Fig. 2

Expression of bmpr2a and bmpr2b in zebrafish development. (A) Analysis of bmpr2a and bmpr2b expression by RT-PCR. RNA for both receptors was detected from 1-cell stage embryos to 52 hpf. (B–E) In situ hybridization shows bmpr2a and bmpr2b are ubiquitously expressed at 30% and 50% epiboly. At 12 somite-stage, bmpr2a is broadly expressed throughout the embryo (F) whereas expression of bmpr2b is stronger in the most posterior and anterior regions (H). At 23 somites, both genes show a diffuse expression in the trunk and stronger staining in the head and tail regions (G, I). Bmpr2b is further expressed in the proctodeum at this stage (I, black arrow). (J) Bmpr2a is expressed in the head region, in the trunk vessels (dorsal aorta and cardinal vein) and in the posterior intermediate cell mass (ICM) at 25 hpf. (K) Bmpr2b is expressed in the head region and strongly in the posterior ICM and proctodeum (black arrow) but weakly in the trunk vessels. At 36 hpf, expression of bmpr2a (L) is restricted to the anterior region, including the heart (black arrowheads) and to the posterior blood vessels and pronephros (see inset). (M) Bmpr2b shows similar expression to bmpr2a, but it is not expressed in the dorsal aorta (see inset). (B–E) are lateral views and (B′–E′) are top views. (G, I–M) Lateral view, anterior to the left; (F,H) anterior to the top. Cv, cardinal vein, da, dorsal aorta, p, pronephros.