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.

scholarly journals RESOLUTION OF DICENTRIC CHROMOSOMES BY TY-MEDIATED RECOMBINATION IN YEAST

Genetics ◽  
1985 ◽  
Vol 110 (3) ◽  
pp. 397-419
Author(s):  
Richard T Surosky ◽  
Bik-Kwoon Tye
Keyword(s):  
Centromeric Region ◽  
Ring Chromosome ◽  
Normal Chromosome ◽  
Meiotic Segregation ◽  
Linear Chromosome ◽  
Ty Elements ◽  
Dicentric Chromosomes ◽  
Chromosome Iii ◽  
The Right ◽  
Diploid Cells

ABSTRACT We have integrated a plasmid containing a yeast centromere, CEN5, into the HIS4 region of chromosome III by transformation. Of the three transformant colonies examined, none contained a dicentric chromosome, but all contained a rearranged chromosome III. In one transformant, rearrangement occurred by homologous recombination between two Ty elements; one on the left arm and the other on the right arm of chromosome III. This event produced a ring chromosome (ring chromosome III) of about 60 kb consisting of CEN3 and all other sequences between the two Ty elements. In addition, a linear chromosome (chromosome IIIA) consisting of sequences distal to the two Ty elements including CEN5, but lacking 60 kb of sequences from the centromeric region, was produced. Two other transformants also contain a similarly altered linear chromosome III as well as an apparently normal copy of chromosome III. These results suggest that dicentric chromosomes cannot be maintained in yeast and that dicentric structures must be resolved for the cell to survive.—The meiotic segregation properties of ring chromosome III and linear chromosome IIIA were examined in diploid cells which also contained a normal chromosome III. Chromosome IIIA and normal chromosome III disjoined normally, indicating that homology or parallel location of the centromeric regions of these chromosomes are not essential for proper meiotic segregation. In contrast, the 60-kb ring chromosome III, which is homologous to the centromeric region of the normal chromosome III, did not appear to pair with fidelity with chromosome III.

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 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.

Efficient production of a ring derivative of chromosome III by the mating-type switching mechanism in Saccharomyces cerevisiae

1983 ◽  
Vol 3 (5) ◽  
pp. 803-810
Author(s):  
A J Klar ◽  
J N Strathern ◽  
J B Hicks ◽  
D Prudente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Genetic Information ◽  
Recombination Event ◽  
Ring Chromosome ◽  
Efficient Production ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Type Switching ◽  
Chromosome Iii

The mating-type switches in the yeast Saccharomyces cerevisiae occur by unidirectional transposition of replicas of unexpressed genetic information, residing at HML or HMR, into the mating-type locus (MAT). The source loci, HML and HMR, remain unchanged. Interestingly, when the HM cassettes are expressed, as in marl strains, the HML and HMR cassettes can also efficiently switch, apparently by obtaining genetic information from either of the other two cassettes (Klar et al., Cell 25:517-524, 1981). We have isolated a novel chromosome III rearrangement in heterothallic (marl ho) strains, which is also produced efficiently in marl HO cells, presumably the consequence of a recombination event between HML and HMR. The fusion results in the loss of sequences which are located distal to HML and to HMR and produces a ring derivative of chromosome III. Cells containing such a ring chromosome are viable as haploids; apparently, no essential loci are located distal to the HM loci. The fusion cassette behaves as a standard HM locus with respect to both regulation by the MAR/SIR control and its role in switching MAT.

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 replication map of a 61-kb circular derivative of Saccharomyces cerevisiae chromosome III.

1992 ◽  
Vol 3 (9) ◽  
pp. 999-1013 ◽  
Author(s):  
S A Greenfeder ◽  
C S Newlon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Ring Chromosome ◽  
Replication Initiation ◽  
Cis Acting ◽  
Dna Replication Initiation ◽  
Ars Elements ◽  
Highly Active ◽  
Origin Function ◽  
Chromosome Iii

Using two-dimensional agarose gel electrophoresis, we determined the replication map of a 61-kb circular derivative of Saccharomyces cerevisiae chromosome III. The three sites of DNA replication initiation on the ring chromosome are specific and coincide with ARS elements. The three origins are active to different degrees; two are used > 90% of the time, whereas the third is used only 10-20% of the time. The specificity of these origins is shown by the fact that only ARS elements were competent for origin function, and deletion of one of the ARS elements removed the corresponding replication origin. The activity of the least active origin was not increased by deletion of the nearby highly active origin, demonstrating that the highly active origin does not repress function of the relatively inactive origin. Replication termination on the ring chromosome does not occur at specific sites but rather occurs over stretches of DNA ranging from 3 to 10 kb. A new region of termination was created by altering the sites of initiation. The position of the new termination site indicates that termination is not controlled by specific cis-acting DNA sequences, but rather that replication termination is determined primarily by the positions at which replication initiates. In addition, two sites on the ring chromosome were found to slow the progression of replication forks through the molecule: one is at the centromere and one at the 3' end of a yeast transposable element.

