Modulation of induced reversion frequency by nucleotide pool imbalance as a tool for mutant characterization

1987 ◽  
Vol 10 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Rosalba Randazzo ◽  
A. di Leonardo ◽  
Stefania Bonatti ◽  
A. Abbondandolo
Keyword(s):  
Reversion Frequency

Controlling vitrification in Larixdecidua via culture media manipulation

1989 ◽  
Vol 19 (10) ◽  
pp. 1334-1337 ◽  
Author(s):  
J. McLaughlin ◽  
D. F. Karnosky
Keyword(s):  
Mortality Rate ◽  
Total Nitrogen ◽  
Normal Development ◽  
Culture Media ◽  
Adventitious Bud ◽  
Adventitious Buds ◽  
Reversion Frequency ◽  
The Media ◽  
Media Manipulation ◽  
Bacto Agar

Vitrification rates obtained from our inverted embryo system were significantly decreased by lowering the cytokinin concentrations in Brown and Lawrence medium containing 10 mM L-glutamine from 10 to 1 mg/L, or by replacing 10 mM L-glutamine with equimolar concentrations of Ca(NO3)2 or by adding 1 g/L Gelrite to the normal 10 g/L Difco–Bacto agar in the culture media. In all treatments, decreased vitrification was accompanied with decreased adventitious bud production. With reduced N6-benzylaminopurine, vitrification decreased from 77 to 29%, but bud production decreased from 61 to 17 buds per explant and mortality increased from 3 to 33%. Incorporation of Ca(NO3)2 into the media decreased vitrification from 87 to 21%, but the number of adventitious buds per embryo decreased from 75 to 42. Vitreous shoots were reverted to normal development with an 81% reversion frequency and a 6% mortality rate by culturing these shoots on Gresshof and Doy medium with one-half total nitrogen. Elongation of previously vitreous shoots was best when these shoots were cultured on Gresshof and Doy medium + 0.5 mg/L N6-benzylaminopurine for 2 weeks, followed by subculture on Gresshof of and Doy medium + 10 g/L charcoal.

scholarly journals Radiation-Induced Reversion of Transition Mutants

1964 ◽  
Vol 17 (4) ◽  
pp. 907 ◽  
Author(s):  
GW Grigg
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Base Pair ◽  
The Other ◽  
Wild Type ◽  
Lethal Effects ◽  
Reversion Frequency ◽  
X Irradiation ◽  
Radiation Induced ◽  
Adenine Thymine

X-irradiation increased the reversion frequency of two transition mutants of Escherichia coli, one of which (meth-) differed genetically from wild type by an adenine-thymine substitution of a guanine-cytosine base pair, the other (urg-2-) by a guanine-cytosine substitution of an adenine-thymine base pair. The lethal effects of the radiation were greatest when protein synthesis was prevented for a period immediately after irradiation. A period of 30 min at 37�0 was as effective as 22 hr. Irradiation of a saline suspension gave a lower survival of 0�2 times that of bacteria irradiated after being spread on minimal agar plates.

Inheritance of a mutable phenotype that is activated in alfalfa tissue culture

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 35-40 ◽  
Author(s):  
I. M. Ray ◽  
E. T. Bingham
Keyword(s):  
Tissue Culture ◽  
Preliminary Evidence ◽  
Anthocyanin Synthesis ◽  
In Planta ◽  
Reversion Frequency ◽  
Dosage Effects ◽  
Mutable Allele ◽  
Basic Color ◽  
Unstable Transmission

Mutable alleles, typically regulated by transposable elements, have been identified in a number of plant species. Tissue culture induced genomic shocks may activate such elements. A mutable recessive condition arose in tissue culture of alfalfa and was highly unstable in subsequent cycles of culture. The mutable allele, designated c2-m4, is allelic to the C2 locus, a basic color factor locus involved in anthocyanin synthesis. Current research has focused on the inheritance and instability of c2-m4 in new genetic backgrounds as well as on dosage effects of the allele. We have confirmed a previous report that c2-m4 reverts to function at much higher frequencies in vitro (reversion frequency ca. 0.23) than in planta (reversion frequency < 0.001). Over sexual generations c2-m4 continues to be unstable. Transmission of the mutable phenotype to selfed, testcross, and F2 populations demonstrated monofactorial inheritance patterns (P > 0.25). In populations expected to have some plants carrying two or more c2-m4 alleles, individuals were found that reverted in vitro at significantly higher frequencies than their parent (0.67 ± 0.04 and 0.44 ± 0.08 versus 0.20 ± 0.09). In planta reversion also increased with increasing c2-m4 dosage. Preliminary evidence indicates that as c2-m4 dosage increases, each allele maintains its original capacity to revert.Key words: somaclonal variation, transposable element, tissue culture, mutable allele.

