Fig. 7. FIGQY tyrosine phosphorylation occurs in regions of neuroblast generation and migration and regions of axon extension. (A) A low magnification image of an E17 rat brain labeled with the phospho-FIGQY polyclonal antibody. The anterior region of developing cortex in E18 brain sections was labeled with the phospho-FIGQY polyclonal antibody (B), a neurofascin polyclonal antibody (C) or an L1 polyclonal antibody (D) showing overlap between expression of these L1 CAMs and phospho-FIGQY. A similar pattern of phospho-FIGQY labeling in E15 embyros (E) was displaced when the phospho-FIGQY polyclonal antibody was pre-incubated in the presence of a fivefold molar excess of tyrosine phosphorylated nfFIGQY peptide (F) but not in the presence of a fivefold molar excess of tyrosine phosphorylated AngII peptide (G). Sections of P8 cerebellum were labeled with the phospho-FIGQY polyclonal antibody (H), a polyclonal antibody against neurofascin FNIII domains (I) or a polyclonal antibody against L1 (J) showing an overlapping distribution of phospho-FIGQY and L1 CAMs. (K-M) The presence of FIGQY phosphorylation in adult brain in neuroblasts migrating in the rostral migratory stream from the lateral ventricle to the olfactory bulb is shown. The phospho-FIGQY polyclonal antibody label partially overlaps with the early neuronal marker ß III tubulin in the subventricular zone (L) and (M) for overlap. CP, cortical plate; EGL, external germinal layer; IGL, internal granule cell layer; IZ, intermediate zone; LV, lateral ventricle; ML, molecular layer; MZ, marginal zone; VZ, ventricular zone. Scale bars: 100 µm in A; 25 µm in B-M.