Increased density of <i>neurog1</i> and <i>deltaB</i>-positive cells in the neurogenic domain after <i>her4</i> blockade.

<p>(<b>A, B</b>) GFP expression in Tg(<i>her4</i>:GFP) line. In <i>her4</i>-MO injected embryos GFP expression is completely lost (B) compared to controls (A). (<b>C–D'</b>) Dorsal views of 24 hpf control (C, C') and <i>her4</i>-MO injected (D, D') embryos stained by in situ hybridization for <i>neurog1</i>. (D, D') <i>neurog1</i> expression in <i>her4</i> morphant embryos is increased in the ventral plane (D') compared to controls (C'). (<b>E–F'</b>) Dorsal views of 27 hpf control (E, E') and <i>her4</i>-MO injected (F, F') embryos stained by in situ hybridization for <i>deltaB</i>. (F, F') <i>deltaB</i> expression in <i>her4</i> morphant embryos is increased in the dorsal and ventral plane (F, F') compared to controls (E, E'). (<b>G–H'</b>) Sequential transversal sections; medial to the left, dorsal to the top of 24 hpf control (G, G') and <i>her4</i>-MO injected (H, H') embryos stained by in situ hybridization for <i>neurog1</i>. In morphant embryos an increased number of cells in the otic epithelium stained for <i>neurog1</i> is observed compared to controls. (<b>I–J'''</b>) Sequential transversal sections; medial to the left, dorsal to the top of 27 hpf control (I–I''') and <i>her4</i>-MO injected (J, J''') embryos stained by in situ hybridization for <i>deltaB</i>. In morphant embryos the number of <i>deltaB</i>-positive cells in the otic epithelium (compare J'' with I') is increased and also the size of the SAG (J, J'). In control embryos SAG is only present in one section (I). Arrowheads point to epithelial neuroblasts. Dashed circles delineate otic vesicles. Scale bar in A and B: 500 µm, Scale bar in C-F': 25 µm, Scale bar G-J''': 25 µm.