, diploid cells homozygous for either of these mutations generally proceeded through premeiotic DNA synthesis and commitment to meiotic levels of recombination, but then arrested at a stage following spindle pole body (SPB) duplication and separation. The two SPBs lacked the interconnection by spindle microtubules typical of the complete meiosis I spindle. Challenge of these homozygotes by a semi-restrictive temperature often caused the production of asci containing two diploid spores. Genetic analysis of the viable pairs of spores revealed that each spore had become homozygous for centromere-linked markers significantly more frequently than for distal markers, indicating that the two spores each contained pairs of sister centromeres that had co-segregated in the reductional division of meiosis I. Ultrastructural analysis of the cdc5 homozygote demonstrated that these cells had completed meiosis I and formed two meiosis II spindles, but that the latter remained unusually short. This resulted in the encapsulation of both poles of each spindle within a single spore wall. These mutations therefore are defective in both meiotic divisions, as well as in the mitotic division described originally.

scholarly journals Residual cell division measurements are unreliable as indicators of the timing of events in the Saccharomyces cerevisiae cell cycle

1983 ◽  
Vol 64 (1) ◽  
pp. 307-322
Author(s):  
K.M. Richmond ◽  
D.H. Williamson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Temperature Shift ◽  
Growth Conditions ◽  
Population Doubling ◽  
Population Doubling Time ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Point Data

We report here an analysis of the execution point of the temperature-sensitive Saccharomyces cerevisiae cell cycle mutant, cdc27-47. When a logarithmically growing culture was shifted from standard growth conditions (strain 27.8B growing in YEPD at 25 degrees C) to the restrictive temperature cell division ceased abruptly and reproducibly within one population doubling time, the extent of cell division indicating an execution point early in the cell cycle. Approximately 50% of stationary-phase cells were able to divide when refed with fresh medium at 37 degrees C, showing that the execution point could be passed before ‘start’. This makes the sharp cut-off in cell division difficult to explain. This difficulty was compounded by observations of the cell cycle stage at which individual cells acquired the capacity to divide at 37 degrees C. Half the cells that were budded at the time of a temperature shift-up formed three division-blocked cells, and in 11 of these 13 cases, two were descended from the original mother cell and one from the original bud. Thus, mother and daughter cells pass the execution point independently; daughters usually during G1, and mothers usually in the budded phase of the previous cycle. The sharp cut-off in cell division is therefore spurious, and a mechanism is proposed to account for it, which has implications for the interpretation of the execution points of other cdc mutants. In addition, the expression of the cdc27-47 execution point was modified by both genetic and environmental factors, being affected by carbon source, by the petite condition, and by genetic background. This illustrates the difficulties of interpreting execution point data and the dangers of extrapolation of cell cycle parameters between strains and growth conditions.

scholarly journals THE ROLE OF S. CEREVISIAE CELL DIVISION CYCLE GENES IN NUCLEAR FUSION

Genetics ◽  
1982 ◽  
Vol 100 (2) ◽  
pp. 175-184
Author(s):  
Susan K Dutcher ◽  
Leland H Hartwell
Keyword(s):  
Cell Division ◽  
Parent Strain ◽  
Nuclear Fusion ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Sensitive Cell ◽  
Single Lesion

ABSTRACT Forty temperature-sensitive cell division cycle (cdc) mutants of Saccharomyces cerevisiae were examined for their ability to complete nuclear fusion during conjugation in crosses to a CDC parent strain at the restrictive temperature. Most of the cdc mutant alleles behaved as the CDC parent strain from which they were derived, in that zygotes produced predominantly diploid progeny with only a small fraction of zygotes giving rise to haploid progeny (cytoductants) that signalled a failure in nuclear fusion. However, cdc4 mutants exhibited a strong nuclear fusion (karyogamy) defect in crosses to a CDC parent and cdc28, cdc34 and cdc37 mutants exhibited a weak karyogamy defect. For all four mutants, the karyogamy defect and the cell cycle defect cosegregated, suggesting that both defects resulted from a single lesion for each of these cdc mutants. Therefore, the cdc 4, 28, 34 and 37 gene products are required in both cell division and karyogamy.

