Fig. 8. Hyperactive BMP signaling in lateral mesoderm restricts hemato-vascular development. Shown are representative sibling embryos that were either control (A,C) or transgenic for the lmo2:caBR transgene (B,D). Embryos were fixed at the 12-somite stage and processed by in situ hybridization to detect the expression patterns of the gata1 gene (A,B; marking committed hematopoietic cells) or the scl gene (C,D; marking hemato-vascular progenitors). The patterns (indicated in the caudal lateral mesoderm by arrows) are markedly repressed by expression of the hyper-activated receptor.