Fig. 1.
Rspo1 is required for HSC specification. The HSC markers runx1 (A,B,D,E) and cmyb (G,H,J,K), which identify HSCs emerging from the dorsal aorta, as well as the T lymphocyte marker rag1 (M,N,P,Q), found in thymic T cells, were examined at 24 hpf, 36 hpf and 96 hpf as indicated, by whole-mount in situ hybridization (WISH) in wild-type (WT; A,G,M), Rspo1 MO-injected (B,H,N), Rspo1 wild-type and heterozygous siblings (D,J,P), or rspo1 dtty135 homozygous mutants (E,K,Q). Red arrowheads indicate HSC precursors in the dorsal aorta (A,B,D,E,G,J,K) or T lymphocytes in the thymus (M,P), when present. Numbers of embryos displaying the depicted phenotype are indicated. (C,F,I,L,O,R) Histograms illustrate percentages of phenotypes. Lateral mid-trunk or ventral head views at 160× magnification.