Figure 1

Differentiation of mESC to ureteric bud cells (eUB) (a) Schematic diagram showing the isolation and culture of eUBs in branching medium. (b) Representative image of embryoid bodies before (48 h) and after differentiation (228 h). Scale bar, 200 µm (c) Immunostaining for tip (SOX9, RET) and trunk markers (DBA, WNT7b) in outgrowths from differentiated embryoid bodies (eUB-EB) and passage 2 eUBs (P2 eUB). Cytokeratin 8 (CK8) is a general ureteric bud marker. Inset figure shows the zoomed view of the SOX9 channel in the marked area (dotted line). n = 5/5. (d) Fluorescence images of eUBs (derived from Sox8-mCherry and Hoxb7-Gfp lines) implanted in metanephric mesenchyme (from E11.5 kidney), showing branching. eUBs isolated from differentiated embryoid bodies (eUB-EB) and passage 2 eUBs (P2 eUB) were used for implantation studies. Images of kidney at Day 0 and Day 3 after implantation is shown. n = 3/3. (e) Fluorescence images of eUBs (derived from the Sox8-mCherry line) implanted in ureteric mesenchyme (from a E11.5 kidney) showing absence of branching at day 3. n = 0/3. (f) Branching morphogenesis of eUBs in branching medium (BM) with BMP4 (BM + BMP4) or without BMP4 (BM): BMP4 inhibits branching but promotes expression of uroplakin: n = 3/3 for BM; n = 5/5 for BM + BMP4. Scale bars, 200 µm.