Fig. 1

Generation of a zebrafish BAC transgenic reporter line for runx1. a Schematic representation of the zebrafish runx1 locus. Exon nomenclature adjusted to the human RUNX1 locus. P1 and P2 indicate the distal and the proximal promoter respectively (TSS: transcriptional start site). b Schematics of the two alternative transcripts derived from the alternative promoters P1 and P2. Transcript-specific and pan binding ISH probes are indicated with their respective lengths. c ISH for runx1 isoforms in 30 hpf embryos. Left panel: trunk region. Right panel: head region. Green arrows point to the HE, yellow arrows show the olfactory placode and purple arrows depict neurons in the brain region. d Schematic of the recombineered 97a02 BAC. A Citrine reporter cassette was placed downstream of the P2 ATG. e Confocal microscopy image of a flat mounted 15 hpf embryo after double FISH for runx1 and Citrine in TgBAC(runx1P2:Citrine) depicting the region of the posterior lateral plate mesoderm (PLM) and Rohon-Beard neurons (RBN). Maximum intensity projection of a 58 µm stack. f–h Gene expression analysis for runx1and runx1P2:Citrine during definitive haematopoiesis. Green arrows point to the HE. Yellow arrowheads point to neurons in the spinal cord. f ISH for runx1 or Citrine in 24 hpf TgBAC(runx1P2:Citrine) embryos. g ISH for runx1 in 30 hpf embryos. hRepresentative fluorescent microscopy image of a 31 hpf TgBAC(runx1P2:Citrine) embryo. Insets in (g and h) enlarge the boxed region. i Fluorescent microscopy image of a 50 hpf double transgenic TgBAC(runx1P2:Citrine);Tg(kdrl:mCherry) embryo focusing on the region of the caudal haematopoietic tissue (CHT)