Fig. 5. Notch receptors and ligands are differentially expressed in Math1^{ß-gal/ß-gal} and Math1^+/+ rhombic lip cells. (A) Expression level of Notch signaling components was tested by real-time quantitative RT-PCR on E14.5 rhombic lips. All Notch receptors and ligands tested were expressed in the rhombic lip, although at various levels (note logarithmic scale). Expression level of Notch receptors (B) and ligands (C) was compared between rhombic lip from Math1-null (open bars) and wild-type (closed bars) littermates at E14.5. ß-actin was used as a control. Values are the mean of at least three measurements +s.e.m.