The loss of chemically induced mutations in excision-deficient and -proficient yeast (Saccharomyces cerevisiae)

1984 ◽  
Vol 130 (3) ◽  
pp. 183
Author(s):  
B.J. Kilbey
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Induced Mutations ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chemically Induced

scholarly journals EFFECT OF GENES CONTROLLING RADIATION SENSITIVITY ON CHEMICALLY INDUCED MUTATIONS IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1976 ◽  
Vol 83 (2) ◽  
pp. 285-301
Author(s):  
Louise Prakash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Radiation Sensitivity ◽  
Chemical Mutagenesis ◽  
Repair System ◽  
Induced Mutations ◽  
Yeast Saccharomyces Cerevisiae ◽  
Chemical Agents ◽  
Gene Coding ◽  
Chemically Induced ◽  
High Doses

ABSTRACT The effect of 16 different genes (rad) conferring radiation sensitivity on chemically induced reversion in the yeast Saccharomyces cerevisiae was determined. The site of reversion used was a well-defined chain initiation mutant mapping in the structural gene coding for iso-1-cytochrome c. High doses of EMS and HNO2 resulted in decreased reversion of cyc1-131 in rad6, rad9 and rad15 strains compared to the normal RAD+ strains. In addition, rad52 greatly decreased EMS reversion of cyc1-131 but had not effect on HNO2-induced reversion; rad18, on the other hand, increased HNO2-induced reversion but did not alter EMS-induced reversion. When NQO was used as the mutagen, every rad gene tested, except for rad14, had an effect on reversion; rad6, rad9, rad15, rad17, rad18, rad22, rev1, rev2 and rev3 lowered NQO reversion while rad1, rad2, rad3, rad4, rad10, rad12 and rad16 increased it compared to the RAD+ strain. The effect of rad genes on chemical mutagenesis is discussed in terms of their effect on UV mutagenesis. It is concluded that although the nature of the repair pathways may differ for UV- and chemically-induced mutations in yeast, a functional repair system is required for the induction of mutation by the chemical agents NQO, EMS and HNO2.

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 FRAMESHIFT SUPPRESSION IN SACCHAROMYCES CEREVISIAE. II. GENETIC PROPERTIES OF GROUP II SUPPRESSORS

Genetics ◽  
1980 ◽  
Vol 95 (4) ◽  
pp. 833-853 ◽  
Author(s):  
Michael R Culbertson ◽  
Karen M Underbrink ◽  
Gerald R Fink
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Linkage ◽  
Suppressor Gene ◽  
Induced Mutations ◽  
Site Mutation ◽  
Yeast Saccharomyces Cerevisiae ◽  
Frameshift Suppression ◽  
Large Numbers ◽  
Informational Suppressors ◽  
Group Ii

ABSTRACT Suppressors of ICR-induced mutations that exhibit behavior similar to bacterial frameshift suppressors have been identified in the yeast Saccharomyces cerevisiae. The yeast suppressors have been divided into two groups. One of these groups (Group II: SUFI, SUF3, SUF4, SUF5 and SUF6) appears to include a set of informational suppressors in which the vehicle of suppression is glycyl-tRNA. Some of the genetic properties of Group II suppressors are described in this communication.—Corevertants of the Group II frameshift mutations his4-519 and leu2-3 have been characterized to determine the spectrum of reversion events induced by the frameshift mutagen ICR-170. Seventythree ICR-induced corevertants were analyzed. With the exception of one corevertant, which carried an allele of SUF1, all carried alleles of SUF3 or SUF5, SUF1, SUF3, SUF4 and SUF6 were represented among spontaneous and UV-induced corevertants. In the course of these experiments one of the suppressors was mapped. SUF5, the probable structural gene for tRNAGLY1, is located between ade2 and ade9 on chromosome XV.—SUF1, SUF4 and SUF6 have novel properties and comprise a distinct subset of suppressors. Although these suppressors show no genetic linkage to each other, they share several common features including lethality in haploid pairwise combinations, reduced tRNAGLY3 isoacceptor activity and increased efficiency of suppression in strains carrying the cytoplasmically inherited [PSI] element. In addition, strains carrying SUFI, SUF4 or SUF6 are phenotypically unstable and give rise to mitotic Suf+ segregants at high frequency. These segregants invariably contain a linked, second-site mutation that maps in or adjacent to the suppressor gene itself. Strains carrying any of these suppressors also give rise to mitotic segregants that exhibit enhanced efficiency of suppression; mutations responsible for this phenotype map at two loci, upf1 and upf2. These genes show no genetic linkage to any of the Group II suppressors.—Methods that permit positive selection for mutants with decreased or enhanced efficiency of suppression have been devised in order to examine large numbers of variants. The importance of these interacting mutants is underscored by their potential utility in studying suppressor function at the molecular level.

