FIGURE 1.

Construction of M. bovis ΔTbD1 mutant and complemented ΔTbD1:TbD1 strain. (A) Diagram showing the TbD1 and flanking genes. The TbD1 region was replaced by a 3.5 kB hyg-cat cassette (green bar) to generate M. bovis ΔTbD1 strains. White arrowheads indicate primer targets (Hyg F&R) to verify the Hyg cassette. (B) Agarose gel electrophoresis image after PCR with primers targeting TbD1 specific internal region and primers targeting hyg-cat cassette to verify the knockout of TbD1 and the presence of hyg-cat cassette on BCG Denmark ΔTbD1 strains and PCR targeting TbD1 locus to verify the complementation of ΔTbD1 on ΔTbD1:TbD1 strains.