Dose-effect curves of s-mutation and killing in Serratia marcescens

Further Studies on the Uv-Induced Photoreversible and Non-Photoreversible Mutation Through the Action Spectra in Yeast Cells

“…tendency of increase around 2537 0 The average value over the wavelengths used is somewhat less if compared with those by Kaplan (1956) in S. marcescens and Zelle et al (1958), in E. coli but the general features of wavelength-dependence among these works are in good conformity.…”

“…2). (Kaplan 1956;Zelle et al 1958). Kaplan (1963), Witkin et al (1963), and Witkin (1964) reported that certain mutations to prototroph are photoreversible in E. coli phr-strain, and concluded that thymine dimer is not the sole mutational damage in DNA.…”

PHOTOREACTIVATION OF INDUCED MUTATION AND INACTIVATION OF ESCHERICHIA COLI EXPOSED TO VARIOUS WAVE LENGTHS OF MONOCHROMATIC ULTRAVIOLET RADIATION

“…The effect of PR on mutation induction has also been studied by a number of investigators in a variety of organisms (see Dulbecco, 1955 andZelle andHollaender, 1955 for discussion), but only one accurate estimate of the nonphotoreversible proportion of the mutagenic effect has thus far been reported. This was an estimate of 0.10 made by Kaplan (1956) for s-mutations in S. marcescens exposed to 2537 A ultraviolet. Despite the difference in behavior of the s-and SD-4 mutation systems, as indicated by the very much larger X-ray target volume for mutation induction and the saturation of the mutation-dose curve at the very high level of about 15 per cent of s-mutants (Kaplan, 1956), the value of 0.10 agrees quite well with the average of 0.18 reported in table 5 for the six wave lengths employed in the present study, since we believe that 0.18 is probably greater than the true value, owing to the unusually high values obtained in replication 1.…”

“…The high degree of similarity between the mutation and inactivation action spectra made it of interest to determine if mutation and inactivation behaved similarly with respect to photoreactivation (hereafter referred to as PR) by subsequent exposure to longer wave lengths of the near-ultraviolet and visible regions of the spectrum. Although a number of investigators have studied the influence of PR on mutation induction (see Zelle andHollaender, 1955, andDulbecco, 1955, for review), the data in general are not extensive and, except for Kaplan (1956), no accurate estimates of the dose-reduction ratios for the PR of mutation induction have been made. In the present experiments, washed cell suspensions of the same total cell concentration employed in the action spectrum studies were exposed to the monochromatic ultraviolet in 1-cm2 quartz Beckman spectrophotometer cuvettes.…”

MUTAGENIC EFFECTS OF NEAR ULTRAVIOLET AND VISIBLE RADIANT ENERGY ON CONTINUOUS CULTURES OF ESCHERICHIA COLI*

“…They also found sunlight to be mutagenic, reporting wavelengths between 290 nm and 320 nm as the effective cornponent. Kaplan [2] demonstrated the induction of white sectored colonies in Serraria marcescens by 3 13-380 nm ultraviolet (u.v.). Recently, Kubitschek [ 3 ] studied induction of resistance to bacteriophage T5 by 330-380 nm U.V.…”