Figure 9.

six1 acts via two of the three dach genes to promote the proliferation of hair cell progenitors but not SAG neurons. A–F, Whole-mount in situ hybridization to dacha (A, D), dachb (B, E), and dachc (C, F) in otocysts of STD (A–C) and six1-MO (D–F) injected embryos. All stainings have been performed at 28 hpf except B and E, which were performed at 32 hpf. Arrowheads point to ventral expression of dacha (A, D), dachb (B, E), and dachc (C, F). The changed expression was confirmed in at least 21 of 25 embryos scored. Arrows in A and D point to dorsal expression of dacha. G–M, HCS-1 immunostaining of hair cells in STD (G), six1-MO (H), dacha-MO (I), dachb-MO (J), six1-MO/dacha-MO (K), six1-MO/dachb-MO (L), and dachc-MO (M) injected 3 dpf embryos. N–Q, Whole-mount in situ hybridization to six1 in otocysts of STD control (N), dacha-MO (O), dachb-MO (P), and dachc-MO (Q) injected 28 hpf embryos. Arrowheads point to six1 expression in SAG; arrows point to six1 expression in the ventral otic epithelium. At least 30 embryos for each condition have been scored for six1 expression. All panels are lateral views with anterior to left and dorsal up, except for G–M, which are dorsal views with medial to the top. The otocyst is outlined by a dashed line in A–F and N–Q. Scale bars: A–F, N–Q, 15 μm; G–M, 5 μm.