Fig. 3. Activity of the electroporated ATH5 promoter in stage 22-23 retina. (A) When controlled by the ubiquitous CMV promoter, GFP and lac reporters are both expressed in the electroporated peripheral retina. (B-F) The ATH5-promoter/lac and the CMV-promoter/GFP reporter plasmids were electroporated alone (B,C), in combination with a NGN2 expression vector (D,E) or in combination with NGN2 and HES1 expression vectors (F). (B) GFP-positive cells are distributed throughout the peripheral (p) and central (c) retina, whereas lac⁺ cells are confined to the central region (arrowhead). (C) lac⁺ cells (arrowheads) are sparse in the central retina. (D) Overexpression of NGN2 increases the proportion of lac⁺ cells in the central, but not in the peripheral retina (arrowhead in E). (F) No lac⁺ cells were detected when both NGN2 and HES1 were overexpressed in the central retina. Data presented in each panel are representative of at least five independent experiments. l, lens. Scale bar: 170 µm in A; 120 µm in B; 30 µm in C; 40 µm in D,F; 80 µm in E.