Highly mutable sites for ICR-170-induced frameshift mutations are associated with potential DNA hairpin structures: studies with SUP4 and other Saccharomyces cerevisiae genes

1986 ◽  
Vol 6 (12) ◽  
pp. 4425-4432
Author(s):  
D M Hampsey ◽  
R A Koski ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Base Pair ◽  
Temporal Stability ◽  
Loop Formation ◽  
Induced Mutations ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mutagen Specificity ◽  
Hairpin Structures

The majority of the mutations induced by ICR-170 in both the CYC1 gene (J. F. Ernst et al. Genetics 111:233-241, 1985) and the HIS4 gene (L. Mathison and M. R. Culbertson, Mol. Cell. Biol. 5:2247-2256, 1985) of the yeast Saccharomyces cerevisiae were recently shown to be single G . C base-pair insertions at monotonous runs of two or more G . C base pairs. However, not all sites were equally mutable; in both the CYC1 and HIS4 genes there is a single highly mutable site where a G . C base pair is preferentially inserted at a [sequence in text]. Here we report the ICR-170 mutagen specificity at the SUP4-o tyrosine tRNA gene of yeast. Genetic fine structure analysis and representative DNA sequence determination of ICR-170-induced mutations revealed that there is also a single highly mutable site in SUP4-o and that the mutation is a G . C base-pair insertion at a monotonous run of G . C base pairs. Analysis of DNA sequences encompassing the regions of highly mutable sites for all three genes indicated that the mutable sites are at the bases of potential hairpin structures; this type of structure could not be found at any of the other, less mutable G . C runs in SUP4, CYC1, and HIS4. Based on these results and recent information regarding novel DNA structural conformations, we present a mechanism for ICR-170-induced mutagenesis. (i) ICR-170 preferentially binds to DNA in the beta conformation; factors that increase the temporal stability of this structure, such as adjacent stem-and-loop formation, increase the frequency of ICR-170 binding; (ii) the observed mutagen specificity reflects formation of a preferred ICR-170 intercalative geometry at [sequence in text] sites; (iii) during replication or repair, ICR-170 remains associated with the single-stranded template; (iv) stuttering or strand slippage by the polymerization complex as it encounters the mutagen results in nucleotide duplication; (v) subsequent replication or mismatch repair fixes the insertion into the genome. This mechanism accounts for both the IRC-170 mutagenic specificity and the molecular basis of the highly mutable sites in S. cerevisiae.

scholarly journals Masking and purging mutations following EMS treatment in haploid, diploid and tetraploid yeast (Saccharomyces cerevisiae)

2001 ◽  
Vol 77 (1) ◽  
pp. 9-26 ◽  
Author(s):  
BARBARA K. MABLE ◽  
SARAH P. OTTO
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ploidy Level ◽  
Ancestral State ◽  
Relative Importance ◽  
Deleterious Mutations ◽  
Induced Mutations ◽  
Yeast Saccharomyces Cerevisiae ◽  
Ploidy Levels ◽  
Type Locus ◽  
Volume Measurements

