A, A diagram of the flhDC-yecG region in 'A' (motile), isolate 'B' (less motile) and in the IS5:kanr mutant. The location of IS5 relative to flhDC transcriptional start site is shown. The position of the primers used for the verification PCR and the length of the expected PCR products are indicated. The wide arrow at the bottom of the diagram indicates the direction of transcription. B, Confirmation of the presence of an IS5 element in the flhDC-yecG region. 1.0% agarose gel shows the products of the PCR reactions confirming the IS5 mapping predictions as well as the replacement and deletion of the IS5 element by the lambda red recombinase system. The PCR products shown were obtained from reactions done with flhDC F3 and yecG R primers. Lane1: isolate 'A' (motile); lane2: isolate 'B' (less motile); lane3: IS5: kanr; lane4: isolate 'AΔIS5'-colony #1; lane5: isolate 'AΔIS5' – colony #2, lane6: no template negative control; lane7: Hi-lo DNA marker ladder. The size of the PCR reaction products is shown in kb.