Throughout the long history of the bacteriophage T4 research, the phenomenon of lysis inhibition (LIN) became an exclusive point of interest of T4 physiology. An ability to control the timing of cell lysis in response to the availability of bacterial hosts in the environment is considered to contribute significantly to the prevalence of T-even phages in nature. In this study, we investigated lysis inhibition in the significantly diverged pseudo T-even bacteriophage RB49. Although the phage RB49 possesses a highly diverged homologue of the T4 major lysis inhibition gene rI, the Escherichia coli B^E and K-12 cells infected with RB49 do not display lysis inhibition. In addition, we demonstrated that secondary infection by RB49 phage induces the lysis inhibition of T4-infected cells. The evidence suggests that phylogenetically distant T4-type phages have elements that constitute a signal of the LIN induction.

Keywords: bacteriophage RB49; rapid lysis, gene rI; lysis inhibition