Fig. 2

PGE2 Regulates Wnt-Mediated Effects on HSC Formation at the Level of β-catenin

(A–D) wnt8 induction in hs:wnt8-GFP transgenic embryos increased runx1/cmyb+ HSCs compared to WT; indo decreased HSCs in WT and wnt8 embryos.

(E–L) Induction of dkk diminished runx1/cmyb expression compared to WT. dmPGE2 enhanced HSCs in WT embryos, and rescued runx1/cmyb expression to approximately WT levels in dkk embryos. Axin (hs:axin-GFP) and dnTCF (hs:dnTCF-GFP) reduced runx1/cmyb expression, and dmPGE2 could not rescue those effects.

(M) Schematic of confocal microscopy. Imaging was performed in the trunk/tail region of the embryo, centered around the tip of the yolk sac extension (YSE, blue arrowhead), encompassing the dorsal aorta (red dots) and vein (blue dots), as indicated by the pink bracket.

(N-Y) In vivo confocal microscopy of wnt pathway inducible embryos crossed into the cmyb:GFP HSC reporter line confirmed the in situ hybridization analysis and demonstrated quantifiable effects on cell number.

(Z) Cell counts (5 embryos/treatment, data represented as mean ± SD) were conducted in the major vessels (pink bracket) in a 40x field centered at the YSE; ^*sig versus con; ^**sig versus wnt8; ^***sig versus dkk; ANOVA, p < 0.001.