An analysis of the clone size distribution of ΦX174 mutants and recombinants

Abstract

In a quasi-single-burst experiment the clone size distribution of the number of wild-type bacteriophage ΦX174 appearing after a single cycle of growth of ΦX amber mutants in the permissive host Escherichia coli CR34/C416 was determined by plating on the nonpermissive host E. coli C. The distribution of revertant phage (mutants) was almost random, not clonal as found for T2. This result is consistent with a theory that the progeny single-stranded DNA molecules are synthesized off one or a few templates in a “stamping machine” fashion; however, other explanations for the random distribution are not excluded. The distribution of recombinants approximates a clonal distribution like the distribution of recombinants between loosely linked markers of T4. This result can perhaps be considered to indicate a geometric replication process; however, it is argued that the distribution is also explainable by the stamping machine model for ΦX replication.