Recent studies on the nucleolus

Abstract

Scope and Method of Study: This report has been undertaken in an attempt to obtain information on the structure, composition and function of the nucleolus. Information on the possible connections of the nucleolus with the mitotic cycle and cytoplasm was also obtained. Publications since the year 1959 were consulted. The materials used were chiefly periodicals and a few books.

Findings and Conclusions: Progress of research on the nucleolus has awaited improved techniques and new types of equipment. The structure of the nucleolus is described as a two component system. The nucleolus was seen to disperse during the mitotic cycle and to form on a particular chromosomal region. The possibility of nucleolar control on mitosis is indicated. The composition of the nucleolus is chiefly RNA and proteins. It may also contain certain enzymes and lipids. The synthesis of RNA in the nucleolus is generally accepted. The types are not agreed on. The transfer of RNA to the cytoplasm seems probable but the method is not apparent. Protein synthesis within the nucleolus is Iittle, if any. Considering the conflicting information obtained, it is evident that nucleolar research has just obtained a good beginning.