Figure 5.

Characterization of the pSym of strains CFNX501 and CFNX502. (A) Plasmid profiles stained with ethidium bromide. W and 3, wild-type strain NGR234; 1, CFNX501; 2, CFNX502. The position of the plasmids in the wild-type strain is indicated: a, pNGR234a; b, pNGR234b; c, well entry. (B) HindIII maps. A region of the pSym (from the HindIII site at base 439,970 to the HindIII site at base 501,514) of the wild-type strain NGR234 is shown. The HindIII sites are indicated by arrows and the HindIII fragments are labeled with numbers from 1 to 9. Two small fragments located between fragments labeled 3 and 4 were not taken into account in the analysis. The reiterated sequences nifHDK1 (□) and nifHDK2 (■) are located in HindIII fragments 3 and 7, respectively. The position of the PCR products covering this region is shown below the HindIII map of NGR234; each product is labeled with a number from 81 to 90. The predicted HindIII maps for the corresponding region of strains CFNX501 and CFNX501 also are shown. The new recombinant HindIII fragments produced by the del event in strain CFNX501 (╡) and by the amp event in strain CFNX502 (╞) are labeled X and Y, respectively. (C) Southern blots of total DNA digested with HindIII hybridized against the PCR products covering the region. For each PCR product (indicated at the top), three lines of a Southern blot are shown. The left line corresponds to strain NGR234, the middle line to strain CFNX501, and the right line to strain CFNX502. The position of the corresponding HindIII fragments is indicated.