Linear Dose Response of Gene Conversion in Saccharomyces cerevisiae after Ionizing Radiation

1981 ◽  
Vol 85 (2) ◽  
pp. 349 ◽  
Author(s):  
P. Unrau ◽  
F. K. Zimmermann ◽  
L. D. Johnson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ionizing Radiation ◽  
Gene Conversion ◽  
Dose Response ◽  
Linear Dose

Non-Linear Dose-Response Relationships in Biology, Toxicology and Medicine

2002 ◽  
Author(s):  
Edward J. Calabrese
Keyword(s):  
Dose Response ◽  
Linear Dose ◽  
Non Linear

Analysis of Plasmid Deletion Induced by Ionizing Radiation in Yeast Saccharomyces cerevisiae

2007 ◽  
Author(s):  
E. Yatsevich ◽  
A. Stepanova ◽  
A. Sprincova ◽  
N. Koltovaya ◽  
Carlos Granja ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Ionizing Radiation ◽  
Yeast Saccharomyces Cerevisiae

A non-linear dose-response relation of female body mass index and in vitro fertilization outcomes

2021 ◽  
Author(s):  
Kefu Tang ◽  
Yuanqing Guo ◽  
Lei Wu ◽  
Ying Luo ◽  
Bo Gong ◽  
...  
Keyword(s):  
Body Mass Index ◽  
In Vitro Fertilization ◽  
Body Mass ◽  
Dose Response ◽  
Female Body ◽  
Vitro Fertilization ◽  
Linear Dose ◽  
Non Linear ◽  
Female Body Mass

scholarly journals Effects of exposure to low-dose ionizing radiation on changing platelets: a prospective cohort study

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Ning Liu ◽  
Yang Peng ◽  
Xinguang Zhong ◽  
Zheng Ma ◽  
Suiping He ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Ionizing Radiation ◽  
Dose Response ◽  
Low Dose ◽  
Linear Trend ◽  
Hematological Parameters ◽  
Response Relationship ◽  
Dose Response Relationship ◽  
Spline Models ◽  
Cumulative Radiation Dose

Abstract Background Numerous studies have concentrated on high-dose radiation exposed accidentally or through therapy, and few involve low-dose occupational exposure, to investigate the correlation between low-dose ionizing radiation and changing hematological parameters among medical workers. Methods Using a prospective cohort study design, we collected health examination reports and personal dose monitoring data from medical workers and used Poisson regression and restricted cubic spline models to assess the correlation between changing hematological parameters and cumulative radiation dose and determine the dose-response relationship. Results We observed that changing platelet of 1265 medical workers followed up was statistically different among the cumulative dose groups (P = 0.010). Although the linear trend tested was not statistically significant (Ptrend = 0.258), the non-linear trend tested was statistically significant (Pnon-linear = 0.007). Overall, there was a correlation between changing platelets and cumulative radiation dose (a change of βa 0.008 × 109/L during biennially after adjusting for gender, age at baseline, service at baseline, occupation, medical level, and smoking habits; 95% confidence interval [CI] = 0.003,0.014 × 109/L). Moreover, we also found positive first and then negative dose-response relationships between cumulative radiation dose and changing platelets by restricted cubic spline models, while there were negative patterns of the baseline service not less than 10 years (− 0.015 × 109/L, 95% CI = − 0.024, − 0.007 × 109/L) and radiation nurses(− 0.033 × 109/L, 95% CI = − 0.049, − 0.016 × 109/L). Conclusion We concluded that although the exposure dose was below the limit, medical workers exposed to low-dose ionizing radiation for a short period of time might have increased first and then decreased platelets, and there was a dose-response relationship between the cumulative radiation dose and platelets changing.

scholarly journals Role of DNA Replication Proteins in Double-Strand Break-Induced Recombination in Saccharomyces cerevisiae

2004 ◽  
Vol 24 (16) ◽  
pp. 6891-6899 ◽  
Author(s):  
Xuan Wang ◽  
Grzegorz Ira ◽  
José Antonio Tercero ◽  
Allyson M. Holmes ◽  
John F. X. Diffley ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dna Synthesis ◽  
Gene Conversion ◽  
Strand Break ◽  
Double Strand Break ◽  
S Phase ◽  
Temperature Sensitive ◽  
Replication Proteins ◽  
Dna Ligases ◽  
Mcm Proteins

ABSTRACT Mitotic double-strand break (DSB)-induced gene conversion involves new DNA synthesis. We have analyzed the requirement of several essential replication components, the Mcm proteins, Cdc45p, and DNA ligase I, in the DNA synthesis of Saccharomyces cerevisiae MAT switching. In an mcm7-td (temperature-inducible degron) mutant, MAT switching occurred normally when Mcm7p was degraded below the level of detection, suggesting the lack of the Mcm2-7 proteins during gene conversion. A cdc45-td mutant was also able to complete recombination. Surprisingly, even after eliminating both of the identified DNA ligases in yeast, a cdc9-1 dnl4Δ strain was able to complete DSB repair. Previous studies of asynchronous cultures carrying temperature-sensitive alleles of PCNA, DNA polymerase α (Polα), or primase showed that these mutations inhibited MAT switching (A. M. Holmes and J. E. Haber, Cell 96:415-424, 1999). We have reevaluated the roles of these proteins in G2-arrested cells. Whereas PCNA was still essential for MAT switching, neither Polα nor primase was required. These results suggest that arresting cells in S phase using ts alleles of Polα-primase, prior to inducing the DSB, sequesters some other component that is required for repair. We conclude that DNA synthesis during gene conversion is different from S-phase replication, involving only leading-strand polymerization.