The yeast, Saccharomyces cerevisiae, was used as a model to investigate theories of ploidy evolution. Mutagenesis experiments using the alkylating agent EMS (ethane methyl sulphonate) were conducted to assess the relative importance that masking of deleterious mutations has on response to and recovery from DNA damage. In particular, we tested whether cells with higher ploidy levels have relatively higher fitnesses after mutagenesis, whether the advantages of masking are more pronounced in tetraploids than in diploids, and whether purging of mutations allows more rapid recovery of haploid cells than cells with higher ploidy levels. Separate experiments were performed on asexually propagating stationary phase cells using (1) prototrophic haploid (MATα) and diploid (MATa/α) strains and (2) isogenic haploid, diploid and tetraploid strains lacking a functional mating type locus. In both sets of experiments, haploids showed a more pronounced decrease in apparent growth rate than diploids, but both haploids and diploids appeared to recover very rapidly. Tetraploids did not show increased benefits of masking compared with diploids but volume measurements and FACScan analyses on the auxotrophic strains indicated that all treated tetraploid strains decreased in ploidy level and that some of the treated haploid lines increased in ploidy level. Results from these experiments confirm that while masking deleterious mutations provides an immediate advantage to higher ploidy levels in the presence of mutagens, selection is extremely efficient at removing induced mutations, leading growth rates to increase rapidly over time at all ploidy levels. Furthermore, ploidy level is itself a mutable trait in the presence of EMS, with both haploids and tetraploids often evolving towards diploidy (the ancestral state of S. cerevisiae) during the course of the experiment.

scholarly journals EXPRESSION OF RADIATION-INDUCED MUTATIONS AT THE ARGININE PERMEASE (CAN1) LOCUS IN SACCHAROMYCES CEREVISIAE

Genetics ◽  
1979 ◽  
Vol 91 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Elmar Gocke ◽  
Thomas R Manney
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Medium ◽  
Culture Conditions ◽  
X Rays ◽  
Induced Mutations ◽  
Rapid Decay ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mutant Genotype ◽  
Radiation Induced ◽  
Arginine Permease

ABSTRACT In the yeast Saccharomyces cerevisiae, the expression of resistance to the L-arginine analog, L-canavanine, after mutagenesis, is strongly dependent on the metabolic state of the cell. The frequency of mutations recovered after exposure to ultraviolet light or X rays was measured under a variety of culture conditions. The results indicate that the frequency of mutants recovered is determined by the following three factors: (1) The potential mutants still possess enough permease activity to take up some of the cell poison, and some are therefore killed before they can express the mutant genotype. The sensitivity is strongly influenced by the endogenous free arginine, which is in turn influenced by the growth medium. (2) The rapid decay of the permease molecules and the inability of the potential mutants to resynthesize this protein results in a rapidly increasing chance of expression when selection is delayed. (3) During the time when the permease activity is decaying, repair of the mutagen-induced damage appears to occur.

scholarly journals FRAMESHIFT SUPPRESSION IN SACCHAROMYCES CEREVISIAE. III. ISOLATION AND GENETIC PROPERTIES OF GROUP III SUPPRESSORS

Genetics ◽  
1980 ◽  
Vol 95 (4) ◽  
pp. 855-875 ◽  
Author(s):  
Claudia M Cummins ◽  
Richard F Gaber ◽  
Michael R Culbertson ◽  
Richard Mann ◽  
Gerald R Fink
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Induced Mutations ◽  
Yeast Saccharomyces Cerevisiae ◽  
Nonsense Mutations ◽  
Mapping Procedure ◽  
Group Iii ◽  
Frameshift Suppression ◽  
Group Ii ◽  
Chromosome Iii

