Molecular hybridization used to characterize the RNA synthesized by isolated bovine thymus nuclei

Abstract

In vitro synthesis of RNA by nuclei isolated from various tissues has been observed in many laboratories (1-3). Several investigators have realized the usefulness of isolated nuclei for studying the regulation of RNA synthesis. The effects of nuclear proteins (4) and various hormones, (5-7) for example, on the incorporation of various precursors into RNA have been analyzed recently. However, if the full potential of isolated nuclei as an assay system for studying the regulation of RNA synthesis is to be realized, then it is necessary that the characterization of the synthesized RNA be more complete. In the present studies, we have used the technique of DNA-RNA hybridization in an attempt to characterize the RNA synthesized in vitro by thymus nuclei. We have shown that the isolated thymus nucleus is capable of synthesizing a population of RNA molecules that is specific to thymus. The intracellular distribution of RNA species was also investigated and differences were found between nuclear RNA and cytoplasmic RNA. The isolated nucleus was shown to synthesize RNA similar to that found in the nucleus and in the cytoplasm.