FIG. 8.
The absence of chromosome healing in Ganr/G418r subclones of 10-7. (a) The structure of the integrated plasmid sequences and the sizes of the predicted BamHI restriction fragments are shown for the parental clone 10-7 and for subclones with chromosome healing at the I-SceI site. (b) Genomic DNA from the parental clone 10-7A and eight of its Ganr/G418r subclones was digested with the BamHI restriction enzyme, and Southern blot analysis was performed using the pNCTΔ plasmid as a probe. Terminal deletions are evident by the loss of the 6.0-kb fragment containing the pZTILtel plasmid. The absence of chromosome healing is evident by the lack of diffuse bands (Fig. 4b) that are approximately 5 to 7.5 kb in length (bracket). Instead, there are discrete bands that vary in size, typical of rearrangements resulting from GCRs. The locations of the molecular size markers (kb) that consist of lambda bacteriophage HindIII fragments are shown.