Fig. 1. Supernumerary poles in RanBP1-overexpressing cells contain centrosomal
components. (A) RanBP1-HA-transfected NIH/3T3 cells were double-stained with
antibodies to glutamylated tubulin (GT335) and anti-HA-antibody to identify
transfected cells (a); with antibodies coupled to centrosomal markers (b,c);
and with anti-
-tubulin to label the spindle (d) and anti-centrin 2 to
visualize centrioles. Experiments were carried out using all combinations of
coupled antibodies to HA, -tubulin and centrosomal markers, and
selected examples are shown. DNA was counterstained with DAPI (third column
from the left). Merged pictures are shown on the rightmost column. Scale bar,
10 µm. (B) Quantification of RanBP1-induced abnormalities in spindle
polarity (visualized by -tubulin staining) and in centrosomes (shown as
either >4 or abnormally separated centrin spots). Data from three
independent experiments were pooled and 100 mitoses per group were scored in
each experiment. Histograms show the proportion of cells with abnormalities in
vector-transfected (gray) and RanBP1-transfected (white) cultures. P
values calculated using the 
2 test were highly
significant.