Expression pattern of TGF-β1 and TGF-β responsive Smads, Smad2 and Smad3.

A) Top left panel shows H & E staining of mouse bladder anatomy from E12.5 to E16.5. B) Negative control sections of TGF-β1 and C) Smad2 and Smad3 incubated only with secondary antibodies (no primary antibodies, top middle and right panel). D) At E12.5, TGF-β1 expression was faint and localized in the epithelium and urethra (bottom left panel). At E14.5 and E16.5, TGF-β1 was localized in the transitional epithelium, adjacent to the lamina propia and muscularis mesenchyme (arrow). E and F) At E12.5, Smad2 and Smad3 were in the bladder epithelium and urethra (arrow, bottom middle and right panel). At E14.5, Smad2 and Smad3 were localized in the transitional epithelium, lamina propia and muscularis mucosa (arrow). Insert: positive staining of phosphorylated Smad2 and Smad3 (bottom middle right panel). At E16.5, Smad2 was localized in the transitional epithelium and periphery of the detrusor muscle (arrow, bottom middle panel) and Smad3 was localized in the transitional epithelium, muscularis mesenchyme and periphery of the detrusor muscle (arrow, bottom right panel). Insert: positive staining of phosphorylated Smad2 and Smad3. Magnification ×40. e: epithelum, l: lumen, bw: body wall, u: urethra, lp:- lamina propia, mm: muscularis mesenchyme, dm: detrusor muscle. (Green color: Respective Smads, Blue color: DAPI).