Uneven distribution of nitrosoguanidine- and hydroxylamine-induced mutants of three coliphages

Abstract

166 suppressor-sensitive (sus) mutants belonging to phages HK243, HKO22, and λ were analysed. N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-in-duced mutants of all three phages showed a restricted distribution; a majority being of one or the other of two cistrons. Hydroxylamine (HA)-induced mutants of phage HKO22 were found to be randomly distributed over a number of cistrons but in the case of phage λ, out of 21 HA-induced mutants 10 were of cistron P and 6 of cistron R.