Figure 2.

The MT-nucleating activity of GPM complexes changes during the differentiation. (Left and middle) GPM complexes were prepared from cells at 20, 40, 60, and 80 min after initiation of differentiation and incubated with anti–γ-tubulin Ab and Texas red–conjugated second Ab and examined under DIC (left) and epifluorescence (γ-tubulin) optics as described in Fig. 1 A. GPM complexes (arrows) from different stages of the differentiation contain γ-tubulin. (Right) In vitro MT-nucleation was performed with GPM complexes from 20, 40, 60, and 80 min cells with rhodamine-tubulin and observed under an epifluorescence microscope. Bar, 10 μm.