Figure 5.

Visualizing integrated Mu with TetR-mCherry.

(A) The TetO array was substituted for the SE region of the prophage, which is dispensable for phage growth. A compensatory deletion in another non-essential region near the R end restored the original Mu DNA length, ensuring that head-full packaging would yield viable phage progeny (Symonds et al., 1987). See Experimental Procedures for construction details. (B) Lysis profiles of Mu::TetO (SJ012) and Mu wild-type (HM8305) prophage strains. Similar phage titers were obtained from both strains (see C). Error bars indicate standard deviation from the mean of triplicate data sets obtained from three independent colonies of the same strain. (C) Plaque morphologies of wild-type and Mu::TetO, titered on BW25113. Mutations in the SE region are known to affect plaque size (inset) (Symonds et al., 1987). (D) Snapshot of Mu::TetO infection (MOI = 1) into WT strain BW25113 expressing TetR-mCherry (pDB317), photographed before (−Mu) and after ~15–20 min of infection (+Mu). (E) Quantitation of uninfected and infected cells in D by counting mCherry foci. > 80% of the cells had mCherry foci, and a majority of these had single foci.