scholarly journals Acquisition and processing of a conditional dicentric chromosome in Saccharomyces cerevisiae.

1989 ◽  
Vol 9 (3) ◽  
pp. 1368-1370 ◽  
Author(s):  
A Hill ◽  
K Bloom
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Frequency ◽  
Dicentric Chromosome ◽  
Dicentric Chromosomes ◽  
Chromosome Iii ◽  
Derivatives Of ◽  
In Cells

The introduction of a conditional centromere into chromosome III of Saccharomyces cerevisiae provided an opportunity to evaluate phenotypic and karyotypic consequences in cells harboring dicentric chromosomes upon entry into mitosis. A mitotic pause ensued, and monocentric derivatives of chromosome III were generated at a high frequency.

scholarly journals Acquisition and processing of a conditional dicentric chromosome in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (3) ◽  
pp. 1368-1370
Author(s):  
A Hill ◽  
K Bloom
Keyword(s):  
Saccharomyces Cerevisiae ◽  
High Frequency ◽  
Dicentric Chromosome ◽  
Dicentric Chromosomes ◽  
Chromosome Iii ◽  
Derivatives Of ◽  
In Cells

The introduction of a conditional centromere into chromosome III of Saccharomyces cerevisiae provided an opportunity to evaluate phenotypic and karyotypic consequences in cells harboring dicentric chromosomes upon entry into mitosis. A mitotic pause ensued, and monocentric derivatives of chromosome III were generated at a high frequency.

scholarly journals MEIOTIC AND MITOTIC BEHAVIOR OF DICENTRIC CHROMOSOMES IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1984 ◽  
Vol 106 (2) ◽  
pp. 185-205
Author(s):  
James E Haber ◽  
Patricia C Thorburn ◽  
David Rogers
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Recombinant Dna ◽  
Ring Chromosome ◽  
Dicentric Chromosome ◽  
Linear Chromosome ◽  
Dicentric Chromosomes ◽  
Ring Chromosomes ◽  
Mitotic Instability ◽  
Unequal Number ◽  
Chromosome Iii

ABSTRACT Meiotic recombination between a circular and a linear chromosome in Saccharomyces cerevisiae has been investigated. The circle was a haploid-viable derivative of chromosome III constructed by joining regions near the two chromosome ends via a recombinant DNA construction: (HMR/MAT-URA3-pBR322-MAT/HML) and was also deleted for MAL2(which therefore uniquely marks a linear chromosome III). Recombination along chromosome III was measured for eight intervals spanning the entire length of the circular derivative. Only 25% of all tetrads from a ring/rod diploid contained four viable spores. These proved to be cases in which there was either no recombination along chromosome III or in which there were two-strand double crossovers or higher order crossovers that would not produce a dicentric chromosome.—At least half of the tetrads with three viable spores included one Ura+ Mal+ spore that was genetically highly unstable. The Ura+ Mal+ spore colonies gave rise to as many as seven genetically distinct, stable ("healed") derivatives, some of which had lost either URA3 or MAL2. Analysis of markers on chromosome III suggests that dicentric chromosomes frequently do not break during meiosis but are inherited intact into a haploid spore. In mitosis, however, the dicentric chromosome is frequently broken, giving rise to a variety of genetically distinct derivatives. We have also shown that dicentric ring chromosomes exhibit similar behavior: at least half the time they are not broken during meiosis but are broken and healed during mitosis.—The ring/rod diploid can also be used to determine the frequency of sister chromatid exchange (SCE) along an entire yeast ring chromosome. We estimate that an unequal number of SCE events occurs in approximately 15% of all cells undergoing meiosis. In contrast, the mitotic instability (and presumably SCE events) of a ring chromosome is low, occurring at a rate of about 1.2 x 10-3 per cell division.

