scholarly journals High mutation frequency in DNA transfected into mammalian cells.

1983 ◽  
Vol 80 (10) ◽  
pp. 3015-3019 ◽  
Author(s):  
M. P. Calos ◽  
J. S. Lebkowski ◽  
M. R. Botchan
Keyword(s):  
Mammalian Cells ◽  
Mutation Frequency ◽  
High Mutation Frequency

scholarly journals Transfected DNA is mutated in monkey, mouse, and human cells.

1984 ◽  
Vol 4 (10) ◽  
pp. 1951-1960 ◽  
Author(s):  
J S Lebkowski ◽  
R B DuBridge ◽  
E A Antell ◽  
K S Greisen ◽  
M P Calos
Keyword(s):  
Mammalian Cells ◽  
Time Course ◽  
Mutation Frequency ◽  
Spontaneous Mutation ◽  
Bacterial Cells ◽  
Shuttle Vectors ◽  
High Mutation Frequency ◽  
Mouse Cells ◽  
Nih 3T3 ◽  
Viral Sequences

Papovavirus-based shuttle vectors containing the bacterial lacI gene were used to show that a mutation frequency in the range of 1% occurs in lacI when such vectors are transfected into COS7 and CV-1 simian cells, NIH 3T3, 3T6, L, and C127 mouse cells, and human 293 and HeLa cells. This frequency is approximately four orders of magnitude higher than the spontaneous mutation frequency in either mammalian or bacterial cells. The mutations are predominantly base substitutions and deletions and also include insertions from the mammalian genome. Time course experiments argue that mutagenesis occurs soon after arrival of the DNA into the nucleus. However, replication of the vector is not required since mutations occur even when the vector lacks all viral sequences. The high mutation frequency appears to be the characteristic outcome of transfection of DNA into mammalian cells.

Transfected DNA is mutated in monkey, mouse, and human cells

1984 ◽  
Vol 4 (10) ◽  
pp. 1951-1960
Author(s):  
J S Lebkowski ◽  
R B DuBridge ◽  
E A Antell ◽  
K S Greisen ◽  
M P Calos
Keyword(s):  
Mammalian Cells ◽  
Time Course ◽  
Mutation Frequency ◽  
Spontaneous Mutation ◽  
Bacterial Cells ◽  
Shuttle Vectors ◽  
High Mutation Frequency ◽  
Mouse Cells ◽  
Nih 3T3 ◽  
Viral Sequences

Papovavirus-based shuttle vectors containing the bacterial lacI gene were used to show that a mutation frequency in the range of 1% occurs in lacI when such vectors are transfected into COS7 and CV-1 simian cells, NIH 3T3, 3T6, L, and C127 mouse cells, and human 293 and HeLa cells. This frequency is approximately four orders of magnitude higher than the spontaneous mutation frequency in either mammalian or bacterial cells. The mutations are predominantly base substitutions and deletions and also include insertions from the mammalian genome. Time course experiments argue that mutagenesis occurs soon after arrival of the DNA into the nucleus. However, replication of the vector is not required since mutations occur even when the vector lacks all viral sequences. The high mutation frequency appears to be the characteristic outcome of transfection of DNA into mammalian cells.

scholarly journals Nucleoside Analogues Are Potent Inducers of Pol V-mediated Mutagenesis

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 843
Author(s):  
Balagra Kasim Sumabe ◽  
Synnøve Brandt Ræder ◽  
Lisa Marie Røst ◽  
Animesh Sharma ◽  
Eric S. Donkor ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Mutation Frequency ◽  
Nucleoside Analogues ◽  
Cancer Therapies ◽  
E Coli ◽  
Replicative Stress ◽  
Pol V ◽  
Dna And Rna ◽  
Sos Induction ◽  
Anti Cancer

Drugs targeting DNA and RNA in mammalian cells or viruses can also affect bacteria present in the host and thereby induce the bacterial SOS system. This has the potential to increase mutagenesis and the development of antimicrobial resistance (AMR). Here, we have examined nucleoside analogues (NAs) commonly used in anti-viral and anti-cancer therapies for potential effects on mutagenesis in Escherichia coli, using the rifampicin mutagenicity assay. To further explore the mode of action of the NAs, we applied E. coli deletion mutants, a peptide inhibiting Pol V (APIM-peptide) and metabolome and proteome analyses. Five out of the thirteen NAs examined, including three nucleoside reverse transcriptase inhibitors (NRTIs) and two anti-cancer drugs, increased the mutation frequency in E. coli by more than 25-fold at doses that were within reported plasma concentration range (Pl.CR), but that did not affect bacterial growth. We show that the SOS response is induced and that the increase in mutation frequency is mediated by the TLS polymerase Pol V. Quantitative mass spectrometry-based metabolite profiling did not reveal large changes in nucleoside phosphate or other central carbon metabolite pools, which suggests that the SOS induction is an effect of increased replicative stress. Our results suggest that NAs/NRTIs can contribute to the development of AMR and that drugs inhibiting Pol V can reverse this mutagenesis.