The Escherichia coli recA gene increases UV-induced mitotic gene conversion in Saccharomyces cerevisiae

1994 ◽  
Vol 25 (5) ◽  
pp. 472-474 ◽  
Author(s):  
Viera Vlčková ◽  
Luba Černáková ◽  
Eva Farkašová ◽  
Jela Brozmanová
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Reca Gene ◽  
Mitotic Gene Conversion

Homothallic switching of Saccharomyces cerevisiae mating type genes by using a donor containing a large internal deletion

1985 ◽  
Vol 5 (8) ◽  
pp. 2154-2158
Author(s):  
B Weiffenbach ◽  
J E Haber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Mating Type ◽  
Gene Conversion Event ◽  
Conversion Event ◽  
Base Pair Deletion ◽  
Mating Type Genes ◽  
Type Gene ◽  
Mat Locus ◽  
Donor Locus

Homothallic switching of the mating type genes of Saccharomyces cerevisiae occurs by a gene conversion event, replacing sequences at the expressed MAT locus with a DNA segment copied from one of two unexpressed loci, HML or HMR. The transposed Ya or Y alpha sequences are flanked by homologous regions that are believed to be essential for switching. We examined the transposition of a mating type gene (hmr alpha 1-delta 6) which contains a 150-base-pair deletion spanning the site where the HO endonuclease generates a double-stranded break in MAT that initiates the gene conversion event. Despite the fact that the ends of the cut MAT region no longer share homology with the donor hmr alpha 1-delta 6, switching of MATa or MAT alpha to mat alpha 1-delta 6 was efficient. However, there was a marked increase in the number of aberrant events, especially the formation of haploid-inviable fusions between MAT and the hmr alpha 1-delta 6 donor locus.

scholarly journals Effects of Temperature on the Meiotic Recombination Landscape of the Yeast Saccharomyces cerevisiae

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Ke Zhang ◽  
Xue-Chang Wu ◽  
Dao-Qiong Zheng ◽  
Thomas D. Petes
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Conversion ◽  
Meiotic Recombination ◽  
Hot Spots ◽  
Genetic Maps ◽  
Dna Breaks ◽  
Low Levels ◽  
C 30 ◽  
Recombination Hot Spots ◽  
In Cells

ABSTRACT Although meiosis in warm-blooded organisms takes place in a narrow temperature range, meiosis in many organisms occurs over a wide variety of temperatures. We analyzed the properties of meiosis in the yeast Saccharomyces cerevisiae in cells sporulated at 14°C, 30°C, or 37°C. Using comparative-genomic-hybridization microarrays, we examined the distribution of Spo11-generated meiosis-specific double-stranded DNA breaks throughout the genome. Although there were between 300 and 400 regions of the genome with high levels of recombination (hot spots) observed at each temperature, only about 20% of these hot spots were found to have occurred independently of the temperature. In S. cerevisiae , regions near the telomeres and centromeres tend to have low levels of meiotic recombination. This tendency was observed in cells sporulated at 14°C and 30°C, but not at 37°C. Thus, the temperature of sporulation in yeast affects some global property of chromosome structure relevant to meiotic recombination. Using single-nucleotide polymorphism (SNP)-specific whole-genome microarrays, we also examined crossovers and their associated gene conversion events as well as gene conversion events that were unassociated with crossovers in all four spores of tetrads obtained by sporulation of diploids at 14°C, 30°C, or 37°C. Although tetrads from cells sporulated at 30°C had slightly (20%) more crossovers than those derived from cells sporulated at the other two temperatures, spore viability was good at all three temperatures. Thus, despite temperature-induced variation in the genetic maps, yeast cells produce viable haploid products at a wide variety of sporulation temperatures. IMPORTANCE In the yeast Saccharomyces cerevisiae , recombination is usually studied in cells that undergo meiosis at 25°C or 30°C. In a genome-wide analysis, we showed that the locations of genomic regions with high and low levels of meiotic recombination (hot spots and cold spots, respectively) differed dramatically in cells sporulated at 14°C, 30°C, and 37°C. Thus, in yeast, and likely in other non-warm-blooded organisms, genetic maps are strongly affected by the environment.

Cytogenetic dose–response and adaptive response in cells of ungulate species exposed to ionizing radiation

2004 ◽  
Vol 74 (1-3) ◽  
pp. 73-81 ◽  
Author(s):  
B.A Ulsh ◽  
S.M Miller ◽  
F.F Mallory ◽  
R.E.J Mitchel ◽  
D.P Morrison ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Dose Response ◽  
Adaptive Response ◽  
In Cells
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