Fig. 1

Fig. 1 Sfrp1a is expressed in endothelial cells and affects HSPC development. A. fli1a:GFP fish were dissociated at 16.5 hpf and endothelial cells (GFP+) were collected by FACS for qPCR. B. qPCR for each zebrafish sfrp (n = 3 biological replicates). C. Representative 3 at 13 hpf (scale bar = 30 μm), 16.5 hpf (scale bar = 30 μm), and 19 hpf (scale bar = 50 μm). Arrow heads indicating sfrp1a expression near endothelial cells. D. AB∗ embryos (wild-type animals) were injected with scramble MO and sfrp1a MO: ATG and splice blocking (SB), fixed at 40 hpf, and analyzed by WISH for cmyb. Scale bar = 100 μm. Imaged area in the 40 hpf fish for WISH is shown in purple. E. Quantification of D (n = 21, 27, 20, and 34 biological replicates from left to right). Each dot represents a biological replicate, the bars represent the mean and the error bars represent the standard deviation. One-Way ANOVA with post hoc Tukey comparisons, ∗∗∗∗p < 0.0001. F. sfrp1a mutants were generated by CRISPR/Cas9 and representative WISH images for cmyb expression at 40 hpf. Scale bar = 100 μm. G. Quantification of F (n = 16, 31, and 14 biological replicates from left to right). Each dot represents a biological replicate, the bars represent the mean and the error bars represent the standard deviation. One-Way ANOVA with post hoc Tukey comparisons, ∗p < 0.05. H. gata2b:KalTA4; UAS:GFP; kdrl:mCherry embryos were injected with scramble MO and sfrp1a ATG MO, incubated for 2 h with 500 μM EdU at 38 hpf, fixed at 40 hpf, and labeled with AlexaFluor-647. Representative images of proliferating HSPCs, defined as cells positive for GFP and AlexaFluor-647 (white arrow heads) in the floor of the aorta (A). HSPCs that are not proliferating are indicated by green arrow heads. Scale bar = 15 μm. I. Quantification of H (n = 17 and 15 biological replicates from left to right). Each dot represents a biological replicate, the bars represent the mean and the error bars represent the standard deviation. Two-tailed Student's, ∗p < 0.05.