Smad1 morphants have an increase in gata1 expression, but lack l-plastin, while piggytail embryos lose most posterior hematopoietic marker expression at 24 hpf. Shown are representative embryos, 50 to 75 embryos per sample, following in situ hybridization. Uninjected control embryos (left column) (A,D,G,J,M,P,S) were compared with smad1 morphants (S1MO; middle column) (B,E,H,K,N,Q,T), and pgy/pgy mutant embryos (right column) (C,F,I,L,O,R,U) for primitive and definitive hematopoietic transcripts: gata1 (A-C), lmo2 (D-F), pu.1 (G-I), l-plastin (J-L), myeloperoxidase (mpo) (M-O), c-myb (P-R), and runx1 (S-U). At 24 hpf, smad1 morphants have an increase in gata1 expression in the tail (◀ in panel B), while pgy/pgy embryos have a significant decrease (◀ in panel C). In contrast, pgy/pgy have normal l-plastin (long arrow, panel L) and mpo (long arrow, panel O) expression, while smad1 morphants lack all l-plastin expression (long arrow, panel K) and most mpo expression (long arrow, panel N). Loss of either Smad1 or Smad5 leads to a lack of the definitive markers c-myb and runx1 (noted by ). In all images, the embryos are shown whole mount with anterior to the left.