The MCM16 gene of the yeast Saccharomyces cerevisiae is required for chromosome segregation

1998 ◽  
Vol 260 (2-3) ◽  
pp. 242-250 ◽  
Author(s):  
K. Sanyal ◽  
S. K. Ghosh ◽  
P. Sinha
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Yeast Saccharomyces Cerevisiae

In vivo analysis of the Saccharomyces cerevisiae centromere CDEIII sequence: requirements for mitotic chromosome segregation

1991 ◽  
Vol 11 (10) ◽  
pp. 5212-5221
Author(s):  
B Jehn ◽  
R Niedenthal ◽  
J H Hegemann
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Artificial Chromosome ◽  
Complete Information ◽  
Saturation Mutagenesis ◽  
Chromosome Loss ◽  
Single Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Double Base

In the yeast Saccharomyces cerevisiae, the complete information needed in cis to specify a fully functional mitotic and meiotic centromere is contained within 120 bp arranged in the three conserved centromeric (CEN) DNA elements CDEI, -II, and -III. The 25-bp CDEIII is most important for faithful chromosome segregation. We have constructed single- and double-base substitutions in all highly conserved residues and one nonconserved residue of this element and analyzed the mitotic in vivo function of the mutated CEN DNAs, using an artificial chromosome. The effects of the mutations on chromosome segregation vary between wild-type-like activity (chromosome loss rate of 4.8 x 10(-4)) and a complete loss of CEN function. Data obtained by saturation mutagenesis of the palindromic core sequence suggest asymmetric involvement of the palindromic half-sites in mitotic CEN function. The poor CEN activity of certain single mutations could be improved by introducing an additional single mutation. These second-site suppressors can be found at conserved and nonconserved positions in CDEIII. Our suppression data are discussed in the context of natural CDEIII sequence variations found in the CEN sequences of different yeast chromosomes.

scholarly journals Role of astral microtubules and actin in spindle orientation and migration in the budding yeast, Saccharomyces cerevisiae.

1992 ◽  
Vol 119 (3) ◽  
pp. 583-593 ◽  
Author(s):  
R E Palmer ◽  
D S Sullivan ◽  
T Huffaker ◽  
D Koshland
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Mother Cell ◽  
Fold Increase ◽  
Spindle Pole ◽  
Spindle Orientation ◽  
Temperature Sensitive ◽  
Chromosome Movement ◽  
Yeast Saccharomyces Cerevisiae ◽  
Cytoskeletal Elements

In the yeast Saccharomyces cerevisiae, before the onset of anaphase, the spindle apparatus is always positioned with one spindle pole at, or through, the neck between the mother cell and the growing bud. This spindle orientation enables proper chromosome segregation to occur during anaphase, allowing one replicated genome to be segregated into the bud and the other to remain in the mother cell. In this study, we synchronized a population of cells before the onset of anaphase such that > 90% of the cells in the population had spindles with the correct orientation, and then disrupted specific cytoskeletal elements using temperature-sensitive mutations. Disruption of either the astral microtubules or actin function resulted in improper spindle orientation in approximately 40-50% of the cells. When cells with disrupted astral microtubules or actin function entered into anaphase, there was a 100-200-fold increase in the frequency of binucleated cell bodies. Thus, the maintenance of proper spindle orientation by these cytoskeletal elements was essential for proper chromosome segregation. These data are consistent with the model that proper spindle orientation is maintained by directly or indirectly tethering the astral microtubules to the actin cytoskeleton. After nuclear migration, but before anaphase, bulk chromosome movement occurs within the nucleus apparently because the chromosomes are attached to a mobile spindle. The frequency and magnitude of bulk chromosome movement is greatly diminished by disruption of the astral microtubules but not by disruption of the nonkinetochore spindle microtubules. These results suggest that astral microtubules are not only important for spindle orientation before anaphase, but they also mediate force on the spindle, generating spindle displacement and in turn chromosome movement. Potential roles for this force in spindle assembly and orientation are discussed.

