Fig. 2

Relative survival of the pooled total population of the wildtype (closed triangles and bold solid line, n = 16) and the transformant fractions obtained with either pSBP1 DNA (0.1 μg ml⁻¹; open circles with dotted line, n = 10) or with homologous genomic DNA (2 μg ml⁻¹; open squares with solid line, n = 6) with increasing levels of UV irradiation. We also determined the relative survival of the total population (closed triangles and bold dashed line, n = 10) and the transformant fraction in the ∆uvrA mutant obtained with homologous DNA (2 μg ml⁻¹; open squares and dashed line, n = 10). Error bars denote the 95% confidence intervals. The transformation frequencies without UV irradiation were (7.7 ± 1.4) × 10⁻⁴ (pSBP1 DNA) and (2.5 ± 2.8) × 10⁻² (genomic DNA) for the wildtype; and (1.9 ± 1.0) × 10⁻² (genomic DNA) for the ∆uvrA mutant. Mean initial titers (CFU/ml) for the wildtype and the ∆uvrA mutant were 1.8 × 10⁷ and 4.2 × 10⁷, respectively