STUDIES ON LYSOGENESIS III

Open Access
Publisher Website
Google Scholar
Abstract
No lysis or killing of the superinfected S. dvsenteria cells was observed. The type of phage produced after superinfection was studied in mass culture and in single burst expts. Mixed liberation of the 2 phage types, the carried and the superinfecting one, occurred with a frequency decreasing with time after superinfection. The concept of preprophage is introduced; this is a developmental stage of the superinfecting phage, which does not multiply as such, is passed on to either daughter cell at cell division, and participates in the phage yield when the cell that carries it shifts into the lytic cycle. The progeny of superinfected cells was examined for permanent modification produced by superinfection. In a small proportion of cells the carried phage disappeared, being substituted either by the superinfecting type or by a new type that was a genetic recombinant of the two. A still smaller proportion of cells became lysogenic for both the previously carried type and the superinfecting one. A method for estimating avg. number of prophages in a lysogenic cell is indicated. The estimate obtained is consistent with the hypothesis that one prophage is present in each nucleus of a (singly) lysogenic cell.

This publication has 16 references indexed in Scilit: