Micronuclear DNA sequences from Tetrahymena do not confer mitotic stability on ARS plasmids in Saccharomyces

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 690-696 ◽  
Author(s):  
Wendy H. Horsfall ◽  
Ronald E. Pearlman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Copy Number ◽  
Tetrahymena Thermophila ◽  
Assay System ◽  
Mitotic Stability ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genomic Libraries ◽  
Ade2 Gene

Genomic libraries containing micronuclear DNA sequences from Tetrahymena thermophila have been constructed in a vector containing ARS1, SUP11, and ura3 sequences from the yeast Saccharomyces cerevisiae. When transformed into a strain of S. cerevisiae carrying a suppressible ochre mutation in the ade2 gene, viable transformants are obtained only if the transforming plasmid is maintained at a copy number of one or two per cell. Mitotic segregation of the plasmid is easily assessed in a colour assay of transformants. Using this assay system, we showed that micronuclear DNA from Tetrahymena does not contain sequences that confer mitotic stability on yeast ARS-containing plasmids; i.e., sequences that function analogously to yeast centromere sequences. One transformant was analyzed that carries Tetrahymena sequences that maintain the copy number of the ARS plasmid at one or two per cell. However, these sequences do not confer mitotic stability on the transformants and they confer a phenotype in this assay similar to that of the REP3 gene of the yeast 2 μm plasmid.Key words: mitotic stability, centromere, Tetrahymena, Saccharomyces.

scholarly journals DNA SEQUENCES OF FRAMESHIFT AND OTHER MUTATIONS INDUCED BY ICR-170 IN YEAST

Genetics ◽  
1985 ◽  
Vol 111 (2) ◽  
pp. 233-241
Author(s):  
Joachim F Ernst ◽  
D Michael Hampsey ◽  
Fred Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Sequence Analysis ◽  
Genetic Analysis ◽  
Dna Sequences ◽  
Induced Mutations ◽  
Sequence Analyses ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Frameshift Mutations

ABSTRACT ICR-170-induced mutations in the CYC1 gene of the yeast Saccharomyces cerevisiae were investigated by genetic and DNA sequence analyses. Genetic analysis of 33 cyc1 mutations induced by ICR-170 and sequence analysis of eight representatives demonstrated that over one-third were frameshift mutations that occurred at one site corresponding to amino acid positions 29-30, whereas the remaining mutations were distributed more-or-less randomly, and a few of these were not frameshift mutations. The sequence results indicate that ICR-170 primarily induces G·C additions at sites containing monotonous runs of three G·C base pairs. However, some (see PDF) sites within the CYC1 gene were not mutated by ICR-170. Thus, ICR-170 is a relatively specific mutagen that preferentially acts on certain sites with monotonous runs of G·C base pairs.

scholarly journals Either of the major H2A genes but not an evolutionarily conserved H2A.F/Z variant of Tetrahymena thermophila can function as the sole H2A gene in the yeast Saccharomyces cerevisiae.

1996 ◽  
Vol 16 (6) ◽  
pp. 2878-2887 ◽  
Author(s):  
X Liu ◽  
J Bowen ◽  
M A Gorovsky
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Tetrahymena Thermophila ◽  
Yeast Species ◽  
Budding Yeast ◽  
Yeast Cells ◽  
Ciliated Protozoan ◽  
Yeast Saccharomyces Cerevisiae ◽  
Evolutionarily Conserved ◽  
Cold Sensitive ◽  
Conserved Epitope

H2A.F/Z histones are conserved variants that diverged from major H2A proteins early in evolution, suggesting they perform an important function distinct from major H2A proteins. Antisera specific for hv1, the H2A.F/Z variant of the ciliated protozoan Tetrahymena thermophila, cross-react with proteins from Saccharomyces cerevisiae. However, no H2A.F/Z variant has been reported in this budding yeast species. We sought to distinguish among three explanations for these observations: (i) that S. cerevisiae has an undiscovered H2A.F/Z variant, (ii) that the major S. cerevisiae H2A proteins are functionally equivalent to H2A.F/Z variants, or (iii) that the conserved epitope is found on a non-H2A molecule. Repeated attempts to clone an S. cerevisiae hv1 homolog only resulted in the cloning of the known H2A genes yHTA1 and yHTA2. To test for functional relatedness, we attempted to rescue strains lacking the yeast H2A genes with either the Tetrahymena major H2A genes (tHTA1 or tHTA2) or the gene (tHTA3) encoding hv1. Although they differ considerably in sequence from the yeast H2A genes, the major Tetrahymena H2A genes can provide the essential functions of H2A in yeast cells, the first such case of trans-species complementation of histone function. The Tetrahymena H2A genes confer a cold-sensitive phenotype. Although expressed at high levels and transported to the nucleus, hv1 cannot replace yeast H2A proteins. Proteins from S. cerevisiae strains lacking yeast H2A genes fail to cross-react with anti-hv1 antibodies. These studies make it likely that S. cerevisiae differs from most other eukaryotes in that it does not have an H2A.F/Z homolog. A hypothesis is presented relating the absence of H2A.F/Z in S. cerevisiae to its function in other organisms.

scholarly journals Introduction of extra telomeric DNA sequences into Saccharomyces cerevisiae results in telomere elongation.

