Co-expression of nestin and pcna in the zebrafish forebrain. Double fluorescent ISH was performed for 2 dpf (A-I) and 3 dpf (J-L) zebrafish embryos. nestin is shown in green (A, D, G, J); pcna in red (B, E, H, K); overlay (C, F, I, L). Inserted pictures in (J-L) show a higher magnification of the boxed areas. (A-C): Overview over the proliferation zones in the 2 dpf zebrafish forebrain. (D-F): Higher magnification of the ventricular zone of the TC shows co-expression. (G-H): Higher magnification of the subventricular zone in the ventral DC reveals co-expression of nestin and pcna. (J-L): At 3 dpf cells co-expressing nestin and pcna are detectable along the walls of the telencephalic ventricle. Abbreviations: DC: diencephalon; Ret: retina; TC: telencephalon. Scale bar: 50 μm.