Fig. 3. Some, but not all otic markers are expanded at the expense of epidermis in conditionally activated Notch1 (cN1ICD) embryos. (A-C') Expanded otic placode in cN1ICD embryos hybridized with probes for Pax8 (A,A'), Pax2 (B,B') and the epidermal marker Foxi2 (C,C'). Arrowheads indicate ectopic expression. Dotted outline in C indicates the invaginating otic cup (controls) or expanded otic region (cN1ICD mutants). (A'-C') Corresponding transverse sections. Brackets indicate the lateral ectopic placode region. Scale bars: 100 µm. (D) Hmx3, Sox9 and Gbx2 otic markers are not expanded in cN1ICD mutants. (E) In β-cat-CKO; cN1ICD mutants, Pax8 (top row) and Jag1 (green, bottom row) are expanded at the expense of Foxi2 (middle row). (Bottom row) β-catenin (red) and Jag1 protein expression in Foxi2 hybridized embryos. Insets show whole mounts. Scale bar: 100 µm.