Fig. 2
Expression of the bre:egfp transgene is responsive to changes in BMP type I receptor signaling. Embryos were left uninjected (a–c) or injected with 5 pg alk1CA mRNA (d–f) or 100 pg alk5CA mRNA (g–i) at the one- to two-cell stage and assayed at shield stage (6 hpf). a, d, g: Expression of bre-driven EGFP fluorescence in live embryos. b, e, h: Expression of bre-driven egfp mRNA assayed by in situ hybridization. c, f, i: Expression of pSmad1/5/8 assayed by immunofluorescence. Inset in f is pSmad1/5/8 (green)/DAPI (magenta) merge. Lateral views, animal pole up, dorsal right. Original magnification 80× except inset, 200×. |