Fig. 1

Wnt Signaling Is Required Transiently Prior to 20 hpf for HSPC Development

(A) kdrl:mCherry; cmyb:eGFP fish were treated with IWP-L6 or LiCl to inhibit and activate Wnt signaling, respectively ( van de Water et al., 2001 and Wang et al., 2013), from 10 hpf to 36 hpf and imaged at 36 hpf. A, aorta; V, vein. Scale bar, 30 μm.

(B) Quantitation of HSPCs per millimeter of aorta.

(C) Schematic of heat shock regimen.

(D) hsp:dntcf fish were heat shocked every hour from 13 hpf to 24 hpf, fixed at 40 hpf, and analyzed for cmyb expression by WISH. Scale bar, 100 μm.

(E) Quantitation of cmyb+ cells from (D).

(F) Schematic of experimental layout.

(G) hsp:dntcf fish were heat shocked at 16.5 hpf, pools were fixed every hour from 23 to 36 hpf, and they were analyzed for cmyb expression by WISH. Scale bar, 100 μm.

(H) Quantitation of cmyb+ cells from (G).

(I) HSPCs are specified as endothelial cells ingress toward the midline. Endothelial cells receive specification cues, at least in part, from somatic cells. At 26 hpf, HSPCs start to emerge from the floor of the dorsal aorta. A, aorta; V, vein.

^∗∗p < 0.01; ^∗∗∗p < 0.001; n.s., not significant. Error bars represent SD. See also Figure S1.