Test for temporal or spatial restrictions in gene product function during the cell division cycle

1983 ◽  
Vol 3 (7) ◽  
pp. 1255-1265
Author(s):  
S K Dutcher ◽  
L H Hartwell
Keyword(s):  
Cell Division ◽  
Gene Product ◽  
Gene Mutations ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Product Function ◽  
Complete Cell ◽  
Relationship Of ◽  
Gene Product Function

The ability of a functional gene to complement a nonfunctional gene may depend upon the intracellular relationship of the two genes. If so, the function of the gene product in question must be limited in time or in space. CDC (cell division cycle) gene products of Saccharomyces cerevisiae control discrete steps in cell division; therefore, they constitute reasonable candidates for genes that function with temporal or spatial restrictions. In an attempt to reveal such restrictions, we compared the ability of a CDC gene to complement a temperature-sensitive cdc gene in diploids where the genes are located within the same nucleus to complementation in heterokaryons where the genes are located in different nuclei. In CDC X cdc matings, complementation was monitored in rare heterokaryons by assaying the production of cdc haploid progeny (cytoductants) at the restrictive temperature. The production of cdc cytoductants indicates that the cdc nucleus was able to complete cell division at the restrictive temperature and implies that the CDC gene product was provided by the other nucleus or by cytoplasm in the heterokaryon. Cytoductants from cdc28 or cdc37 crosses were not efficiently produced, suggesting that these two genes are restricted spatially or temporally in their function. We found that of the cdc mutants tested 33 were complemented; cdc cytoductants were recovered at least as frequently as CDC cytoductants. A particularly interesting example was provided by the CDC4 gene. Mutations in CDC4 were found previously to produce a defect in both cell division and karyogamy. Surprisingly, the cell division defect of cdc4 nuclei is complemented by CDC4 nuclei in a heterokaryon, whereas the karyogamy defect is not.

scholarly journals Cell cycle arrest of cdc mutants and specificity of the RAD9 checkpoint.

Genetics ◽  
1993 ◽  
Vol 134 (1) ◽  
pp. 63-80 ◽  
Author(s):  
T A Weinert ◽  
L H Hartwell
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Control ◽  
Dna Lesions ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
A Cell ◽  
G2 Phase ◽  
Rad Mutants

Abstract In eucaryotes a cell cycle control called a checkpoint ensures that mitosis occurs only after chromosomes are completely replicated and any damage is repaired. The function of this checkpoint in budding yeast requires the RAD9 gene. Here we examine the role of the RAD9 gene in the arrest of the 12 cell division cycle (cdc) mutants, temperature-sensitive lethal mutants that arrest in specific phases of the cell cycle at a restrictive temperature. We found that in four cdc mutants the cdc rad9 cells failed to arrest after a shift to the restrictive temperature, rather they continued cell division and died rapidly, whereas the cdc RAD cells arrested and remained viable. The cell cycle and genetic phenotypes of the 12 cdc RAD mutants indicate the function of the RAD9 checkpoint is phase-specific and signal-specific. First, the four cdc RAD mutants that required RAD9 each arrested in the late S/G2 phase after a shift to the restrictive temperature when DNA replication was complete or nearly complete, and second, each leaves DNA lesions when the CDC gene product is limiting for cell division. Three of the four CDC genes are known to encode DNA replication enzymes. We found that the RAD17 gene is also essential for the function of the RAD9 checkpoint because it is required for phase-specific arrest of the same four cdc mutants. We also show that both X- or UV-irradiated cells require the RAD9 and RAD17 genes for delay in the G2 phase. Together, these results indicate that the RAD9 checkpoint is apparently activated only by DNA lesions and arrests cell division only in the late S/G2 phase.

scholarly journals Effects of a temperature-sensitiveMinutemutation on gene expression inDrosophila melanogaster

1984 ◽  
Vol 43 (3) ◽  
pp. 257-275 ◽  
Author(s):  
Donald A. R. Sinclair ◽  
Thomas A. Grigliatti ◽  
Thomas C. Kaufman
Keyword(s):  
Gene Expression ◽  
Temperature Shift ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
The Past ◽  
Reciprocal Temperature ◽  
Sex Comb ◽  
Mutant Phenotypes

