Immunolocalization of shortened CO.1 and CO.2 isoforms at the centrosome.

Lymphoid control (not shown) and CO cells (panels A and B) were cultured in the absence (−Noc) or presence (+Noc) of nocodazole. (A) Double staining with AbHP and AbγT revealed the presence of 4.1R epitopes at the centrosome, in a microtubule-independent manner. Further staining with specific antibodies ascertained the absence of NuMA at the spindle poles in nocodazole-treated cells and the chromosome condensation between the centrosomes. (B) Staining with AbCO antibody showed a punctate distribution of CO.1 isoform throughout the cell, but failed to show a specific localization at the centrosome, in both microtubule-stabilizing and microtubule-destabilizing (not shown) conditions. Bar indicates 10 μm.