Single-cell RNA-Seq reveals the presence of retinoma and Rb cells in H9 RB1-null organoids. (A, B) UMAPs showing the cell clusters in control and RB1-null hESC organoids (A) and cell cycle distribution (B). (C) UMAP of integrated control and H9 RB1-null hESC organoids with cell cluster annotations. (D) Expression of key retinal cell type markers genes used to facilitate cluster definition in C overlaid onto the UMAPs. (E) Percentages of cells in each cell cluster of control and RB1-null hESC organoids. (F) Monocle-2 pseudotime showing progression from UPRCs to retinoma and Rb cell clusters. Cluster 11 was exempted from analysis because of low read number. RPCs: retinal progenitor cells, MGs: Müller glia cells, NRPCs: neurogenic RPCs, RGCs: retinal ganglion cells, UPRCs: cones with high expression of genes involved in unfolded protein response, RGCP: RGC precursor, T1, T2, T3: transient neurogenic progenitor populations.