SUMMARYMinute(M) lesions exhibit a striking propensity for interacting with many different mutations. In the past, few attempts have been made to explain these diverse phenomena. This study describes a variety of temperature-sensitive (ts) interactions exhibited by the ts third chromosomeMinutemutationM(3)LS4Q-III(Q-III). Most of these interactions (i.e. those involvingvg, cp, Dl, DfdorLy) reflectQ-III-induced enhancement of the respective mutant phenotypes at the restrictive temperature. However,Q-IIIalso suppresses the extra-sex-comb phenotypes ofPcandMscat 29 °C and evokes lethal and bristle traits when combined withJ34eat the restrictive temperature. All of these interactions are characteristic of non-tsMinutelesions and thus they appear to be correlated with general physiological perturbations associated with theMsyndrome. In addition, our findings show that mutations that affect ribosome production and/or function, namelysu(f)ts67gandbbts−1, exhibit interactions comparable to those elicited byQ-III. Hence, in accordance with previous findings, we argue that most of theQ-IIIinteractions can be attributed to reduced translational capacity at the restrictive temperature. Finally, reciprocal temperature shift studies were used to delineate TSPs for interactions betweenQ-IIIandvg(mid to late second instar),cp(about mid-third instar),Dfd(early third instar) andDl(late second to mid third instar). We believe that these TSPs represent developmental intervals during which the respective gene products are utilized.

scholarly journals MEIOTIC RECOMBINATION AND DNA SYNTHESIS IN A NEW CELL CYCLE MUTANT OF SACCHAROMYCES CEREVISIAE

Genetics ◽  
1978 ◽  
Vol 90 (1) ◽  
pp. 49-68
Author(s):  
Yona Kassir ◽  
Giora Simchen
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Nuclear Division ◽  
Temperature Shift ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Permissive Temperature ◽  
Essential Function ◽  
Normal Meiosis

ABSTRACT Vegetative cells carrying the new temperature-sensitive mutation cdc40 arrest at the restrictive temperature with a medial nuclear division phenotype. DNA replication is observed under these conditions, but most cells remain sensitive to hydroxyurea and do not complete the ongoing cell cycle if the drug is present during release from the temperature block. It is suggested that the cdc40 lesion affects an essential function in DNA synthesis. Normal meiosis is observed at the permissive temperature in cdc40 homozygotes. At the restrictive temperature, a full round of premeiotic DNA replication is observed, but neither commitment to recombination nor later meiotic events occur. Meiotic cells that are already committed to the recombination process at the permissive temperature do not complete it if transferred to the restrictive temperature before recombination is realized. These temperature shift-up experiments demonstrate that the CDC40 function is required for the completion of recombination events, as well as for the earlier stage of recombination commitment. Temperature shift-down experiments with cdc40 homozygotes suggest that meiotic segregation depends on the final events of recombination rather than on commitment to recombination.

Mating-defective ste mutations are suppressed by cell division cycle start mutations in Saccharomyces cerevisiae

1982 ◽  
Vol 2 (9) ◽  
pp. 1052-1063
Author(s):  
J R Shuster
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Temperature Characteristic ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Wild Type ◽  
Mating Pheromone ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mating Pheromones

Temperature-sensitive mutants which arrest in the G1 phase of the cell cycle have been described for the yeast Saccharomyces cerevisiae. One class of these mutants (carrying cdc28, cdc36, cdc37, or cdc39) forms a shmoo morphology at restrictive temperature, characteristic of mating pheromone-arrested wild-type cells. Therefore, one hypothesis to explain the control of cell division by mating factors states that mating pheromones arrest wild-type cells by inactivating one or more of these CDC gene products. A class of mutants (carrying ste4, ste5, ste7, ste11, or ste12) which is insensitive to mating pheromone and sterile has also been described. One possible function of the STE gene products is the inactivation of the CDC gene products in the presence of a mating pheromone. A model incorporating these two hypotheses predicts that such STE gene products will not be required for mating in strains carrying an appropriate cdc lesion. This prediction was tested by assaying the mating abilities of double mutants for all of the pairwise combinations of cdc and ste mutations. Lesions in either cdc36 or cdc39 suppressed the mating defect due to ste4 and ste5. Allele specificity was observed in the suppression of both ste4 and ste5. The results indicate that the CDC36, CDC39, STE4, and STE5 gene products interact functionally or physically or both in the regulation of cell division mediated by the presence or absence of mating pheromones. The cdc36 and cdc39 mutations did not suppress ste7, ste11, or ste12. Lesions in cdc28 or cdc37 did not suppress any of the ste mutations. Other models of CDC and STE gene action which predicted that some of the cdc and ste mutations would be alleles of the same locus were tested. None of the cdc mutations was allelic to the ste mutations and, therefore, these models were eliminated.

