Fig. 1. Myc expression in NPCs. (A) MycER and the mutated Myc deficient in Miz-1 binding (MycV394D) were transduced to NPCs with retroviruses and the expression was analyzed by western blotting with an anti-Myc antibody. The 100 kDa transgene is not seen in the control NPCs. The endogenous 64 kDa Myc is only poorly visible in the control neurosphere lysates but increased in the Myc NPCs. The MycV394D mutant protein is of the same size as the endogenous mouse Myc. (B) 91.4% (s.d.=5.0, n=4) of the transduced NPCs express Myc as shown by flow cytometry. (C) RT-PCR shows the expression of the endogenous Myc in the mouse neurospheres (NPCs). (D) A sagittal section of an embryonic E16 mouse brain shows Myc immunoreactive cells in the lateral ventricle wall area.