Hapln1b overexpression inhibits HSPC budding and development. (A) ISH expression of kdrl, runx1, and cmyb in non-injected or hapln1b mRNA–injected embryos. (B-C) ISH expression of cmyb in non-injected or hapln1b mRNA–injected embryos. (D-D′) Double-transgenic kdrl:mCherry/cmyb:GFP embryos at 36 and 48 hpf. Bar represents 50 µm. (D′) NI vs +h1b-injected at 36 hpf, P < .0001; and at 48 hpf, P = .0003. (E-E′) Imaging double-transgenic kdrl:mCherry/cmyb:GFP embryos at 3 and 4 dpf. Bar represents 50 µm. (E′) NI vs +h1b injected at 3 dpf, P = .0003; and at 4 dpf, P = .004. NI, non-injected, +h1b: hapln1b mRNA–injected.