Fig. 6

Knockdown of nog3 Derepresses Bmp Signaling and Induces Chondrogenic Progenitor Apoptosis

(A) Pharyngeal cartilage defects in nog3 morphants. Wild-type embryos were injected at the one-cell stage with different doses of nog3-MO and stained for cartilages with Alcian blue.

(B and C) nog3-MO-induced cartilage defects were alleviated by inhibition of Bmp activity with dorsomorphin. nog3-MO-injected (1 ng) embryos at 36 hpf were treated in DMSO or dorsomorphin of different concentrations and stained for cartilages at 80 hpf with Alcian blue. The extents of cartilage defects were categorized into four groups, DR1–4 (B), and the ratio of each group was shown in (C).

(D and E) Detection of apoptotic cells in nog3 morphants. Tg(fli1:EGFP) transgenic embryos were injected at the one-cell stage with 1 ng nog3-rMO or nog3-MO and subjected to TUNEL assay (red) at 42 hpf. For dorsomorphin treatment, injected embryos at 36 hpf were incubated with 5 µM dorsomorphin until 42 hpf. The images shown were lateral views of the first two pharyngeal arches (PA1 and PA2) (D). Scale bar, 20µm. The percentage of TUNEL-positive cells among the total number of pharyngeal chondrogenic progenitors (GFP-positive) in the imaged region was calculated based on five embryos each group (E). p < 0.001; error bars indicated SD.

See also Fig. S6.