Episomes

Abstract

The temperate phages and the sex factor provide a much clearer understanding of how episomes may interact with the chromosome, particularly at the genetic level. The episomes are useful as genetic tools in the study of regulatory and other mechanisms and of gene regulation. The epi-somes integrate by recombination which can occur within regions of only limited homology. Analysis of the properties of operons should assist in the study of genetic regulation of many metabolic systems. The experiments may indicate the mechanism of recombination by permitting analysis of crossover events outside regions of gross homology. The analogy between the autonomous sex factor and the normal bacterial chromosome makes it of particular interest. There is a discussion of the evidence for insertion of an integrated episome into the bacterial chromosome, recombination in bacteria, induction of lysogens and the mechanism of phage transductlon and replication.