As in the induction of r mutants in bacteriophage T4 by gamma-rays, the radiation-induced reversion of T4 amber mutants to wild-type was found to depend on the product of the DNA-repair gene x of the phage. Neither the efficiency of induction of r mutants nor the efficiency of reversion of ambers was enhanced by the presence of oxygen during irradiation. T4 differed in this respect from phage T7, for which no indication has been found that gamma-ray mutagenesis results from error-prone repair of DNA damage. Notwithstanding the substantial contribution of misrepair to mutation induction in T4, the efficiency of induction per base-pair observed for irradiation under oxygen was lower than that found previously for T7.
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http://dx.doi.org/10.1016/0027-5107(79)90120-9 | DOI Listing |
Mutat Res Rev Mutat Res
January 2025
Radiation Epidemiology Branch, National Cancer Institute, MD 20892-9778, USA; Faculty of Health, Science and Technology, Oxford Brookes University, Headington Campus, OX3 0BP, UK.
Biological effects of ionizing radiation vary not merely with total dose but also with temporal dose distribution. Sparing dose protraction effects, in which dose protraction reduces effects of radiation have widely been accepted and generally assumed in radiation protection, particularly for stochastic effects (e.g.
View Article and Find Full Text PDFPLoS One
January 2025
Fig Research Station, Fars Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Estahban, Iran.
The dried fig cv. Sabz of Iran, distinguishes out among the several fig cultivars for its unique characteristics and excellent properties. The aims to this study were 1) Carefully monitoring the resulting phenotypic changes in growth patterns, leaf morphology, shoot traits, root characteristics, and other relevant traits after irradiated with different gamma rays; 2) Investigating the LD25, 50, 75 and GR25, 50, 75 values at different gamma radiation doses for chose optimum dose.
View Article and Find Full Text PDFIn Saccharomyces cerevisiae cells, the bulk of mitochondrial DNA (mtDNA) replication is mediated by the replicative high-fidelity DNA polymerase γ. However, upon UV irradiation low-fidelity translesion polymerases: Polη, Polζ and Rev1, participate in an error-free replicative bypass of UV-induced lesions in mtDNA. We analysed how translesion polymerases could function in mitochondria.
View Article and Find Full Text PDFAppl Radiat Isot
November 2024
Division of Crop Improvement, ICAR-Sugarcane Breeding Institute, Coimbatore, 641007, India. Electronic address:
Sugarcane is an economically important polyploid crop whose genetic complexity and limited fertility poses a challenge for crop improvement programs. Gamma radiation-induced mutagenesis is an alternate approach for generating a diverse array of agronomically useful mutants, accelerating varietal development in a long-duration crop like sugarcane. To develop agronomically useful mutants of a commercial sugarcane genotype Co 99004, gamma ray induced in vitro mutagenesis was carried out.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
Department of Molecular Science and Technology, Advanced College of Bio-Convergence Engineering, Ajou University, Woncheon-dong, Yeongtong-gu, Suwon 16499, Republic of Korea.
The gamma-ray-induced random mutagenesis of an engineered β-carotene-producing XL1-Blue resulted in the variant Ajou 45, which exhibits significantly enhanced β-carotene production. The whole-genome sequencing of Ajou 45 identified 55 mutations, notably including a reduction in the copy number of , encoding adenylate cyclase, a key enzyme regulating intracellular cyclic AMP (cAMP) levels. While the parental XL1-Blue strain harbors two copies of , Ajou 45 retains only one, potentially leading to reduced intracellular cAMP concentrations.
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