Mapping the transposon insertion sites.

<p>(A) Diagram showing the insertion of the transposon cassette into a chromosomal region (in grey). Primers specific to the transposon ends were paired with universal primers to amplify the chromosome- transposon junctions (red triangles), using semi-random nested PCR. Two nested PCR reactions were done to improve amplification of the chromosome-transposon junction directly from boiled bacteria. (B) <i>R</i>. <i>parkeri</i> chromosomal map showing all transposon insertion sites (see red lines) identified in this screen.