Fig. 4

Dnmt1-mediated methylation controls HSPC generation through blocking arterial endothelial identity. (A) WISH analysis showing the expression of arterial endothelial genes dll4, dltC, ephrin-B2a and hey2 in siblings and dnmt1 mutants at 36?hpf. The arrowheads indicate the expression of corresponding arterial endothelial genes. n?3 replicates. (B) Statistical analysis of the WISH in A. (C) qPCR analysis of arterial endothelial genes dltC, ephrin-B2a and hey2 in kdrl⁺ ECs in siblings and dnmt1 mutants. n=3 replicates. (D) WISH results showing expression of runx1 and cmyb (black arrowheads) at 36?hpf in sibling, dnmt1 mutant and dnmt1 mutant embryos injected with fli1a: mismatch-dnmt1-EGFP constructs (upper panels) and FISH analysis of cmyb and egfp (white arrowheads) at 36?hpf in control, dnmt1 morphants and embryos co-injected with dnmt1 atgMO and fli1a:mismatch-dnmt1-EGFP constructs showing that endothelial-derived Dnmt1-EGFP overexpression rescued the population of cmyb⁺ cells (bottom panel). n=3 replicates. (E) Statistical analysis of the WISH data in D. Data are mean±s.d. *P<0.05, **P<0.01 ***P<0.001 (unpaired two-tailed Student's t-test). Scale bars: 100?µm (A,D upper panels); 50?µm (D bottom panels).