Fig. 1

Generation of Runx1 ^P2TAG mutant allele. a Schematic structure of murine Runx1 locus. The murine Runx1 gene is transcribed from distal (P1) and proximal (P2) promoters. Open and closed boxes represent the 5′ untranslated region (UTR) and coding region, respectively. Red dashed lines show the RNA splice junction in the P1-Runx1 transcript. Nucleotide sequences around the translational start ATG of P1- and P2-Runx1 transcripts are shown. Dashed line in P1-Runx1 transcript indicates omitted intermediate sequences between the ATG and splice donor signals. Deduced amino acid sequences are shown as a single letter. b Schematic representation of the targeting strategy used to generate the Runx1 ^P2TAG allele. The targeting vector was designed to delete the P2-Runx1 promoter between SmaI and XhoI sites and replace the ATG with TAG, marked with *. Triangles represent loxP sequences. Restriction enzymes shown are; BglII (Bg), PstI (P), SmaI (Sm) and XhoI (X). c Representative Southern blot of ES clones that underwent homologous recombination. PstI digested genome DNA was hybridized with a probe, grey box in b. d Gel image of DNA-PCR analysis showing incorporation of the P2-promoter deletion in an ES clone. e Sequence analysis of the genomic region around the ATG in exon II of the Runx1 gene. PCR product from ES clone 16–7 was sequenced. f Genotyping of offspring obtained by intercrossing between Runx1 ^+/P2TAG heterozygous mice. Numbers and those in parenthesis represent live and total embryos, respectively. g Representative images of E12.5 dpc Runx1 ^+/+ and Runx1 ^P2TAG/P2TAG embryos. A Runx1-null mutant (Runx1 ^Δ/Δ) embryo is shown for references