Fig. 3. GFP and Lim1 immunohistochemistry in biolistically transfected stage 31 retinas. (A-C) A time-lapse series of a retinal slice from a biolistically transfected stage 31 retina using a green fluorescent protein (GFP) expression vector. A cell indicated by a large arrowhead is migrating towards the ventricular side in relation to its starting point (small arrowhead). (D) Lim1 (red) and GFP (green) co-labelling in cells fixed and cryosectioned 24 hours after gene transfer. (E-H) GFP (green), and other markers (red) in fixed and cryosectioned retinas at different time points after transfection. White arrows indicate gold particles in the internal retina. Black arrows indicate GFP and antibody co-expression. (E) GFP and Prox1 22 hours after transfection. (F) Ganglion cell marker Ng-CAM (G4) expression and gold particle penetration 15 minutes after transfection. GFP is not yet expressed. (G) Ganglion cell marker Islet1 and GFP, 22 hours after transfection. (H) GFP and Ng-CAM (G4) in a retina 18 hours after transfection. Gold particles as well as cells expressing GFP are found on the ventricular side of the retina (white arrow). Scale bars: in A (for A-C), D,E (for E-H) 20 µm.