scholarly journals Structure/Function Analysis of the Hif1 Histone Chaperone in Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Nora Saud Dannah
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Genome Stability ◽  
Function Analysis ◽  
Molecular Genetic ◽  
Histone Chaperone ◽  
Chromatin Assembly ◽  
Biological Processes ◽  
Genetic Approach ◽  
Yeast Saccharomyces Cerevisiae

Understanding the regulation of chromatin structure is a vital aspect of molecular biology regarding its influences on biological processes such as DNA replication, transcription (gene expression), DNA repair, chromosome segregation and recombination. In the budding yeast Saccharomyces cerevisiae, a histone chaperone called Hif1 has been found in the nuclei as having a functional role in chromatin assembly. Hif1 is a homolog of the human protein NASP that is involved in the maintenance of genome stability. Previously, Hif1 has been shown to physically interact with Hat1, Hat2 and H3/H4 to form the NuB4 complex directly involved in chromatin assembly. A molecular genetic approach was conducted to determine which domain of Hif1 is involved in the interaction with the HAT1 complex.

scholarly journals In vivo analysis of the Saccharomyces cerevisiae centromere CDEIII sequence: requirements for mitotic chromosome segregation.

1991 ◽  
Vol 11 (10) ◽  
pp. 5212-5221 ◽  
Author(s):  
B Jehn ◽  
R Niedenthal ◽  
J H Hegemann
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Artificial Chromosome ◽  
Complete Information ◽  
Saturation Mutagenesis ◽  
Chromosome Loss ◽  
Single Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Double Base

In the yeast Saccharomyces cerevisiae, the complete information needed in cis to specify a fully functional mitotic and meiotic centromere is contained within 120 bp arranged in the three conserved centromeric (CEN) DNA elements CDEI, -II, and -III. The 25-bp CDEIII is most important for faithful chromosome segregation. We have constructed single- and double-base substitutions in all highly conserved residues and one nonconserved residue of this element and analyzed the mitotic in vivo function of the mutated CEN DNAs, using an artificial chromosome. The effects of the mutations on chromosome segregation vary between wild-type-like activity (chromosome loss rate of 4.8 x 10(-4)) and a complete loss of CEN function. Data obtained by saturation mutagenesis of the palindromic core sequence suggest asymmetric involvement of the palindromic half-sites in mitotic CEN function. The poor CEN activity of certain single mutations could be improved by introducing an additional single mutation. These second-site suppressors can be found at conserved and nonconserved positions in CDEIII. Our suppression data are discussed in the context of natural CDEIII sequence variations found in the CEN sequences of different yeast chromosomes.

scholarly journals SSP1, a gene necessary for proper completion of meiotic divisions and spore formation in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (12) ◽  
pp. 7029-7039 ◽  
Author(s):  
D K Nag ◽  
M P Koonce ◽  
J Axelrod
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Nuclear Division ◽  
Diploid Cell ◽  
Spore Formation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Expression Of Genes ◽  
Diploid Cells ◽  
Differential Expression Of Genes

During meiosis, a diploid cell undergoes two rounds of nuclear division following one round of DNA replication to produce four haploid gametes. In yeast, haploid meiotic products are packaged into spores. To gain new insights into meiotic development and spore formation, we followed differential expression of genes in meiotic versus vegetatively growing cells in the yeast Saccharomyces cerevisiae. Our results indicate that there are at least five different classes of transcripts representing genes expressed at different stages of the sporulation program. Here we describe one of these differentially expressed genes, SSP1, which plays an essential role in meiosis and spore formation. SSP1 is expressed midway through meiosis, and homozygous ssp1 diploid cells fail to sporulate. In the ssp1 mutant, meiotic recombination is normal but viability declines rapidly. Both meiotic divisions occur at the normal time; however, the fraction of cells completing meiosis is significantly reduced, and nuclei become fragmented soon after meiosis II. The ssp1 defect does not appear to be related to a microtubule-cytoskeletal-dependent event and is independent of two rounds of chromosome segregation. The data suggest that Ssp1 is likely to function in a pathway that controls meiotic nuclear divisions and coordinates meiosis and spore formation.

