Adaptive Reversion of an Episomal Frameshift Mutation in Escherichia coli Requires Conjugal Functions but not Actual Conjugation

Adaptive reversion of a lac-frameshift mutation in Escherichia coli appears to be due to DNA polymerase errors, implying that DNA is being synthesized although the cells are not dividing. Here we report that the production of adaptive lac+revertants (i) is much higher when the mutational target is o...

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Bibliographic Details
Published in:Proceedings of the National Academy of Sciences of the United States of America, Vol. 92, No. 12 (1995), p. 5487-5490
Main Author: Foster, Patricia L.
Other Involved Persons: Trimarchi, Jeffrey M.
Format: electronic Article
Language:English
ISSN:0027-8424
Item Description:Copyright: Copyright 1995 The National Academy of Sciences of the United States of America
Physical Description:Online-Ressource
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  • Adaptive reversion of a lac-frameshift mutation in Escherichia coli appears to be due to DNA polymerase errors, implying that DNA is being synthesized although the cells are not dividing. Here we report that the production of adaptive lac+revertants (i) is much higher when the mutational target is on the F' episome than when it is on the bacterial chromosome; (ii) is enhanced by functions required for conjugation; but (iii) does not require conjugation per se. These results suggest that, in static cells, DNA synthesis is initiated from the conjugal origin of transfer. Mutations may arise as polymerase errors during this synthesis or during synthesis stimulated by recombination among the multiple gene copies.