title: Transcription-associated mutation in Bacillus subtilis cells under stress.
abstract: Adaptive (stationary phase) mutagenesis is a phenomenon by which nondividing cells acquire beneficial mutations as a response to stress. Although the generation of adaptive mutations is essentially stochastic, genetic factors are involved in this phenomenon. We examined how defects in a transcriptional factor, previously reported to alter the acquisition of adaptive mutations, affected mutation levels in a gene under selection. The acquisition of mutations was directly correlated to the level of transcription of a defective leuC allele placed under selection. To further examine the correlation between transcription and adaptive mutation, we placed a point-mutated allele, leuC427, under the control of an inducible promoter and assayed the level of reversion to leucine prototrophy under conditions of leucine starvation. Our results demonstrate that the level of Leu(+) reversions increased significantly in parallel with the induced increase in transcription levels. This mutagenic response was not observed under conditions of exponential growth. Since transcription is a ubiquitous biological process, transcription-associated mutagenesis may influence evolutionary processes in all organisms.
authors.affiliation: School of Life Sciences, University of Nevada, Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Pybus
authors.forename: Mario
authors.initials: M
authors.lastname: Pedraza-Reyes
authors.forename: Christian A
authors.initials: CA
authors.lastname: Ross
authors.forename: Holly
authors.initials: H
authors.lastname: Martin
authors.forename: Katherine
authors.initials: K
authors.lastname: Ona
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Yasbin
authors.forename: Eduardo
authors.initials: E
authors.lastname: Robleto
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D007930:Leucine / Q000172:deficiency; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D007930:Leucine