Dispersion of CBs in a coilin mutant. Owing to expression of the CB marker U2B″:GFP, CBs are visible as single, highly fluorescent spots, often close to the nucleolus (dark spherical area), in leaf nuclei of wild-type plants (top). By contrast, in the hgf1-7 coilin mutant, CBs are either uniformly absent or much smaller and less intensely fluorescent in all cells examined. The white bar indicates 10 µm.