%0 Journal Article %A Furness, G. %A Rowley, D. %T The Presence of the Transmissible Aǵent F in Non-Recombininǵ Strains of >Escherichia coli %D 1957 %J Microbiology, %V 17 %N 3 %P 550-561 %@ 1465-2080 %R https://doi.org/10.1099/00221287-17-3-550 %I Microbiology Society, %X SUMMARY: A proportion of wild-type strains of >Escherichia coli unable to recombine with >E. coli K12 F − mutants can ‘infect’ them with the sex-differentiating character known as F. Of these strains, not all infect the same >E. coli K12 F − mutants and the ease of transfer of F varies among them, suggesting that there are different F agents. This is supported by the finding that there are great variations in the transfer of unselected markers in crosses in which the only known difference is the origin of the F factor possessed by the F + parent. Colicinogenicity and F are frequently associated and all of nine strains producing colicin I possess F, but they are not identical, since the two properties have been separated by treatment with cobalt chloride. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-17-3-550