Fig. 1. PITP is highly enriched in the adult and developing brain. (A) Comparison of PITP and PITPβ expression in the adult rat. Equal protein amounts of indicated tissue extracts were separated by SDS-PAGE and probed using anti-PITP or anti-PITPβ antibodies. For quantification of PITP and PITPβ expression see Fig. S1 in the supplementary material. Bars show the mean of three independent analyses ± s.e.m. (B) In the adult mouse cerebellum, anti-PITP labelling was detected in the molecular layer and the granule cell layer, whereas low signals were associated with the Purkinje cell layer and the white matter tract. (C) In the P15 mouse cerebellum, PITP was expressed in the molecular layer and in the granule cell layer. In addition, afferent fibres in the developing white matter tract were positive for PITP immunoreactivity. In control experiments performed in parallel, no signal was detected in the presence of control serum (see insert). (D) PITP was broadly expressed in the CA3 cells of the adult hippocampus. A higher magnification of the outlined box in D is shown in E. (E) Particularly enriched labelling was seen in the stratum radiatum. The cell bodies of the pyramidal neurons were devoid of PITP. (F) PITP was broadly expressed in the P15 hippocampus. Scale bars: 200 µm in B; 100 µm in D,F; 50 µm in E. m, molecular layer; g, granule cell layer; pl, Purkinje cell layer; py, pyramidal neurons; sr, stratum radiatum; wm, white matter tract.