The effect of donor-specific phage on bacterial conjugation

Donor strains of E. coli have hollow, filamentous appendages (F-pill) to which a number of RNA bacteriophages specifically adsorb. Two principal models of bacterial conjugation have been proposed which involve F-pill: (1) the DNA from the donor bacterium travels into the recipient bacterium through the F-pilus, (2) the F-pilus holds the recipient bacterium to the donor during conjugation. In an effort to distinguish between the two models, wild type donor (F-pilus) specific phages were added to donor bacteria before, during, and after mixing with recipient bacteria. The efficiency of conjugation was reduced. [...]