Fig. 6

Donor CSSC culture and gene expression. A Clonal growth of P2 cells in JM-H medium. The crystal violet-stained colonies were imaged under brightfield microscopy. Phase-contrast micrograph showing a multicellular cluster (colony) of CSSC (HC641 at P2). B Colony-forming efficiency of 18 donor CSSC batches. The percentages of colonies (> 50 cells) were ranged from 18% to 41.1% and the mean CFU was 29.8 ± 6.5%. C The expression of stemness genes (ABCG2, nestin, Pax6, Bmi1, Sox2, NGFR) and keratocyte-specific genes (Kera, Lum and ALDH3A1) in cultured CSSCs (at P2) compared to quiescent keratocytes. D Passage-dependent changes of stemness genes in three representative CSSC batches derived from different donors. From P1 to P3, the cellular expression of ABCG2 and nestin remained consistent, whereas Pax6, Bmi1, Sox2, Oct4 and NGFR were gradually downregulated. E The expression patterns of ABCG2 and nestin were mostly consistent among 18 donor CSSC batches at P2