Cloning and molecular analysis of the HAP2 locus: a global regulator of respiratory genes in Saccharomyces cerevisiae

1985 ◽  
Vol 5 (12) ◽  
pp. 3410-3416
Author(s):  
J L Pinkham ◽  
L Guarente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Analysis ◽  
Carbon Sources ◽  
Direct Integration ◽  
Global Regulator ◽  
Low Levels ◽  
Gene Maps ◽  
Derivatives Of ◽  
In Cells

We report here the cloning of the HAP2 gene, a locus required for the expression of many cytochromes and respiratory functions in Saccharomyces cerevisiae. The cloned sequences were found to direct integration of a marked vector to the chromosomal HAP2 locus, and derivatives of these sequences were shown to yield chromosomal disruptions with a Hap2- phenotype. The gene maps 18 centimorgans centromere proximal to ade5 on the left arm of chromosome VII, distinguishing it from any other previously characterized nuclear petite locus. The HAP2 locus encodes a 1.3-kilobase transcript which is present at extremely low levels and which is derepressed in cells grown in media containing nonfermentable carbon sources. Levels of HAP2 mRNA are not reduced in strains bearing a mutation at the HAP3 locus, which is also required for expression of respiratory functions. Models outlining possible interactions of the products of the HAP2 and HAP3 genes are presented.

scholarly journals HEALING OF BROKEN LINEAR DICENTRIC CHROMOSOMES IN YEAST

Genetics ◽  
1984 ◽  
Vol 106 (2) ◽  
pp. 207-226
Author(s):  
James E Haber ◽  
Patricia C Thorburn
Keyword(s):  
Dna Sequences ◽  
Meiotic Recombination ◽  
Recombinant Dna ◽  
Dicentric Chromosome ◽  
Homologous Region ◽  
Repeated Dna ◽  
Circular Chromosome ◽  
Dicentric Chromosomes ◽  
Chromosome Iii ◽  
Linear Chromosomes

ABSTRACT In yeast, meiotic recombination between a linear chromosome III and a haploid-viable circular chromosome will yield a dicentric, tandemly duplicated chromosome. Spores containing apparently intact dicentric chromosomes were recovered from tetrads with three viable spores. The spore containing the dicentric inherited URA3 (part of the recombinant DNA used to join regions near the ends of the chromosome into a circle) as well as HML, HMR and MAL2 (located near the two ends of a linear but deleted from the circle). The Ura+ Mal+ colonies were highly variegated, giving rise to as many as seven distinctly different stable ("healed") derivatives, some of which were Ura+ Mal+, others Ura+ Mal- and others Ura- Mal+. The colonies were also sectored for five markers (HIS4, LEU2, CRY1, MAT and THR4) initially heterozygous in the tandemly duplicated dicentric chromosome.—Southern blot and genetic analyses have demonstrated that these stable derivatives arose from mitotic break-age of the dicentric chromosome, followed by one of several different healing events. The majority of the stable derivatives contained circular or linear chromosomes apparently resulting from homologous recombination between a broken chromosome end and a homologous region on the other end of the original dicentric duplicated chromosome. A smaller proportion of events resulted in apparently uniquely healed linear chromosomes in which the broken chromosome acquired a new telomere. In two instances we recovered chromosome III partially duplicated with a novel right end. We have also found one derivative that had also experienced rearrangement of repeated DNA sequences found adjacent to yeast telomeres.

scholarly journals A delay in the Saccharomyces cerevisiae cell cycle that is induced by a dicentric chromosome and dependent upon mitotic checkpoints.

1992 ◽  
Vol 12 (9) ◽  
pp. 3857-3864 ◽  
Author(s):  
M W Neff ◽  
D J Burke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Cellular Response ◽  
Chromosome Breakage ◽  
Dicentric Chromosome ◽  
Chromosome Loss ◽  
Mitotic Checkpoints ◽  
Dicentric Chromosomes ◽  
Microtubule Function

Dicentric chromosomes are genetically unstable and depress the rate of cell division in Saccharomyces cerevisiae. We have characterized the effects of a conditionally dicentric chromosome on the cell division cycle by using microscopy, flow cytometry, and an assay for histone H1 kinase activity. Activating the dicentric chromosome induced a delay in the cell cycle after DNA replication and before anaphase. The delay occurred in the absence of RAD9, a gene required to arrest cell division in response to DNA damage. The rate of dicentric chromosome loss, however, was elevated in the rad9 mutant. A mutation in BUB2, a gene required for arrest of cell division in response to loss of microtubule function, diminished the delay. Both RAD9 and BUB2 appear to be involved in the cellular response to a dicentric chromosome, since the conditionally dicentric rad9 bub2 double mutant was highly inviable. We conclude that a dicentric chromosome results in chromosome breakage and spindle aberrations prior to nuclear division that normally activate mitotic checkpoints, thereby delaying the onset of anaphase.

