Fig. 4
3-OST-7 controls region-specific BMP signaling in differentiating heart.
ISH for tbx2b (A and D), notch1B (B and E) showed normal AV-restricted expression, whereas bmp4 expression (C and F) showed ectopic expression in ventricular myocardium of 3-OST-7 morphants at 48 hpf (n = 30 for each group). IHC for P-Smad at 48 hpf showed delocalized expression in nuclei of 3-OST-7 morphant ventricle (H) compared to localized AV canal expression in control (G) (n = 10 for each group). (I) Graph depicting increased P-Smad-positive nuclei in the ventricle several unit distances away from the AV in 3-OST-7 morphants compared to P-Smad-positive nuclei localized in the AV for control (error bars, standard deviation). Imaging of live Tg(BRE:d2GFP) fish (J and L) showed GFP expression localized to the AV junction in control (K) and expanded expression in ventricle in morphant (M). V, ventricle; At, atrium; red arrows point to AV; white dashed lines outline the hearts.