Recovery of the priming activity of DNA in x-irradiated Escherichia coli.

The template activity of DNA in RNA synthesis in vitro has been studied in Escherichia coli B/r and Bs-1 after exposure to X-rays and postirradiation incubation in growth medium for 60 min at 37 degrees C. The incubation of E. coli B/r after irradiation with 9.3 krad results in the increase of the priming activity of DNA practically to that of unirradiated cells, while after exposure to 18.6 krad the incubation leads to a partial increase in its priming activity. As for E. coli Bs-1, the incubation of the bacteria irradiated with 9.3 krad causes a slight recovery in the priming activity of DNA.