Physical mapping of genes on the F plasmid of Escherichia coli responsible for inhibition of growth of female-specific bacteriophages.

By correlating the resistance or sensitivity to female-specific phages of strains carrying F plasmids with deletions for part of the region 32.6 to 42.9 F, cloned F fragments, and other plasmids, it was shown that the pif loci are located near and clockwise to a point on F with coordinate 38.3 F.