Figure 4

stag1a and stag2b mutations alter the number of scl-positive cells in the posterior lateral mesoderm at 15 hpf. (A)runx1 expression in whole-mount embryos at 15 hpf. Posterior views of the PLM are shown; dorsal to the top. In stag1a^nz204 homozygous mutant embryos, runx1 expression is slightly increased. In stag2b^nz207 homozygous mutant embryos, runx1 expression is slightly reduced. Changes in expression are marked by arrows and the number of embryos is indicated below each panel. (B)scl expression in whole-mount embryos at 15 hpf. Posterior views of the PLM are shown; dorsal to the top. In stag1a^nz204 homozygous mutant embryos, expanded expression of scl laterally into the PLM is dampened upon injection of functional stag1a mRNA. In stag2b^nz207 homozygous mutant embryos, scl expression is reduced in the anterior PLM and is rescued upon injection of functional stag2b mRNA. Changes in expression are marked by arrows and the number of embryos is indicated below each panel. (C) mRNA levels of mesoderm-derived haematopoietic and endothelial markers at 15 hpf. The bar graph shows the mean +/- one standard deviation. *P ≤ 0.05, **P ≤ 0.01; one-way ANOVA. Expression was normalized to the reference genes, b-actin and rpl13a (Supplementary Figure 1B).