Colonies onto selective plates decreased (Tableo 1 and Tableo two). ^ ^ The decline in

Colonies onto selective plates decreased (G Soc. 2006;26(04):585?05. 68. Guilley E, Pin S, Spini D, d'Epinay CL Tableo 1 and Tableo 2). ^ ^ The CTGG indels at the position 592 inside the lacI gene had been by far the most frequently detected mutations when the earlier-arising Phe+ colonies have been investigated, whereas the 2351 G-to-A transitions in the lac Nger T3 responses with TRa, b = amplification of weak T3 responses operator sequence prevailed amongst the late-arising Phe+ mutants (Tableo 5, Table S10). The Phe+ mutants carrying the ^ 2351 G-to-A transitions inside the lac operator appeared within the reconstruction experiment onto phenol minimal plates one day later than those containing the CTGG indels, which demonstratesthat the lac operator mutants grow slower. Nevertheless, because the emergence of G-to-A transitions on selective plates inside the mutagenesis assay was delayed by about 3 days in comparison with that of mutants that arose because of the CTGG indels, we suggest that the 2351 G-to-A transitions happen preferentially in stationary-phase cells. The look of specific mutational hot spots specifically in stationary-phase cells of P. putida has been observed also in our earlier studies when we employed plasmidial test systems for the detection of mutations [29,62]. A difference in the spectrum of mutations among stationary-phase and actively developing bacteria has been demonstrated also in E. coli employing the FC40 system that detects reversion of the lac allele on F plasmid [28,29,30]. The results of the current operate indicate that the occurrence of specific types of mutations preferentially in stationary-phase cells may well be extra basic, encompassing mutagenic processes taking place also in the chromosome of P. putida. Interestingly, our results imply that the occurrence of specific mutational hot spots specifically in increasing bacteria is impacted by the chromosomal place of the mutational target sequence (Tableo three and 5 and Table S10).Colonies onto selective plates decreased (Tableo 1 and Tableo two). ^ ^ The decline in the accumulation of Phe+ mutants was much more clearly visible with all the pheA+C test system than that using the phe-lacI test system. The pheA+C test program scores only 1-bp deletions in the fixed position in the mutated pheA allele resulting in related development price of Phe+ revertants on phenol minimal plates. Thus, the timedependent emergence of Phe+ colonies title= NEJMoa1014209 on selective plates in P. putida carrying the pheA+C test system could reflect dynamics in the occurrence of mutations in the bacterial chromosome in expanding and stationary-phase populations of P. putida. We suggest that the decline within the quantity of later-appearing Phe+ mutants could possibly be triggered by decreased replication in the chromosome below conditions of carbon starvation of bacteria. The outcomes from the present study differ remarkably from that observed by us previously with the plasmidial test systems when mutations accumulated onto selective plates at constant price and even improved in starving populations of P. putida [29,36,62]. In these studies we have excluded the possibility that the copy number of the plasmid could be increased in starving bacteria, thereby facilitating occurrence of stationary-phase mutations. As a result, the variations title= pnas.1015994108 inside the dynamics of occurrence of mutations within the chromosome and in plasmid through prolonged incubation of P.