Figure 4. λrexB is involved in the transfer from lysogenic to lytic stage.

(A) Cell viability (CFU/ml) and (B) λ plaque forming units (PFU/ml). The E. coli strains AB1932λ ⁺ or AB1932λ ⁺ΔrexB or AB1932λ ⁺ΔrexB/pZA31-rexB were grown as described in the Legend to Figure 2. We carried out viability assays on LB plates as we have described previously (19) and the PFU were determined as described in Materials and Methods.