FIG. 2.

Disruption of the talB gene in talA⁻ cells. (A) Schematic representation of the talB gene disruption with the disruption construct (36). The sites of the first codon of talB and the positions of the primers used to confirm the disruption are indicated by an arrow and arrowheads, respectively. (B) Confirmation of talB gene disruption by PCR using genomic DNA as the template. The bands obtained with the indicated primers (arrowheads in panel A) were approximately 4 kb in size in the parent talA⁻ strain and also in the two clones of random integrants (RI-1 and 2) whose talB genes were not disrupted. In contrast, the bands obtained from genomic DNA of the talB⁻ strain and the two clones of the talA⁻ talB⁻ strain were 0.8 kb larger in size due to the replacement of a 1.1-kb fragment of talB gene by the 1.9-kb hygromycin cassette.