Figure 3. Effect of E14 rcSF3 on the maturation of E7 cultures. E14 rcSF3 made gene expression in E7 cultures more like that of E14 RPE in vivo. The following select genes were analyzed if their expression in vivo changed more than 1.6X during development [1]: genes involved in the visual cycle, phagocytosis, junctional complexes, cytoskeleton, matrix, and matrix receptors or plasma membrane transport (A); genes involved in the regulation of transcription or signal transduction (B). Each pair of green and red bars represents a single gene. Green bars indicate expression when E7 RPE was maintained in basal conditions (SF3); red bars indicate expression in retinal conditioned medium (rcSF3). The bars indicate the natural logarithm of the ratio (expression in culture)/(expression in native E14 RPE), where 0.0 indicates no difference between the E7 culture and native E14 RPE. A natural logarithm of 0.7 (dashed blue lines) indicates a 2X deviation of the E7 cultures from E14 RPE expression in vivo. Positive values indicate overexpression of a gene in culture. For most genes, the green and red bars are the same length, indicating no effect of rcSF3 on expression. For most of the genes that were affected by rcSF3, the red bar is shorter than the green bar, which indicates that expression levels approached the levels observed in native E14 RPE.