Fig. 4

Propagation and characterization of photoreceptor progenitors (PRP). a, b Bright-field images during the course of differentiation. a Rosette population selected for expanding neuroretinal cells. b Formation of contact synapses in photoreceptors. c–g Immunofluorescence images representing the protein expression during stages of PRP differentiation. c Photoreceptor progenitor markers PAX6, RX, and LHX2 at day 35. d Photoreceptor commitment factors OTX2 and CRX at days 35 and 70. e Retinal ganglion marker BRN3A at day 35. f Cone cell markers THRβ at days 50 and 70 and visual arrestin at day 70. g Rod cell markers Recoverin and Rhodopsin at days 50 and 70 and NRL2 at day 70. h Gene quantification profile using real-time PCR of selected markers represented as fold change in 35-, 60-, 75-day RPE with respect to undifferentiated iPSC. i Flow cytometry analysis for CRX, OTX2, THRβ, Rhodopsin, and Ki67 in day 70 PRP. Images and graphs are representative of a minimum of three independent experiments. Scale bars represent 100 μm