Fig. 6. CrkRS strongly associates with nuclear speckles. (A) CrkRS remains associated with nuclear speckles after DNase and RNase treatment. Hela cells were fixed and left untreated (top row) or treated with DNase 1 (middle row) or with RNase A (bottom row). Cells were costained with anti-CrkRS (green), anti-snRNPs (Y12, red) and a DNA marker (TOTO-3, blue). The localisations of CrkRS and snRNPs did not alter significantly in DNase I-treated cells. In RNase A-treated cells, the localisation of CrkRS did not alter significantly but the anti-snRNP staining was less punctate and more uniformly distributed throughout the nuclei. (B) -amanitin alters the pattern of both CrkRS and SC35. In HeLa cells treated with -amanitin both anti-CrkRS (left) and SC35 immunofluorescence patterns (middle) alter to one of fewer, larger and rounder speckles and these colocalise (merged image). (C) Localisation of CrkRS during metaphase and telophase. At metaphase (top), anti-CrkRS (left) and anti-SC35 (middle) immunofluorescence patterns become diffusely distributed throughout the cells, and do not stain the chromosomes (right). At telophase (bottom), anti-CrkRS antibodies and anti-SC35 both stain the reforming nuclear speckles.