Description of an Incompatibility Mutant of Escherichia coli

Abstract
A mutant Hfr strain of Escherichia coli which has an impaired incompatibility function but is normal for other F factor functions has been isolated. This Inc Hfr permits the maintenance and transfer of both the integrated F factor and an F′ factor. F′ factors have been isolated from the integrated F factor of the Inc Hfr strain. When these episomes were tested in matings with Hfr or F′ strains, they did not differ in any observed way from wild-type F′ factors.