scholarly journals Structure/Function Analysis of the Hif1 Histone Chaperone in Saccharomyces cerevisiae

2021 ◽  
Author(s):  
Nora Saud Dannah
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Genome Stability ◽  
Function Analysis ◽  
Molecular Genetic ◽  
Histone Chaperone ◽  
Chromatin Assembly ◽  
Biological Processes ◽  
Genetic Approach ◽  
Yeast Saccharomyces Cerevisiae

Understanding the regulation of chromatin structure is a vital aspect of molecular biology regarding its influences on biological processes such as DNA replication, transcription (gene expression), DNA repair, chromosome segregation and recombination. In the budding yeast Saccharomyces cerevisiae, a histone chaperone called Hif1 has been found in the nuclei as having a functional role in chromatin assembly. Hif1 is a homolog of the human protein NASP that is involved in the maintenance of genome stability. Previously, Hif1 has been shown to physically interact with Hat1, Hat2 and H3/H4 to form the NuB4 complex directly involved in chromatin assembly. A molecular genetic approach was conducted to determine which domain of Hif1 is involved in the interaction with the HAT1 complex.

scholarly journals Sli15 Associates with the Ipl1 Protein Kinase to Promote Proper Chromosome Segregation in Saccharomyces cerevisiae

1999 ◽  
Vol 145 (7) ◽  
pp. 1381-1394 ◽  
Author(s):  
Jae-hyun Kim ◽  
Jung-seog Kang ◽  
Clarence S.M. Chan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Chromosome Segregation ◽  
Genetic Interaction ◽  
Spindle Pole ◽  
Mutant Phenotype ◽  
Yeast Saccharomyces Cerevisiae ◽  
Synthetic Lethal ◽  
Mutant Cells

The conserved Ipl1 protein kinase is essential for proper chromosome segregation and thus cell viability in the budding yeast Saccharomyces cerevisiae. Its human homologue has been implicated in the tumorigenesis of diverse forms of cancer. We show here that sister chromatids that have separated from each other are not properly segregated to opposite poles of ipl1-2 cells. Failures in chromosome segregation are often associated with abnormal distribution of the spindle pole–associated Nuf2-GFP protein, thus suggesting a link between potential spindle pole defects and chromosome missegregation in ipl1 mutant cells. A small fraction of ipl1-2 cells also appears to be defective in nuclear migration or bipolar spindle formation. Ipl1 associates, probably directly, with the novel and essential Sli15 protein in vivo, and both proteins are localized to the mitotic spindle. Conditional sli15 mutant cells have cytological phenotypes very similar to those of ipl1 cells, and the ipl1-2 mutation exhibits synthetic lethal genetic interaction with sli15 mutations. sli15 mutant phenotype, like ipl1 mutant phenotype, is partially suppressed by perturbations that reduce protein phosphatase 1 function. These genetic and biochemical studies indicate that Sli15 associates with Ipl1 to promote its function in chromosome segregation.

scholarly journals Single base-pair mutations in centromere element III cause aberrant chromosome segregation in Saccharomyces cerevisiae.

