Figure 3.

The Tiny Cells in the Regions of Lower Tubules and Ureters are Pluripotent Stem Cells.

GFP (green) label cells derived from PMML clones.

(A) GFP marks primarily the small nuclear cells (white arrow) in the region of lower tubules and ureters but not the TSH-positive (red, green arrow) type II cells in the upper tubules of the MTs (two days ACI). One transient large nuclear cell GFP clone (white arrowhead) was also detected in the MTs. DAPI staining in blue.

(B) An enlarged view of GFP-marked clones (two days ACI) showing that the GFP marks primarily the small nuclear cells (anti-Arm, red; anti-GFP, green; DAPI, blue).

(C-F) 4 days ACI. The GFP marks clones of cluster cells with small, intermediate, and large nuclei. Two examples of clones show the basal RNSC (arrowheads), RB (arrows) and apical direction of growth (dashed arrows; anti-GFP, green; DAPI, blue).

(G and H) 6 days ACI. The GFP marks cluster cells with small, intermediate, and large nuclei in the region of the lower tubules and ureters (anti-Arm, red; anti-GFP, green; DAPI, blue).

(I) 4 days ACI. Some of the GFP-marked small nuclear cells (arrows) migrated to the main segment (anti-Arm, red; anti-GFP, green; DAPI, blue).

(J-N) 10 days ACI. In the region of the lower tubules and ureters, the GFP marks cell clusters (one cluster of cells is highlighted in [K]). In the upper tubule, the GFP labels both Cut-positive (red in [M] and [N]) type I cells (yellow arrowheads) and TSH-positive (red in [L]) type II cells (yellow arrows in [L–N]). White dashed arrows in (A) point from the ureter to upper tubules. Scale bars: in (A) represents 20 μm; in (G) and (J), 10 μm; in (B–F), (H–I), and (K–N), 5 μm.