Answer to Question #307276 in Genetics for Jess

Question

One type of conditional mutation is a temperature-sensitive mutation, which expresses the mutant phenotype only at certain temperatures. Strains of E. coli have been isolated that contain temperature-sensitive mutations in the genes encoding different components of the replication machinery. In each of these strains, the protein produced by the mutated gene is non-functional under the restrictive conditions. These strains are grown under permissive conditions and then abruptly switched to the restrictive condition. After one round of replication under the restrictive condition, the DNA from each strain is isolated and analysed. What characteristics would you expect to see in the DNA isolated from each strain with a temperature sensitive mutation in its gene that encodes a) DNA polymerase III, b) primase and c) initiator protein?

Answer 1

a) DNA polymerase III