Fig. 3.

Alteration of microtubule assembly pattern in the absence of CAMSAPs. (A) Double immunostaining for α-tubulin (green) and γ-tubulin (red) in Caco2 cells transfected with the indicated siRNA. (Inset) Enlargement of boxed area. The arrowheads point to centrosomes, which are generally detected as a doublet in each cell. (B) Microtubule growth after nocodazole washout. Confluent cells transfected with the indicated siRNAs were treated with 10 μM nocodazole for 1 h at 4 °C, incubated for another 7 min after removing nocodazole, and then fixed and immunostained for α-tubulin and γ-tubulin. The relative differences in the degree of centrosomal radiation of microtubules between the samples are maintained during further incubation periods, although noncentrosomal microtubule fragments gradually increase after 10 min. (Scale bars, 10 μm.) (C) The number of cells with an array of microtubules radiating from the centrosomes in A was quantified. Date represent the mean ± SEM from six independent experiments, in which 100 cells were analyzed per experiment. *P < 0.01. (D) The extent of microtubule radiation from the centrosomes in B was quantified by measuring the length of the four longest microtubules in each cell. Data were collected from three independent experiments. Values indicate mean ± SEM. ***P < 0.0001.