We wish to learn why organisms have evolved a variety of strategies for the replication of their genes. In many bacteriophages, DNA replication initiates from a well defined origin, but in some instances the genes are replicated unidirectionally, whereas in others a bidirectional mechanism is employed.
Some genomes replicate as circular structures while others are linear.
In higher organisms replication initiates from a large number of positions along the genome. Another related area of interest concerns the control of DNA replication. We have recently discovered how to interfere with the control process that is concerned with the primary initiation of DNA replication in bacteriophage lambda, and in this way hope to gain insights into the control process itself. Phage lambda DNA initiates bidirectional replication from a unique position on its genome, and once replication has started, two daughter origin sequences are formed. Normally these daughter origins are inactive while a round of replication is in progress.