Abstract
The patterns and changes of nucleic-acid synthetic activity during the course of nuclear-olyhedrosis were demonstrate in the fat body and some other tissues of the silkworm larva (Bombyx mori L.) by means of autoradiography with tritiated thymidine and uridine as nucleic-acid precursors. The results indicated that both activities of DNA and RNA syntheses in the infected nucleus of the fat body increased progressively up to a point just prior to the polyhedra development. Beyond this period, there was a sudden breakdown of DNA synthesis, while the activity of RNA synthesis decreased gradually with the polyhedral growth. Some of the newly synthesized RNA in the diseased nuclei seemed to be adsorbed onto polyhedra during their formation. Essentially the same pattern of nucleic-acid synthesis was noted in the other infected tissues such as hypodermis, muslce and tracheal epithelium.
