Conjugation is not required for adaptive reversion of an episomal frameshift mutation in Escherichia coli.

Adaptive reversion of a lac allele on an F' episome in a strain of Escherichia coli is dependent on the RecA-BCD pathway for recombination and is enhanced by conjugal functions. However, conjugation, i.e., transfer of the episome, whether between distinct populations of cells or between newly divided siblings, does not contribute to the mutational process.