Fig. 1. Widespread occurrence of PCM-1 granules. Cultured mouse L fibroblasts (a), Eph-4 epithelial cells (b) or frozen sections of mouse intestine (c) or kidney (d) were triple stained with anti-mPCM-1 pAb (green), anti--tubulin mAb (red) and anti--tubulin mAb (blue, turned white) (a,b) or anti-mPCM-1 pAb (green), anti--tubulin mAb (red) and DAPI (blue) (c,d). In cultured cells (a,b), some PCM-1 granules were gathered around the centrosomes (arrows) but the others were scattered in the cytoplasm. In intestinal and renal epithelial cells (c,d), PCM-1 granules were concentrated abundantly in the apical region of the cytoplasm (arrows). The liver (e) or the brain (f) were triple stained with anti-mPCM-1 pAb (green), anti-occludin mAb (red) and DAPI (blue) (e) or anti-mPCM-1 pAb (green), Cy3-conjugated anti--tubulin pAb (red) and DAPI (blue) (f). In hepatocytes (e), a fairly small number of PCM-1 granules were detected, which were scattered around the occludin-positive bile canaliculi (arrow) where the centrosomes (and minus ends of microtubules) were located. In nerve cells in the brain (f), PCM-1 granules were scattered over the cytoplasm, showing no significant concentration around the -tubulin-positive centrosomes (arrow). Bars, 10 µm. (g) To clarify the spatial relationship of PCM-1 granules with centrosomes quantitatively, four distinct types of cultured cells were double stained with anti-mPCM-1 pAb and Cy3-conjugated anti--tubulin pAb, and the number of PCM-1 granules inside (red) and outside (black) a radius of 3 µm of the -tubulin-positive centrioles were counted for 16 L cells, 10 Eph4 cells, 18 CSG cells and 8 A6 cells as described in Materials and Methods. Error bars show the s.e.m.