Lavi, U., Department of Genetics, The Hebrew University, Jerusalem, Israel
Marcus, M., Department of Genetics, The Hebrew University, Jerusalem, Israel

Arrest of host DNA synthesis in Bacillus subtilis infected with the virulent phage ∅e is dependent on the synthesis of a phage-coded protein (Marcus and Newlon, 1971). The mechanism of host DNA arrest was studied in toluene-treated B. subtilis cells. The results showed that preparations of toluenized phage infected cells manifest faithfully the kinetics and specificity of host DNA arrest and the appearance of phage DNA synthesis. The arrest of host DNA synthesis is not caused by the production in the host DNA of single strand breaks that can be repaired by the DNA polymerase repair enzyme (Pol I). Neither hydroxymethyl deoxyuridylate (HMdUMP) nor probably any other small molecule is responsible for host DNA arrest. © 1972.