We propose to extend and improve a recently developed Transposon-facilitated recombination (Tfr) donor system for genetic analysis of an E1 Tor biotype of Vibrio cholerae. In this study procedures are outlined to isolate additional Hfr-like donors and mutant recipients and to further refine the genetic map. Similar studies are proposed for isolating Tfr donors in classical biotypes of V. cholerae. Genetic properties of classical and E1 Tor biotypes will be compared, and interstrain crosses will be attempted. As part of these studies, plasmids of V. cholerae will be further characterized. Existing hypo- and hypertoxinogenic mutants will be genetically analyzed and additional mutants altered in toxin production will be isolated. Our previously described procedures will be used. Procedures for transductional analyses of V. cholerae will be investigated.
