Appendix Determination of probability of plasmid loss per generation

Pirojkov, V.; Tsouladze, A.; Kouprina, Natalya; Larionov, Vladimir

doi:10.1016/0378-1119(84)90261-0

Cited by 9 publications

(2 citation statements)

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“…Quantitative measurements of the frequencies of cells derived from chromosome III loss and recombination (17) and the frequency of centromeric plasmid loss per generation (37) were performed as previously described. Genotypes of the strains characterized are found in (ctf4-1 leu2Al) for complementation of the sectoring phenotype.…”

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“…In one, the copy number of the circular minichromosome YCp41 (6) in ctf4-1 mutant cells was determined by observing its segregation in tetrads after it was mated to wild-type cells. First, the mitotic instability of YCp41 minichromosomes was assessed by measuring the frequency of minichromosome-lacking cells in selectively grown cultures as previously described (37). The measured frequencies for CTF4 (YNK29) and ctf4-1 (YNK30) strains were 2.0 x 10-2 and 1.5 x 10-1, respectively, indicating a 7.5-fold increase in minichromosome loss in the mutant.…”

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CTF4 (CHL15) mutants exhibit defective DNA metabolism in the yeast Saccharomyces cerevisiae.

Kouprina¹,

Kroll²,

Bannikov³

et al. 1992

Mol. Cell. Biol.

101

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We have analyzed the CTF4 (CHL15) gene, earlier identified in two screens for yeast mutants with increased rates of mitotic loss of chromosome III and artificial circular and linear chromosomes. Analysis of the segregation properties of circular minichromosomes and chromosome fragments indicated that sister chromatid loss (1:0 segregation) is the predominant mode of chromosome destabilization in ctf4 mutants, though nondisjunction events (2:0 segregation) also occur at an increased rate. Both inter-and intrachromosomal mitotic recombination levels are elevated in cf4 mutants, whereas spontaneous mutation to canavanine resistance was not elevated. A genomic clone of CTF4 was isolated and used to map its physical and genetic positions on chromosome XVI. Nucleotide sequence analysis of CTF4 revealed a 2.8-kb open reading frame with a 105-kDa predicted protein sequence. The CTF4 DNA sequence is identical to that of POBI, characterized as a gene encoding a protein that associates in vitro with DNA polymerase ao At the N-terminal region of the protein sequence, zinc finger motifs which define potential DNA-binding domains were found. The C-terminal region of the predicted protein displayed similarity to sequences of regulatory proteins known as the helix-loop-helix proteins. Data on the effects of a frameshift mutation suggest that the helix-loop-helix domain is essential for CTF4 function. Analysis of sequences upstream of the CTF4 open reading frame revealed the presence of a hexamer element, ACGCGT, a sequence associated with many DNA metabolism genes in budding yeasts. Disruption of the coding sequence of CTF4 did not result in inviability, indicating that the CTF4 gene is nonessential for mitotic cell division. However, c1f4 mutants exhibit an accumulation of large budded cells with the nucleus in the neck. ctf4 rad52 double mutants grew very slowly and produced extremely high levels (50%) of inviable cell division products compared with either single mutant alone, which is consistent with a role for CTF4 in DNA metabolism.

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confidence: 99%

mentioning

confidence: 99%

CTF4 (CHL15) mutants exhibit defective DNA metabolism in the yeast Saccharomyces cerevisiae.

Kouprina¹,

Kroll²,

Bannikov³

et al. 1992

Mol. Cell. Biol.

101

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A model for growth of Saccharomyces cerevisiae containing a recombinant plasmid in selective media

Sardonini

DiBiasio

1987

Biotech & Bioengineering

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A major problem in the use of plasmids as recombinant vectors is the problem of plasmid-free cell generation from plasmid shedding and subsequent growth. A common technique for controlling the population of plasmidfree cells is the use of selective media against these cells using an auxotrophic host and a plasmid that has the ability to produced the essential metabolite. A distributed model describing the growth of Saccharomyces cerevisiae containing a recombinant plasmid in selective media was developed. The model allows for growth and production of a metabolite by the plasmid-carrying strain and growth of the plasmid-free cells on resulting metabolite concentrations. Through a determination of system constants and numerical solution to the equations, experimental batch and continuous culture results for cell concentration transients could be simulated by the model. The results indicated that despite selective pressure, plasmid-free cell growth was significant.

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Genetic control of chromosone stability in the yeast Saccharomyces cerevisiae

Kouprina

Pashina

Nikolaishwili

et al. 1988

Yeast

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We have identified four new genetic loci: CHL2 (on chromosome XII), CHL3 (on chromosome XII); CHL4 (on chromosome IV), and CHL5 (on chromosome IX), controlling mitotic transmission of yeast chromosomes. The frequency of loss of chromosomes is 10-100-fold higher in chl5, chl2, chl3 and chl4 mutants than observed in wild-type strains. The mutants also show unstable maintenance of artificial circular minichromosomes with various chromosomal replicators (ARS) and one of the centromeric loci (CEN3, CEN4, CEN5 or CEN6). The instability of minichromosomes in the chl5, chl2, and chl4 mutants is due to the loss of minichromosomes in mitosis (1:0 segregation). In the chl3 mutant the instability of artificial minichromosomes is due to nondisjunction (2:0 segregation). The CHL3 gene therefore appears to affect the segregation of chromosomes during cell division.

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Appendix Determination of probability of plasmid loss per generation

Cited by 9 publications

References 1 publication

CTF4 (CHL15) mutants exhibit defective DNA metabolism in the yeast Saccharomyces cerevisiae.

CTF4 (CHL15) mutants exhibit defective DNA metabolism in the yeast Saccharomyces cerevisiae.

A model for growth of Saccharomyces cerevisiae containing a recombinant plasmid in selective media

Genetic control of chromosone stability in the yeast Saccharomyces cerevisiae

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