1986 ◽  
Vol 6 (2) ◽  
pp. 530-538 ◽  
Author(s):  
J McGrew ◽  
B Diehl ◽  
M Fitzgerald-Hayes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Segregation ◽  
Dna Sequences ◽  
Base Pair ◽  
Site Directed Mutagenesis ◽  
Chromosome Stability ◽  
Functional Requirements ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Centromere Function

In this paper we show that a 211-base pair segment of CEN3 DNA is sufficient to confer wild-type centromere function in the yeast Saccharomyces cerevisiae. We used site-directed mutagenesis of the 211-base pair fragment to examine the sequence-specific functional requirements of a conserved 11-base pair segment of centromere DNA, element III (5'-TGATTTATCCGAA-3'). Element III is the most highly conserved of the centromeric DNA sequences, differing by only a single adenine X thymine base pair among the four centromere DNAs sequenced thus far. All of the element III sequences contain specific cytosine X guanine base pairs, including a 5'-CCG-3' arrangement, which we targeted for single cytosine-to-thymine mutations by using sodium bisulfite. The effects of element III mutations on plasmid and chromosome segregation were determined by mitotic stability assays. Conversion of CCG to CTG completely abolished centromere function both in plasmids and in chromosome III, whereas conversion of CCG to TCG decreased plasmid and chromosome stability moderately. The other two guanine X cytosine base pairs in element III could be independently converted to adenine X thymine base pairs without affecting plasmid or chromosome stability. We concluded that while some specific nucleotides within the conserved element III sequence are essential for proper centromere function, other conserved nucleotides can be changed.

Meiotic Crossing Over Between Nonhomologous Chromosomes Affects Chromosome Segregation in Yeast

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 69-78
Author(s):  
Sue Jinks-Robertson ◽  
Shariq Sayeed ◽  
Tamara Murphy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Chromosome Segregation ◽  
Meiotic Recombination ◽  
Southern Blot Analysis ◽  
Meiotic Chromosome ◽  
Crossing Over ◽  
Yeast Saccharomyces Cerevisiae ◽  
Reciprocal Translocations ◽  
Ectopic Recombination

Meiotic recombination between artificial repeats positioned on nonhomologous chromosomes occurs efficiently in the yeast Saccharomyces cerevisiae. Both gene conversion and crossover eventS have been observed, with crossovers yielding reciprocal translocations. In the current study, 5.5-kb ura3 repeats positioned on chromosomes V and XV were used to examine the effect of ectopic recombination on meiotic chromosome segregation. Ura+ random spores were selected and gene conversion vs. crossover events were distinguished by Southern blot analysis. Approximately 15% of the crossover events between chromosomes V and XV were associated with missegregation of one of these chromosomes. The missegregation was manifest as hyperploid spores containing either both translocations plus a normal chromosome, or both normal chromosomes plus one of the translocations. In those cases where it could be analyzed, missegregation occurred at the first meiotic division. These data are discussed in terms of a model in which ectopic crossovers compete efficiently with normal allelic crossovers in directing meiotic chromosome segregation.

scholarly journals Nutritional regulation of late meiotic events in Saccharomyces cerevisiae through a pathway distinct from initiation.

1996 ◽  
Vol 16 (6) ◽  
pp. 3222-3232 ◽  
Author(s):  
R H Lee ◽  
S M Honigberg
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Signal Transduction ◽  
Complex Formation ◽  
Stationary Phase ◽  
Chromosome Segregation ◽  
Sporulation Medium ◽  
Nutritional Regulation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Synaptonemal Complex Formation ◽  
Late Stages

The IME1 gene is essential for initiation of meiosis in the yeast Saccharomyces cerevisiae, although it is not required for growth. Here we report that in stationary-phase cultures containing low concentration of glucose, cells overexpressing IME1 undergo the early meiotic events, including DNA replication, commitment to recombination, and synaptonemal complex formation and dissolution. In contrast, later meiotic events, such as chromosome segregation, commitment to meiosis, and spore formation, do not occur. Thus, nutrients can repress the late stages of meiosis independently of their block of initiation. Cells arrested at this midpoint in meiosis are relatively stable and can resume meiotic differentiation if transferred to sporulation conditions. Resumption of meiosis does not require repression of IME1 expression, since IME1 RNA levels stay high after transfer of the arrested cells to sporulation medium. These results suggest that meiosis in S. cerevisiae is a paradigm of a differentiation pathway regulated by signal transduction at both early and late stages.

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