Fig. 4. Real time RT-PCR analysis on mRNA expressions of Ptc1, Gli1, and Bmp4 in laser captured mesenchymal components of each gestational stage.

Ptc1, Gli1, and Bmp4. expression were restricted to a thin layer of mesenchymal cells in the submucosa immediately adjacent to the epithelium. Both Ptc1 and Bmp4 genes were significantly decreased in all mesenchymal cells in the E13.5 bladder. Ptc1 remained at a low level in contrast to Bmp4 in which was increased at E15 and E16. Gli1 gene expression was up regulated in the submucosa at E13.5. At E15 the expression changed to the smooth muscle layer (Mann-Whitney test, p<0.001). a, Serosal zone. a1, Smooth muscle layer. a2, Intermediate zone. b, Submucosal zone.