Figure 2

SMG aplasia in Fgfr2b and Fgf10 null mice. A. E13.5 WT mouse. B. E13.5 Fgfr2b^-/- null mouse. C. E13.5 Fg10^-/- null mouse. The E13.5 WT SMG (A) has achieved the Late Initial Bud Stage, with several branches being seen in the end-bulb epithelium; a small sublingual gland (SL) bud is seen lateral to the SMG bud. In Fgfr2b^-/- (B) and Fg10^-/- (C) embryos, no SMGs are found; undifferentiated mesenchyme is seen in the site normally occupied by SMG epithelia. PS-palatal shelf. Bar, 50 μm.