FIG.1.

(A) Schematic diagram showing the region of homologous recombination in H37Rv to create a mutant lacking the ggtA gene and the regions amplified using the primers F1 and R1 (N terminus) and F2 and R2 (C terminus). The regions amplified include sequences from the wild-type host DNA and vector DNA. (B) Southern analysis of genomic DNA from H37Rv, the GGTA mutant, or cosmid digested with AgeI and probed with a 500-bp fragment from the hygromycin resistance cassette (left panel) or a 200-bp fragment representing the internal cloned region of ggtA (right panel).