[An electron-autoradiographic study of RNA transfer from nucleus to cytoplasm].

By electron-autoradiographic study of the RNA synthesis in the hepatocytes of mice there were revealed marked differences in the content of labeled RNA in the nucleoli of the same nucleus. The silver granule concentration was sometimes greater in the areas of the cytoplasm located near the nuclear membrane with the neighbouring nucleolus than in the rest of the cytoplasm. It is supposed that the nucleoli of the same nucleus synthesized the RNA at a different time, transfered it to the nuclear membrane and discharged the RNA into the cytoplasm also at a different time. Due to this the discharge of the RNA into the cytoplasm assumed a definite rhythm. The number of nucleoli and the frequency of discharge of the RNA portions into the cytoplasm can increase under pathological conditions.