Fig. 2. Protoplast nuclei contain chromocenters that are reduced in number and size. (A) DAPI-stained nuclei show up to three chromocenters in protoplasts (middle), and up to ten chromocenters in leaf (left) and cultured cells (right). Bar, 5 µm. (B) Relative heterochromatin fraction (RHF) in leaves (black bars), protoplasts (gray bars) and cultured cells (white bars). (C) Confocal images of living cells expressing H2B::YFP from leaf (left), protoplasts (middle) and after 72 hours in culture (right). Bar, 5 µm.