The initiation of chromosome replication is an important event in the cell cycle of both prokaryotic and eukaryotic cells. Discovering how this event is controlled is of fundamental importance to understanding how cells grow and divide. Replication initiation is best understood in E. coli, where many factors that are involved have been identified. The molecular mechanisms which control the process remain mysterious. In the first part of the proposed project, an approach will be taken which has been successful in elucidating mechanisms that control bacterial plasmid replication. Segment of E. coli DNA that inhibit chromosome replication will be cloned and characterized. Among such segments of DNA should be those which carry genes that control chromosome replication. The second part of the proposed research is an analysis of aberrant initiation of chromosome replication that is induced by shifts to high temperature. Studying this novel phenomenon should yield valuable insights into the normal control of chromosome replication.
