The Starting Point and Direction of λ DNA Replication

Excerpt

The replicon theory (Jacob et al., 1963) postulates that there is a specific starting point (the ‘replicator’ site) for DNA replication in bacterial and viral chromosomes. The existence of a specific replicator site has been demonstrated in the case of germinating B. subtilis spores, and its chromosomal location found, by Sueoka and co-workers (cf. Oishi, et al. 1964).

We present here an experiment to find out if there is a unique replicator site for phage λ. The experiment can give both the origin and direction of DNA replication. Phage λ was chosen for this study because the mechanism of control of its DNA replication may soon be worked out at the molecular level, and knowledge of the replicator site is needed for this. Also the special structure of λ DNA facilitates such a study. The properties which we have used are, first, that λ DNA is linear when packaged into...