FIG. 2.
Spoligotype patterns of three independently evolving strain families. Each isolate was spoligotyped with the internationally standardized method (13, 16). The DVRs are numbered according to the variable sequences immobilized on the membrane. Open squares indicate the absence of a specific DVR, and solid squares indicate the presence of a specific DVR. Shaded squares indicate DVR sequences not detected by spoligotyping but shown to be present by DNA sequencing. The ancestral IS6110 insertion is located in DVR 24 at position 15600 in the H37Rv genome sequence (cosmid MTCY16B7) (5). Each DR-RFLP genotype is indicated by a number.