Fig. 7

Radar or BMP signaling knock-down impairs MP formation.

(A) The level of expression of spliced radar and β-actin mRNAs was analysed by semi-quantitative RT-PCR. Total RNA extracts were prepared at 1 dpf from uninjected embryos and from embryos that were injected with morpholinos blocking the splicing of radar (rdr^MO). The number of cycles is shown. (B) Graphic representation of the number of MPs per somite at 1 dpf in the indicated conditions, values = mean, error bars = s.e.m., ***p<0.001. (C–D) eng2a expression at the 12-somite stage in (C) uninjected, or (D) rdr^MO-injected embryos, as determined by ISH. (E–J) MPs staining with anti-Eng (green) and anti-Prox1 (red) antibodies at 1 dpf embryos in (E) uninjected, (F) rdr^MO-injected embryos, (G) p53^MO- and rdr^MO-injected embryos, (H) radar mutant (rdr^s327), (I) Dorsomorphin (DM) treated embryos and (J) SU5402-treated embryos that were injected with rdr^MO, scale bar = 20 μm. (K–M) sMyhc (red) expression in the somites of (K) WT, (L) radar morphans and (M) P53/radar double morphans (rdr^MO/P53^MO) at 1 dpf, 3D reconstructions of multiple confocal scans, lateral and cross section views, scale bar = 20 μm. (N–Q) Eng2a expression in the somites of 1 dpf embryos after treatment with increasing doses of Dorsomorphin (10, 20 and 50 μM) or with DMSO (1%), scale bar 100 μm. (R–S) GFP expression in Tg(5XBRE[vent2]:-20lid3:GFP) embryos at 60 hpf after (S) DM (50 μM) or (R) DMSO (1%) treatments, showing that DM treatment inhibits BMP signaling. (T–W) Eng2a expression in 1 dpf embryos that were (U–W) injected or (T–V) not with rdr^MO and treated with either (T–U) DMSO or (V–W) SU5402.