Transduction mechanisms of bacteriophage epsilon 15. I. General properties of the system

A simple technique for the identification of chain termination suppressor mutants in species of Salmonella

Chain-termination suppressors which are almost certainly amber suppressors have been isolated inSalmonella anatumby a technique involving the use of amber mutants of bacteriophage 01. The same technique could be used in any species ofSalmonella(and many strains of Arizona) and analogous techniques are suggested for use in other genera of bacteria and in higher plants.

Transduction mechanisms of bacteriophage epsilon 15. 3. A new class of mutations affecting the conversion of Salmonella anatum by bacteriophage epsilon 15

Salmonella anatumlysogenized by a doubly mutant strain of bacteriophage εγshows a markedly rough colonial phenotype on tetrazolium agar. Mutants that abolish the roughness are reported.

Transduction mechanisms of bacteriophage epsilon 15. II. Isolation of a bacteriophage related to epsilon 15

A bacteriophage was isolated from a strain ofSalmonella manilla. This phage, υ15, was found to have adsorption and conversion properties similar to phage ε15. The two phages show similar transduction efficiencies but phage υ15lysogenizes more efficiently. Phage υ15is not subject to repression by ε15type prophage. The densities of the two phages are indistinguishable.

Phage υ15can ‘cure’ ε15type prophages and recombination is possible between genomes of the two phages. It seems probable that they are heteroimmune representatives of a single bacteriophage family.