Zinder and Lederberg (Nobel 1958) placed two auxotrophic strains of Salmonella on opposite sides of a Davis U-tube.
Prototrophs were recovered from the side containing
LA-22 cells, but not from the side containing
Adding DNase, an enzyme that digests DNA, did not prevent recombination, so this is not transformation.
The filter prevented cell contact, so this is not conjugation.
LA-22cells. Rarely, some P22 enter the lytic phase, exit the
LA-22cells, and cross the filter to infect
LA-2cells are lysed, some
LA-2DNA may be packaged in P22 heads, which can move back across the filter to infect
LA-22cells, enter lysogeny and producing recombinants.