Table 1.

Effect of streptomycin treatment of E. colicells on mutation fixation at an ɛC residue borne on transfected M13 ssDNA

ExptHost strainaStreptomycin concn (μg/ml)bSurvival of ɛC DNA (C-DNA)cMutation frequency ± SD (%)d
TotalC→AC→T
AKH201,470 (4,410)2 ± 12 ± 11 ± 0
0.51,510 (4,630)8 ± 27 ± 11 ± 0
21,630 (5,079)15 ± 215 ± 11 ± 0
51,230 (4,359)24 ± 322 ± 32 ± 1
BKH2R01,250 (4,224)2 ± 11 ± 11 ± 0
0.51,500 (3,928)8 ± 16 ± 12 ± 1
21,410 (3,648)14 ± 111 ± 13 ± 1
51,010 (3,584)26 ± 124 ± 11 ± 1
CSR1000400 (1,044)5 ± 24 ± 11 ± 0
21,040 (2,500)13 ± 212 ± 12 ± 1
51,120 (2,870)23 ± 220 ± 22 ± 0
  • a KH2, wild type; KH2R, ΔrecA; SR100, ΔumuDC.

  • b Streptomycin was added to LB cultures inoculated with fresh overnight cell cultures, the cultures were allowed to grow to an optical density at 600 nm of 0.3 to 0.4 (about 100 min at 37°C with aeration), the streptomycin in the medium was removed by centrifugation and washing steps as described in the text, and the cells were processed for transfection.

  • c Values are numbers of infectious centers per transfection (50 ng of ssDNA); data shown are averages of results from three transfections of DNA bearing ɛC. The parenthetical numbers represent values from a single transfection of control DNA (ssDNA bearing a normal cytosine in place of ɛC).

  • d Multiplex sequence analysis data shown are averages of results from three to six independent elongation assays; the numbers were rounded to the nearest integer.