scholarly journals SPONTANEOUS UNSTABLE UNC-22 IV MUTATIONS IN C. ELEGANS VAR. BERGERAC

Genetics ◽  
1984 ◽  
Vol 108 (4) ◽  
pp. 859-877
Author(s):  
D G Moerman ◽  
R H Waterston
Keyword(s):  
Mutation Frequency ◽  
Spontaneous Mutation ◽  
Phenotypic Effect ◽  
C Elegans ◽  
High Mutation Frequency ◽  
Mutator Activity ◽  
Discrete Site ◽  
Unstable Mutations ◽  
Spontaneous Mutation Frequency ◽  
Forward Mutation

ABSTRACT This paper describes a mutator system in the nematode Caenorhabditis elegans var. Bergerac for the gene unc-22. Of nine C. elegans and two C. briggsae strains tested only the Bergerac BO strain yielded mutant animals at a high frequency and the unc-22 IV gene is a preferred mutational target. The forward spontaneous mutation frequency at the unc-22 locus in Bergerac BO is about 1 × 10-4, and most of these spontaneous unc-22 mutations revert at frequencies between 2 × 10-3 and 2 × 10-4. Both the forward mutation frequency and the reversion frequency are sensitive to genetic background. Spontaneous unc-22 mutations derived in a Bergerac background and placed in a primarily Bristol background revert at frequencies of <10-6. When reintroduced into a Bergerac/Bristol hybrid background the mutations once again become unstable. The mutator activity could not be localized to a discrete site in the Bergerac genome. Nor did mutator activity require the Bergerac unc-22 gene as a target since the Bristol unc-22 homolog placed in a Bergerac background also showed high mutation frequency. Intragenic mapping of two spontaneous unc-22 alleles, st136 and st137, place both mutations in the central region of the known unc-22 map. However, these mutations probably recombine with one another, suggesting that the unstable mutations can occur in more than one site in unc-22. Examination of the phenotypic effect of these mutations on muscle structure indicates that they are less severe in their effect than a known amber allele. We suggest that this mutator system is polygenic and dispersed over the nematode genome and could represent activity of the transposable element Tc1.

scholarly journals Allele Frequency of the C.5G>A Mutation in the PRCD Gene Responsible for Progressive Retinal Atrophy in English Cocker Spaniel Dogs

Animals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 844 ◽  
Author(s):  
Larissa R. Andrade ◽  
Amanda M. Caceres ◽  
Anelize S. Trecenti ◽  
Claudia Valeria S. Brandão ◽  
Micaella G. Gandolfi ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Genetic Disease ◽  
Mutation Frequency ◽  
Progressive Retinal Atrophy ◽  
Cocker Spaniel ◽  
High Mutation Frequency ◽  
Retinal Atrophy ◽  
History Of ◽  
Eye Examination ◽  
Mutation Region

Progressive retinal atrophy (PRA) due to the c.5G>A mutation in the progressive rod–cone degeneration (PRCD) gene is an important genetic disease in English cocker spaniel (ECS) dogs. Because the prevalence of this disease has not been verified in Brazil, this study aimed to evaluate the allele frequency of the c.5G>A mutation in the PRCD gene. Purified DNA from 220 ECS dogs was used for genotyping, of which 131 were registered from 18 different kennels and 89 were unregistered. A clinical eye examination was performed in 28 of the genotyped animals; 10 were homozygous mutants. DNA fragments containing the mutation region were amplified by PCR and subjected to direct genomic sequencing. The prcd-PRA allele frequency was 25.5%. Among the registered dogs, the allele frequency was 14.9%; among the dogs with no history of registration, the allele frequency was 41%. Visual impairment was observed in 80% (8/10) of the homozygous mutant animals that underwent clinical eye examination. The high mutation frequency found in this study emphasizes the importance of genotyping ECSs as an early diagnostic test, especially as part of an informed breeding program, to avoid clinical cases of PRA.

scholarly journals Mutation and Recombination Frequencies Reveal a Biological Contrast within Strains of Cucumber Mosaic Virus

