Fig. 7

Whole-mount in situ hybridization of zebrafish embryos. Expression of ghra and ghrb mRNAs analyzed at the indicated stages of zebrafish embryos with antisense (A, C, E,G, I, K, M and O) and sense (control) probes (B, D, F, H, J, L, N and P). Ghra and ghrb are expressed ubiquitously from 0 hpf onwards (A and I), indicating they are maternal transcripts. At 16 hpf (C and K) expression continue to be ubiquitous and at 30 hpf several structures are differentially stained. Ghra expression was observed in the lens, hindbrain and the notochord (E), and ghrb transcripts were localized in the hindbrain, lens, notochord and intestine (M). At 48 hpf ghra continued to be detected in the notochord and lens and was detected in the liver, myotomes and pronephric ducts (G). Ghrb was detected in the lens, liver, myotomes, notochord and spinal cord (O). An intense positive signal in the yolk cell was observed for both receptors from 16 hpf onwards (C, E, G and K, M, O). We did not detect positive signals when the embryos and larvae were incubated with the sense probes (B, D, F, H, J, L, N and P). Abbreviations: l, lens; hb, hindbrain; nc, notochord; y, yolk cell; m, myotome; pd, pronephric duct; sc, spinal cord; L, liver.