The Nucleolus

The nucleolus is a prominent structure within the interphase nucleus that is visible by conventional light microscopy. Nucleoli are highly dynamic, polymorphic structures. Nucleolar function and architecture are temporally and developmentally regulated in response to changing cellular and environmental conditions. The function of the nucleolus was first identified as being essential in coordinating ribosomal subunit biogenesis. However, more recent advances in nucleolar research have revealed it to have additional important roles in other aspects of cell biology and in human disease. These results have shaped the current view of the “multifunctional” or “plurifunctional” nucleolus. This article will provide an overview of nucleolar architecture, its many functions, and its dynamic behavior.