scholarly journals A delay in the Saccharomyces cerevisiae cell cycle that is induced by a dicentric chromosome and dependent upon mitotic checkpoints

1992 ◽  
Vol 12 (9) ◽  
pp. 3857-3864
Author(s):  
M W Neff ◽  
D J Burke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Division ◽  
Cellular Response ◽  
Chromosome Breakage ◽  
Dicentric Chromosome ◽  
Chromosome Loss ◽  
Mitotic Checkpoints ◽  
Dicentric Chromosomes ◽  
Microtubule Function

Dicentric chromosomes are genetically unstable and depress the rate of cell division in Saccharomyces cerevisiae. We have characterized the effects of a conditionally dicentric chromosome on the cell division cycle by using microscopy, flow cytometry, and an assay for histone H1 kinase activity. Activating the dicentric chromosome induced a delay in the cell cycle after DNA replication and before anaphase. The delay occurred in the absence of RAD9, a gene required to arrest cell division in response to DNA damage. The rate of dicentric chromosome loss, however, was elevated in the rad9 mutant. A mutation in BUB2, a gene required for arrest of cell division in response to loss of microtubule function, diminished the delay. Both RAD9 and BUB2 appear to be involved in the cellular response to a dicentric chromosome, since the conditionally dicentric rad9 bub2 double mutant was highly inviable. We conclude that a dicentric chromosome results in chromosome breakage and spindle aberrations prior to nuclear division that normally activate mitotic checkpoints, thereby delaying the onset of anaphase.

scholarly journals Cloning and molecular analysis of the HAP2 locus: a global regulator of respiratory genes in Saccharomyces cerevisiae.

1985 ◽  
Vol 5 (12) ◽  
pp. 3410-3416 ◽  
Author(s):  
J L Pinkham ◽  
L Guarente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Analysis ◽  
Carbon Sources ◽  
Direct Integration ◽  
Global Regulator ◽  
Low Levels ◽  
Gene Maps ◽  
Derivatives Of ◽  
In Cells

We report here the cloning of the HAP2 gene, a locus required for the expression of many cytochromes and respiratory functions in Saccharomyces cerevisiae. The cloned sequences were found to direct integration of a marked vector to the chromosomal HAP2 locus, and derivatives of these sequences were shown to yield chromosomal disruptions with a Hap2- phenotype. The gene maps 18 centimorgans centromere proximal to ade5 on the left arm of chromosome VII, distinguishing it from any other previously characterized nuclear petite locus. The HAP2 locus encodes a 1.3-kilobase transcript which is present at extremely low levels and which is derepressed in cells grown in media containing nonfermentable carbon sources. Levels of HAP2 mRNA are not reduced in strains bearing a mutation at the HAP3 locus, which is also required for expression of respiratory functions. Models outlining possible interactions of the products of the HAP2 and HAP3 genes are presented.

scholarly journals Allelic and ectopic interactions in recombination-defective yeast strains.

Genetics ◽  
1991 ◽  
Vol 127 (1) ◽  
pp. 53-60
Author(s):  
D F Steele ◽  
M E Morris ◽  
S Jinks-Robertson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chromosome Pairing ◽  
Parental Strain ◽  
Gene Products ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Ectopic Recombination ◽  
Yeast Strains ◽  
Chromosome Iii ◽  
Derivatives Of

Abstract Ectopic recombination in the yeast Saccharomyces cerevisiae has been investigated by examining the effects of mutations known to alter allelic recombination frequencies. A haploid yeast strain disomic for chromosome III was constructed in which allelic recombination can be monitored using leu2 heteroalleles on chromosome III and ectopic recombination can be monitored using ura3 heteroalleles on chromosomes V and II. This strain contains the spo13-1 mutation which permits haploid strains to successfully complete meiosis and which rescues many recombination-defective mutants from the associated meiotic lethality. Mutations in the genes RAD50, SPO11 and HOP1 were introduced individually into this disomic strain using transformation procedures. Mitotic and meiotic comparisons of each mutant strain with the wild-type parental strain has shown that the mutation in question has comparable effects on ectopic and allelic recombination. Similar results have been obtained using diploid strains constructed by mating MATa and MAT alpha haploid derivatives of each of the disomic strains. These data demonstrate that ectopic and allelic recombination are affected by the same gene products and suggest that the two types of recombination are mechanistically similar. In addition, the comparison of disomic and diploid strains indicates that the presence of a chromosome pairing partner during meiosis does not affect the frequency of ectopic recombination events involving nonhomologous chromosomes.

