Fig 1.
Southern blot analysis for tap gene inactivation in M. bovis BCG. Genomic DNA isolated from M. bovis BCG wild type (lane 1) and the M. bovis BCG double-crossover (DXO) strain (lane 2) was digested with HindIII and hybridized to a probe corresponding to a 0.86-kb tapTB internal region flanking the Ωhyg insertion point. HindIII digestion released the Ωhyg cassette, yielding two fragments of 5.2 kb and 2.2 kb for the DXO strain, while a single 7.4-kb fragment was observed in the wild-type strain. Loading wells and undigested DNA can be also seen on the upper part of the image. The diagram showing the expected HindIII digestion fragment is not shown to scale. In M. bovis BCG Pasteur, the RD13 deletion (4) comprises the region containing the Rv1255c, Rv1256c, and Rv1257c genes, compared to the M. tuberculosis H37Rv genome. The chimeric gene after the fusion of the Rv1255c and Rv1257c genes is shown in white and black.