FIG. 1.

Strategies for plasmid insertion mutagenesis and conformation of the insertion in the targeted gene. (A) Schematic representation of the location of the genomic and plasmid-borne genes before and after integration of the plasmid into the genome. The locations of primers used to amplify the middle parts of targeted genes and the junction between the targeted gene and the suicide plasmid are also indicated. (B) Agarose gel with a DNA size marker and DNA fragments amplified with different combinations of primers and genomic DNA. Lane A, primers for amplifying the junction of the lsrA gene and the inserted suicide plasmid mixed with genomic DNA from the lsrA mutant; lane B, primers for amplifying the junction of the lsrA gene and the inserted suicide plasmid mixed with genomic DNA from wild-type strain Rm1021; lane C, primers for amplifying the junction of the lsrB gene and the inserted suicide plasmid mixed with genomic DNA from the lsrB1 mutant; lane D, primers for amplifying the junction of the lsrB gene and the inserted plasmid mixed with genomic DNA from strain Rm1021.