Fig. 2

Expression patterns of GAP-43 and pT172 in developing mouse brain. a Immunoblotting of mouse frontal brain lysates. The expression of GAP-43 and pT172 persists throughout life. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH): positive control. The mouse strain was C57BL/6. b Immunohistochemistry of pT172, pan-GAP-43 and the cell adhesion molecule (L1), in E15 mouse brain in sagittal sections. Scale Bar; 500 μm. c, d Immunostaining of pT172Ab, GAP-43 Ab and co-staining of 4′,6-diamidino-2-phenylindole (DAPI) (c), or Immunostaining pT172, GAP-43 and L1 Abs (d). These views were obtained by Z-stack maximum-intensity projection fluorescence images of the neocortex. Cell body-specific nuclear staining with DAPI is shown. GAP-43 itself was expressed by migrating neurons and ingrowing axons in the intermediate zone (IZ). pT172 expression was restricted to the L1-positive thalamocortical axons in the upper IMZ. MZ marginal zone; CP cortical plate and VZ ventricular zone. Scale bar; 50 μm. e–h Spatial distribution pattern of pT172 (e, f) and GAP-43 (g, h) in E15 mouse brain. The immunoreactivity of GAP-43 was found in most of the differentiated neurons. In contrast, pT172 was distributed to the developing axonal processes, but was not detected in the neuronal cell bodies. Fi fimbria, Och optic chiasm, OB olfactory bulb, sc superior colliculus; Teg longitudinal tegmental tracts; CB cerebellum; dTH dorsal thalamus; MED medulla oblongata; NCx neocortex; and PON pons. Scale bars: 500 μm. Immunohistochemical studies (DAB staining) were performed using pAb against T172 (e–h). See also Additional file 4: Fig. S3