Behavior of Coliphage Lambda in Hybrids Between Escherichia coli and Salmonella

L. S. Baron, Elisa Penido, I. R. Ryman, Stanley Falkow
1970 Journal of Bacteriology  
Salmonella typhosa hybrids able to adsorb lambda were obtained by mating S. typhosa recipients with Escherichia coli K-12 donors. After adsorption of wild-type X to these S. typhosa hybrids, no plaques or infective centers could be detected. E. coli K-12 gal+ genes carried by the defective phage Xdg were transduced to S. typhosa hybrids with HFT lysates derived from E. coli heterogenotes. The lysogenic state which resulted in the S. typhosa hybrids after gal+ transduction differed from that of
more » ... . coli. Ability to produce X, initially present, was permanently segregated by transductants of the S. typhosa hybrid. S. typhosa lysogens did not lyse upon treatment for phage induction with mitomycin C, ultraviolet light, or heat in the case of thermoinducible X. A further difference in the behavior of X in Salmonella hybrids was the absence of zygotic induction of the prophage when transferred from E. coli K-12 donors to S. typhosa. A new X mutant class, capable of forming plaques on S. typhosa hybrids refractory to wild-type X, was isolated at low frequency by plating X on S. typhosa hybrid WR4254. Such mutants have been designated as Xsx, and a mutant allele of Xsx was located between the P and Q genes of the X chromosome. Phage methods were essentially those described by Adams (1). Procedures for the production of ultraviolet (UV)-induced low-frequency-transducing (LFT) and high-frequency-transducing (HFT) lysates of X, and transduction methods were similar to those originally devised by Morse et al. (18). Induction of lysogens by using mitomycin C (Calbiochem, Los Angles, Calif.) or ultraviolet light was performed as described by Korn and Weissbach (14). Induction of strains lysogenic for thermo-inducible X was per-221 on May 8, 2020 by guest
doi:10.1128/jb.102.1.221-233.1970 fatcat:d6uytnadzbdr7domyzv6ui2c3e