A Replicator’s View of Recombination (and Repair)

Abstract

During the course of studies on the growth of gamma λ mutants in rec ⁺ and rec ^- cells, L. W. Enquist and I (Enquist and Skalka, 1973) observed a growth defect in λ red mutants that was independent of the rec condition of the host. Red mutants synthesize their DNA at only 1/3 to 1/2 the wild-type rate, and concatemers formed at late times are on the average shorter than normal. Red ^- DNA also seems to be packaged with somewhat less than the wild-type efficiency, and phage bursts are only about 30 to 40% that of wild type (Table 1). The importance of red genes to λ growth is further emphasized by the occurrence of a number of bacterial mutants on which λ red mutants do not plate at all. This class, called feb ^-, includes polA^- and lig ^- strains (Zissler et al., 1971). The following section summarizes results from studies of DNA synthesis and phage production in red ^- and gam ^- infection of these feb ^- hosts.