(A) qPCR analysis showed il6 and its’ receptor and co-receptor, il6R and gp130, are upregulated in pdgfb mRNA-injected embryos (*p<0.05, **p<0.01, two-tailed t-test, n≥3).
(B) Morpholino knockdown of il6 blocked the ability of pdgfb mRNA to increase runx1;cmyb expression in the AGM.
(C) Qualitative phenotypic distribution of embryos from panel 4B (n≥20/condition × 3 replicate clutches).
(D) Absolute counts of Flk1:dsRed+cMyb:GFP+ HSPCs from embryos overexpressing pdgfb were significantly reduced with MO-mediated loss of il6 (***p<0.0005, *p<0.05, two-tailed t-test, n≥15/condition).
(E) FACS analysis for Flk1+cMyb+ HSPCs at 48hpf showed that overexpression of il6 significantly increases HSPCs (1.49-fold vs. control, *p<0.02, two-tailed t-test, n≥5 replicates/condition).
(F) Absolute cell counts of phospho histone H3 expressing (pHH3+) cells in the VDA were increased in both pdgfb and il6 mRNA-injected embryos compared to matched sibling controls (*p<0.05, **p<0.01, two-tailed t-test, n ≥10/condition).