INVITRO DNA-SYNTHESIS IN THE LEFT COLLETERIAL GLAND OF PERIPLANETA-AMERICANA FROM DIFFERENT STAGES OF THE REPRODUCTIVE-CYCLE

1. In vitro DNA synthesis in the left colleterial gland of the cockroach Periplaneta americana from different stages of the reproductive cycle was compared. 2. H-3-thymidine incorporation into TCA insoluble material by LCG DNA varied at different stages of the reproductive cycle. 3. Labelling of DNA with phosphorus-32, followed by electrophoresis of restriction enzyme digested DNA, showed that total genomic DNA was labelled. 4. Tissue autoradiography of H-3-thymidine labelled colleterial gland and fat body revealed that the incorporation was specific to the nuclei of the gland and not of the fat body. Nucleoli showed no labelling. 5. Cytological analysis suggested that the LCG has polytene nuclei.