Double-label immunofluorescence was performed with monoclonal mouse anti-c-myc (clone 9E10, Santa Cruz Biotechnology), rabbit anti-Tub2 antisera (gift of Frank Solomon), goat anti-rabbit IgG-FITC conjugate (Santa Cruz Biotechnology), and goat anti-mouse IgG-AlexaFluor594 conjugate (Molecular Probes) as primary and secondary Abs.