Formation of cytoplasmic nucleolus-like bodies from pre-existing nucleolar material in the mitotic cells of Vicia faba

Abstract

The origin and behaviour of cytoplasmic nucleolus-like bodies was examined and correlated with the fate of the nucleolar material during mitosis of Vicia faba. The minute cytoplasmic nucleolus-like bodies first appeared in late anaphase. Relatively large bodies more than 1 μm in diameter were detected almost exclusively in early telophase but did not persist long in mid or late telophase. Ultrastructural survey revealed that the minute cytoplasmic nucleolus-like bodies in late anaphase consisted of ribosome-like granules and/or a fibrillogranular substance similar to the nucleolar remnants in prometaphase. Two types of the nucleolus-like bodies, however, were discerned in early telophase; one was composed of ribosome-like granules and/or the fibrillogranular substance and the other was exclusively fibrous in texture.