Fig. 2. Expression of runx1 in zebrafish wild-type (A-N) and mutant (O,P) embryos. In situ was performed with the longer probe, except D,E, which were carried out with the shorter probe. (A-E,O,P) Whole embryos; dorsal views, anterior upwards (A-C), lateral views, anterior towards the left (D,E,O,P). (F-H) Posterior halves of embryos; dorsal view, posterior downwards (F), lateral views, anterior towards the left (G,H). (I,J) Transverse sections of the embryo corresponding to a line in H, with J a higher magnification of the area marked in I. (K-N) Dorsal views of head areas, except K, dorsolateral. Stages in hpf are indicated. (A) Diffuse pre-zygotic expression. (B-F) Expression within the LPM (arrowheads) and in Rohon-Beard cells (arrows). (G-J) Expression in the ICM (arrowheads), Rohon-Beard cells (arrow in G) and ventral wall of the dorsal aorta (arrows in H-J). Endothelial cells are indicated in J. Cells with runx1 expression show a different nuclear morphology. (K-N) Expression in the olfactory epithelium (arrowheads) and in putative cranial nerve VIII ganglia (arrows). (O,P) Arrows indicate markedly reduced runx1 expression in the ICM in spadetail and cloche respectively. NT, neural tube; NO, notochord; AV, axial vein; e, endothelial cell, ov, otic vesicle. Scale bars: 
25 µm.
