On the action of ribonuclease in salivary gland cells of drosophila

Summary It was shown that ribonuclease degrades the nucleolus in actively metabolizing cells. It does this without inhibiting RNA synthesis in the puffs and the nucleolus organizer. DNA synthesis still continues before or after puff formation, while amino acid incorporation is inhibited before the puffs are formed, indicating pre-existence of proteins involved in the process of puff formation.Dedicated to Professor H. Bauer on the occasion of his 60th birthday. — Research sponsored jointly by the U. S. Atomic Energy Commission under contract with the Union Carbide Corporation, the International Laboratory of Genetics and Biophysics, Naples, Italy (Partially supported by Euratom), and the Whitman Laboratory, University of Chicago, Chicago, Illinois.Supported by NTH Postdoctoral Fellowship 2-F 2–6 M-17, 187-02.