title: Some features of the mutability of bacteria during nonlethal selection.
abstract: We describe the mutability of the Trp(-) chromosomal +1 frameshift mutation trpE7999 during nonlethal selection, finding that the appearance of Trp(+) revertants behaves similarly to that of episomal Lac(+) revertants. In addition, we show that a feature of the Lac(+) and Trp(+) mutability is the accumulation of Trp(+) and Lac(+) revertants with additional unselected mutations, most of which are not due to heritable mutators. The cells undergoing nonlethal selection apparently experience an epigenetic change resulting in a subset of bacteria with elevated mutability that often remain hypermutable for the duration of selection. The epigenetic change provoked by nonlethal selection appears to be mediated by a unique function provided by the F'128 episome.
authors.affiliation: Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: V G
authors.initials: VG
authors.lastname: Godoy
authors.forename: F S
authors.initials: FS
authors.lastname: Gizatullin
authors.forename: M S
authors.initials: MS
authors.lastname: Fox
mesh_terms: D001419:Bacteria / Q000235:genetics*; D001426:Bacterial Proteins; D002876:Chromosomes, Bacterial; D007763:Lac Operon / Q000235:genetics; D009154:Mutation; D012097:Repressor Proteins / Q000235:genetics; D012641:Selection, Genetic; D029968:Escherichia coli Proteins
chemical_list: D001426:Bacterial Proteins; D012097:Repressor Proteins; C027190:TRPR protein, E coli; D029968:Escherichia coli Proteins