DIFFERENT RESTRICTION PROFILES OF CHI-PROPHAGE IN SERRATIA-MARCESCENSK AND HY

Temperate phage it originated from the defectively lysogenic Serratia marcescens strain K, from where it was liberated after uv irradiation with low efficiency. The phage is usually indicated on strain HY that can be easily lysogenized by it and rather efficiently uv-induced. Com paring the Eco RI restriction profiles of the kappa prophage in HY rev ealed a DNA rearrangement, by which the precursor structure in K is co nverted into the non-defective form. Apparently the fragment containin g the pac sequence is concerned since a phage DNA probe prepared from the assumed initiation fragments of the first particles of the packagi ng series gave two signals instead of one with genomic K DNA. Since se veral independent new kappa isolates showed the same Eco RI restrictio n pattern as the original phage of ELLMAUER and KAPLAN (1959), the gen eration of kappa is a reproducible event.