Representative flat-mount 26 hpf embryos following in situ hybridization analyses. Lateral view of gene expression in the dorsal aorta region of the trunk is shown with anterior to the left. Compared to DMSO-treated controls (A, B), embryos treated with 2.5 μM DEAB exhibit normal notch1a (A’), and notch1b (B’) gene expression within the trunk and dorsal aorta. notch3 is expressed at normal levels in the dorsal aorta (C, C’), but is mildly upregulated in the somites of 2.5 μM DEAB-treated versus DMSO-treated control embryos (data not shown). Compared to DMSO-treated controls (D, E) embryos treated with 2.5 μM DEAB exhibit normal gene expression levels of the Notch1-signaling pathway transcriptional targets dlc (D’) and her6 (E’).