Specialized transduction in Bacillus subtilis by the phages IG1, IG3, and IG4

The temperate phages IG1, IG3, and IG4 ofBacillus subtilis were found to mediate specialized transduction of a λ-like type. High frequency transducing lysates were also obtained. In many instances the transductants were shown to be heterogenotes, segregating the mutant alleles. They are presumably the result of transduction by addition. These findings are discussed together with data on other members of the group III of temperate bacteriophages aiming to a deeper understanding of that group, and of its evolutionary history.