Fig. 3. (i) Three-dimensional projections of cells from line YFPSmBE1 fused to cells from line CFPSmBE8.8. A to C shows one cell from each line fused together, fixed two hours after fusion, YFPSmB has accumulated in the Cajal bodies of the nucleus from line CFPSmBE8.8 (arrows in A), while CFPSmB has accumulated in the Cajal bodies of the nucleus from line YFPSmBE1 (arrowheads in B). D to F shows three cells fused together, fixed 16 hours after fusion. Each of the nuclei shows a pattern of Cajal bodies (arrows) and speckles (arrowheads) for both YFPSmB (D) and CFPSmB (E). (ii) Conventional fluorescence images of cells from line YFPSmBE1 injected with the expression vector for ECFPSmD1, fixed after 1hour (A,D), 2 hours (B,E) and 16 hours (C,F). YFPSmB shows a speckled pattern in cells at all time points (D-F), while CFPSmD1 appears first in Cajal bodies after 1 hour (arrows in A), in nucleoli after 2 hours (arrowhead in B), finally showing a speckled pattern after 16 hours (arrows in C and F). Bar, 10 µm.