scholarly journals Nonrecombinant meiosis I nondisjunction in Saccharomyces cerevisiae induced by tRNA ochre suppressors.

Genetics ◽  
1989 ◽  
Vol 123 (1) ◽  
pp. 81-95 ◽  
Author(s):  
E J Louis ◽  
J E Haber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitotic Chromosome ◽  
Stop Codon ◽  
Fold Increase ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Nonsense Mutations ◽  
Chromosome Iii ◽  
Meiosis I ◽  
Chromosome Nondisjunction

Abstract The presence of the tRNA ochre suppressors SUP11 and SUP5 is found to induce meiosis I nondisjunction in the yeast Saccharomyces cerevisiae. The induction increases with increasing dosage of the suppressor and decreases in the presence of an antisuppressor. The effect is independent of the chromosomal location of SUP11. Each of five different chromosomes monitored exhibited nondisjunction at frequencies of 0.1%-1.1% of random spores, which is a 16-160-fold increase over wild-type levels. Increased nondisjunction is reflected by a marked increase in tetrads with two and zero viable spores. In the case of chromosome III, for which a 50-cM map interval was monitored, the resulting disomes are all in the parental nonrecombinant configuration. Recombination along chromosome III appears normal both in meioses that have no nondisjunction and in meioses for which there was nondisjunction of another chromosome. We propose that a proportion of one or more proteins involved in chromosome pairing, recombination or segregation are aberrant due to translational read-through of the normal ochre stop codon. Hygromycin B, an antibiotic that can suppress nonsense mutations via translational read-through, also induces nonrecombinant meiosis I nondisjunction. Increases in mistranslation, therefore, increase the production of aneuploids during meiosis. There was no observable effect of SUP11 on mitotic chromosome nondisjunction; however some disomes caused SUP11 ade2-ochre strains to appear white or red, instead of pink.

scholarly journals The PBN1 Gene of Saccharomyces cerevisiae: An Essential Gene That Is Required for the Post-translational Processing of the Protease B Precursor

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1277-1292 ◽  
Author(s):  
Rajesh R Naik ◽  
Elizabeth W Jones
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Secretory Pathway ◽  
Transmembrane Domain ◽  
Essential Gene ◽  
Signal Sequence ◽  
Signal Peptidase ◽  
Amino Terminal ◽  
Autocatalytic Cleavage ◽  
Protease B ◽  
Chromosome Iii

Abstract The vacuolar hydrolase protease B in Saccharomyces cerevisiae is synthesized as an inactive precursor (Prb1p). The precursor undergoes post-translational modifications while transiting the secretory pathway. In addition to N- and O -linked glycosylations, four proteolytic cleavages occur during the maturation of Prb1p. Removal of the signal peptide by signal peptidase and the autocatalytic cleavage of the large aminoterminal propeptide occur in the endoplasmic reticulum (ER). Two carboxy-terminal cleavages of the post regions occur in the vacuole: the first cleavage is catalyzed by protease A and the second results from autocatalysis. We have isolated a mutant, pbn1-1, that exhibits a defect in the ER processing of Prb1p. The autocatalytic cleavage of the propeptide from Prb1p does not occur and Prb1p is rapidly degraded in the cytosol. PBN1 was cloned and is identical to YCL052c on chromosome III. PBN1 is an essential gene that encodes a novel protein. Pbn1p is predicted to contain a sub-C-terminal transmembrane domain but no signal sequence. A functional HA epitope-tagged Pbn1p fusion localizes to the ER. Pbn1p is N-glycosylated in its amino-terminal domain, indicating a lumenal orientation despite the lack of a signal sequence. Based on these results, we propose that one of the functions of Pbn1p is to aid in the autocatalytic processing of Prb1p.

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