1989 ◽  
Vol 9 (4) ◽  
pp. 1488-1497 ◽  
Author(s):  
K W Runge ◽  
V A Zakian
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Copy Number ◽  
Plasmid Copy Number ◽  
High Copy Number ◽  
Limiting Factor ◽  
Telomeric Dna ◽  
Base Pairs ◽  
Plasmid Copy ◽  
Telomere Elongation

The termini of Saccharomyces cerevisiae chromosomes consist of tracts of C1-3A (one to three cytosine and one adenine residue) sequences of approximately 450 base pairs in length. To gain insights into trans-acting factors at telomeres, high-copy-number linear and circular plasmids containing tracts of C1-3A sequences were introduced into S. cerevisiae. We devised a novel system to distinguish by color colonies that maintained the vector at 1 to 5, 20 to 50, and 100 to 400 copies per cell and used it to change the amount of telomeric DNA sequences per cell. An increase in the number of C1-3A sequences caused an increase in the length of telomeric C1-3A repeats that was proportional to plasmid copy number. Our data suggest that telomere growth is inhibited by a limiting factor(s) that specifically recognizes C1-3A sequences and that this factor can be effectively competed for by long tracts of C1-3A sequences at telomeres or on circular plasmids. Telomeres without this factor are exposed to processes that serve to lengthen chromosome ends.

The DLP1 mutant of the yeast Saccharomyces cerevisiae with an increased copy number of the 2μ plasmid shows a shortened lifespan

1999 ◽  
Vol 110 (1-2) ◽  
pp. 119-129 ◽  
Author(s):  
Zhaojun Xu ◽  
Kazuhiro Mitsui ◽  
Mitsuyoshi Motizuki ◽  
So-Ichi Yaguchi ◽  
Kunio Tsurugi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Copy Number ◽  
Yeast Saccharomyces Cerevisiae

scholarly journals Transformation of Saccharomyces cerevisiae with nonhomologous DNA: illegitimate integration of transforming DNA into yeast chromosomes and in vivo ligation of transforming DNA to mitochondrial DNA sequences

1993 ◽  
Vol 13 (5) ◽  
pp. 2697-2705
Author(s):  
R H Schiestl ◽  
M Dominska ◽  
T D Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Dna Sequences ◽  
Topoisomerase I ◽  
Target Sequence ◽  
Base Pairing ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Dna Fragment

When the yeast Saccharomyces cerevisiae was transformed with DNA that shares no homology to the genome, three classes of transformants were obtained. In the most common class, the DNA was inserted as the result of a reaction that appears to require base pairing between the target sequence and the terminal few base pairs of the transforming DNA fragment. In the second class, no such homology was detected, and the transforming DNA was integrated next to a CTT or GTT in the target; it is likely that these integration events were mediated by topoisomerase I. The final class involved the in vivo ligation of transforming DNA with nucleus-localized linear fragments of mitochondrial DNA.

scholarly journals A gene with specific and global effects on recombination of sequences from tandemly repeated genes in Saccharomyces cerevisiae.

Genetics ◽  
1993 ◽  
Vol 135 (3) ◽  
pp. 711-718 ◽  
Author(s):  
R L Keil ◽  
A D McWilliams
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Copy Number ◽  
Tandem Repeats ◽  
Chromosomal Location ◽  
Specific Factor ◽  
Yeast Saccharomyces Cerevisiae ◽  
Naturally Occurring ◽  
Type Information ◽  
Repeated Genes

Abstract The preservation of sequence homogeneity and copy number of tandemly repeated genes may require specific mechanisms or regulation of recombination. We have identified mutations that specifically affect recombination among natural repetitions in the yeast Saccharomyces cerevisiae. The rrm3 mutation stimulates mitotic recombination in the naturally occurring tandem repeats of the rDNA and copper chelatin (CUP1) genes. This mutation does not affect recombination of several other types of repeated genes tested including Ty elements, mating type information and duplications created by transformation. In addition to stimulating exchange among the multiple CUP1 repeats at their natural chromosomal location, rrm3 also increases recombination of a duplication of CUP1 units present at his4. This suggests that the RRM3 gene may encode a sequence-specific factor that contributes to a global suppression of mitotic exchange in sequences that can be maintained as tandem arrays.

scholarly journals Two Saccharomyces cerevisiae genes which control sensitivity to G1 arrest induced by Kluyveromyces lactis toxin.

