FIG. 1.

Characterization of CCE-ES cells and their transformants expressing Rx/rax or Chx10. (A) Semiquantitative RT-PCR of genes expressed in retinal progenitor cells in CCE (feeder-free mouse) ES cells. cDNA from EBs formed by CCE, EBs treated with RA, and eyes from E15 mouse embryos were used. (B) Morphology of CCE, CCE-CH, and CCE-RX cells. (C) Proliferation of CCE, CCE-RX, and CCE-CH cells. Cells were seeded in 6-cm plates, and cell numbers were counted every 2 days. Values are the average of two independent samples. Experiments were done twice, and essentially the same results were obtained. (D) Differentiation molecular markers were examined by semiquantitative RT-PCR analysis of EB cultures taken at different time points.