Fig. 6: Generation of ureter-like organoids derived entirely from mouse and human PSCs.

a Schematic diagram of reconstitution methods between iUBs and iSPs derived entirely from mouse ESCs or human iPSCs. Isolated UB tip and SPs derived from Hoxb7-GFP mouse ESC or human iPSCs are combined, and cultured at the air/liquid interface for 7 days (mouse) or 21 days (human). b Bright-field images of reconstituted organoids entirely derived from mouse ESCs. The experiments were performed three times, with a minimum of three reconstituted spheroids per condition per experiment. All of the 11 organoids showed spherical morphology. Scale bars: 100 μm. c Bright-field images of contraction and relaxation states in the reconstituted organoids using mouse ESC-derived iUBs and ventral iSPs at day 8. The outlines of the organoid in relaxation and contraction states are shown by the dotted black and red lines, respectively. 8 out of 11 spherical organoids showed contraction.d Contraction intensity of reconstituted organoids using several types of SPs from mouse embryos or mouse ESCs. Data are shown as mean ± SD (n = 3 biologically independent samples, respectively). The one-way ANOVA was performed. Tbx18-GFP⁻ vs Tbx18-GFP⁺; p < 0.0001, dorsal iSP vs Tbx18-GFP⁺; p < 0.0001. The source data are provided as a Source Data file. e Immunostaining of reconstituted organoids derived entirely from mouse ESCs at day 8. Scale bars: 100 μm. One or two samples from each condition in each experiment were subjected to histological analysis, and similar results were observed in all of the samples (n = 5). The representative images are shown (eventual success rate; 73%). f Bright-field images of reconstituted organoids entirely derived from human iPSCs. Scale bars: 100 μm. The experiments were performed three times, with a minimum of two reconstituted spheroids per condition per experiment. Out of 9 organoids, 5 showed spherical morphology, while the rest degenerated. g Immunostaining of reconstituted organoids entirely derived from human iPSCs at day 21. Scale bars: 100 μm. One or two samples from each condition in each experiment were subjected to histological analysis. Similar results were observed in all of the samples (n = 4), and the representative images are shown (eventual success rate; 56%).