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Science 13 November 1964:
Vol. 146. no. 3646, pp. 927 - 929
DOI: 10.1126/science.146.3646.927
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Articles

Ionizing Radiation: Effect on Genetic Transcription

Ernest C. Pollard 1

1 Biophysics Department, Pennsylvania State University, University Park

Cells of Escherichia coli grown on maltose can be induced by the addition of thiomethyl galactoside to produce beta-galactosidase. If cells are irradiated shortly after induction, the transcription of the DNA ceases, and the enzyme produced by the messenger RNA is observed to reach a maximum. From these data the calculated half-life of unstable messenger RNA is given over a temperature range from 8.1 minutes at 10°C to 0.7 minute at 45°C. The kinetics of cessation of transcription give information on both meassenger RNA decay and rate of transcription. Arrhenius graphs for both these rates are given, and the activation energies mtieasured are 11,000 calories per mole for decay and 22,000 calories per mole for transcription. This relation to temperature is characteristic of enzymatic behavior.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Effect of Gamma Radiation on Dietary and Hormonal Induction of Enzymes in Rat Liver.
H. C. Pitot, C. Peraino, C. Lamar Jr., and S. Lesher (1965)
Science 150, 901-903
   Abstract »    PDF »
Ionizing Radiation: Effect of Irradiated Medium on Synthetic Processes.
E. C. Pollard, M. J. Ebert, C. Miller, K. Kolacz, and T. F. Barone (1965)
Science 147, 1045-1047
   Abstract »    PDF »


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