Table 1.

Fluctuation test data (mean ± SEM) of ϕX174 WT and GATC mutants.

Virus	Testsa	N0b	N1c × 10–6	P0d	me × 106	µf × 106	rg
WT	15	211 ± 25	0.28 ± 0.05	0.52 ± 0.05	3.69 ± 1.03	1.58 ± 0.44	8.11 ± 0.29
20GATC	3	320 ± 134	3.09 ± 1.03	0.29 ± 0.13	0.48 ± 0.04	0.21 ± 0.15	8.68 ± 0.29
4GATC	3	117 ± 16	0.11 ± 0.00	0.76 ± 0.05	2.50 ± 0.37	1.07 ± 0.16	7.38 ± 0.26
4iGATC	3	128 ± 3	4.06 ± 1.10	0.74 ± 0.11	0.08 ± 0.02	0.03 ± 0.01	8.27 ± 0.11
A3963G	3	197 ± 30	1.15 ± 0.73	0.54 ± 0.23	0.79 ± 0.05	0.33 ± 0.02	8.24 ± 0.58
C3934G/C3935A	3	326 ± 76	1.17 ± 0.31	0.75 ± 0.04	0.27 ± 0.03	0.12 ± 0.01	8.19 ± 0.33
A3940G/T3943C	3	395 ± 207	0.21 ± 0.16	0.35 ± 0.20	16.6 ± 6.95	7.13 ± 2.98	7.78 ± 0.32

^aEach test consists of twenty-four independent cultures.

^bInitial number of pfu per culture.

^cFinal number of pfu per culture.

^dFraction of cultures showing no gro87 resistant plaques.

^egro-resistance mutation rate estimated by the null-class method as $m= \frac{-\text{ln}{P}_0}{N_1-N_0}$.

^f$\mu = \frac{3m}{T}$, where T = 7 is the number of substitutions leading to gro87 resistance.

^g$r= \text{ln}(N_1/N_0)/t$, where t is the incubation time in hours.