2015 ◽  
Vol 89 (13) ◽  
pp. 6817-6823 ◽  
Author(s):  
Justin S. Pita ◽  
Viktoriya Morris ◽  
Marilyn J. Roossinck
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Mutation Frequency ◽  
Recombination Frequency ◽  
In Planta ◽  
Emerging Viruses ◽  
Content Type ◽  
Viral Genomes ◽  
High Mutation Frequency ◽  
Major Player

ABSTRACTRecentin plantastudies have shown that strains Fny and LS ofCucumber mosaic virus(CMV) display differential genetic diversities, Fny and LS having higher and lower mutation frequencies, respectively (J. S. Pita and M. J. Roossinck, J Virol 87:790–797, 2012http://dx.doi.org/10.1128/JVI.01891-12). In this article, we show that these virus strains have differential recombination frequencies as well. However, the high-diversity Fny strain is a low-recombination virus, whereas the very-low-diversity LS strain is instead a high-recombination virus. Unlike the mutation frequency that was determined by both RNAs 1 and 2, the control elements of recombination frequency reside predominantly within RNA 2, specifically within the 2a gene.IMPORTANCERecombination is an important mechanism in virus evolution that can lead to increased or decreased variation and is a major player in virus speciation events that can lead to emerging viruses. Although viral genomes show very frequent evidence of recombination, details of the mechanism involved in these events are still poorly understood. We show here that the reciprocal effects of high mutation frequency and low recombination frequency (andvice versa) involve the RNA-dependent RNA polymerase of the virus, and we speculate that these evolutionary events are related to differences in processivity for two strains of the same virus.

scholarly journals Superoxide is a mediator of an altruistic aging program in Saccharomyces cerevisiae

2004 ◽  
Vol 166 (7) ◽  
pp. 1055-1067 ◽  
Author(s):  
Paola Fabrizio ◽  
Luisa Battistella ◽  
Raffaello Vardavas ◽  
Cristina Gattazzo ◽  
Lee-Loung Liou ◽  
...  
Keyword(s):  
Mutation Frequency ◽  
Premature Aging ◽  
Natural Environments ◽  
Computational Simulations ◽  
Changing Environments ◽  
High Mutation Frequency ◽  
Aging Program ◽  
Programmed Aging ◽  
Age Dependent

Aging is believed to be a nonadaptive process that escapes the force of natural selection. Here, we challenge this dogma by showing that yeast laboratory strains and strains isolated from grapes undergo an age- and pH-dependent death with features of mammalian programmed cell death (apoptosis). After 90–99% of the population dies, a small mutant subpopulation uses the nutrients released by dead cells to grow. This adaptive regrowth is inversely correlated with protection against superoxide toxicity and life span and is associated with elevated age-dependent release of nutrients and increased mutation frequency. Computational simulations confirm that premature aging together with a relatively high mutation frequency can result in a major advantage in adaptation to changing environments. These results suggest that under conditions that model natural environments, yeast organisms undergo an altruistic and premature aging and death program, mediated in part by superoxide. The role of similar pathways in the regulation of longevity in organisms ranging from yeast to mice raises the possibility that mammals may also undergo programmed aging.

Mutagenesis of a shuttle vector plasmid in mammalian cells

1984 ◽  
Vol 4 (3) ◽  
pp. 435-441
Author(s):  
A Razzaque ◽  
S Chakrabarti ◽  
S Joffee ◽  
M Seidman
Keyword(s):  
Mammalian Cells ◽  
Mutation Frequency ◽  
Shuttle Vector ◽  
Marker Gene ◽  
Point Mutations ◽  
Deletion Mutagenesis ◽  
Bacterial Marker ◽  
Cellular Markers ◽  
Microbiological Procedures ◽  
Insertion Mutants

Recently we and others have reported a high frequency of mutagenesis of shuttle vector plasmids after passage in mammalian cells (Razzaque et al., Proc. Natl. Acad. Sci. U.S.A. 80:3010-3014, 1983; Calos et al., Proc. Natl. Acad. Sci. U.S.A. 80:3015-3019, 1983). The mutation frequency was determined by monitoring the integrity of a bacterial marker gene on the plasmid by standard microbiological procedures. Mutant plasmids contained deletions, insertions of cell DNA, and point mutations. The observed mutation frequency of 1% is much higher than that of cellular markers and could be due to the induction of a mutagenic environment by infection with a replicating plasmid. Alternatively, the hypermutagenesis may be due to some critical transient or persistent difference between the DNA in the plasmid and the cellular chromosome. We performed a number of experiments designed to distinguish between these alternatives, with particular reference to deletion mutagenesis. We conclude that mutagenesis was specific to the plasmid and propose that the majority of the deletion and insertion mutants were generated very early in the infection, before replication of the vector. However, some deletion mutagenesis also occurred after plasmid replication had begun.

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