gfi1b induction restores the number of embryonic HSCs in gata2b^−/− zebrafish. (A) Gene set enrichment plot depicting the expression of genes involved in blood vessel morphogenesis, highly enriched in gata2b^+/−CD41^int cells at 48 hpf compared with WT. (B) Expression data of endothelial markers from RNA sequencing results of CD41^int HSCs of WT (green) and Gata2b^+/− (orange) HSCs at 48 hpf in 3 biological replicates. Significance is shown as ∗adjusted P < .05 and ∗∗adjusted P < .001. (C) Representative images of 3 different staining intensities of cmyb whole-mount in situ expression detecting HSPCs along the dorsal aorta of 33 hpf zebrafish embryos. High cmyb expression is depicted in red, intermediate cmyb expression is depicted in green, and low cmyb expression is depicted in yellow. (D) Quantification of cmyb signal intensity analyzed at 33 hpf using ISH and compared between uninjected (WT, n = 2; gata2b^−/−, n = 16) and injected (WT, n = 18; gata2b^−/−, n = 16) WT and gata2b^−/− embryos. Representative images of the number of CD41^int HSCs compared between the uninjected (n = 5) and injected (n = 4) groups of WT (E), and uninjected (n = 5) and injected (n = 6) groups of gata2b^−/− embryos (F). (G) The proportion of CD41^int HSCs compared between the uninjected and injected groups of WT and gata2b^−/− embryos. The dots represent individual samples and each sample contains 4 pooled embryos. dpf, days postfertilization; FACS, fluorescence-activated cell sorting; FDR, false discovery rate; GFP, green fluorescent protein; NES, normalized enrichment score.