NEW TOOLS FOR INTEGRATED GENETIC AND PHYSICAL ANALYSES OF THE ESCHERICHIA-COLI CHROMOSOME

Genetic and biophysical techniques have traditionally been applied to genome mapping independently of one another. We present a series of Es cherichia coli mini-Tn10 insertions that contain the rare-cutting poly linker 1 (RCP1) of rare restriction sites [including BlnI/AvrII, SpeI, NheI, XbaI, NotI, PacI and SfiI; Mahillon and Kleckner, Gene 116 (199 2) 69-74] which allows them to be used not just for genetic mapping, b ut also for rapid physical mapping and integrated physical and genetic mapping of the E. coli chromosome. Their isolation and their physical and genetic coordinates in K-12 strain MG1655 are presented. Also, th eir use in purifying insertion-delimited DNAs from E. coli K-12 and in macrorestriction mapping of a pathogenic strain's chromosome is demon strated. These insertions allow integration of (i) different macrorest riction patterns of a single strain's chromosome, (ii) the physical ma p of a single strain's chromosome with the genetic map of the species, and (iii) the physical maps of different strains' chromosomes.