Abstract
Changes in nucleolar morphology and function are tightly associated with cellular activity, such as growth, proliferation, and cell cycle progression. Historically, these relationships have been extensively examined in cancer cells, which frequently exhibit large nucleoli and increased ribosome biogenesis. Recent findings indicate that alteration of nucleolar activity is a key regulator of development and aging. In this review, we have provided evidences that the nucleolus is not just a housekeeping factor but is actively involved in the regulation of cell proliferation, differentiation, and senescence both in vitro and in vivo. In addition, we have discussed how alteration of nucleolar function and nucleolar proteins induces specific physiological effects rather than widespread effects.