Figure 1. Large-scale comparative genome analysis. (a) Genetic clamping between copies of the Escherichia coli genome. NotI restriction digestion patterns are shown of wild-type (wt) and mutagenized E. coli genome copies from a nonpathogenic (NP) and a pathogenic (P) strain background. At different genomic locations (at positions 72 min and 78 min), the changes introduced into each strain background by the identical genome insert (crossed between strains by P1 transduction) carrying the NotI recognition site are indicated by missing native NotI fragments and novel NotI subfragments. (b) Heteroduplex analysis of the lambdoid phages genome.