FIG. 3.

Comparison of parental and recombinant phages. (Top) Schematic map of the prolate phages with the relevant genes indicated. First two lines, restriction maps of the parent phages. Arrow indicates the insert in plasmid pAJ376. Panels A and B show restriction maps of the recombinants. Black box, c2-derived sequences; white box, 923-derived sequences. Restriction sites: BstUI (vertical lines), EcoRI (lollipops). (A) Hybrid phages whose recombination endpoints were determined by sequencing. The exchanged DNA fragment sequences have been deposited in GenBank. (See Material and Methods section for the accession numbers.) Table contains the titers of each phage on strains MG1363 and 112. (B) Hybrid phages Rc1 through Rc4 and Rc7 through Rc12, whose recombination endpoints were determined by restriction mapping only. Stippled lines denote the fragments where the crossover points were expected to be based on the restriction mapping. The titers of these phages were similar to those of the phages in panel A (data not shown).