Fig. 6 LR asymmetry of the heart and viscerae is perturbed in bmpr2a and bmpr2b morpholino-knockdown embryos. Analysis of cmlc2 expression at 32 hpf (A–G) and 48 hpf (H–N) in bmpr2aMO3 and bmpr2bMO3-injected embryos. (A) Wild type embryos show normal left-sided heart jog. Morpholino knockdown of bmpr2a (B, C) or bmpr2b (E–G) causes the heart to jog to the left, the right or stay at the midline. At 48 hpf, the linear heart tube has looped to the right (D-loop) and changed into an S-shaped tube (H). bmpr2a morphants show normal (I), no/reduced (J) or reversed looping (K). Similar results were found upon bmpr2b knockdown by bmpr2bMO3 (L–N). Comparison of foxa3 expression between wild type (O) and bmpr2a (P–R) or bmpr2b (S–U) morphants at 48 hpf showed that the direction of gut looping is also affected in these embryos. (A–G, O–U) Dorsal view, anterior to the top. (H–N) Frontal view, anterior to the top.
Reprinted from Developmental Biology, 315(1), Monteiro, R., van Dinther, M., Bakkers, J., Wilkinson, R., Patient, R., Ten Dijke, P., and Mummery, C., Two novel type II receptors mediate BMP signalling and are required to establish left-right asymmetry in zebrafish, 55-71, Copyright (2008) with permission from Elsevier. Full text @ Dev. Biol.