Fig. 1. The detection of MUK protein in developing mouse telencephalon. (A) Western blot analysis of proteins extracted from 293T cells (–), 293T cells overexpressing MUK (M) and E16 telencephalic vesicles (T), using affinity-purified rabbit antibody against the C-terminal 276 amino acids (left panel) or normal rabbit IgG as a control (right panel). The arrowhead indicates the position of a 120 kDa protein (MUK). (B) Sagittal sections of paraffin wax-embedded E16 embryo head were immunostained (blue) using the anti-MUK antibody, alkaline phosphatase-conjugated secondary antibody and BM purple. Positions of the telencephalon (T), diencephalon (Dc), midbrain (Mb), cerebellar primordium (Cb), medulla oblongata (MO), spinal cord (SC), dorsal root ganglia (DRG) and lateral ventricle (LV) are indicated. The insert is a control staining with normal rabbit IgG. (C) Higher magnification of the telencephalic region in B, showing predominant expression of MUK in the subplate, intermediate zone and subventricular zone. (D-I) Paraffin wax-embedded sections were prepared of the heads of E11, E13, E14 and E15 embryos and the isolated brain of an E18 embryo or 5-day-old mouse (P5) and used for the immunostaining. Distinct layers observed in the cortical region, neuroepithelium (NE), ventricular zone (VZ), pre-plate (PP), subventricular zone (SVZ), intermediate zone (IZ), subplate (SP), cortical plate (CP), marginal zone (MZ) and neocortex consisting of six presumptive layers (I-VI) are indicated. Scale bars: 500 µm.