a
Exp#
|
b
Bkg (CMF × 10
−3
)
|
2 mM MgCl
2
|
0.4 mM ZnCl
2
|
0.25 mM CoCl
2
|
|---|
c
1.6 mM free
|
0.15 mM free
|
0.07 mM free
|
|---|
(CMF × 10
−3
)
|
(CMF × 10
−3
)
|
(CMF × 10
−3
)
|
|---|
d1 | 4/1205 | 10/960 | 7/1328 | |
3.3 | 10 (6.7) | 5.3 (2.0) |
2 | 3/1726 | 13/1826 | 5/1315 | 16/1639 |
1.7 | 7.1 (5.4) | 3.8 (2.1) | 9.8 (8.1) |
3 | 1/1577 | 13/1899 | 6/2195 | 11/1520 |
0.6 | 6.8 (6.2) | 2.7 (2.1) | 7.2 (6.6) |
4 | 7/2942 | 26/3318 | 18/2977 | |
2.4 | 7.8 (5.4) | 6.0 (3.6) |
eAvg. ± S.D. | 1.9 ± 1.4 | 7.9 ± 1.4 | 4.5 ± 1.5 | 8.5 ± 1.8 |
(5.9 ± 0.6) | (2.5 ± 0.8) | (7.4 ± 1.1) |
fP-value | | 4.4 x 10−4
| 0.098 |
gRelative fidelity | | 1.0 | 2.4 | 0.8 |
hTukey HSD | | P < 0.01 (Zn2+) | P < 0.01 (Mg2+) | P < 0.01 (Zn2+) |
P- N.S. (Co2+) | P < 0.01 (Co2+) | P- N.S. (Mg2+) |
-
aIndependent experiments performed at different times. In typical experiments, 1000–3500 colonies were scored for each condition.
-
bIn background assays, plasmid pBSM13ΔPVUII (Figure, 1B) was used as a template in PCR reactions to generate the insert that was scored in the assays. Numbers shown are the “colony mutation frequency” (CMF) defined as white + faint blue colonies divided by total colonies. Refer to the Results and Methods sections for details.
-
cFree cation concentration under each condition was calculated as described in Materials and Methods using the dissociation constant for Mg2+ and ATP.
-
dNumbers shown on top are: (white + faint blue colonies)/total colonies. The bottom number is the colony mutation frequency (CMF) (see b above) for experiments under the listed condition. The CMF minus the background frequency from column two is in parentheses.
-
eAverages ± standard deviations from the experiments in the column are shown.
-
fValues were calculated using a standard Student’s t-test and the background subtracted values from each condition. All values were compared to the 2 mM Mg2+ condition.
-
gAll values are relative to the 2 mM MgCl2 average CMF-Bkg. value (0.0059). The 0.0059 value was divided by the average CMF-Bkg. value for each condition to determine relative fidelity. Higher numbers indicate greater fidelity.
-
hIn order to address the effect of comparing multiple sample conditions on statistical significance, ANOVA analysis coupled with a Tukey’s honest significance of difference (Tukey HSD) test were conducted using the background subtracted values from all samples and the calculator available online from Statistica: http://statistica.mooo.com/OneWay_Anova_with_TukeyHSD. The cation in parenthesis is being compared to the one listed in the column. N.S.- Not Significant.