ABSTRACT Suppressors of ICR-induced mutations that exhibit behavior similar to bacterial frameshift suppressors have been identified in the yeast Saccharomyces cerevisiae. The yeast suppressors have been divided into two groups. Previous evidence indicated that suppressors of one group (Group II: SUFI, SUF3, SUF4, SUF5 and SUF6) represent mutations in the structural genes for glycyl-tRNA's. Suppressors of the other group (Group III: SUF2 and SUF7) were less well characterized. Although they suppressed some ICR-revertible mutations, they failed to suppress Group II frameshift mutations. This communication provides a more thorough characterization of the Group III suppressors and describes the isolation and properties of four new suppressors in that group (SUF1, SUF9, SUF10 and suf11).—In our original study, Group III suppressors were isolated as revertants of the Group III mutations his4-712 and his4-713. All suppressors obtained as ICR-induced revertants of these mutations mapped at the SUF2 locus near the centromere of chromosome III. Suppressors mapping at other loci were obtained in this study by analyzing spontaneous and UV-induced revertants of the Group III mutations. SUF2 and SUF10 suppress both Group III his4 mutations, whereas SUF7, SUF8, SUF9 and suf11 suppress his4-713, but not his4-712. All of the suppressors except suf11 are dominant in diploids homozygous for his4-713. The suppressors fail to suppress representative UAA, UAG and UGA nonsense mutations.—SUP9 is linked to the centromere of chromosome VI, and SUF10 is linked to the centromere of chromosome XIV. A triploid mapping procedure was used to determine the chromosome locations of SUF7 and SUF8. Subsequent standard crosses revealed linkage of SUF7 to cdc5 on chromosome XIII and linkage of SUF8 to cdcl2 and pet3 on chromosome VIII.

scholarly journals Highly mutable sites for ICR-170-induced frameshift mutations are associated with potential DNA hairpin structures: studies with SUP4 and other Saccharomyces cerevisiae genes.

1986 ◽  
Vol 6 (12) ◽  
pp. 4425-4432 ◽  
Author(s):  
D M Hampsey ◽  
R A Koski ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Sequences ◽  
Base Pair ◽  
Temporal Stability ◽  
Loop Formation ◽  
Induced Mutations ◽  
Base Pairs ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mutagen Specificity ◽  
Hairpin Structures

The majority of the mutations induced by ICR-170 in both the CYC1 gene (J. F. Ernst et al. Genetics 111:233-241, 1985) and the HIS4 gene (L. Mathison and M. R. Culbertson, Mol. Cell. Biol. 5:2247-2256, 1985) of the yeast Saccharomyces cerevisiae were recently shown to be single G . C base-pair insertions at monotonous runs of two or more G . C base pairs. However, not all sites were equally mutable; in both the CYC1 and HIS4 genes there is a single highly mutable site where a G . C base pair is preferentially inserted at a [sequence in text]. Here we report the ICR-170 mutagen specificity at the SUP4-o tyrosine tRNA gene of yeast. Genetic fine structure analysis and representative DNA sequence determination of ICR-170-induced mutations revealed that there is also a single highly mutable site in SUP4-o and that the mutation is a G . C base-pair insertion at a monotonous run of G . C base pairs. Analysis of DNA sequences encompassing the regions of highly mutable sites for all three genes indicated that the mutable sites are at the bases of potential hairpin structures; this type of structure could not be found at any of the other, less mutable G . C runs in SUP4, CYC1, and HIS4. Based on these results and recent information regarding novel DNA structural conformations, we present a mechanism for ICR-170-induced mutagenesis. (i) ICR-170 preferentially binds to DNA in the beta conformation; factors that increase the temporal stability of this structure, such as adjacent stem-and-loop formation, increase the frequency of ICR-170 binding; (ii) the observed mutagen specificity reflects formation of a preferred ICR-170 intercalative geometry at [sequence in text] sites; (iii) during replication or repair, ICR-170 remains associated with the single-stranded template; (iv) stuttering or strand slippage by the polymerization complex as it encounters the mutagen results in nucleotide duplication; (v) subsequent replication or mismatch repair fixes the insertion into the genome. This mechanism accounts for both the IRC-170 mutagenic specificity and the molecular basis of the highly mutable sites in S. cerevisiae.

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