TABLE 3.

Mutation rates of M. smegmatis strains examined by fluctuation experiment

Fluctuation experiment group number	Strain	No. of cultures	Nt valuea	Lea-Coulson m valueb	Mutation ratec
1	M. smegmatis mc2155	30	3.2×109	9	2.8×10−9
2	M. smegmatis ΔMs2694	30	3.5×109	13	*3.7×10−9
3	M. smegmatis ΔMs2694/pMindD2694	30	4.5×109	11	2.4×10−9

^a Final number of cells in the culture.

^b Number of mutations per culture.

^c Probability of mutation per cell per generation. p values of the results were calculated by unpaired two-tailed Student's t test using GraphPad Prism 5. p value of the result (indicated by an asterisk) was <0.05.