Fig. 3. Comparison of localization of SMN proteins using the CB marker coilin. The constructs indicated were transiently transfected into COS cells. Overexpression of FP-SMN, SMNex7, SMN4725 and SMNN86 colocalized with coilin in CBs (red), whereas SMNN86, SMNex2B, SMNTudor, SMNC40 and SMNN189 did not form nuclear foci, and were excluded from CBs. Mutants SMNN86 and SMNex2B accumulated also in nucleoli (see Fig. S1). The microscope was focused on coilin-positive CBs. Inserts show staining for FPs (left) and coilin (middle), and merged images (right). Bars, 3 µm.