Abstract
DNA synthesis was studied in silkworm pupae after infection with nuclear polyhedrosis virus. Infection resulted in a marked change in the rate of DNA synthesis in the pupal bodies. The change was found to be due to the apparent DNA polymerase activity. The activity did not increase until 20 hr after infection, and then increased logarithmically from 24 and 48 hr. Sixty hours after infection, the activity was twenty times that in normal pupae, and then began to decrease. Actinomycin D and chloramphenicol inhibited the development and increase in enzyme activity. Partially purified DNA polymerase [EC 2. 7. 7. 7] was prepared from extracts of infected pupae. It required all four 5'-deoxyribonucleoside triphosphates, Mg++ and native or thermally denatured DNA as primer.
