Table 1.

Frequency of Tn7 transposition into pOX-attTn7 or control site when transcription in pOX-attTn7 is off or ona

Test group% of target sites with a Tn7 insertion
Transcription offTranscription on
pOX-attTn7Control attTn744 siteRatiopOX-attTn7Control attTn744 siteRatio
Population 13.11.420.51.40.4
Population 23.31.420.61.40.4
Population 33.91.530.61.40.4
Population 43.61.520.61.40.4
  • a Southern blot analysis of Tn7 transposition fromattTn7 84::Tn7 in the chromosome to a control site,attTn7 44, and a pOX-attTn7 plasmid in cells grown on Luria-Bertani plates without (transcription off in pOX-attTn7) or with (transcription on in pOX-attTn7) tetracycline. Total DNA from ∼108 cells of each clonal population was examined for Tn7 inserts.