Induction of prophage lambda in Escherichia coli recA- strain by N-methyl-N'-nitro-N-nitrosoguanidine

Mutat Res. 1983 Jan;107(1):33-40. doi: 10.1016/0027-5107(83)90076-3.


Induction of prophage by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) occurred in a recA- strain lysogenic for lambda phage at a level significantly higher than the spontaneous level although the frequency was much lower than that of induction in a recA+(lambda) strain. The plaque-forming ability of lambda c17 super-infecting the recA-(lambda) strain pretreated with MNNG increased with dose of MNNG as it did for super-infection of the recA+(lambda) strain, indicating that the frequency of maturation of lambda c17 increased owing to a decrease in the immunity of the lambda lysogen with dose of MNNG given to it. Further, the activity of lambda repressor in the recA-(lambda) strain decreased after treatment with MNNG as measured by the decrease of repressor-binding activity to lambda DNA although it decreased at a 3-fold slower rate than that in recA+(lambda) strain. From these results and others previously reported we conclude that inactivation of repressor leading to MNNG-initiated prophage induction takes place through two pathways, one being the recA-dependent normal process and the other a recA-independent process unique to the effect of MNNG.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacteriophage lambda / drug effects
  • Bacteriophage lambda / genetics*
  • Bacteriophage lambda / radiation effects
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / radiation effects
  • Lysogeny
  • Methylnitronitrosoguanidine / pharmacology*
  • Mutation*
  • Rec A Recombinases
  • Ultraviolet Rays


  • Bacterial Proteins
  • Methylnitronitrosoguanidine
  • Rec A Recombinases