scholarly journals Ring chromosome 3 instability at mitosis

2019 ◽  
pp. 40-45
Author(s):  
Н.В. Шилова ◽  
М.Е. Миньженкова ◽  
Ж.Г. Маркова ◽  
А.А. Тарлычева ◽  
Д.А. Юрченко
Keyword(s):  
Ring Chromosome ◽  
Postnatal Growth ◽  
Chromosome 3 ◽  
Fish Analysis ◽  
Developmental Abnormalities ◽  
Dysmorphic Features ◽  
Severe Intellectual Disability ◽  
Ring Chromosomes ◽  
Mitotic Instability ◽  
Variable Phenotype

Актуальность. Кольцевая хромосома 3 - редкая хромосомная аномалия, характеризующаяся выраженной вариабельностью фенотипических отклонений. Наиболее характерными проявлениями присутствия в кариотипе кольцевой хромосомы 3 являются пре- и постнатальная задержка роста, задержка психомоторного развития, микроцефалия и другие аномалии развития. Кольцевая структура может приводить к нарушению нормального расхождения хромосом при клеточном делении и вызывает митотическую нестабильность, приводящую к динамическому мозаицизму. В данном сообщении представлен случай митотической нестабильности кольцевой хромосомы 3 у ребенка с множественными пороками и аномалиями развития, демонстрирующий влияние вторичного хромосомного дисбаланса на степень выраженности фенотипических аномалий. Цель: исследование митотической нестабильности кольцевой хромосомы 3. Методы: FISH с ДНК-зондами на хромосому 3. Результаты. При стандартном цитогенетическом исследовании определен кариотип 46,XX,r(3)(p26q29). При FISH-анализе обнаружено наличие нескольких клонов клеток, содержащих различные варианты аномальных по структуре производных кольцевой хромосомы 3. Выводы. Присутствие кольцевых хромосом в геноме является причиной митотической нестабильности, что приводит к формированию соматического динамического мозаицизма. Соматический динамический мозаицизм, вследствие которого образуются клоны клеток с различным хромосомным дисбалансом, вносит существенный вклад в формирование аномального фенотипа. Ring chromosome 3 is a rare chromosomal abnormality with a highly variable phenotype principally characterized by pre- and postnatal growth retardation, developmental delay, mild to severe intellectual disability, microcephaly and mild dysmorphic features. The presence of a ring chromosome causes mitotic instability and often results in dynamic mosaicism with cells showing chromosomal or segmental aneuploidies and leading to various phenotypic consequences. We present a case of mitotic instability of ring chromosome 3 in a child with multiple malformations and developmental abnormalities. Aim: The investigation of ring chromosome 3 instability at mitosis. Methods: FISH with DNA probe on chromosome 3. Results: The karyotype of a child - 46,XX,r(3)(p26q29). FISH analysis revealed a mosaic clones derived from ring chromosome 3. Conclusions: The ring chromosomes are unstable at mitosis and lead to the formation of somatic dynamic mosaicism. Mitotic instability of ring chromosome 3 demonstrates the influence of secondary genetic imbalance on severity of symptoms in our patient.

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 Efficient production of a ring derivative of chromosome III by the mating-type switching mechanism in Saccharomyces cerevisiae.

1983 ◽  
Vol 3 (5) ◽  
pp. 803-810 ◽  
Author(s):  
A J Klar ◽  
J N Strathern ◽  
J B Hicks ◽  
D Prudente
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Genetic Information ◽  
Recombination Event ◽  
Ring Chromosome ◽  
Efficient Production ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Mating Type Switching ◽  
Chromosome Iii

The mating-type switches in the yeast Saccharomyces cerevisiae occur by unidirectional transposition of replicas of unexpressed genetic information, residing at HML or HMR, into the mating-type locus (MAT). The source loci, HML and HMR, remain unchanged. Interestingly, when the HM cassettes are expressed, as in marl strains, the HML and HMR cassettes can also efficiently switch, apparently by obtaining genetic information from either of the other two cassettes (Klar et al., Cell 25:517-524, 1981). We have isolated a novel chromosome III rearrangement in heterothallic (marl ho) strains, which is also produced efficiently in marl HO cells, presumably the consequence of a recombination event between HML and HMR. The fusion results in the loss of sequences which are located distal to HML and to HMR and produces a ring derivative of chromosome III. Cells containing such a ring chromosome are viable as haploids; apparently, no essential loci are located distal to the HM loci. The fusion cassette behaves as a standard HM locus with respect to both regulation by the MAR/SIR control and its role in switching MAT.

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