Assessment of Pax8 function in otic vesicle patterning. (A,E) Otic vesicles at 32 hpf stained with anti-Pax2 (red) and anti-acetylated tubulin (green) antibodies to label hair cells (Riley et al., 1999) in wild-type (A) and pax8-MO-injected (E) embryos. Hair cell patches are indicated (white arrows). Injected embryos produce fewer hair cells than normal. In the experiment shown here, an average of 5.2±1.1 hair cells were seen in pax8 morphants (n=59 ears), compared to 9.2±1.4 hair cells in wild type embryos (n=10 ears); 5-10% of pax8 morphants produce only one macula per ear (not shown). (B,F) pax5 expression at 24 hpf in wild-type (B) and pax8-MO-injected (F) embryos. (C,G) dlx3b expression at 33 hpf in wild-type (C) and pax8-MO-injected (G) embryos. (D,H) msxC expression marks developing cristae in the otic vesicle at 78 hpf in wild-type (D) and pax8-MO-injected (H) embryos. The lateral crista is present in the injected embryo but shows strongly reduced expression of msxC. Defects in development of cristae and semicircular canals are highly variable in pax8 morphants. Images show lateral views with anterior to the left and dorsal to the top. ac, anterior crista; lc, lateral crista; pc, posterior crista. Scale bar in H: 90 μm for D,H, 40 μm for C,G, and 30 μm for A,B,E,F.
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