Suppressor analyses of temperature-sensitive cbp1 strains of Saccharomyces cerevisiae: the product of the nuclear gene SOC1 affects mitochondrial cytochrome b mRNA post-transcriptionally.

Genetics ◽  
1994 ◽  
Vol 138 (3) ◽  
pp. 565-575
Author(s):  
R R Staples ◽  
C L Dieckmann
Keyword(s):  
Cytochrome B ◽  
Nuclear Gene ◽  
State Level ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Mitochondrial Cytochrome ◽  
Mitochondrial Cytochrome B ◽  
Cytochrome B Mrna ◽  
Bypass Mechanism

Abstract The induction of mitochondrial function is dependent upon both nuclearly encoded and mitochondrially encoded gene products. To understand nuclear-mitochondrial interactions, we must first understand gene-specific interactions. The accumulation of mitochondrial cytochrome b (COB) RNA is dependent upon Cbp1p, encoded by the nuclear gene CBP1. Thus, respiration is dependent upon Cbp1p. In this study, suppressors of temperature-sensitive cbp1 (cbp1ts) strains were selected for restoration of respiratory capability at the restrictive temperature Ts+). One nuclearly encoded suppressor, extragenic to CBP1, is recessive with respect to the wild-type suppressor allele and is unlinked to other known genetic loci whose gene products are necessary for expression of COB mRNA. The suppressor, called soc1 for Suppressor of cbp1, suppresses several other cbp1ts alleles but does not operate via a bypass mechanism. Molecular analyses indicate that soc1 allows the steady-state level of COB mRNA to increase at high temperature but has little or no effect on the levels of COB pre-mRNA. These data have led us to propose that the product of the nuclear gene SOC1 is required for normal turnover of COB mRNA.

scholarly journals Test for temporal or spatial restrictions in gene product function during the cell division cycle.

1983 ◽  
Vol 3 (7) ◽  
pp. 1255-1265 ◽  
Author(s):  
S K Dutcher ◽  
L H Hartwell
Keyword(s):  
Cell Division ◽  
Gene Product ◽  
Gene Mutations ◽  
Cell Division Cycle ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Product Function ◽  
Complete Cell ◽  
Relationship Of ◽  
Gene Product Function

The ability of a functional gene to complement a nonfunctional gene may depend upon the intracellular relationship of the two genes. If so, the function of the gene product in question must be limited in time or in space. CDC (cell division cycle) gene products of Saccharomyces cerevisiae control discrete steps in cell division; therefore, they constitute reasonable candidates for genes that function with temporal or spatial restrictions. In an attempt to reveal such restrictions, we compared the ability of a CDC gene to complement a temperature-sensitive cdc gene in diploids where the genes are located within the same nucleus to complementation in heterokaryons where the genes are located in different nuclei. In CDC X cdc matings, complementation was monitored in rare heterokaryons by assaying the production of cdc haploid progeny (cytoductants) at the restrictive temperature. The production of cdc cytoductants indicates that the cdc nucleus was able to complete cell division at the restrictive temperature and implies that the CDC gene product was provided by the other nucleus or by cytoplasm in the heterokaryon. Cytoductants from cdc28 or cdc37 crosses were not efficiently produced, suggesting that these two genes are restricted spatially or temporally in their function. We found that of the cdc mutants tested 33 were complemented; cdc cytoductants were recovered at least as frequently as CDC cytoductants. A particularly interesting example was provided by the CDC4 gene. Mutations in CDC4 were found previously to produce a defect in both cell division and karyogamy. Surprisingly, the cell division defect of cdc4 nuclei is complemented by CDC4 nuclei in a heterokaryon, whereas the karyogamy defect is not.

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