Table 1 Results from Luria–Delbrück fluctuation tests
am432am696am1067
Fluctuation testa123123123
Embedded Image (pfu)b24.124.724.913.063.312.034.617.139.0
Initial revertants (pfu)c0.000.270.530.000.270.007.20.400.80
Embedded Image × 10−3 (pfu)d8.395.696.4714.311.63.1911.41.636.21
Embedded Image × 10−3 (pfu)e2.182.254.284.856.152.674.691.184.07
Cultures with no revertants921129618132011
Cultures with 1 revertant736564637
Cultures with 2 revertants303462114
Cultures with 3 revertants102210000
Cultures with 4–100 revertants301450102
Cultures with >100 revertants100000300
P0f9/2321/2412/249/246/2418/2413/2120/2411/24
Reversion rateg m × 1041.10.241.10.691.20.900.421.11.3
Reversion rateh Embedded Image × 1044.40.601.62.02.31.11.01.61.9
Reversion ratei m(z) × 1041.40.291.30.861.51.10.531.41.6
Reversion ratej m(z, R) × 1040.340.911.0
  • a Each test consisted of 24 parallel cultures.

  • b As determined from three independent titrations of the inoculum.

  • c Expected initial number of revertants in 24 cultures as determined from three independent titrations of the inoculum.

  • d Arithmetic mean of Embedded Image obtained from 6/24 random cultures.

  • e Harmonic mean of Embedded Image obtained from the same random cultures.

  • f Fraction of cultures showing no revertants, excluding cultures with >100 revertants from the total.

  • g Embedded Image.

  • h Embedded Image.

  • i Correction for incomplete plating using a numerically estimated Embedded Image, where Embedded Image.

  • j Correction for incomplete plating and selection, using a numerically estimated Embedded Image, where Embedded Image. R was quantified only for am1067 and its CAG revertant by fitness assays. For am432 and am696 selection bias should be lower, because probably the fittest revertants were those carrying the wild-type CAG codon.