Hif1α stabilization induces the expression of Pdgfb and pdgfrb in zebrafish embryos. PDGFRβ function is necessary for Hif1α-mediated stimulation of HSPC number. Pdgfb overexpression increases the proliferative expansion of HSPCs during development. PDGF-B/PDGFRβ binding upregulates the expression of the inflammatory factors il6 and il6r. IL-6 acts downstream of Hif1α and PDGFRβ to control embryonic HSPC production.