FIG. 1.

Transposon mutagenesis of R. rickettsii resulted in the generation of 8 unique clones. (A) Southern blot demonstrating a single transposition event that occurred in the generation of each mutant. Purified genomic DNA from mutant clones 9-1 through 9-8 and the congenic parental R. rickettsii strain (R) was digested with HindIII and subjected to Southern blotting with a ³²P-labeled gfp-specific probe (GFP). Positive controls included pMW1650, as well as gfp-specific DNA used as the probe. Clone 9-2 did not appear to grow well and was not included in the Southern blot because of limited amounts of DNA recovered. (B) Diagram of the R. rickettsii chromosome depicting the relative locations of the insertion sites for each of the 8 mutants generated by transposon mutagenesis.