Fig. 1. Misregulation of BMP signaling in Xenopus embryos inhibits erythropoiesis. RNAs encoding ß-gal, tBR, caALK3 or BMP4 were injected near the ventral (VMZ) or dorsal marginal zone (DMZ) of 4-cell embryos. (A) Tailbud stage 32 embryos were stained for globin RNA (purple) by in situ hybridization. BMP-injected embryos were subdivided into those with normal dorsal-ventral pattern (DAI 5) and those with a ventralized phenotype (DAI 0). Ventral views of embryos are shown except for the BMP-injected, DAI 0 embryo for which ventral and lateral views are provided. (B) Northern blot analysis of globin expression. Levels of globin transcripts, normalized relative to levels of EF-1
transcripts, are expressed as percentage of control, below each lane.
