Smad1 can rescue the hematopoietic defect in smad5 morphants. (A) In vitro transcription-translation of ³⁵S-methionine–labeled Smad proteins. Translation of wobbled-changed Smad1 and Smad5 (Smad1* or S1* and Smad5* or S5*) are not inhibited by their own MO or the opposite Smad MO (Smad1*, lanes 1-3; Smad5*, lanes 4-6). (B-S) Embryos were either uninjected control (left column) (B,E,H,K,N,Q), coinjected with Smad1 MO plus Smad5 mRNA (middle column) (C,F,I,L,O,R), or Smad5 MO plus Smad1 mRNA (right column) (D,G,J,M,P,S) and processed at 24 hpf for in situ hybridization to identify hematopoietic transcripts: gata1 (B-D), lmo2 (E-G), pu.1 (15 somites, panels H- J; 24 hpf, panels K-M), l-plastin (N-P), and c-myb (Q-S). Smad1 is capable of rescuing gata1 (D) (◀), lmo2 (G), pu.1 (J) (◀), and c-myb (S) (small arrow) in smad5 morphants. However, Smad5 is unable to rescue the loss of l-plastin expression in smad1 morphants (O) (long arrow). Each panel is a representative embryo of a 25-embryo sample. All images are shown whole mount. In panels B-G and L-S, anterior is to the left; in panels H-J, anterior is to the top.