1994 ◽  
Vol 14 (9) ◽  
pp. 6306-6316 ◽  
Author(s):  
A R Butler ◽  
J H White ◽  
Y Folawiyo ◽  
A Edlin ◽  
D Gardiner ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Copy Number ◽  
Kluyveromyces Lactis ◽  
Yeast Cells ◽  
Yeast Genome ◽  
G1 Arrest ◽  
Yeast Saccharomyces Cerevisiae ◽  
Toxin Resistance ◽  
Complementation Groups ◽  
Diploid Cells

The Kluyveromyces lactis toxin causes an arrest of sensitive yeast cells in the G1 phase of the cell division cycle. Two complementary genetic approaches have been undertaken in the yeast Saccharomyces cerevisiae to understand the mode of action of this toxin. First, two sequences conferring toxin resistance specifically in high copy number have been isolated and shown to encode a tRNA(Glu3) and a novel polypeptide. Disruption of the latter sequence in the yeast genome conferred toxin resistance and revealed that it was nonessential, while the effect of the tRNA(Glu)3 was highly specific and mediated resistance by affecting the toxin's target. An alpha-specific, copy number-independent suppressor of toxin sensitivity was also isolated and identified as MATa, consistent with the observation that diploid cells are partially resistant to the toxin. Second, in a comprehensive screen for toxin-resistant mutants, representatives of 13 complementation groups have been obtained and characterized to determine whether they are altered in the toxin's intracellular target. Of 10 genes found to affect the target process, one (KTI12) was found to encode the novel polypeptide previously identified as a multicopy resistance determinant. Thus, both loss of KTI12 function and elevated KTI12 copy number can cause resistance to the K. lactis toxin.

Reorganization of unique and repetitive sequences during nuclear development in Tetrahymena thermophila

1982 ◽  
Vol 60 (9) ◽  
pp. 847-853 ◽  
Author(s):  
Clifford F. Brunk ◽  
Smiley G. S. Tsao ◽  
Catherine H. Diamond ◽  
Pamela S. Ohashi ◽  
Nora N. G. Tsao ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Nuclear Dna ◽  
Tetrahymena Thermophila ◽  
Repetitive Sequences ◽  
Repeated Sequence ◽  
Sequence Family ◽  
Sequence Element ◽  
Genomic Libraries ◽  
Hybridization Probes ◽  
Nuclear Development

Genomic libraries of macro- and micro-nuclear DNA of the ciliate protozoan Tetrahymena thermophila were constructed in the bacteriophage vector λgtWESλB. Screening of these libraries with a probe for the repeated hexanucleotide sequence C4A2 showed many phage from the micronuclear library but few if any macronuclear sequences having homology to this probe. This is consistent with C4A2-repeating elements being present predominantly if not exclusively at or near the termini of macronuclear DNA. Sequences flanking C4A2-repeating elements were isolated from a number of purified phage and were used as hybridization probes to restriction endonuclease digested macro- and micro-nuclear DNA. These experiments revealed a repeated sequence family as well as unique sequences present only in micronuclear DNA. The repeated sequence element appears to be dispersed throughout the genome. Phage-containing individual members of this micronucleus limited sequence family were purified from the micronuclear library. Some of these phage contained sequences which hybridized to macronuclear DNA. These fragments therefore contain a "transition" region between micronucleus-limited sequences and sequences present in both nuclei.

scholarly journals Recombination of plasmids into the Saccharomyces cerevisiae chromosome is reduced by small amounts of sequence heterogeneity.

1983 ◽  
Vol 3 (7) ◽  
pp. 1204-1211 ◽  
Author(s):  
S Smolik-Utlaut ◽  
T D Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Recombinant Plasmid ◽  
Mitotic Recombination ◽  
Model System ◽  
Rrna Genes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Sequence Heterogeneity ◽  
Recombinant Plasmids ◽  
Chromosomal Loci

As a model system for studying the properties of mitotic recombination in the yeast Saccharomyces cerevisiae, we have examined recombination between a recombinant plasmid (introduced into the S. cerevisiae cell by transformation) and homologous chromosomal loci. The recombinant plasmids used in these experiments contained S. cerevisiae rRNA genes. We found that the frequency of integrative recombination is sensitive to small amounts of sequence heterogeneity. In addition, the frequency and specificity of these recombination events are affected by the lengths of the interacting homologous DNA sequences.

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