Interaction Between Ultraviolet Light and γ-Radiation Damage in the Induction of Mutants of Escherichia coli: the Response in Strains with Normal and Reduced Ability to Repair Ultraviolet Damage
The exposure of tryptophan-requiring Escherichia colib/r wp2 to u.v.- and γ-irradiation (in either order) results in more revertants than would be expected if the two treatments were independent. The excess mutants (‘interaction mutants’) were produced in increasing number by increasing doses of u. v.-or γ-radiation. Evidence is presented that the interaction occurs post-irradiation. Although the excision-repair and mutation frequency decline systems for u.v. damage are not involved in the interaction itself (since a strain deficient in these systems, E. coliwp2 her–, is no less efficient at producing interaction mutants than E.colib/r wp 2) the u.v. component involved in interaction is sensitive to one or both of these systems as is shown by the very much lower u.v. doses at which interaction occurs in E. coliwp2 her–.
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Interaction Between Ultraviolet Light and γ-Radiation Damage in the Induction of Mutants of Escherichia coli: the Response in Strains with Normal and Reduced Ability to Repair Ultraviolet Damage