Mutations affecting genetic recombination in bacteriophage T4D: II. Genetic properties

Abstract

Experiments were performed to assess the effects of mutations in genes 46–47, 58, 59, w, x, and y on the correlation of genetic exchanges, on the production ofheterozygotes, and on the extent of high negative interference in bacteriophage T4D. Mutations in these genes of T4 which alter genetic recombination also alter the relative ratio of double to single crossover events and the frequency of heterozygotes for a point mutation in the rIIA cistron. In contrast, the frequency of heterozygotes for a small deletion in the rIIA cistron is essentially constant in wild-type and mutant infections. The reduction in the index of interference caused by substituting a deletion for a point mutation as the central marker in a three-factor cross is eliminated in 46 −–47 −, 59 −, w − , and y − infections.