INDUCTION BY MUTAGENS OF TANDEM GENE DUPLICATIONS IN THE glyS REGION OF THE ESCHERICHIA COLI CHROMOSOME

Genetics ◽  
1974 ◽  
Vol 78 (3) ◽  
pp. 823-830
Author(s):  
Daniel S Straus
Keyword(s):  
Escherichia Coli ◽  
Ultraviolet Light ◽  
Nitrous Acid ◽  
Trna Synthetase ◽  
Gene Duplications ◽  
Reversion Frequency

ABSTRACT Four mutagens (ultraviolet light, nitrous acid, the acridine half mustard ICR 372, and niridazole) have been found to increase the frequency of tandem gene duplications in the glyS region of the Escherichia coli chromosome. This result was obtained by quantitating the spontaneous and mutagen-induced reversion frequency of a glycyl-tRNA synthetase (glyS) mutant. Following mutagenesis, as many as 0.2% of the survivors were obszrved to contain duplications in the glyS region. In addition, several classes of stable revertants of the glyS mutant have been identified.

scholarly journals Increased levels of RNA oxidation enhance the reversion frequency in aging pro-apoptotic yeast mutants

APOPTOSIS ◽  
2016 ◽  
Vol 22 (2) ◽  
pp. 200-206 ◽  
Author(s):  
Mariarita Stirpe ◽  
Vanessa Palermo ◽  
Matteo Ferrari ◽  
Seweryn Mroczek ◽  
Joanna Kufel ◽  
...  
Keyword(s):  
Reversion Frequency ◽  
Rna Oxidation ◽  
Yeast Mutants

scholarly journals SPECIFICITY OF INSERTION BY THE TRANSLOCATABLE TETRACYCLINE-RESISTANCE ELEMENT Tn10

Genetics ◽  
1979 ◽  
Vol 92 (4) ◽  
pp. 1023-1040
Author(s):  
Nancy Kleckner ◽  
David A Steele ◽  
Katherine Reichardt ◽  
David Botstein
Keyword(s):  
Genetic Analysis ◽  
Genetic Mapping ◽  
Salmonella Typhimurium ◽  
Tetracycline Resistance ◽  
Equal Frequency ◽  
Reversion Frequency ◽  
Upper Limit ◽  
Phage P22 ◽  
Simple Possibility ◽  
The Relationship

ABSTRACT Genetic analysis of 131 independent transpositions of the tetracycline-resistance element TnlO from a single site in phage P22 into the histidine operon of Salmonella typhimurium reveals that Tn1O insertions are not randomly distributed along this chromosomal target. The insertions occur in 22 different "clusters"; insertions within each cluster are very tightly linked in recombination tests. TnlO insertions are not evenly distributed among the identified clusters. The existence of these clusters suggests that this chromosomal target contains particular genetic signals that guide TnlO to particular preferred positions for insertion. Insertions within each cluster occur in both orientations with roughly equal frequency.——The relationship among different insertions within each cluster has been examined. The resolution of genetic mapping places an upper limit of about 50 basepairs on the distance between different insertions within a cluster. Different insertions within a cluster usually have the same reversion frequency; however, heterogeneity in reversion frequency has been detected in at least two clusters. For most clusters, the available data are consistent with the simple possibility that all insertions within a cluster are at identical positions; however, the data do not exclude other possibilities.

scholarly journals DOMINANT CHROMOSOMAL MUTATION BYPASSING CHROMOSOMAL GENES NEEDED FOR KILLER RNA PLASMID REPLICATION IN YEAST

Genetics ◽  
1977 ◽  
Vol 87 (3) ◽  
pp. 453-469
Author(s):  
Reed B Wickner ◽  
Michael J Leibowitz
Keyword(s):  
Plasmid Replication ◽  
Wild Type ◽  
Double Stranded Rna ◽  
Virus Like Particles ◽  
Chromosomal Mutation ◽  
Reversion Frequency ◽  
Yeast Strains ◽  
Chromosomal Genes ◽  
Chromosomal Changes ◽  
Killer Plasmid

ABSTRACT Yeast strains carrying a double-stranded RNA plasmid of 1.4-1.7 × 106 daltons encapsulated in virus-like particles secrete a toxin that kills strains lacking this plasmid. The plasmid requires at least 24 chromosomal genes (pets, and mak1 through mak23) for its replication or maintenance. We have detected dominant Mendelian mutations (called KRB1 for killer replication bypass) that bypass two chromosomal genes, mak7 and pets, normally needed for plasmid replication. Strains mutant in mak7 and carrying the bypass mutation (mak7-1 KRB1) are isolated as frequent K+R+ sectors of predominantly K-R- segregants from crosses of mak7-1 with a wild-type killer. All KRB1 mutations isolated in this way are inherited as single dominant centromere-linked chromosomal changes. They define a new centromere. KRB1 is not a translational suppressor. KRB1 strains contain a genetically normal killer plasmid and ds RNA species approximately the same in size and amount as do wild-type killers. Bypass of both mak7 and pets by one mutation suggests that these two genes are functionally related. Two properties of the inheritance of KRB1 indicate an unusually high reversion frequency: (1) Heat or cycloheximide (treatments known to cure strains of the wild-type killer plasmid) readily induce conversion of mak7-1 KRB1 strains from killers to nonkillers with concomitant disappearance of KRB1 as judged by further crosses, and (2) mating two strains of the type mak7-1 KRB1 with each other yields mostly 2 K+R+: 2 K-R- segregation, although the same KRB1 mutation and the same killer plasmid are present in both parents.

Sign in / Sign up

Export Citation Format

Share Document