Fig. 5

Changes and abnormalities of cell nuclei. Acridine orange (AO) fluorescence (a, b, d) and TEM (c) micrographs of PEG-treated polyploid NIHs cells. AO staining, performed according to a standard protocol, allowed us to observe yellow/green nuclear DNA and red cytoplasmic RNA fluorescence. In a, a trinucleated cell with micronuclei in the cytoplasm (arrows). In b, c, and d, events of nuclear envelope budding (arrows) resulting in the detachment of nuclear portions and the presence of micronuclei with heterogeneous sizes are shown (b, c, and d). The ultrastructural image in c shows a situation similar to that shown in d. The arrow in c indicates a possible detachment of a nuclear portion. Scale bars in a: 10 µm, in b and d: 5 µm, in c: 1 µm