Further Experiments on the Role of the Nucleolus in the Transfer of Rna From Nucleus to Cytoplasm

Abstract

The role of the nucleolus in the transfer of RNA from nucleus to cytoplasm was examined by means of experiments in which the nucleolus or other parts of the nucleus were inactivated by a microbeam of ultraviolet light. These experiments confirmed previous work in showing that such inactivation of the nucleolus inhibited the appearance in the cytoplasm, not only of ribosomal RNA, but also of other types of RNA made in the nucleus, in particular transfer RNA.